1
|
Barber BE, Webster R, Potter AJ, Llewellyn S, Sahai N, Leelasena I, Mathison S, Kuritz K, Flynn J, Chalon S, Marrast AC, Gobeau N, Moehrle JJ. Characterising the blood-stage antimalarial activity of pyronaridine in healthy volunteers experimentally infected with Plasmodium falciparum. Int J Antimicrob Agents 2024; 64:107196. [PMID: 38734217 DOI: 10.1016/j.ijantimicag.2024.107196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 04/23/2024] [Accepted: 05/03/2024] [Indexed: 05/13/2024]
Abstract
With the spread of artemisinin resistance throughout Southeast Asia and now in Africa, the antimalarial drug pyronaridine is likely to become an increasingly important component of new antimalarial drug regimens. However, the antimalarial activity of pyronaridine in humans has not been completely characterised. This volunteer infection study aimed to determine the pharmacokinetic/pharmacodynamic (PK/PD) relationship of pyronaridine in malaria naïve adults. Volunteers were inoculated with Plasmodium falciparum-infected erythrocytes on day 0 and administered different single oral doses of pyronaridine on day 8. Parasitaemia and concentrations of pyronaridine were measured and standard safety assessments performed. Curative artemether-lumefantrine therapy was administered if parasite regrowth occurred, or on day 47 ± 2. Outcomes were parasite clearance kinetics, PK and PK/PD parameters from modelling. Ten participants were inoculated and administered 360 mg (n = 4), 540 mg (n = 4) or 720 mg (n = 1) pyronaridine. One participant was withdrawn without receiving pyronaridine. The time to maximum pyronaridine concentration was 1-2 h, the elimination half-life was 8-9 d, and the parasite clearance half-life was approximately 5 h. Parasite regrowth occurred with 360 mg (4/4 participants) and 540 mg (2/4 participants). Key efficacy parameters including the minimum inhibitory concentration (5.5 ng/mL) and minimum parasiticidal concentration leading to 90% of maximum effect (MPC90: 8 ng/mL) were derived from the PK/PD model. Adverse events considered related to pyronaridine were predominantly mild to moderate gastrointestinal symptoms. There were no serious adverse events. Data obtained in this study will support the use of pyronaridine in new antimalarial combination therapies by informing partner drug selection and dosing considerations.
Collapse
Affiliation(s)
- Bridget E Barber
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia; University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia; Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Rebecca Webster
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Adam J Potter
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Stacey Llewellyn
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Nischal Sahai
- University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia
| | - Indika Leelasena
- University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia
| | - Susan Mathison
- University of the Sunshine Coast Clinical Trials, Morayfield, QLD, Australia
| | | | - Julia Flynn
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | | | | | | |
Collapse
|
2
|
Cao P, Kho S, Grigg MJ, Barber BE, Piera KA, William T, Poespoprodjo JR, Jang IK, Simpson JA, McCaw JM, Anstey NM, McCarthy JS, Britton S. Characterisation of Plasmodium vivax lactate dehydrogenase dynamics in P. vivax infections. Commun Biol 2024; 7:355. [PMID: 38519588 PMCID: PMC10959993 DOI: 10.1038/s42003-024-05956-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 02/22/2024] [Indexed: 03/25/2024] Open
Abstract
Plasmodium vivax lactate dehydrogenase (PvLDH) is an essential enzyme in the glycolytic pathway of P. vivax. It is widely used as a diagnostic biomarker and a measure of total-body parasite biomass in vivax malaria. However, the dynamics of PvLDH remains poorly understood. Here, we developed mathematical models that capture parasite and matrix PvLDH dynamics in ex vivo culture and the human host. We estimated key biological parameters characterising in vivo PvLDH dynamics based on longitudinal data of parasitemia and PvLDH concentration collected from P. vivax-infected humans, with the estimates informed by the ex vivo data as prior knowledge in a Bayesian hierarchical framework. We found that the in vivo accumulation rate of intraerythrocytic PvLDH peaks at 10-20 h post-invasion (late ring stage) with a median estimate of intraerythrocytic PvLDH mass at the end of the life cycle to be 9.4 × 10-3ng. We also found that the median estimate of in vivo PvLDH half-life was approximately 21.9 h. Our findings provide a foundation with which to advance our quantitative understanding of P. vivax biology and will facilitate the improvement of PvLDH-based diagnostic tools.
Collapse
Affiliation(s)
- Pengxing Cao
- School of Mathematics and Statistics, University of Melbourne, Melbourne, VIC, Australia
| | - Steven Kho
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
- Papuan Community Health and Development Foundation, Timika, Papua, Indonesia
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Bridget E Barber
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Kim A Piera
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Timothy William
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Jeanne R Poespoprodjo
- Papuan Community Health and Development Foundation, Timika, Papua, Indonesia
- Department of Pediatrics, Timika General Hospital, Timika, Papua, Indonesia
| | | | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
| | - James M McCaw
- School of Mathematics and Statistics, University of Melbourne, Melbourne, VIC, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
- Department of Infectious Diseases, Melbourne Medical School, Melbourne, VIC, Australia.
| | - Sumudu Britton
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| |
Collapse
|
3
|
Yin X, Li Y, Bagchus W, Yalkinoglu Ö, Bezuidenhout D, Tappert A, McCarthy J, Marquart L, Oeuvray C. Evaluation of a multiphasic parasite clearance profile after treatment of experimental human infection with the investigational anti-malarial M5717 using segmented mixed effect models. Malar J 2023; 22:199. [PMID: 37381013 DOI: 10.1186/s12936-023-04627-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 06/16/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Evaluation of parasite clearance patterns in experimental human infection trials helps increase understanding of drug action. In a previously reported phase Ib trial of a new investigational anti-malarial drug M5717, parasite clearance showed a biphasic linear pattern: slow removal phase with a near flat clearance rate followed by a fast clearance phase with a steep slope. In this study three statistical approaches were implemented and compared to estimate the parasite clearance rate for each phase and the time point corresponding to the change of clearance rates (changepoint between the two phases). METHODS Data using three M5717 doses 150 mg (n = 6), 400 mg (n = 8), 800 mg (n = 8) were used to estimate biphasic clearance rates. Three models were investigated: firstly, segmented mixed models with estimated changepoint-models with/without random effects in various parameters were compared. Secondly, a segmented mixed model using grid search-this method is similar to the first except that changepoints were not estimated, instead they were selected based on model fit from given candidate values. Thirdly, a two-stage approach whereby a segmented regression model fit to each participant followed by a meta-analysis method. Hourly rate of parasite clearance (HRPC) interpreted as the percentage of parasites removed each hour was calculated. RESULTS The three models generated similar results. Using segmented mixed models, the estimated changepoints after treatment in hours (95% CI) were: 150 mg: 33.9 (28.7, 39.1); 400 mg: 57.4 (52.5, 62.4); and 800 mg: 52.8 (47.4, 58.1). For all three treatment groups, there was nearly no clearance before the changepoints, but rapid clearance in the second phase (HRPC [95% CI]): 150 mg: 16.8% (14.3, 19.1%); 400 mg: 18.6% (16.0, 21.1%); and 800 mg: 11.7% (9.3, 14.1%). CONCLUSIONS All three statistical approaches are effective tools to characterize the bi-phasic clearance of M5717 in the phase 1b experimental Plasmodium falciparum malaria human infection study. The statistical approaches produced similar results to estimate the two-phase clearance rates and the changepoint for each treatment dose of M5717. However, the segmented mixed model with random changepoints has several advantages: it is computationally efficient, provides precision for changepoint estimates and is robust concerning outlying datapoints or individuals.
Collapse
Affiliation(s)
- Xiaoyan Yin
- EMD Serono Research & Development Institute, Inc. (an Affiliate of Merck KGaA), 45 Middlesex Turnpike, Billerica, MA, 01821, USA.
| | - Ying Li
- EMD Serono Research & Development Institute, Inc. (an Affiliate of Merck KGaA), 45 Middlesex Turnpike, Billerica, MA, 01821, USA
| | - Wilhelmina Bagchus
- WMB: Merck Serono S.A (an Affiliate of Merck KGaA), Lausanne, Switzerland
| | | | - Deon Bezuidenhout
- WMB: Merck Serono S.A (an Affiliate of Merck KGaA), Lausanne, Switzerland
| | | | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
- School of Public Health, University of Queensland, Brisbane, Australia
| | - Claude Oeuvray
- The Global Health Institute of Merck (an Affiliate of Merck KGaA), Eysins, Switzerland
| |
Collapse
|
4
|
Barber BE, Abd-Rahman AN, Webster R, Potter AJ, Llewellyn S, Marquart L, Sahai N, Leelasena I, Birrell GW, Edstein MD, Shanks GD, Wesche D, Moehrle JJ, McCarthy JS. Characterizing the Blood-Stage Antimalarial Activity of Tafenoquine in Healthy Volunteers Experimentally Infected With Plasmodium falciparum. Clin Infect Dis 2023; 76:1919-1927. [PMID: 36795050 PMCID: PMC10249991 DOI: 10.1093/cid/ciad075] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/10/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND The long-acting 8-aminoquinoline tafenoquine may be a good candidate for mass drug administration if it exhibits sufficient blood-stage antimalarial activity at doses low enough to be tolerated by glucose 6-phosphate dehydrogenase (G6PD)-deficient individuals. METHODS Healthy adults with normal levels of G6PD were inoculated with Plasmodium falciparum 3D7-infected erythrocytes on day 0. Different single oral doses of tafenoquine were administered on day 8. Parasitemia and concentrations of tafenoquine and the 5,6-orthoquinone metabolite in plasma/whole blood/urine were measured and standard safety assessments performed. Curative artemether-lumefantrine therapy was administered if parasite regrowth occurred, or on day 48 ± 2. Outcomes were parasite clearance kinetics, pharmacokinetic and pharmacokinetic/pharmacodynamic (PK/PD) parameters from modelling, and dose simulations in a theoretical endemic population. RESULTS Twelve participants were inoculated and administered 200 mg (n = 3), 300 mg (n = 4), 400 mg (n = 2), or 600 mg (n = 3) tafenoquine. The parasite clearance half-life with 400 mg or 600 mg (5.4 hours and 4.2 hours, respectively) was faster than with 200 mg or 300 mg (11.8 hours and 9.6 hours, respectively). Parasite regrowth occurred after dosing with 200 mg (3/3 participants) and 300 mg (3/4 participants) but not after 400 mg or 600 mg. Simulations using the PK/PD model predicted that 460 mg and 540 mg would clear parasitaemia by a factor of 106 and 109, respectively, in a 60-kg adult. CONCLUSIONS Although a single dose of tafenoquine exhibits potent P. falciparum blood-stage antimalarial activity, the estimated doses to effectively clear asexual parasitemia will require prior screening to exclude G6PD deficiency. Clinical Trials Registration. Australian and New Zealand Clinical Trials Registry (ACTRN12620000995976).
Collapse
Affiliation(s)
- Bridget E Barber
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- University of the Sunshine Coast, Morayfield, Australia
- Royal Brisbane and Women's Hospital, Brisbane, Australia
| | | | - Rebecca Webster
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Adam J Potter
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- The University of Queensland, Brisbane, Australia
| | - Nischal Sahai
- University of the Sunshine Coast, Morayfield, Australia
| | | | - Geoffrey W Birrell
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Michael D Edstein
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - G Dennis Shanks
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | | | | | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| |
Collapse
|
5
|
Webster R, Mitchell H, Peters JM, Heunis J, O'Neill B, Gower J, Lynch S, Jennings H, Amante FH, Llewellyn S, Marquart L, Potter AJ, Birrell GW, Edstein MD, Shanks GD, McCarthy JS, Barber BE. Transmission Blocking Activity of Low-dose Tafenoquine in Healthy Volunteers Experimentally Infected With Plasmodium falciparum. Clin Infect Dis 2023; 76:506-512. [PMID: 35731843 DOI: 10.1093/cid/ciac503] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/13/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Blocking the transmission of parasites from humans to mosquitoes is a key component of malaria control. Tafenoquine exhibits activity against all stages of the malaria parasite and may have utility as a transmission blocking agent. We aimed to characterize the transmission blocking activity of low-dose tafenoquine. METHODS Healthy adults were inoculated with Plasmodium falciparum 3D7-infected erythrocytes on day 0. Piperaquine was administered on days 9 and 11 to clear asexual parasitemia while allowing gametocyte development. A single 50-mg oral dose of tafenoquine was administered on day 25. Transmission was determined by enriched membrane feeding assays predose and at 1, 4, and 7 days postdose. Artemether-lumefantrine was administered following the final assay. Outcomes were the reduction in mosquito infection and gametocytemia after tafenoquine and safety parameters. RESULTS Six participants were enrolled, and all were infective to mosquitoes before tafenoquine, with a median 86% (range, 22-98) of mosquitoes positive for oocysts and 57% (range, 4-92) positive for sporozoites. By day 4 after tafenoquine, the oocyst and sporozoite positivity rate had reduced by a median 35% (interquartile range [IQR]: 16-46) and 52% (IQR: 40-62), respectively, and by day 7, 81% (IQR 36-92) and 77% (IQR 52-98), respectively. The decline in gametocyte density after tafenoquine was not significant. No significant participant safety concerns were identified. CONCLUSIONS Low-dose tafenoquine (50 mg) reduces P. falciparum transmission to mosquitoes, with a delay in effect.
Collapse
Affiliation(s)
- Rebecca Webster
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Hayley Mitchell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Jenny M Peters
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Juanita Heunis
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Brighid O'Neill
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Jeremy Gower
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Sean Lynch
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Helen Jennings
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Fiona H Amante
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | | | - Adam J Potter
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Geoffrey W Birrell
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Michael D Edstein
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - G Dennis Shanks
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | | |
Collapse
|
6
|
Edwards CL, Ng SS, de Labastida Rivera F, Corvino D, Engel JA, Montes de Oca M, Bukali L, Frame TC, Bunn PT, Chauhan SB, Singh SS, Wang Y, Na J, Amante FH, Loughland JR, Soon MS, Waddell N, Mukhopadhay P, Koufariotis LT, Johnston RL, Lee JS, Kuns R, Zhang P, Boyle MJ, Hill GR, McCarthy JS, Kumar R, Engwerda CR. IL-10-producing Th1 cells possess a distinct molecular signature in malaria. J Clin Invest 2023; 133:e153733. [PMID: 36594463 PMCID: PMC9797345 DOI: 10.1172/jci153733] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/18/2022] [Indexed: 01/04/2023] Open
Abstract
Control of intracellular parasites responsible for malaria requires host IFN-γ+T-bet+CD4+ T cells (Th1 cells) with IL-10 produced by Th1 cells to mitigate the pathology induced by this inflammatory response. However, these IL-10-producing Th1 (induced type I regulatory [Tr1]) cells can also promote parasite persistence or impair immunity to reinfection or vaccination. Here, we identified molecular and phenotypic signatures that distinguished IL-10-Th1 cells from IL-10+Tr1 cells in Plasmodium falciparum-infected people who participated in controlled human malaria infection studies, as well as C57BL/6 mice with experimental malaria caused by P. berghei ANKA. We also identified a conserved Tr1 cell molecular signature shared between patients with malaria, dengue, and graft-versus-host disease. Genetic manipulation of primary human CD4+ T cells showed that the transcription factor cMAF played an important role in the induction of IL-10, while BLIMP-1 promoted the development of human CD4+ T cells expressing multiple coinhibitory receptors. We also describe heterogeneity of Tr1 cell coinhibitory receptor expression that has implications for targeting these molecules for clinical advantage during infection. Overall, this work provides insights into CD4+ T cell development during malaria that offer opportunities for creation of strategies to modulate CD4+ T cell functions and improve antiparasitic immunity.
Collapse
Affiliation(s)
- Chelsea L. Edwards
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- University of Queensland, School of Medicine, Brisbane, Australia
| | - Susanna S. Ng
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Griffith University, School of Natural Sciences, Nathan, Australia
- Institute of Experimental Oncology, University of Bonn, Bonn, Germany
| | | | - Dillon Corvino
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Institute of Experimental Oncology, University of Bonn, Bonn, Germany
| | | | - Marcela Montes de Oca
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- York Biomedical Research Institute, Hull York Medical School, University of York, York, United Kingdom
| | - Luzia Bukali
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- University of Queensland, School of Medicine, Brisbane, Australia
| | - Teija C.M. Frame
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- University of Queensland, School of Medicine, Brisbane, Australia
| | - Patrick T. Bunn
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Shashi Bhushan Chauhan
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Siddharth Sankar Singh
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Yulin Wang
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Griffith University, School of Natural Sciences, Nathan, Australia
| | - Jinrui Na
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- University of Queensland, School of Medicine, Brisbane, Australia
| | - Fiona H. Amante
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Megan S.F. Soon
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nicola Waddell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | | | | | - Jason S. Lee
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Rachel Kuns
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Ping Zhang
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Clinical Research Division, Fred Hutchinson Cancer Research Centre, Seattle, Washington, USA
| | | | - Geoffrey R. Hill
- Clinical Research Division, Fred Hutchinson Cancer Research Centre, Seattle, Washington, USA
| | - James S. McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Victorian Infectious Diseases Services, Doherty Institute, University of Melbourne, Melbourne, Australia
| | - Rajiv Kumar
- Centre of Experimental Medicine and Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | | |
Collapse
|
7
|
Barber BE, Fernandez M, Patel HB, Barcelo C, Woolley SD, Patel H, Llewellyn S, Abd-Rahman AN, Sharma S, Jain M, Ghoghari A, Di Resta I, Fuchs A, Deni I, Yeo T, Mok S, Fidock DA, Chalon S, Möhrle JJ, Parmar D, McCarthy JS, Kansagra K. Safety, pharmacokinetics, and antimalarial activity of the novel triaminopyrimidine ZY-19489: a first-in-human, randomised, placebo-controlled, double-blind, single ascending dose study, pilot food-effect study, and volunteer infection study. THE LANCET INFECTIOUS DISEASES 2022; 22:879-890. [DOI: 10.1016/s1473-3099(21)00679-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/30/2021] [Accepted: 10/13/2021] [Indexed: 01/04/2023]
|
8
|
Positron emission tomography and magnetic resonance imaging of the brain in experimental human malaria, a prospective cohort study. Sci Rep 2022; 12:5696. [PMID: 35383257 PMCID: PMC8983718 DOI: 10.1038/s41598-022-09748-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/01/2022] [Indexed: 12/25/2022] Open
Abstract
Cerebral malaria is the most serious manifestation of severe falciparum malaria. Sequestration of infected red blood cells and microvascular dysfunction are key contributing processes. Whether these processes occur in early stage disease prior to clinical manifestations is unknown. To help localize and understand these processes during the early stages of infection, we performed 18-F fluorodeoxyglucose positron emission tomography/magnetic resonance imaging in volunteers with Plasmodium falciparum induced blood stage malaria (IBSM) infection, and compared results to individuals with P. vivax infection, in whom coma is rare. Seven healthy, malaria-naïve participants underwent imaging at baseline, and at early symptom onset a median 9 days following inoculation (n = 4 P. falciparum, n = 3 P. vivax). Participants with P. falciparum infection demonstrated marked lability in radiotracer uptake across all regions of the brain, exceeding expected normal variation (within subject coefficient of variation (wCV): 14.4%) compared to the relatively stable uptake in participants with P. vivax infection (wCV: 3.5%). No consistent imaging changes suggestive of microvascular dysfunction were observed in either group. Neuroimaging in early IBSM studies is safe and technically feasible, with preliminary results suggesting that differences in brain tropism between P. falciparum and P. vivax may occur very early in infection.
Collapse
|
9
|
Makunin A, Korlević P, Park N, Goodwin S, Waterhouse RM, von Wyschetzki K, Jacob CG, Davies R, Kwiatkowski D, St Laurent B, Ayala D, Lawniczak MKN. A targeted amplicon sequencing panel to simultaneously identify mosquito species and Plasmodium presence across the entire Anopheles genus. Mol Ecol Resour 2022; 22:28-44. [PMID: 34053186 PMCID: PMC7612955 DOI: 10.1111/1755-0998.13436] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 05/19/2021] [Indexed: 01/04/2023]
Abstract
Anopheles is a diverse genus of mosquitoes comprising over 500 described species, including all known human malaria vectors. While a limited number of key vector species have been studied in detail, the goal of malaria elimination calls for surveillance of all potential vector species. Here, we develop a multilocus amplicon sequencing approach that targets 62 highly variable loci in the Anopheles genome and two conserved loci in the Plasmodium mitochondrion, simultaneously revealing both the mosquito species and whether that mosquito carries malaria parasites. We also develop a cheap, nondestructive, and high-throughput DNA extraction workflow that provides template DNA from single mosquitoes for the multiplex PCR, which means specimens producing unexpected results can be returned to for morphological examination. Over 1000 individual mosquitoes can be sequenced in a single MiSeq run, and we demonstrate the panel's power to assign species identity using sequencing data for 40 species from Africa, Southeast Asia, and South America. We also show that the approach can be used to resolve geographic population structure within An. gambiae and An. coluzzii populations, as the population structure determined based on these 62 loci from over 1000 mosquitoes closely mirrors that revealed through whole genome sequencing. The end-to-end approach is quick, inexpensive, robust, and accurate, which makes it a promising technique for very large-scale mosquito genetic surveillance and vector control.
Collapse
Affiliation(s)
- Alex Makunin
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | - Petra Korlević
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
- European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, Cambridge, UK
| | - Naomi Park
- Wellcome Sanger Institute, Hinxton, Cambridge, UK
| | | | - Robert M Waterhouse
- Department of Ecology and Evolution, University of Lausanne, and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | | | | | | | | | | | - Diego Ayala
- MIVEGEC, Univ. Montpellier, CNRS, IRD, Montpellier, France
- CIRMF, Franceville, Gabon
| | | |
Collapse
|
10
|
McCarthy JS, Yalkinoglu Ö, Odedra A, Webster R, Oeuvray C, Tappert A, Bezuidenhout D, Giddins MJ, Dhingra SK, Fidock DA, Marquart L, Webb L, Yin X, Khandelwal A, Bagchus WM. Safety, pharmacokinetics, and antimalarial activity of the novel plasmodium eukaryotic translation elongation factor 2 inhibitor M5717: a first-in-human, randomised, placebo-controlled, double-blind, single ascending dose study and volunteer infection study. THE LANCET. INFECTIOUS DISEASES 2021; 21:1713-1724. [PMID: 34715032 PMCID: PMC8612936 DOI: 10.1016/s1473-3099(21)00252-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 03/02/2021] [Accepted: 04/13/2021] [Indexed: 01/28/2023]
Abstract
BACKGROUND M5717 is the first plasmodium translation elongation factor 2 inhibitor to reach clinical development as an antimalarial. We aimed to characterise the safety, pharmacokinetics, and antimalarial activity of M5717 in healthy volunteers. METHODS This first-in-human study was a two-part, single-centre clinical trial done in Brisbane, QLD, Australia. Part one was a double-blind, randomised, placebo-controlled, single ascending dose study in which participants were enrolled into one of nine dose cohorts (50, 100, 200, 400, 600, 1000, 1250, 1800, or 2100 mg) and randomly assigned (3:1) to M5717 or placebo. A sentinel dosing strategy was used for each dose cohort whereby two participants (one assigned to M5717 and one assigned to placebo) were initially randomised and dosed. Randomisation schedules were generated electronically by independent, unblinded statisticians. Part two was an open-label, non-randomised volunteer infection study using the Plasmodium falciparum induced blood-stage malaria model in which participants were enrolled into three dose cohorts. Healthy men and women of non-childbearing potential aged 18-55 years were eligible for inclusion; individuals in the volunteer infection study were required to be malaria naive. Safety and tolerability (primary outcome of the single ascending dose study and secondary outcome of the volunteer infection study) were assessed by frequency and severity of adverse events. The pharmacokinetic profile of M5717 was also characterised (primary outcome of the volunteer infection study and secondary outcome of the single ascending dose study). Parasite clearance kinetics (primary outcome of the volunteer infection study) were assessed by the parasite reduction ratio and the corresponding parasite clearance half-life; the incidence of recrudescence up to day 28 was determined (secondary outcome of the volunteer infection study). Recrudescent parasites were tested for genetic mutations (exploratory outcome). The trial is registered with ClinicalTrials.gov (NCT03261401). FINDINGS Between Aug 28, 2017, and June 14, 2019, 221 individuals were assessed for eligibility, of whom 66 men were enrolled in the single ascending dose study (eight per cohort for 50-1800 mg cohorts, randomised three M5717 to one placebo, and two in the 2100 mg cohort, randomised one M5717 to one placebo) and 22 men were enrolled in the volunteer infection study (six in the 150 mg cohort and eight each in the 400 mg and 800 mg cohorts). No adverse event was serious; all M5717-related adverse events were mild or moderate in severity and transient, with increased frequency observed at doses above 1250 mg. In the single ascending dose study, treatment-related adverse events occurred in three of 17 individuals in the placebo group; no individual in the 50 mg, 100 mg, or 200 mg groups; one of six individuals in each of the 400 mg, 1000 mg, and 1250 mg groups; two of six individuals in the 600 mg group; and in all individuals in the 1800 mg and 2100 mg groups. In the volunteer infection study, M5717-related adverse events occurred in no participants in the 150 mg or 800 mg groups and in one of eight participants in the 400 mg group. Transient oral hypoesthesia (in three participants) and blurred vision (in four participants) were observed in the 1800 mg or 2100 mg groups and constituted an unknown risk; thus, further dosing was suspended after dosing of the two sentinel individuals in the 2100 mg cohort. Maximum blood concentrations occurred 1-7 h after dosing, and a long half-life was observed (146-193 h at doses ≥200 mg). Parasite clearance occurred in all participants and was biphasic, characterised by initial slow clearance lasting 35-55 h (half-life 231·1 h [95% CI 40·9 to not reached] for 150 mg, 60·4 h [38·6 to 138·6] for 400 mg, and 24·7 h [20·4 to 31·3] for 800 mg), followed by rapid clearance (half-life 3·5 h [3·1 to 4·0] for 150 mg, 3·9 h [3·3 to 4·8] for 400 mg, and 5·5 h [4·8 to 6·4] for 800 mg). Recrudescence occurred in three (50%) of six individuals dosed with 150 mg and two (25%) of eight individuals dosed with 400 mg. Genetic mutations associated with resistance were detected in four cases of parasite recrudescence (two individuals dosed with 150 mg and two dosed with 400 mg). INTERPRETATION The safety, pharmacokinetics, and antimalarial activity of M5717 support its development as a component of a single-dose antimalarial combination therapy or for malaria prophylaxis. FUNDING Wellcome Trust and the healthcare business of Merck KGaA, Darmstadt, Germany.
Collapse
Affiliation(s)
- James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; The Peter Doherty Institute for Infection and Immunity, The University of Melbourne and the Royal Melbourne Hospital, Melbourne, VIC, Australia
| | | | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; Liverpool School of Tropical Medicine, Liverpool, UK
| | - Rebecca Webster
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Claude Oeuvray
- The Global Health Institute of Merck (an affiliate of Merck KGaA), Eysin, Switzerland
| | - Aliona Tappert
- the healthcare business of Merck KGaA, Darmstadt, Germany
| | | | - Marla J Giddins
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - Satish K Dhingra
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, USA; Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Lachlan Webb
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Xiaoyan Yin
- Global Statistics for NDD, Immunology, Endocrinology, Fertility & Others, EMD Serono, Billerica, MA, USA
| | | | | |
Collapse
|
11
|
Webster R, Sekuloski S, Odedra A, Woolley S, Jennings H, Amante F, Trenholme KR, Healer J, Cowman AF, Eriksson EM, Sathe P, Penington J, Blanch AJ, Dixon MWA, Tilley L, Duffy MF, Craig A, Storm J, Chan JA, Evans K, Papenfuss AT, Schofield L, Griffin P, Barber BE, Andrew D, Boyle MJ, de Labastida Rivera F, Engwerda C, McCarthy JS. Safety, infectivity and immunogenicity of a genetically attenuated blood-stage malaria vaccine. BMC Med 2021; 19:293. [PMID: 34802442 PMCID: PMC8606250 DOI: 10.1186/s12916-021-02150-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/30/2021] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND There is a clear need for novel approaches to malaria vaccine development. We aimed to develop a genetically attenuated blood-stage vaccine and test its safety, infectivity, and immunogenicity in healthy volunteers. Our approach was to target the gene encoding the knob-associated histidine-rich protein (KAHRP), which is responsible for the assembly of knob structures at the infected erythrocyte surface. Knobs are required for correct display of the polymorphic adhesion ligand P. falciparum erythrocyte membrane protein 1 (PfEMP1), a key virulence determinant encoded by a repertoire of var genes. METHODS The gene encoding KAHRP was deleted from P. falciparum 3D7 and a master cell bank was produced in accordance with Good Manufacturing Practice. Eight malaria naïve males were intravenously inoculated (day 0) with 1800 (2 subjects), 1.8 × 105 (2 subjects), or 3 × 106 viable parasites (4 subjects). Parasitemia was measured using qPCR; immunogenicity was determined using standard assays. Parasites were rescued into culture for in vitro analyses (genome sequencing, cytoadhesion assays, scanning electron microscopy, var gene expression). RESULTS None of the subjects who were administered with 1800 or 1.8 × 105 parasites developed parasitemia; 3/4 subjects administered 3× 106 parasites developed significant parasitemia, first detected on days 13, 18, and 22. One of these three subjects developed symptoms of malaria simultaneously with influenza B (day 17; 14,022 parasites/mL); one subject developed mild symptoms on day 28 (19,956 parasites/mL); and one subject remained asymptomatic up to day 35 (5046 parasites/mL). Parasitemia rapidly cleared with artemether/lumefantrine. Parasitemia induced a parasite-specific antibody and cell-mediated immune response. Parasites cultured ex vivo exhibited genotypic and phenotypic properties similar to inoculated parasites, although the var gene expression profile changed during growth in vivo. CONCLUSIONS This study represents the first clinical investigation of a genetically attenuated blood-stage human malaria vaccine. A P. falciparum 3D7 kahrp- strain was tested in vivo and found to be immunogenic but can lead to patent parasitemia at high doses. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry (number: ACTRN12617000824369 ; date: 06 June 2017).
Collapse
Affiliation(s)
- Rebecca Webster
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Silvana Sekuloski
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Current address: PharmOut, 111 Eagle Street, Brisbane, Queensland, 4000, Australia
| | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Liverpool School of Tropical Medicine, Liverpool, UK
| | - Stephen Woolley
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Liverpool School of Tropical Medicine, Liverpool, UK.,Centre of Defence Pathology, Royal Centre for Defence Medicine, Joint Hospital Group, Birmingham, UK
| | - Helen Jennings
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Fiona Amante
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Katharine R Trenholme
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,The University of Queensland, Brisbane, Australia
| | - Julie Healer
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia
| | - Emily M Eriksson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Priyanka Sathe
- Current address: Medicines Development for Global Health Limited, 18 Kavanagh Street, Southbank, Victoria, 3006, Australia
| | - Jocelyn Penington
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Adam J Blanch
- Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Australia
| | - Matthew W A Dixon
- Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Australia
| | - Leann Tilley
- Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Australia
| | - Michael F Duffy
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia.,Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia.,The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Department of Medicine, Royal Melbourne Hospital, Melbourne, Australia
| | - Alister Craig
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Janet Storm
- Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Krystal Evans
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Current address: GSK, 436 Johnston Street, Abbotsford, Victoria, 3067, Australia
| | - Anthony T Papenfuss
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Louis Schofield
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.,Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Paul Griffin
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,The University of Queensland, Brisbane, Australia.,Department of Medicine and Infectious Diseases, Mater Hospital and Mater Research, Brisbane, Australia
| | | | - Dean Andrew
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | | | | | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia. .,The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.
| |
Collapse
|
12
|
Fabri LV, Azzopardi KI, Osowicki J, Frost HR, Smeesters PR, Steer AC. An emm-type specific qPCR to track bacterial load during experimental human Streptococcus pyogenes pharyngitis. BMC Infect Dis 2021; 21:463. [PMID: 34020607 PMCID: PMC8138111 DOI: 10.1186/s12879-021-06173-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 05/12/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Streptococcus pyogenes causes a profound global burden of morbidity and mortality across its diverse clinical spectrum. To support a new controlled human infection ('challenge') model seeking to accelerate S. pyogenes vaccine development, we aimed to develop an accurate and reliable molecular method for quantifying bacterial load from pharyngeal swabs collected during experimental human pharyngitis. METHODS Combined sequential RNA + DNA extraction from throat swabs was compared to traditional separate RNA-only and DNA-only extractions. An emm-type specific qPCR was developed to detect the emm75 challenge strain. Results from the qPCR were compared to culture, using throat swab samples collected in a human challenge study. RESULTS The qPCR was 100% specific for the emm75 challenge strain when tested against a panel of S. pyogenes emm-types and other respiratory pathogens. Combined RNA + DNA extraction had similar yield to traditional separate extractions. The combined extraction method and emm75 qPCR had 98.8% sensitivity compared to culture for throat swabs collected from challenge study participants. CONCLUSIONS We have developed a reliable molecular method for measuring S. pyogenes bacterial load from throat swabs collected in a controlled human infection model of S. pyogenes pharyngitis. TRIAL REGISTRATION NCT03361163 on 4th December 2017.
Collapse
Affiliation(s)
- Loraine V Fabri
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, Université Libre de Bruxelles, Brussels, Belgium
| | - Kristy I Azzopardi
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Joshua Osowicki
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia.
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
- Infectious Diseases Unit, Department of General Medicine, The Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia.
| | - Hannah R Frost
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Pierre R Smeesters
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, Université Libre de Bruxelles, Brussels, Belgium
- Academic Children Hospital Queen Fabiola, Université Libre de Bruxelles, Brussels, Belgium
- Molecular Bacteriology Laboratory, Université Libre de Bruxelles, Brussels, Belgium
| | - Andrew C Steer
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
- Infectious Diseases Unit, Department of General Medicine, The Royal Children's Hospital Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
13
|
Woodford J, Gillman A, Jenvey P, Roberts J, Woolley S, Barber BE, Fernandez M, Rose S, Thomas P, Anstey NM, McCarthy JS. Positron emission tomography and magnetic resonance imaging in experimental human malaria to identify organ-specific changes in morphology and glucose metabolism: A prospective cohort study. PLoS Med 2021; 18:e1003567. [PMID: 34038421 PMCID: PMC8154100 DOI: 10.1371/journal.pmed.1003567] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 02/17/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Plasmodium vivax has been proposed to infect and replicate in the human spleen and bone marrow. Compared to Plasmodium falciparum, which is known to undergo microvascular tissue sequestration, little is known about the behavior of P. vivax outside of the circulating compartment. This may be due in part to difficulties in studying parasite location and activity in life. METHODS AND FINDINGS To identify organ-specific changes during the early stages of P. vivax infection, we performed 18-F fluorodeoxyglucose (FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) at baseline and just prior to onset of clinical illness in P. vivax experimentally induced blood-stage malaria (IBSM) and compared findings to P. falciparum IBSM. Seven healthy, malaria-naive participants were enrolled from 3 IBSM trials: NCT02867059, ACTRN12616000174482, and ACTRN12619001085167. Imaging took place between 2016 and 2019 at the Herston Imaging Research Facility, Australia. Postinoculation imaging was performed after a median of 9 days in both species (n = 3 P. vivax; n = 4 P. falciparum). All participants were aged between 19 and 23 years, and 6/7 were male. Splenic volume (P. vivax: +28.8% [confidence interval (CI) +10.3% to +57.3%], P. falciparum: +22.9 [CI -15.3% to +61.1%]) and radiotracer uptake (P. vivax: +15.5% [CI -0.7% to +31.7%], P. falciparum: +5.5% [CI +1.4% to +9.6%]) increased following infection with each species, but more so in P. vivax infection (volume: p = 0.72, radiotracer uptake: p = 0.036). There was no change in FDG uptake in the bone marrow (P. vivax: +4.6% [CI -15.9% to +25.0%], P. falciparum: +3.2% [CI -3.2% to +9.6%]) or liver (P. vivax: +6.2% [CI -8.7% to +21.1%], P. falciparum: -1.4% [CI -4.6% to +1.8%]) following infection with either species. In participants with P. vivax, hemoglobin, hematocrit, and platelet count decreased from baseline at the time of postinoculation imaging. Decrements in hemoglobin and hematocrit were significantly greater in participants with P. vivax infection compared to P. falciparum. The main limitations of this study are the small sample size and the inability of this tracer to differentiate between host and parasite metabolic activity. CONCLUSIONS PET/MRI indicated greater splenic tropism and metabolic activity in early P. vivax infection compared to P. falciparum, supporting the hypothesis of splenic accumulation of P. vivax very early in infection. The absence of uptake in the bone marrow and liver suggests that, at least in early infection, these tissues do not harbor a large parasite biomass or do not provoke a prominent metabolic response. PET/MRI is a safe and noninvasive method to evaluate infection-associated organ changes in morphology and glucose metabolism.
Collapse
Affiliation(s)
- John Woodford
- Clinical Tropical Medicine Laboratory, QIMR-Berghofer Medical Research Institute, Brisbane, Australia
- University of Queensland, Brisbane, Australia
| | - Ashley Gillman
- Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia
| | - Peter Jenvey
- Department of Radiology, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Jennie Roberts
- Department of Radiology, Royal Brisbane and Women’s Hospital, Brisbane, Australia
| | - Stephen Woolley
- Clinical Tropical Medicine Laboratory, QIMR-Berghofer Medical Research Institute, Brisbane, Australia
- Centre for Defence Pathology, Royal Centre for Defence Medicine, Birmingham, United Kingdom
| | - Bridget E. Barber
- Clinical Tropical Medicine Laboratory, QIMR-Berghofer Medical Research Institute, Brisbane, Australia
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Melissa Fernandez
- Clinical Tropical Medicine Laboratory, QIMR-Berghofer Medical Research Institute, Brisbane, Australia
| | - Stephen Rose
- Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia
| | - Paul Thomas
- Herston Imaging Research Facility, Brisbane, Australia
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - James S. McCarthy
- Clinical Tropical Medicine Laboratory, QIMR-Berghofer Medical Research Institute, Brisbane, Australia
- University of Queensland, Brisbane, Australia
| |
Collapse
|
14
|
McCarthy JS, Donini C, Chalon S, Woodford J, Marquart L, Collins KA, Rozenberg FD, Fidock DA, Cherkaoui-Rbati MH, Gobeau N, Möhrle JJ. A Phase 1, Placebo-controlled, Randomized, Single Ascending Dose Study and a Volunteer Infection Study to Characterize the Safety, Pharmacokinetics, and Antimalarial Activity of the Plasmodium Phosphatidylinositol 4-Kinase Inhibitor MMV390048. Clin Infect Dis 2021; 71:e657-e664. [PMID: 32239164 PMCID: PMC7744986 DOI: 10.1093/cid/ciaa368] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/01/2020] [Indexed: 02/01/2023] Open
Abstract
Background MMV390048 is the first Plasmodium phosphatidylinositol 4-kinase inhibitor to reach clinical development as a new antimalarial. We aimed to characterize the safety, pharmacokinetics, and antimalarial activity of a tablet formulation of MMV390048. Methods A 2-part, phase 1 trial was conducted in healthy adults. Part 1 was a double-blind, randomized, placebo-controlled, single ascending dose study consisting of 3 cohorts (40, 80, 120 mg MMV390048). Part 2 was an open-label volunteer infection study using the Plasmodium falciparum induced blood-stage malaria model consisting of 2 cohorts (40 mg and 80 mg MMV390048). Results Twenty four subjects were enrolled in part 1 (n = 8 per cohort, randomized 3:1 MMV390048:placebo) and 15 subjects were enrolled in part 2 (40 mg [n = 7] and 80 mg [n = 8] cohorts). One subject was withdrawn from part 2 (80 mg cohort) before dosing and was not included in analyses. No serious or severe adverse events were attributed to MMV390048. The rate of parasite clearance was greater in subjects administered 80 mg compared to those administered 40 mg (clearance half-life 5.5 hours [95% confidence interval {CI}, 5.2–6.0 hours] vs 6.4 hours [95% CI, 6.0–6.9 hours]; P = .005). Pharmacokinetic/pharmacodynamic modeling estimated a minimum inhibitory concentration of 83 ng/mL and a minimal parasiticidal concentration that would achieve 90% of the maximum effect of 238 ng/mL, and predicted that a single 120-mg dose would achieve an adequate clinical and parasitological response with 92% certainty. Conclusions The safety, pharmacokinetics, and pharmacodynamics of MMV390048 support its further development as a partner drug of a single-dose combination therapy for malaria. Clinical Trials Registration NCT02783820 (part 1); NCT02783833 (part 2).
Collapse
Affiliation(s)
- James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | | | - John Woodford
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | - Felix D Rozenberg
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, USA
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, USA.,Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | | | | | | |
Collapse
|
15
|
Wang CYT, Ballard EL, Pava Z, Marquart L, Gaydon J, Murphy SC, Whiley D, O'Rourke P, McCarthy JS. Analytical validation of a real-time hydrolysis probe PCR assay for quantifying Plasmodium falciparum parasites in experimentally infected human adults. Malar J 2021; 20:181. [PMID: 33838672 PMCID: PMC8035755 DOI: 10.1186/s12936-021-03717-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 03/29/2021] [Indexed: 11/10/2022] Open
Abstract
Background Volunteer infection studies have become a standard model for evaluating drug efficacy against Plasmodium infections. Molecular techniques such as qPCR are used in these studies due to their ability to provide robust and accurate estimates of parasitaemia at increased sensitivity compared to microscopy. The validity and reliability of assays need to be ensured when used to evaluate the efficacy of candidate drugs in clinical trials. Methods A previously described 18S rRNA gene qPCR assay for quantifying Plasmodium falciparum in blood samples was evaluated. Assay performance characteristics including analytical sensitivity, reportable range, precision, accuracy and specificity were assessed using experimental data and data compiled from phase 1 volunteer infection studies conducted between 2013 and 2019. Guidelines for validation of laboratory-developed molecular assays were followed. Results The reportable range was 1.50 to 6.50 log10 parasites/mL with a limit of detection of 2.045 log10 parasites/mL of whole blood based on a parasite diluted standard series over this range. The assay was highly reproducible with minimal intra-assay (SD = 0.456 quantification cycle (Cq) units [0.137 log10 parasites/mL] over 21 replicates) and inter-assay (SD = 0.604 Cq units [0.182 log10 parasites/mL] over 786 qPCR runs) variability. Through an external quality assurance program, the QIMR assay was shown to generate accurate results (quantitative bias + 0.019 log10 parasites/mL against nominal values). Specificity was 100% after assessing 164 parasite-free human blood samples. Conclusions The 18S rRNA gene qPCR assay is specific and highly reproducible and can provide reliable and accurate parasite quantification. The assay is considered fit for use in evaluating drug efficacy in malaria clinical trials. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03717-y.
Collapse
Affiliation(s)
- Claire Y T Wang
- Centre for Children's Health Research, Children's Health Queensland, Brisbane, Australia. .,Child Health Research Centre, The University of Queensland, Brisbane, Australia.
| | - Emma L Ballard
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Zuleima Pava
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Jane Gaydon
- Centre for Children's Health Research, Children's Health Queensland, Brisbane, Australia.,Child Health Research Centre, The University of Queensland, Brisbane, Australia
| | - Sean C Murphy
- Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, WA, USA.,Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - David Whiley
- Centre for Children's Health Research, Children's Health Queensland, Brisbane, Australia.,UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Peter O'Rourke
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, The University of Queensland, Brisbane, Australia
| |
Collapse
|
16
|
Woolley SD, Fernandez M, Rebelo M, Llewellyn SA, Marquart L, Amante FH, Jennings HE, Webster R, Trenholme K, Chalon S, Moehrle JJ, McCarthy JS, Barber BE. Development and evaluation of a new Plasmodium falciparum 3D7 blood stage malaria cell bank for use in malaria volunteer infection studies. Malar J 2021; 20:93. [PMID: 33593375 PMCID: PMC7885253 DOI: 10.1186/s12936-021-03627-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 02/05/2021] [Indexed: 11/23/2022] Open
Abstract
Background New anti-malarial therapeutics are required to counter the threat of increasing drug resistance. Malaria volunteer infection studies (VIS), particularly the induced blood stage malaria (IBSM) model, play a key role in accelerating anti-malarial drug development. Supply of the reference 3D7-V2 Plasmodium falciparum malaria cell bank (MCB) is limited. This study aimed to develop a new MCB, and compare the safety and infectivity of this MCB with the existing 3D7-V2 MCB, in a VIS. A second bank (3D7-V1) developed in 1995 was also evaluated. Methods The 3D7-V2 MCB was expanded in vitro using a bioreactor to produce a new MCB designated 3D7-MBE-008. This bank and 3D7-V1 were then evaluated using the IBSM model, where healthy participants were intravenously inoculated with blood-stage parasites. Participants were treated with artemether-lumefantrine when parasitaemia or clinical thresholds were reached. Safety, infectivity and parasite growth and clearance were evaluated. Results The in vitro expansion of 3D7-V2 produced 200 vials of the 3D7-MBE-008 MCB, with a parasitaemia of 4.3%. This compares to 0.1% in the existing 3D7-V2 MCB, and < 0.01% in the 3D7-V1 MCB. All four participants (two per MCB) developed detectable P. falciparum infection after inoculation with approximately 2800 parasites. For the 3D7-MBE-008 MCB, the parasite multiplication rate of 48 h (PMR48) using non-linear mixed effects modelling was 34.6 (95% CI 18.5–64.6), similar to the parental 3D7-V2 line; parasitaemia in both participants exceeded 10,000/mL by day 8. Growth of the 3D7-V1 was slower (PMR48 of 11.5 [95% CI 8.5–15.6]), with parasitaemia exceeding 10,000 parasites/mL on days 10 and 8.5. Rapid parasite clearance followed artemether-lumefantrine treatment in all four participants, with clearance half-lives of 4.01 and 4.06 (weighted mean 4.04 [95% CI 3.61–4.57]) hours for 3D7-MBE-008 and 4.11 and 4.52 (weighted mean 4.31 [95% CI 4.16–4.47]) hours for 3D7-V1. A total of 59 adverse events occurred; most were of mild severity with three being severe in the 3D7-MBE-008 study. Conclusion The safety, growth and clearance profiles of the expanded 3D7-MBE-008 MCB closely resemble that of its parent, indicating its suitability for future studies. Trial Registration: Australian New Zealand Clinical Trials registry numbers: P3487 (3D7-V1): ACTRN12619001085167. P3491 (3D7-MBE-008): ACTRN12619001079134
Collapse
Affiliation(s)
- Stephen D Woolley
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Centre for Defence Pathology, Royal Centre for Defence Medicine, Joint Hospital Group, ICT Building, Birmingham Research Park, Vincent Drive, Birmingham, UK.,Clinical Sciences Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | | | - Maria Rebelo
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | | | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Fiona H Amante
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Helen E Jennings
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Rebecca Webster
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Katharine Trenholme
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,School of Medicine, University of Queensland, Herston, QLD, Australia
| | - Stephan Chalon
- Medicines for Malaria Venture, 20 Route de Pre-Bois, PO Box 1826, 1215, Geneva 15, Switzerland
| | - Joerg J Moehrle
- Medicines for Malaria Venture, 20 Route de Pre-Bois, PO Box 1826, 1215, Geneva 15, Switzerland
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Bridget E Barber
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| |
Collapse
|
17
|
Defining the Antimalarial Activity of Cipargamin in Healthy Volunteers Experimentally Infected with Blood-Stage Plasmodium falciparum. Antimicrob Agents Chemother 2021; 65:AAC.01423-20. [PMID: 33199389 PMCID: PMC7849011 DOI: 10.1128/aac.01423-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 11/08/2020] [Indexed: 12/11/2022] Open
Abstract
The spiroindolone cipargamin, a new antimalarial compound that inhibits Plasmodium ATP4, is currently in clinical development. This study aimed to characterize the antimalarial activity of cipargamin in healthy volunteers experimentally infected with blood-stage Plasmodium falciparum. The spiroindolone cipargamin, a new antimalarial compound that inhibits Plasmodium ATP4, is currently in clinical development. This study aimed to characterize the antimalarial activity of cipargamin in healthy volunteers experimentally infected with blood-stage Plasmodium falciparum. Eight subjects were intravenously inoculated with parasite-infected erythrocytes and received a single oral dose of 10 mg cipargamin 7 days later. Blood samples were collected to monitor the development and clearance of parasitemia and plasma cipargamin concentrations. Parasite regrowth was treated with piperaquine monotherapy to clear asexual parasites, while allowing gametocyte transmissibility to mosquitoes to be investigated. An initial rapid decrease in parasitemia occurred in all participants following cipargamin dosing, with a parasite clearance half-life of 3.99 h. As anticipated from the dose selected, parasite regrowth occurred in all 8 subjects 3 to 8 days after dosing and allowed the pharmacokinetic/pharmacodynamic relationship to be determined. Based on the limited data from the single subtherapeutic dose cohort, a MIC of 11.6 ng/ml and minimum parasiticidal concentration that achieves 90% of maximum effect of 23.5 ng/ml were estimated, and a single 95-mg dose (95% confidence interval [CI], 50 to 270) was predicted to clear 109 parasites/ml. Low gametocyte densities were detected in all subjects following piperaquine treatment, which did not transmit to mosquitoes. Serious adverse liver function changes were observed in three subjects, which led to premature study termination. The antimalarial activity characterized in this study supports the further clinical development of cipargamin as a new treatment for P. falciparum malaria, although the hepatic safety profile of the compound warrants further evaluation. (This study has been registered at ClinicalTrials.gov under identifier NCT02543086.)
Collapse
|
18
|
Safety and feasibility of apheresis to harvest and concentrate parasites from subjects with induced blood stage Plasmodium vivax infection. Malar J 2021; 20:43. [PMID: 33446191 PMCID: PMC7807416 DOI: 10.1186/s12936-021-03581-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 01/04/2021] [Indexed: 11/27/2022] Open
Abstract
Background In the absence of a method to culture Plasmodium vivax, the only way to source parasites is ex vivo. This hampers many aspects of P. vivax research. This study aimed to assess the safety of apheresis, a method for selective removal of specific components of blood as a means of extracting and concentrating P. vivax parasites. Methods An iterative approach was employed across four non-immune healthy human subjects in single subject cohorts. All four subjects were inoculated with ~ 564 blood stage P. vivax (HMP013-Pv) and subjected to apheresis 10 to 11 days later. Blood samples collected during apheresis (haematocrit layers 0.5% to 11%) were tested for the presence and concentration of P. vivax by microscopy, flow cytometry, 18S rDNA qPCR for total parasites, and pvs25 qRT-PCR for female gametocyte transcripts. Safety was determined by monitoring adverse events. Malaria transmission to mosquitoes was assessed by membrane feeding assays. Results There were no serious adverse events and no significant safety concerns. Apheresis concentrated asexual parasites by up to 4.9-fold (range: 0.9–4.9-fold) and gametocytes by up to 1.45-fold (range: 0.38–1.45-fold) compared to pre-apheresis densities. No single haematocrit layer contained > 40% of all the recovered P. vivax asexual parasites. Ex vivo concentration of parasites by Percoll gradient centrifugation of whole blood achieved greater concentration of gametocytes than apheresis. Mosquito transmission was enhanced by up to fivefold in a single apheresis sample compared to pre-apheresis. Conclusion The modest level of parasite concentration suggests that the use of apheresis may not be an ideal method for harvesting P. vivax. Trial Registration Australia New Zealand Clinical Trials Registry (ANZCTR) Trial ID: ACTRN12617001502325 registered on 19th October 2017. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373812.
Collapse
|
19
|
Th2-like T Follicular Helper Cells Promote Functional Antibody Production during Plasmodium falciparum Infection. CELL REPORTS MEDICINE 2020; 1:100157. [PMID: 33377128 PMCID: PMC7762767 DOI: 10.1016/j.xcrm.2020.100157] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/08/2020] [Accepted: 11/19/2020] [Indexed: 01/10/2023]
Abstract
CD4+ T follicular helper cells (Tfh) are key drivers of antibody development. During Plasmodium falciparum malaria in children, the activation of Tfh is restricted to the Th1 subset and not associated with antibody levels. To identify Tfh subsets that are associated with antibody development in malaria, we assess Tfh and antibodies longitudinally in human volunteers with experimental P. falciparum infection. Tfh cells activate during infection, with distinct dynamics in different Tfh subsets. Th2-Tfh cells activate early, during peak infection, while Th1-Tfh cells activate 1 week after peak infection and treatment. Th2-Tfh cell activation is associated with the functional breadth and magnitude of parasite antibodies. In contrast, Th1-Tfh activation is not associated with antibody development but instead with plasma cells, which have previously been shown to play a detrimental role in the development of long-lived immunity. Thus, our study identifies the contrasting roles of Th2 and Th1-Tfh cells during experimental P. falciparum malaria.
Collapse
|
20
|
Odedra A, Webb L, Marquart L, Britton LJ, Chalon S, Moehrle JJ, Anstey NM, William T, Grigg MJ, Lalloo DG, Barber BE, McCarthy JS. Liver Function Test Abnormalities in Experimental and Clinical Plasmodium vivax Infection. Am J Trop Med Hyg 2020; 103:1910-1917. [PMID: 32815508 PMCID: PMC7646782 DOI: 10.4269/ajtmh.20-0491] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Liver transaminase elevations after treatment in malaria volunteer infection studies (VISs) have raised safety concerns. We investigated transaminase elevations from two human Plasmodium vivax VISs where subjects were treated with chloroquine (n = 24) or artefenomel (n = 8) and compared them with studies in Thailand (n = 41) and Malaysia (n = 76). In the VISs, alanine transaminase (ALT) increased to ≥ 2.5 × upper limit of normal (ULN) in 11/32 (34%) volunteers, peaking 5–8 days post-treatment. Transaminase elevations were asymptomatic, were not associated with elevated bilirubin, and resolved by day 42. The risk of an ALT ≥ 2.5 × ULN increased more than 4-fold (odds ratio [OR] 4.28; 95% CI: 1.26–14.59; P = 0.02) for every log10 increase in the parasite clearance burden (PCB), defined as the log-fold reduction in parasitemia 24 hours post-treatment. Although an elevated ALT ≥ 2.5 × ULN was more common after artefenomel than after chloroquine (5/8 [63%] versus 6/24 [25%]; OR 5.0; 95% CI: 0.91–27.47; P = 0.06), this risk disappeared when corrected for PCB. Peak ALT also correlated with peak C-reactive protein (R = 0.44; P = 0.012). Elevations in ALT (≥ 2.5 × ULN) were less common in malaria-endemic settings, occurring in 1/41 (2.5%) Thai patients treated with artefenomel, and in none of 76 Malaysians treated with chloroquine or artemisinin combination therapy. Post-treatment transaminase elevations are common in experimental P. vivax infection but do not appear to impact on participant safety. Although the mechanism of these changes remains uncertain, host inflammatory response to parasite clearance may be contributory.
Collapse
Affiliation(s)
- Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lachlan Webb
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Laurence J Britton
- School of Medicine, The University of Queensland, Brisbane, Australia.,Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Australia
| | | | | | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - Timothy William
- Gleneagles Hospital, Kota Kinabalu, Malaysia.,Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - David G Lalloo
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Bridget E Barber
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia.,QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | |
Collapse
|
21
|
Wockner LF, Hoffmann I, Webb L, Mordmüller B, Murphy SC, Kublin JG, O'Rourke P, McCarthy JS, Marquart L. Growth Rate of Plasmodium falciparum: Analysis of Parasite Growth Data From Malaria Volunteer Infection Studies. J Infect Dis 2020; 221:963-972. [PMID: 31679015 PMCID: PMC7198127 DOI: 10.1093/infdis/jiz557] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 10/29/2019] [Indexed: 12/16/2022] Open
Abstract
Background Growth rate of malaria parasites in the blood of infected subjects is an important
measure of efficacy of drugs and vaccines. Methods We used log-linear and sine-wave models to estimate the parasite growth rate of the 3D7
strain of Plasmodium falciparum using data from 177 subjects from 14
induced blood stage malaria (IBSM) studies conducted at QIMR Berghofer. We estimated
parasite multiplication rate per 48 hour (PMR48), PMR per life-cycle
(PMRLC), and parasite life-cycle duration. We compared these parameters to
those from studies conducted elsewhere with infections induced by IBSM (n=66),
sporozoites via mosquito bite (n=336) or injection (n=51). Results The parasite growth rate of 3D7 in QIMR Berghofer studies was 0.75/day (95% CI:
0.73–0.77/day), PMR48 was 31.9 (95% CI: 28.7–35.4),
PMRLC was 16.4 (95% CI: 15.1–17.8) and parasite life-cycle was 38.8
hour (95% CI: 38.3–39.2 hour). These parameters were similar to estimates from
IBSM studies elsewhere (0.71/day, 95% CI: 0.67–0.75/day; PMR48 26.6,
95% CI: 22.2–31.8), but significantly higher (P < 0.001)
than in sporozoite studies (0.47/day, 95% CI: 0.43–0.50/day; PMR48
8.6, 95% CI: 7.3–10.1). Conclusions Parasite growth rates were similar across different IBSM studies and higher than
infections induced by sporozoite.
Collapse
Affiliation(s)
- Leesa F Wockner
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Isabell Hoffmann
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Lachlan Webb
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | - Sean C Murphy
- Departments of Laboratory Medicine and Microbiology, University of Washington, Seattle, Washington, USA
| | - James G Kublin
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Peter O'Rourke
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,School of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| |
Collapse
|
22
|
Rebelo M, Pawliw R, Gower J, Webb L, Mitchell H, Pava Z, Watts RE, Davenport MP, McCarthy JS, Khoury DS. Parasite Viability as a Superior Measure of Antimalarial Drug Activity in Humans. J Infect Dis 2020; 223:2154-2163. [PMID: 33119072 DOI: 10.1093/infdis/jiaa678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/22/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Artemisinin derivatives are the leading class of antimalarial drugs due to their rapid onset of action and rapid clearance of circulating parasites. The parasite clearance half-life measures the rate of loss of parasites from blood after treatment, and this is currently used to assess antimalarial activity of novel agents and to monitor resistance. However, a number of recent studies have challenged the use of parasite clearance to measure drug activity, arguing that many circulating parasites may be nonviable. METHODS Plasmodium falciparum-infected subjects (n = 10) in a malaria volunteer infection study were administered a single dose of artesunate (2 mg/kg). Circulating parasite concentration was assessed by means of quantitative polymerase chain reaction (qPCR). Parasite viability after artesunate administration was estimated by mathematical modeling of the ex vivo growth of parasites collected from subjects. RESULTS We showed that in artemisinin-sensitive infection, viable parasites declined to <0.1% of baseline within 8 hours after artesunate administration, while the total number of circulating parasites measured with quantitative polymerase chain reaction remained unchanged. In artemisinin-resistant infections over the same interval, viable parasites declined to 51.4% (standard error of the mean, 4.6%) of baseline. CONCLUSIONS These results demonstrate that in vivo drug activity of artesunate is faster than is indicated by the parasite clearance half-life.
Collapse
Affiliation(s)
- Maria Rebelo
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Rebecca Pawliw
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Jeremy Gower
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Lachlan Webb
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Hayley Mitchell
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Zuleima Pava
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Rebecca E Watts
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Miles P Davenport
- Kirby Institute, University of New South Wales (Sydney), Sydney, New South Wales, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - David S Khoury
- Kirby Institute, University of New South Wales (Sydney), Sydney, New South Wales, Australia
| |
Collapse
|
23
|
Wu L, Mwesigwa J, Affara M, Bah M, Correa S, Hall T, Singh SK, Beeson JG, Tetteh KKA, Kleinschmidt I, D'Alessandro U, Drakeley C. Antibody responses to a suite of novel serological markers for malaria surveillance demonstrate strong correlation with clinical and parasitological infection across seasons and transmission settings in The Gambia. BMC Med 2020; 18:304. [PMID: 32972398 PMCID: PMC7517687 DOI: 10.1186/s12916-020-01724-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/30/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND As malaria transmission declines, sensitive diagnostics are needed to evaluate interventions and monitor transmission. Serological assays measuring malaria antibody responses offer a cost-effective detection method to supplement existing surveillance tools. METHODS A prospective cohort study was conducted from 2013 to 2015 in 12 villages across five administrative regions in The Gambia. Serological analysis included samples from the West Coast Region at the start and end of the season (July and December 2013) and from the Upper River Region in July and December 2013 and April and December 2014. Antigen-specific antibody responses to eight Plasmodium falciparum (P. falciparum) antigens-Etramp5.Ag1, GEXP18, HSP40.Ag1, Rh2.2030, EBA175 RIII-V, PfMSP119, PfAMA1, and PfGLURP.R2-were quantified using a multiplexed bead-based assay. The association between antibody responses and clinical and parasitological endpoints was estimated at the individual, household, and population level. RESULTS Strong associations were observed between clinical malaria and concurrent sero-positivity to Etramp5.Ag1 (aOR 4.60 95% CI 2.98-7.12), PfMSP119 (aOR 4.09 95% CI 2.60-6.44), PfAMA1 (aOR 2.32 95% CI 1.40-3.85), and PfGLURP.R2 (aOR 3.12, 95% CI 2.92-4.95), while asymptomatic infection was associated with sero-positivity to all antigens. Village-level sero-prevalence amongst children 2-10 years against Etramp5.Ag1, HSP40.Ag1, and PfMSP119 showed the highest correlations with clinical and P. falciparum infection incidence rates. For all antigens, there were increased odds of asymptomatic P. falciparum infection in subjects residing in a compound with greater than 50% sero-prevalence, with a 2- to 3-fold increase in odds of infection associated with Etramp5.Ag1, GEXP18, Rh2.2030, PfMSP119, and PfAMA1. For individuals residing in sero-positive compounds, the odds of clinical malaria were reduced, suggesting a protective effect. CONCLUSIONS At low transmission, long-lived antibody responses could indicate foci of malaria transmission that have been ongoing for several seasons or years. In settings where sub-patent infections are prevalent and fluctuate below the detection limit of polymerase chain reaction (PCR), the presence of short-lived antibodies may indicate recent infectivity, particularly in the dry season when clinical cases are rare. Serological responses may reflect a persistent reservoir of infection, warranting community-targeted interventions if individuals are not clinically apparent but have the potential to transmit. Therefore, serological surveillance at the individual and household level may be used to target interventions where there are foci of asymptomatically infected individuals, such as by measuring the magnitude of age-stratified antibody levels or identifying areas with clustering of above-average antibody responses across a diverse range of serological markers.
Collapse
Affiliation(s)
- Lindsey Wu
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK.
| | - Julia Mwesigwa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Muna Affara
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Arusha, Tanzania
| | - Mamadou Bah
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Simon Correa
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Tom Hall
- St. George's University of London (SGUL), London, UK
| | - Susheel K Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - James G Beeson
- Burnet Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Kevin K A Tetteh
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK
| | - Immo Kleinschmidt
- Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK.,School of Pathology, Wits Institute for Malaria Research, Faculty of Health Science, University of Witwatersrand, Johannesburg, South Africa
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Chris Drakeley
- Faculty of Infectious Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine (LSHTM), London, WC1E 7HT, UK
| |
Collapse
|
24
|
Watts RE, Odedra A, Marquart L, Webb L, Abd-Rahman AN, Cascales L, Chalon S, Rebelo M, Pava Z, Collins KA, Pasay C, Chen N, Peatey CL, Möhrle JJ, McCarthy JS. Safety and parasite clearance of artemisinin-resistant Plasmodium falciparum infection: A pilot and a randomised volunteer infection study in Australia. PLoS Med 2020; 17:e1003203. [PMID: 32822347 PMCID: PMC7444516 DOI: 10.1371/journal.pmed.1003203] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/21/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Artemisinin resistance is threatening malaria control. We aimed to develop and test a human model of artemisinin-resistant (ART-R) Plasmodium falciparum to evaluate the efficacy of drugs against ART-R malaria. METHODS AND FINDINGS We conducted 2 sequential phase 1, single-centre, open-label clinical trials at Q-Pharm, Brisbane, Australia, using the induced blood-stage malaria (IBSM) model, whereby healthy participants are intravenously inoculated with blood-stage parasites. In a pilot study, participants were inoculated (Day 0) with approximately 2,800 viable P. falciparum ART-R parasites. In a comparative study, participants were randomised to receive approximately 2,800 viable P. falciparum ART-R (Day 0) or artemisinin-sensitive (ART-S) parasites (Day 1). In both studies, participants were administered a single approximately 2 mg/kg oral dose of artesunate (AS; Day 9). Primary outcomes were safety, ART-R parasite infectivity, and parasite clearance. In the pilot study, 2 participants were enrolled between April 27, 2017, and September 12, 2017, and included in final analyses (males n = 2 [100%], mean age = 26 years [range, 23-28 years]). In the comparative study, 25 participants were enrolled between October 26, 2017, and October 18, 2018, of whom 22 were inoculated and included in final analyses (ART-R infected participants: males n = 7 [53.8%], median age = 22 years [range, 18-40 years]; ART-S infected participants: males n = 5 [55.6%], median age = 28 years [range, 22-35 years]). In both studies, all participants inoculated with ART-R parasites became parasitaemic. A total of 36 adverse events were reported in the pilot study and 277 in the comparative study. Common adverse events in both studies included headache, pyrexia, myalgia, nausea, and chills; none were serious. Seven participants experienced transient severe falls in white cell counts and/or elevations in liver transaminase levels which were considered related to malaria. Additionally, 2 participants developed ventricular extrasystoles that were attributed to unmasking of a predisposition to benign fever-induced tachyarrhythmia. In the comparative study, parasite clearance half-life after AS was significantly longer for ART-R infected participants (n = 13, 6.5 hours; 95% confidence interval [CI] 6.3-6.7 hours) compared with ART-S infected participants (n = 9, 3.2 hours; 95% CI 3.0-3.3 hours; p < 0.001). The main limitation of this study was that the ART-R and ART-S parasite strains did not share the same genetic background. CONCLUSIONS We developed the first (to our knowledge) human model of ART-R malaria. The delayed clearance profile of ART-R parasites after AS aligns with field study observations. Although based on a relatively small sample size, results indicate that this model can be safely used to assess new drugs against ART-R P. falciparum. TRIAL REGISTRATION The studies were registered with the Australian New Zealand Clinical Trials Registry: ACTRN12617000244303 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372357) and ACTRN12617001394336 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=373637).
Collapse
Affiliation(s)
| | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Lachlan Webb
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Laura Cascales
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Maria Rebelo
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Zuleima Pava
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Cielo Pasay
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nanhua Chen
- Australian Army Malaria Institute, Brisbane, Australia
| | | | | | - James S. McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
- * E-mail:
| |
Collapse
|
25
|
Loughland JR, Woodberry T, Field M, Andrew DW, SheelaNair A, Dooley NL, Piera KA, Amante FH, Kenangalem E, Price RN, Engwerda CR, Anstey NM, McCarthy JS, Boyle MJ, Minigo G. Transcriptional profiling and immunophenotyping show sustained activation of blood monocytes in subpatent Plasmodium falciparum infection. Clin Transl Immunology 2020; 9:e1144. [PMID: 32566226 PMCID: PMC7302943 DOI: 10.1002/cti2.1144] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES Malaria, caused by Plasmodium infection, remains a major global health problem. Monocytes are integral to the immune response, yet their transcriptional and functional responses in primary Plasmodium falciparum infection and in clinical malaria are poorly understood. METHODS The transcriptional and functional profiles of monocytes were examined in controlled human malaria infection with P. falciparum blood stages and in children and adults with acute malaria. Monocyte gene expression and functional phenotypes were examined by RNA sequencing and flow cytometry at peak infection and compared to pre-infection or at convalescence in acute malaria. RESULTS In subpatent primary infection, the monocyte transcriptional profile was dominated by an interferon (IFN) molecular signature. Pathways enriched included type I IFN signalling, innate immune response and cytokine-mediated signalling. Monocytes increased TNF and IL-12 production upon in vitro toll-like receptor stimulation and increased IL-10 production upon in vitro parasite restimulation. Longitudinal phenotypic analyses revealed sustained significant changes in the composition of monocytes following infection, with increased CD14+CD16- and decreased CD14-CD16+ subsets. In acute malaria, monocyte CD64/FcγRI expression was significantly increased in children and adults, while HLA-DR remained stable. Although children and adults showed a similar pattern of differentially expressed genes, the number and magnitude of gene expression change were greater in children. CONCLUSIONS Monocyte activation during subpatent malaria is driven by an IFN molecular signature with robust activation of genes enriched in pathogen detection, phagocytosis, antimicrobial activity and antigen presentation. The greater magnitude of transcriptional changes in children with acute malaria suggests monocyte phenotypes may change with age or exposure.
Collapse
Affiliation(s)
- Jessica R Loughland
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia,Menzies School of Health ResearchDarwinNTAustralia
| | - Tonia Woodberry
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia,Present address:
The University of NewcastleCallaghanNSWAustralia
| | - Matt Field
- Australian Institute of Tropical Health and Medicine and Centre for Tropical Bioinformatics and Molecular BiologyJames Cook UniversityCairnsQLDAustralia,John Curtin School of Medical ResearchAustralian National UniversityCanberraACTAustralia
| | - Dean W Andrew
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia
| | - Arya SheelaNair
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia
| | | | - Kim A Piera
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia
| | - Fiona H Amante
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia
| | - Enny Kenangalem
- Timika Malaria Research ProgramPapuan Health and Community Development FoundationTimikaIndonesia,District Health AuthorityTimikaIndonesia
| | - Ric N Price
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia,Centre for Tropical Medicine and Global HealthNuffield Department of Clinical MedicineUniversity of OxfordOxfordUK,Mahidol‐Oxford Tropical Medicine Research UnitFaculty of Tropical MedicineMahidol UniversityBangkokThailand
| | | | - Nicholas M Anstey
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia
| | | | - Michelle J Boyle
- QIMR Berghofer Medical Research InstituteBrisbaneQLDAustralia,Menzies School of Health ResearchDarwinNTAustralia
| | - Gabriela Minigo
- Menzies School of Health ResearchDarwinNTAustralia,Charles Darwin UniversityDarwinNTAustralia,College of Health and Human SciencesCharles Darwin UniversityDarwinNTAustralia
| |
Collapse
|
26
|
Infection-induced plasmablasts are a nutrient sink that impairs humoral immunity to malaria. Nat Immunol 2020; 21:790-801. [PMID: 32424361 PMCID: PMC7316608 DOI: 10.1038/s41590-020-0678-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 04/01/2020] [Indexed: 01/07/2023]
Abstract
Plasmodium parasite-specific antibodies are critical for
protection against malaria, yet the development of long-lived and effective
humoral immunity against Plasmodium takes many years and
multiple rounds of infection and cure. Here we report that the rapid development
of short-lived plasmablasts during experimental malaria unexpectedly hindered
parasite control by impeding germinal center (GC) responses. Metabolic
hyperactivity of plasmablasts resulted in nutrient deprivation of the GC
reaction limiting the generation of memory B cell and long-lived plasma cell
responses. Therapeutic administration of a single amino acid to experimentally
infected mice was sufficient to overcome the metabolic constraints imposed by
plasmablasts and enhanced parasite clearance and the formation of protective
humoral immune memory responses. Thus, our studies not only challenge the
current paradigm describing the role and function of blood-stage
Plasmodium-induced plasmablasts, but also reveal new
targets and strategies to improve anti-Plasmodium humoral
immunity.
Collapse
|
27
|
Li W, Zhang T, Xu X, Jiang J, Yu C, Tian C, Wang S, Lyu X, Liu Z. Problems Associated with the Diagnosis of Imported Malaria in Anhui Province, China. Am J Trop Med Hyg 2020; 102:142-146. [PMID: 31701862 DOI: 10.4269/ajtmh.19-0471] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Imported malaria in Anhui Province, China, remains a significant public health issue with frequent reporting of severe and fatal cases, partly because of globalization and increased international communication. A retrospective evaluation using surveillance data from 2012 to 2018 was conducted to draw lessons on diagnosis of imported malaria. Epidemiological characteristics, together with diagnostic information, were analyzed using descriptive and comparative statistics. Simultaneously, blinded rechecking of malaria blood slides was performed at general hospitals in Anhui Province in 2018. The results showed that, in their first medical visits, 238 (28.2%) of 844 imported cases were not correctly diagnosed. Notably, the proportion of patients who were misdiagnosed at the first clinic visit was 104/120 (86.7%) at private and village clinics, and 41/81 (50.6%) at primary hospitals. The species identification rates for Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae were 85.2%, 66.7%, 23.2%, and 32.3% (χ2 = 224, P < 0.001), respectively. Nearly 7% of cases lacked laboratory evidence and were classified as presumed cases. Our findings suggest that physicians and health care providers, especially those at the primary level, lacked the awareness of diagnosing imported malaria. The training of physicians in malaria diagnosis needs to be enhanced. In addition, polymerase chain reactions (previously only carried out at the provincial level) should be performed at municipal CDC for rapid species identification, thereby guiding clinical treatment.
Collapse
Affiliation(s)
- Weidong Li
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Tao Zhang
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Xian Xu
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Jingjing Jiang
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Chen Yu
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Cuicui Tian
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Shuqi Wang
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Xiaofeng Lyu
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| | - Zhirong Liu
- Anhui Provincial Center for Disease Control and Prevention, Hefei, China
| |
Collapse
|
28
|
Early Endothelial Activation Precedes Glycocalyx Degradation and Microvascular Dysfunction in Experimentally Induced Plasmodium falciparum and Plasmodium vivax Infection. Infect Immun 2020; 88:IAI.00895-19. [PMID: 32122938 DOI: 10.1128/iai.00895-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/25/2020] [Indexed: 12/13/2022] Open
Abstract
Endothelial activation and microvascular dysfunction are key pathogenic processes in severe malaria. We evaluated the early role of these processes in experimentally induced Plasmodium falciparum and P. vivax infection. Participants were enrolled in induced blood-stage malaria clinical trials. Plasma osteoprotegerin, angiopoietin-2, and von Willebrand Factor (vWF) levels were measured as biomarkers of endothelial activation. Microvascular function was assessed using peripheral arterial tonometry and near-infrared spectroscopy, and the endothelial glycocalyx was assessed by sublingual videomicroscopy and measurement of biomarkers of degradation. Forty-five healthy, malaria-naive participants were recruited from 5 studies. Osteoprotegerin and vWF levels increased in participants following inoculation with P. vivax (n = 16) or P. falciparum (n = 15), with the angiopoietin-2 level also increasing in participants following inoculation with P. falciparum For both species, the most pronounced increase was seen in osteoprotegerin. This was particularly marked in participants inoculated with P. vivax, where the osteoprotegerin level correlated with the levels of parasitemia and the malaria clinical score. There were no changes in measures of endothelial glycocalyx or microvascular function. Plasma biomarkers of endothelial activation increased in early P. falciparum and P. vivax infection and preceded changes in the endothelial glycocalyx or microvascular function. The more pronounced increase in osteoprotegerin suggests that this biomarker may play a role in disease pathogenesis.
Collapse
|
29
|
Chughlay MF, Akakpo S, Odedra A, Csermak-Renner K, Djeriou E, Winnips C, Leboulleux D, Gaur AH, Shanks GD, McCarthy J, Chalon S. Liver Enzyme Elevations in Plasmodium falciparum Volunteer Infection Studies: Findings and Recommendations. Am J Trop Med Hyg 2020; 103:378-393. [PMID: 32314694 PMCID: PMC7356411 DOI: 10.4269/ajtmh.19-0846] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Malaria volunteer infection studies (VISs) accelerate new drug and vaccine development. In the induced blood-stage malaria (IBSM) model, volunteers are inoculated with erythrocytes infected with Plasmodium falciparum. Observations of elevated liver enzymes in the IBSM model with new chemical entities (NCEs) promoted an analysis of available data. Data were reviewed from eight IBSM studies of seven different NCEs, plus two studies with the registered antimalarial piperaquine conducted between June 2013 and January 2017 at QIMR Berghofer, Brisbane, Australia. Alanine aminotransferase (ALT) was elevated (> 2.5 times the upper limit of normal [×ULN]) in 20/114 (17.5%) participants. Of these, 8.9% (10/114) had moderate increases (> 2.5–5 × ULN), noted in seven studies of six different NCEs ± piperaquine or piperaquine alone, and 8.9% (10/114) had severe elevations (> 5 × ULN), occurring in six studies of six different NCEs ± piperaquine. Aspartate aminotransferase (AST) was elevated (> 2.5 × ULN) in 11.4% (13/114) of participants, across six of the 10 studies. Bilirubin was > 2 × ULN in one participant. Published data from other VIS models, using sporozoite inoculation by systemic administration or mosquito feeding, also showed moderate/severe liver enzyme elevations. In conclusion, liver enzyme elevations in IBSM studies are most likely multifactorial and could be caused by the model conditions, that is, malaria infection/parasite density and/or effective parasite clearance, or by participant-specific risk factors, acetaminophen administration, or direct hepatotoxicity of the test drug. We make recommendations that may mitigate the risk of liver enzyme elevations in future VISs and propose measures to assist their interpretation, should they occur.
Collapse
Affiliation(s)
| | | | - Anand Odedra
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | | | | | | | - Aditya H Gaur
- St. Jude Children's Research Hospital, Memphis, Tennessee
| | - G Dennis Shanks
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | |
Collapse
|
30
|
Gaur AH, McCarthy JS, Panetta JC, Dallas RH, Woodford J, Tang L, Smith AM, Stewart TB, Branum KC, Freeman BB, Patel ND, John E, Chalon S, Ost S, Heine RN, Richardson JL, Christensen R, Flynn PM, Van Gessel Y, Mitasev B, Möhrle JJ, Gusovsky F, Bebrevska L, Guy RK. Safety, tolerability, pharmacokinetics, and antimalarial efficacy of a novel Plasmodium falciparum ATP4 inhibitor SJ733: a first-in-human and induced blood-stage malaria phase 1a/b trial. THE LANCET. INFECTIOUS DISEASES 2020; 20:964-975. [PMID: 32275867 DOI: 10.1016/s1473-3099(19)30611-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/11/2019] [Accepted: 10/10/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND (+)-SJ000557733 (SJ733) is a novel, orally bioavailable inhibitor of Plasmodium falciparum ATP4. In this first-in-human and induced blood-stage malaria phase 1a/b trial, we investigated the safety, tolerability, pharmacokinetics, and antimalarial activity of SJ733 in humans. METHODS The phase 1a was a single-centre, dose-escalation, first-in-human study of SJ733 allowing modifications to dose increments and dose-cohort size on the basis of safety and pharmacokinetic results. The phase 1a took place at St Jude Children's Research Hospital and at the University of Tennessee Clinical Research Center (Memphis, TN, USA). Enrolment in more than one non-consecutive dose cohort was allowed with at least 14 days required between doses. Participants were fasted in seven dose cohorts and fed in one 600 mg dose cohort. Single ascending doses of SJ733 (75, 150, 300, 600, 900, or 1200 mg) were administered to participants, who were followed up for 14 days after SJ733 dosing. Phase 1a primary endpoints were safety, tolerability, and pharmacokinetics of SJ733, and identification of an SJ733 dose to test in the induced blood-stage malaria model. The phase 1b was a single-centre, open-label, volunteer infection study using the induced blood-stage malaria model in which fasted participants were intravenously infected with blood-stage P falciparum and subsequently treated with a single dose of SJ733. Phase 1b took place at Q-Pharm (Herston, QLD, Australia) and was initiated only after phase 1a showed that exposure exceeding the threshold minimum exposure could be safely achieved in humans. Participants were inoculated on day 0 with P falciparum-infected human erythrocytes (around 2800 parasites in the 150 mg dose cohort and around 2300 parasites in the 600 mg dose cohort), and parasitaemia was monitored before malaria inoculation, after inoculation, immediately before SJ733 dosing, and then post-dose. Participants were treated with SJ733 within 24 h of reaching 5000 parasites per mL or at a clinical score higher than 6. Phase 1b primary endpoints were calculation of a parasite reduction ratio (PRR48) and parasite clearance half-life, and safety and tolerability of SJ733 (incidence, severity, and drug-relatedness of adverse events). In both phases of the trial, SJ733 hydrochloride salt was formulated as a powder blend in capsules containing 75 mg or 300 mg for oral administration. Healthy men and women (of non-childbearing potential) aged 18-55 years were eligible for both studies. Both studies are registered with ClinicalTrials.gov (NCT02661373 for the phase 1a and NCT02867059 for the phase 1b). FINDINGS In the phase 1a, 23 healthy participants were enrolled and received one to three non-consecutive doses of SJ733 between March 14 and Dec 7, 2016. SJ733 was safe and well tolerated at all doses and in fasted and fed conditions. 119 adverse events were recorded: 54 (45%) were unrelated, 63 (53%) unlikely to be related, and two (2%) possibly related to SJ733. In the phase 1b, 17 malaria-naive, healthy participants were enrolled. Seven participants in the 150 mg dose cohort were inoculated and dosed with SJ733. Eight participants in the 600 mg dose cohort were inoculated, but two participants could not be dosed with SJ733. Two additional participants were subsequently inoculated and dosed with SJ733. SJ733 exposure increased proportional to the dose through to the 600 mg dose, then was saturable at higher doses. Fasted participants receiving 600 mg exceeded the target area under the concentration curve extrapolated to infinity (AUC0-∞) of 13 000 μg × h/L (median AUC0-∞ 24 283 [IQR 16 135-31 311] μg × h/L, median terminal half-life 17·4 h [IQR 16·1-24·0], and median timepoint at which peak plasma concentration is reached 1·0 h [0·6-1·3]), and this dose was tested in the phase 1b. All 15 participants dosed with SJ733 had at least one adverse event. Of the 172 adverse events recorded, 128 (74%) were mild. The only adverse event attributed to SJ733 was mild bilateral foot paraesthesia that lasted 3·75 h and resolved spontaneously. The most common adverse events were related to malaria. Based on parasite clearance half-life, the derived log10PRR48 and corresponding parasite clearance half-lives were 2·2 (95% CI 2·0-2·5) and 6·47 h (95% CI 5·88-7·18) for 150 mg, and 4·1 (3·7-4·4) and 3·56 h (3·29-3·88) for 600 mg. INTERPRETATION The favourable pharmacokinetic, tolerability, and safety profile of SJ733, and rapid antiparasitic effect support its development as a fast-acting component of combination antimalarial therapy. FUNDING Global Health Innovative Technology Fund, Medicines for Malaria Venture, and the American Lebanese Syrian Associated Charities.
Collapse
Affiliation(s)
- Aditya H Gaur
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA.
| | - James S McCarthy
- Department of Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - John C Panetta
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Ronald H Dallas
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - John Woodford
- Department of Clinical Tropical Medicine, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Li Tang
- Department of Biostatistics, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Amber M Smith
- University of Tennessee Health Science Center, University of Tennessee, Memphis, TN, USA
| | - Tracy B Stewart
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Kristen C Branum
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Burgess B Freeman
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Nehali D Patel
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | - Shelley Ost
- University of Tennessee Health Science Center, University of Tennessee, Memphis, TN, USA
| | - Ryan N Heine
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Julie L Richardson
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Robbin Christensen
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Patricia M Flynn
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | | | | | | | - R Kiplin Guy
- University of Kentucky College of Pharmacy, University of Kentucky, Lexington, KY, USA
| |
Collapse
|
31
|
Cunningham JA, Thomson RM, Murphy SC, de la Paz Ade M, Ding XC, Incardona S, Legrand E, Lucchi NW, Menard D, Nsobya SL, Saez AC, Chiodini PL, Shrivastava J. WHO malaria nucleic acid amplification test external quality assessment scheme: results of distribution programmes one to three. Malar J 2020; 19:129. [PMID: 32228615 PMCID: PMC7106789 DOI: 10.1186/s12936-020-03200-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 03/23/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The World Health Organization (WHO) recommends parasite-based diagnosis of malaria. In recent years, there has been surge in the use of various kinds of nucleic-acid amplification based tests (NAATs) for detection and identification of Plasmodium spp. to support clinical care in high-resource settings and clinical and epidemiological research worldwide. However, these tests are not without challenges, including lack (or limited use) of standards and lack of reproducibility, due in part to variation in protocols amongst laboratories. Therefore, there is a need for rigorous quality control, including a robust external quality assessment (EQA) scheme targeted towards malaria NAATs. To this effect, the WHO Global Malaria Programme worked with the UK National External Quality Assessment Scheme (UK NEQAS) Parasitology and with technical experts to launch a global NAAT EQA scheme in January 2017. METHODS Panels of NAAT EQA specimens containing five major species of human-infecting Plasmodium at various parasite concentrations and negative samples were created in lyophilized blood (LB) and dried blood spot (DBS) formats. Two distributions per year were sent, containing five LB and five DBS specimens. Samples were tested and validated by six expert referee laboratories prior to distribution. Between 37 and 45 laboratories participated in each distribution and submitted results using the online submission portal of UK NEQAS. Participants were scored based on their laboratory's stated capacity to identify Plasmodium species, and individual laboratory reports were sent which included performance comparison with anonymized peers. RESULTS Analysis of the first three distributions revealed that the factors that most significantly affected performance were sample format (DBS vs LB), species and parasite density, while laboratory location and the reported methodology used (type of nucleic acid extraction, amplification, or DNA vs RNA target) did not significantly affect performance. Referee laboratories performed better than non-referee laboratories. CONCLUSIONS Globally, malaria NAAT assays now inform a range of clinical, epidemiological and research investigations. EQA schemes offer a way for laboratories to assess and improve their performance, which is critical to safeguarding the reliability of data and diagnoses especially in situations where various NAAT methodologies and protocols are in use.
Collapse
Affiliation(s)
| | | | - Sean C Murphy
- Seattle Malaria Clinical Trials Center, Fred Hutchinson Cancer Research Center, Seattle, USA
| | - Maria de la Paz Ade
- Department of Communicable Diseases and Health Analysis, Pan American Health Organization/World Health Organization, Washington, DC, USA
| | - Xavier C Ding
- Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | | | - Eric Legrand
- Biology of Host-Parasite Interactions Unit, Institut Pasteur, INSERM U1201/CNRS ERL9195, Paris, France
| | - Naomi W Lucchi
- Malaria Branch, Division of Parasitic Diseases and MalariaCenter for Global Health, Centers for Disease Control and Prevention, Atlanta, USA
| | - Didier Menard
- Biology of Host-Parasite Interactions Unit, Institut Pasteur, INSERM U1201/CNRS ERL9195, Paris, France
| | - Samuel L Nsobya
- Department of Pathology, School of Biomedical Science, Makerere University, Kampala, Uganda
| | - Agatha C Saez
- UK NEQAS Parasitology, Public Health England, London, UK
| | - Peter L Chiodini
- UK NEQAS Parasitology, Public Health England, London, UK
- The Hospital for Tropical Diseases, London, UK
| | - Jaya Shrivastava
- UK NEQAS Parasitology, Public Health England, London, UK
- The Hospital for Tropical Diseases, London, UK
| |
Collapse
|
32
|
Sinxadi P, Donini C, Johnstone H, Langdon G, Wiesner L, Allen E, Duparc S, Chalon S, McCarthy JS, Lorch U, Chibale K, Möhrle J, Barnes KI. Safety, Tolerability, Pharmacokinetics, and Antimalarial Activity of the Novel Plasmodium Phosphatidylinositol 4-Kinase Inhibitor MMV390048 in Healthy Volunteers. Antimicrob Agents Chemother 2020; 64:e01896-19. [PMID: 31932368 PMCID: PMC7179259 DOI: 10.1128/aac.01896-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/03/2020] [Indexed: 12/24/2022] Open
Abstract
MMV390048 is a novel antimalarial compound that inhibits Plasmodium phosphatidylinositol-4-kinase. The safety, tolerability, pharmacokinetic profile, and antimalarial activity of MMV390048 were determined in healthy volunteers in three separate studies. A first-in-human, double-blind, randomized, placebo-controlled, single-ascending-dose study was performed. Additionally, a volunteer infection study investigated the antimalarial activity of MMV390048 using the Plasmodium falciparum induced blood-stage malaria (IBSM) model. Due to the high pharmacokinetic variability with the powder-in-bottle formulation used in both of these studies, a third study was undertaken to select a tablet formulation of MMV390048 to take forward into future studies. MMV390048 was generally well tolerated when administered as a single oral dose up to 120 mg, with rapid absorption and a long elimination half-life. Twelve adverse events were considered to be potentially related to MMV390048 in the first-in-human study but with no obvious correlation between these and MMV390048 dose or exposure. Although antimalarial activity was evident in the IBSM study, rapid recrudescence occurred in most subjects after treatment with 20 mg MMV390048, a dose expected to be subtherapeutic. Reformulation of MMV390048 into two tablet formulations (tartaric acid and Syloid) resulted in significantly reduced intersubject pharmacokinetic variability. Overall, the results of this study suggest that MMV390048 is well tolerated in humans, and the pharmacokinetic properties of the compound indicate that it has the potential to be used for antimalarial prophylaxis or inclusion in a single-dose cure. MMV390048 is currently being tested in a phase 2a study in Ethiopian adults with acute, uncomplicated falciparum or vivax malaria monoinfection. (The three clinical trials described here were each registered with ClinicalTrials.gov as follows: first-in-human study, registration no. NCT02230579; IBSM study, registration no. NCT02281344; and formulation optimization study, registration no. NCT02554799.).
Collapse
Affiliation(s)
- Phumla Sinxadi
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- UCT MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
| | | | | | | | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Elizabeth Allen
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- UCT MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
| | | | | | | | | | - Kelly Chibale
- Drug Discovery and Development Centre (H3D) and South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Cape Town, South Africa
| | - Jörg Möhrle
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Karen I Barnes
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
- UCT MRC Collaborating Centre for Optimising Antimalarial Therapy, University of Cape Town, Cape Town, South Africa
| |
Collapse
|
33
|
Atmar RL, Keitel WA. Searching for Improved Flu Vaccines-The Time Is Now. J Infect Dis 2020; 221:1-4. [PMID: 31665360 DOI: 10.1093/infdis/jiz545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/14/2019] [Indexed: 12/21/2022] Open
Affiliation(s)
- Robert L Atmar
- Departments of Medicine and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Wendy A Keitel
- Departments of Medicine and Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
34
|
A Single-Dose Combination Study with the Experimental Antimalarials Artefenomel and DSM265 To Determine Safety and Antimalarial Activity against Blood-Stage Plasmodium falciparum in Healthy Volunteers. Antimicrob Agents Chemother 2019; 64:AAC.01371-19. [PMID: 31685476 PMCID: PMC7187626 DOI: 10.1128/aac.01371-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 11/01/2019] [Indexed: 12/12/2022] Open
Abstract
Artefenomel and DSM265 are two new compounds that have been shown to be well tolerated and effective when administered as monotherapy malaria treatment. This study aimed to determine the safety, pharmacokinetics, and pharmacodynamics of artefenomel and DSM265 administered in combination to healthy subjects in a volunteer infection study using the Plasmodium falciparum-induced blood-stage malaria model. Thirteen subjects were inoculated with parasite-infected erythrocytes on day 0 and received a single oral dose of artefenomel and DSM265 on day 7. Cohort 1 (n = 8) received 200 mg artefenomel plus 100 mg DSM265, and cohort 2 (n = 5) received 200 mg artefenomel plus 50 mg DSM265. Blood samples were collected to measure parasitemia, gametocytemia, and artefenomel-DSM265 plasma concentrations. There were no treatment-related adverse events. The pharmacokinetic profiles of artefenomel and DSM265 were similar to those of the compounds when administered as monotherapy, suggesting no pharmacokinetic interactions. A reduction in parasitemia occurred in all subjects following treatment (log10 parasite reduction ratios over 48 h [PRR48] of 2.80 for cohort 1 and 2.71 for cohort 2; parasite clearance half-lives of 5.17 h for cohort 1 and 5.33 h for cohort 2). Recrudescence occurred in 5/8 subjects in cohort 1 between days 19 and 28 and in 5/5 subjects in cohort 2 between days 15 and 22. Low-level gametocytemia (1 to 330 female gametocytes/ml) was detected in all subjects from day 14. The results of this single-dosing combination study support the further clinical development of the use of artefenomel and DSM265 in combination as a treatment for falciparum malaria. (This study has been registered at ClinicalTrials.gov under identifier NCT02389348.).
Collapse
|
35
|
Cao P, Collins KA, Zaloumis S, Wattanakul T, Tarning J, Simpson JA, McCarthy J, McCaw JM. Modeling the dynamics of Plasmodium falciparum gametocytes in humans during malaria infection. eLife 2019; 8:49058. [PMID: 31658944 PMCID: PMC6819085 DOI: 10.7554/elife.49058] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/15/2019] [Indexed: 12/25/2022] Open
Abstract
Renewed efforts to eliminate malaria have highlighted the potential to interrupt human-to-mosquito transmission — a process mediated by gametocyte kinetics in human hosts. Here we study the in vivo dynamics of Plasmodium falciparum gametocytes by establishing a framework which incorporates improved measurements of parasitemia, a novel gametocyte dynamics model and model fitting using Bayesian hierarchical inference. We found that the model provides an excellent fit to the clinical data from 17 volunteers infected with P. falciparum (3D7 strain) and reliably predicts observed gametocytemia. We estimated the sexual commitment rate and gametocyte sequestration time to be 0.54% (95% credible interval: 0.30–1.00%) per asexual replication cycle and 8.39 (6.54–10.59) days respectively. We used the data-calibrated model to investigate human-to-mosquito transmissibility, providing a method to link within-human host infection kinetics to epidemiological-scale infection and transmission patterns.
Collapse
Affiliation(s)
- Pengxing Cao
- School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
| | - Katharine A Collins
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Sophie Zaloumis
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Thanaporn Wattanakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - James McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - James M McCaw
- School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
- Epidemiology, Peter Doherty Institute for Infection and Immunity, Parkville, Australia
| |
Collapse
|
36
|
Loiseau C, Cooper MM, Doolan DL. Deciphering host immunity to malaria using systems immunology. Immunol Rev 2019; 293:115-143. [PMID: 31608461 DOI: 10.1111/imr.12814] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022]
Abstract
A century of conceptual and technological advances in infectious disease research has changed the face of medicine. However, there remains a lack of effective interventions and a poor understanding of host immunity to the most significant and complex pathogens, including malaria. The development of successful interventions against such intractable diseases requires a comprehensive understanding of host-pathogen immune responses. A major advance of the past decade has been a paradigm switch in thinking from the contemporary reductionist (gene-by-gene or protein-by-protein) view to a more holistic (whole organism) view. Also, a recognition that host-pathogen immunity is composed of complex, dynamic interactions of cellular and molecular components and networks that cannot be represented by any individual component in isolation. Systems immunology integrates the field of immunology with omics technologies and computational sciences to comprehensively interrogate the immune response at a systems level. Herein, we describe the system immunology toolkit and report recent studies deploying systems-level approaches in the context of natural exposure to malaria or controlled human malaria infection. We contribute our perspective on the potential of systems immunity for the rational design and development of effective interventions to improve global public health.
Collapse
Affiliation(s)
- Claire Loiseau
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia
| | - Martha M Cooper
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia
| | - Denise L Doolan
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia
| |
Collapse
|
37
|
Edwards CL, Ng SS, Corvino D, Montes de Oca M, de Labastida Rivera F, Nones K, Lakis V, Waddell N, Amante FH, McCarthy JS, Engwerda CR. Early Changes in CD4+ T-Cell Activation During Blood-Stage Plasmodium falciparum Infection. J Infect Dis 2019; 218:1119-1129. [PMID: 29757416 DOI: 10.1093/infdis/jiy281] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/09/2018] [Indexed: 01/01/2023] Open
Abstract
We examined transcriptional changes in CD4+ T cells during blood-stage Plasmodium falciparum infection in individuals without a history of previous parasite exposure. Transcription of CXCL8 (encoding interleukin 8) in CD4+ T cells was identified as an early biomarker of submicroscopic P. falciparum infection, with predictive power for parasite growth. Following antiparasitic drug treatment, a CD4+ T-cell regulatory phenotype developed. PD1 expression on CD49b+CD4+ T (putative type I regulatory T) cells after drug treatment negatively correlated with earlier parasite growth. Blockade of PD1 but no other immune checkpoint molecules tested increased interferon γ and interleukin 10 production in an ex vivo antigen-specific cellular assay at the peak of infection. These results demonstrate the early development of an immunoregulatory CD4+ T-cell phenotype in blood-stage P. falciparum infection and show that a selective immune checkpoint blockade may be used to modulate early developing antiparasitic immunoregulatory pathways as part of malaria vaccine and/or drug treatment protocols.
Collapse
Affiliation(s)
- Chelsea L Edwards
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | - Susanna S Ng
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Natural Sciences, Griffith University, Brisbane, Australia
| | - Dillon Corvino
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | | | | | - Katia Nones
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Vanessa Lakis
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nicola Waddell
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Fiona H Amante
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | | |
Collapse
|
38
|
Haanshuus CG, Mørch K, Blomberg B, Strøm GEA, Langeland N, Hanevik K, Mohn SC. Assessment of malaria real-time PCR methods and application with focus on low-level parasitaemia. PLoS One 2019; 14:e0218982. [PMID: 31276473 PMCID: PMC6611585 DOI: 10.1371/journal.pone.0218982] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 06/04/2019] [Indexed: 01/04/2023] Open
Abstract
In epidemiological surveys and surveillance the application of molecular tools is essential in detecting submicroscopic malaria. A genus-specific conventional cytochrome b (cytb) PCR has shown high sensitivity in field studies, detecting 70% submicroscopic malaria. The main objective of this study was to assess the conversion from conventional to real-time PCR testing both SYBR and probe protocols, and including quantitative (q) PCR. The protocols were assessed applying well-defined clinical patient material consisting of 33 positive and 80 negative samples. Sequencing of positive PCR products was performed. In addition, a sensitivity comparison of real-time PCR methods was done by including five relevant assays investigating the effect of amplification target and platform. Sensitivity was further examined using field material consisting of 111 P.falciparum positive samples from Tanzanian children (< 5 years), as well as using related patient data to assess the application of q-PCR with focus on low-level parasitaemia. Both the cytb SYBR and probe PCR protocols showed as high sensitivity and specificity as their conventional counterpart, except missing one P. malariae sample. The SYBR protocol was more sensitive and specific than using probe. Overall, choice of amplification target applied is relevant for achieving ultra-sensitivity, and using intercalating fluorescence dye rather than labelled hydrolysis probes is favourable. Application of q-PCR analysis in field projects is important for the awareness and understanding of low-level parasitaemia. For use in clinical diagnosis and epidemiological studies the highly sensitive and user-friendly cytb SYBR q-PCR method is a relevant tool. The genus-specific method has the advantage that species identification by sequencing can be performed as an alternative to species-specific PCR.
Collapse
Affiliation(s)
- Christel Gill Haanshuus
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- * E-mail:
| | - Kristine Mørch
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Bjørn Blomberg
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Nina Langeland
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
- Haraldsplass Deaconess Hospital, Bergen, Norway
| | - Kurt Hanevik
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Stein Christian Mohn
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
39
|
Khoury DS, Aogo R, Randriafanomezantsoa-Radohery G, McCaw JM, Simpson JA, McCarthy JS, Haque A, Cromer D, Davenport MP. Within-host modeling of blood-stage malaria. Immunol Rev 2019; 285:168-193. [PMID: 30129195 DOI: 10.1111/imr.12697] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Malaria infection continues to be a major health problem worldwide and drug resistance in the major human parasite species, Plasmodium falciparum, is increasing in South East Asia. Control measures including novel drugs and vaccines are in development, and contributions to the rational design and optimal usage of these interventions are urgently needed. Infection involves the complex interaction of parasite dynamics, host immunity, and drug effects. The long life cycle (48 hours in the common human species) and synchronized replication cycle of the parasite population present significant challenges to modeling the dynamics of Plasmodium infection. Coupled with these, variation in immune recognition and drug action at different life cycle stages leads to further complexity. We review the development and progress of "within-host" models of Plasmodium infection, and how these have been applied to understanding and interpreting human infection and animal models of infection.
Collapse
Affiliation(s)
| | - Rosemary Aogo
- Kirby Institute, UNSW Sydney, Sydney, NSW, Australia
| | | | - James M McCaw
- School of Mathematics and Statistics, University of Melbourne, Melbourne, VIC, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia.,Peter Doherty Institute for Infection and Immunity, The Royal Melbourne Hospital and University of Melbourne, Melbourne, VIC, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Ashraful Haque
- QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | | | | |
Collapse
|
40
|
Genome Mining-Based Identification of Identical Multirepeat Sequences in Plasmodium falciparum Genome for Highly Sensitive Real-Time Quantitative PCR Assay and Its Application in Malaria Diagnosis. J Mol Diagn 2019; 21:824-838. [PMID: 31158524 DOI: 10.1016/j.jmoldx.2019.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 04/02/2019] [Accepted: 04/30/2019] [Indexed: 11/21/2022] Open
Abstract
Developing ultrasensitive methods capable of detecting submicroscopic parasitemia-a challenge that persists in low transmission areas, asymptomatic carriers, and patients showing recrudescence-is vital to achieving malaria eradication. Nucleic acid amplification techniques offer improved analytical sensitivity but are limited by the number of copies of the amplification targets. Herein, we perform a novel genome mining approach to identify a pair of identical multirepeat sequences (IMRSs) that constitute 170 and 123 copies in the Plasmodium falciparum genome and explore their potential as primers for PCR. Real-time quantitative PCR analyses have shown the ability of P. falciparum IMRSs to amplify as low as 2.54 fg of P. falciparum genomic DNA (approximately 0.1 parasite), with a striking 100-fold increase in detection limit when compared with P. falciparum 18S rRNA (251.4 fg; approximately 10 parasites). Validation with clinical samples from malaria-endemic regions has shown 6.70 ± 1.66 cycle better detection threshold in terms of Ct value for P. falciparum IMRSs, with approximately 100% sensitivity and specificity. Plasmodium falciparum IMRS assays are also capable of detecting submicroscopic infections in asymptomatic samples. To summarize, this approach of initiating amplification at multiple loci across the genome and generating more products with increased analytical sensitivity is different from classic approaches amplifying multicopy genes or tandem repeats. This can serve as a platform technology to develop advanced diagnostics for various pathogens.
Collapse
|
41
|
Rigg CA, Hurtado LA, Calzada JE, Chaves LF. Malaria infection rates in Anopheles albimanus (Diptera: Culicidae) at Ipetí-Guna, a village within a region targeted for malaria elimination in Panamá. INFECTION GENETICS AND EVOLUTION 2019; 69:216-223. [DOI: 10.1016/j.meegid.2019.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/23/2018] [Accepted: 02/02/2019] [Indexed: 10/27/2022]
|
42
|
DSM265 at 400 Milligrams Clears Asexual Stage Parasites but Not Mature Gametocytes from the Blood of Healthy Subjects Experimentally Infected with Plasmodium falciparum. Antimicrob Agents Chemother 2019; 63:AAC.01837-18. [PMID: 30858218 PMCID: PMC6437518 DOI: 10.1128/aac.01837-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/25/2019] [Indexed: 12/19/2022] Open
Abstract
DSM265 is a novel antimalarial drug in clinical development that acts as a selective inhibitor of Plasmodium dihydroorotate dehydrogenase. In a previous phase 1b study, a single 150-mg dose of DSM265 showed partial efficacy against experimentally induced blood-stage Plasmodium falciparum malaria (IBSM). DSM265 is a novel antimalarial drug in clinical development that acts as a selective inhibitor of Plasmodium dihydroorotate dehydrogenase. In a previous phase 1b study, a single 150-mg dose of DSM265 showed partial efficacy against experimentally induced blood-stage Plasmodium falciparum malaria (IBSM). Pharmacokinetic/pharmacodynamic modeling predicted a human efficacious dose of 340 mg. The primary objectives of the current study were to determine the safety and efficacy of a single oral 400-mg dose of DSM265 against P. falciparum in the IBSM model. Eight healthy participants were inoculated intravenously with 2,800 parasites and treated with DSM265 7 days later. Unexpectedly, one participant did not develop parasitemia during the study. All other participants developed parasitemia, with the complete clearance of asexual parasites occurring following DSM265 treatment. All seven subjects also became gametocytemic. The secondary objectives were to investigate the gametocytocidal and transmission-blocking activity of a second 400-mg dose of DSM265, which was administered 23 days after inoculation. Gametocytes were not cleared by the second dose of DSM265, and transmission-blocking activity could not be determined due to low gametocyte densities. Three DSM265-related adverse events occurred, including a cutaneous rash in one subject on the day of the second DSM265 dose. The results obtained in this study support the prediction of the efficacious dose of DSM265 and provide further evidence that DSM265 is generally safe and well tolerated. In addition, this study confirms preclinical data indicating that DSM265 permits the development and maturation of gametocytes and does not clear mature circulating gametocytes. (This study has been registered at ClinicalTrials.gov under identifier NCT02573857.)
Collapse
|
43
|
Simultaneous Quantification of Plasmodium Antigens and Host Factor C-Reactive Protein in Asymptomatic Individuals with Confirmed Malaria by Use of a Novel Multiplex Immunoassay. J Clin Microbiol 2019; 57:JCM.00948-18. [PMID: 30404944 PMCID: PMC6322473 DOI: 10.1128/jcm.00948-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/29/2018] [Indexed: 12/14/2022] Open
Abstract
Malaria rapid diagnostic tests (RDTs) primarily detect Plasmodium falciparum antigen histidine-rich protein 2 (HRP2) and the malaria-conserved antigen lactate dehydrogenase (LDH) for P. vivax and other malaria species. The performance of RDTs and their utility is dependent on circulating antigen concentration distributions in infected individuals in a population in which malaria is endemic and on the limit of detection of the RDT for the antigens. Malaria rapid diagnostic tests (RDTs) primarily detect Plasmodium falciparum antigen histidine-rich protein 2 (HRP2) and the malaria-conserved antigen lactate dehydrogenase (LDH) for P. vivax and other malaria species. The performance of RDTs and their utility is dependent on circulating antigen concentration distributions in infected individuals in a population in which malaria is endemic and on the limit of detection of the RDT for the antigens. A multiplexed immunoassay for the quantification of HRP2, P. vivax LDH, and all-malaria LDH (pan LDH) was developed to accurately measure circulating antigen concentration and antigen distribution in a population with endemic malaria. The assay also measures C-reactive protein (CRP) levels as an indicator of inflammation. Validation was conducted with clinical specimens from 397 asymptomatic donors from Myanmar and Uganda, confirmed by PCR for infection, and from participants in induced blood-stage malaria challenge studies. The assay lower limits of detection for HRP2, pan LDH, P. vivax LDH, and CRP were 0.2 pg/ml, 9.3 pg/ml, 1.5 pg/ml, and 26.6 ng/ml, respectively. At thresholds for HRP2, pan LDH, and P. vivax LDH of 2.3 pg/ml, 47.8 pg/ml, and 75.1 pg/ml, respectively, and a specificity ≥98.5%, the sensitivities for ultrasensitive PCR-confirmed infections were 93.4%, 84.9%, and 48.9%, respectively. Plasmodium LDH (pLDH) concentration, in contrast to that of HRP2, correlated closely with parasite density. CRP levels were moderately higher in P. falciparum infections with confirmed antigenemia versus those in clinical specimens with no antigen. The 4-plex array is a sensitive tool for quantifying diagnostic antigens in malaria infections and supporting the evaluation of new ultrasensitive RDTs.
Collapse
|
44
|
McCarthy JS, Smith B, Reid M, Berman J, Marquart L, Dobbin C, West L, Read LT, Dow GS. Blood Schizonticidal Activity and Safety of Tafenoquine When Administered as Chemoprophylaxis to Healthy, Nonimmune Participants Followed by Blood Stage Plasmodium falciparum Challenge: A Randomized, Double-blind, Placebo-controlled Phase 1b Study. Clin Infect Dis 2018; 69:480-486. [DOI: 10.1093/cid/ciy939] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/01/2018] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Tafenoquine was recently approved for chemoprophylaxis of malaria. Its specific activity against liver and blood stages of Plasmodium species has been separately characterized in animals but not in humans.
Methods
In this randomized, double-blind, placebo-controlled study, 16 malaria-naive, glucose-6-phosphate dehydrogenase–normal participants aged 20–42 years received tafenoquine chemoprophylaxis prior to challenge with blood stage Plasmodium falciparum. Participants were randomly assigned to either tafenoquine (n = 12) or placebo (n = 4) and took blinded study medication (single 200-mg dose) on days 1, 2, 3, and 10, followed by intravenous inoculation with approximately 2800 P. falciparum parasitized erythrocytes on day 13. The primary endpoint was the number of participants requiring rescue treatment with artemether/lumefantrine due to the onset of parasitemia as determined by quantitative polymerase chain reaction.
Results
None of the 12 participants who received tafenoquine developed parasitemia, whereas all placebo participants developed parasitemia (P = .0005). Two cases of mild hemoglobin decrease and a single case of mild hyperbilirubinemia occurred in the tafenoquine group.
Conclusions
Tafenoquine chemoprophylaxis is safe and effective in preventing malaria in healthy nonimmune participants challenged with blood stage P. falciparum.
Clinical Trials Registration
Australian and New Zealand Clinical Trials Registry (ANZCTR): ACTRN12617000102370.
Collapse
Affiliation(s)
| | - Bryan Smith
- 60P Australia Pty Ltd, Sydney, New South Wales
| | - Mark Reid
- Graythan Regulatory Services Pty Ltd, Brisbane, Queensland, Australia
- Clinical Network Services Pty Ltd, Brisbane, Queensland, Australia
| | | | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland
| | - Caroline Dobbin
- Clinical Network Services Pty Ltd, Brisbane, Queensland, Australia
| | - Leanne West
- Clinical Network Services Pty Ltd, Brisbane, Queensland, Australia
| | - Lisa T Read
- US Army Medical Materiel Development Activity, Fort Detrick, Maryland
| | - Geoff S Dow
- 60P Australia Pty Ltd, Sydney, New South Wales
| |
Collapse
|
45
|
Stanisic DI, Fink J, Mayer J, Coghill S, Gore L, Liu XQ, El-Deeb I, Rodriguez IB, Powell J, Willemsen NM, De SL, Ho MF, Hoffman SL, Gerrard J, Good MF. Vaccination with chemically attenuated Plasmodium falciparum asexual blood-stage parasites induces parasite-specific cellular immune responses in malaria-naïve volunteers: a pilot study. BMC Med 2018; 16:184. [PMID: 30293531 PMCID: PMC6174572 DOI: 10.1186/s12916-018-1173-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The continuing morbidity and mortality associated with infection with malaria parasites highlights the urgent need for a vaccine. The efficacy of sub-unit vaccines tested in clinical trials in malaria-endemic areas has thus far been disappointing, sparking renewed interest in the whole parasite vaccine approach. We previously showed that a chemically attenuated whole parasite asexual blood-stage vaccine induced CD4+ T cell-dependent protection against challenge with homologous and heterologous parasites in rodent models of malaria. METHODS In this current study, we evaluated the immunogenicity and safety of chemically attenuated asexual blood-stage Plasmodium falciparum (Pf) parasites in eight malaria-naïve human volunteers. Study participants received a single dose of 3 × 107 Pf pRBC that had been treated in vitro with the cyclopropylpyrolloindole analogue, tafuramycin-A. RESULTS We demonstrate that Pf asexual blood-stage parasites that are completely attenuated are immunogenic, safe and well tolerated in malaria-naïve volunteers. Following vaccination with a single dose, species and strain transcending Plasmodium-specific T cell responses were induced in recipients. This included induction of Plasmodium-specific lymphoproliferative responses, T cells secreting the parasiticidal cytokines, IFN-γ and TNF, and CD3+CD45RO+ memory T cells. Pf-specific IgG was not detected. CONCLUSIONS This is the first clinical study evaluating a whole parasite blood-stage malaria vaccine. Following administration of a single dose of completely attenuated Pf asexual blood-stage parasites, Plasmodium-specific T cell responses were induced while Pf-specific antibodies were not detected. These results support further evaluation of this chemically attenuated vaccine in humans. TRIAL REGISTRATION Trial registration: ACTRN12614000228684 . Registered 4 March 2014.
Collapse
Affiliation(s)
- Danielle I Stanisic
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia.
| | - James Fink
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Johanna Mayer
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Sarah Coghill
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Letitia Gore
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Xue Q Liu
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Ibrahim El-Deeb
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Ingrid B Rodriguez
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Jessica Powell
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Nicole M Willemsen
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Sai Lata De
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | - Mei-Fong Ho
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia
| | | | - John Gerrard
- Gold Coast University Hospital, 1 Hospital Blvd, Southport, Queensland, Australia
| | - Michael F Good
- Institute for Glycomics, Griffith University, Parklands Drive, Southport, Queensland, Australia.
| |
Collapse
|
46
|
Assessing Plasmodium falciparum transmission in mosquito-feeding assays using quantitative PCR. Malar J 2018; 17:249. [PMID: 29976199 PMCID: PMC6034226 DOI: 10.1186/s12936-018-2382-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 06/09/2018] [Indexed: 12/29/2022] Open
Abstract
Background Evaluating the efficacy of transmission-blocking interventions relies on mosquito-feeding assays, with transmission typically assessed by microscopic identification of oocysts in mosquito midguts; however, microscopy has limited throughput, sensitivity and specificity. Where low prevalence and intensity mosquito infections occur, as observed during controlled human malaria infection studies or natural transmission, a reliable method for detection and quantification of low-level midgut infection is required. Here, a semi-automated, Taqman quantitative PCR (qPCR) assay sufficiently sensitive to detect a single-oocyst midgut infection is described. Results Extraction of genomic DNA from Anopheles stephensi midguts using a semi-automated extraction process was shown to have equivalent extraction efficiency to manual DNA extraction. An 18S Plasmodium falciparum qPCR assay was adapted for quantitative detection of P. falciparum midgut oocyst infection using synthetic DNA standards. The assay was validated for sensitivity and specificity, and the limit of detection was 0.7 genomes/µL (95% CI 0.4–1.6 genomes/µL). All microscopy-confirmed oocyst infected midgut samples were detected by qPCR, including all single-oocyst positive midguts. The genome number per oocyst was assessed 8–9 days after feeding assay using both qPCR and droplet digital PCR and was 3722 (IQR: 2951–5453) and 3490 (IQR: 2720–4182), respectively. Conclusions This semi-automated qPCR method enables accurate detection of low-level P. falciparum oocyst infections in mosquito midguts, and may improve the sensitivity, specificity and throughput of assays used to evaluate candidate transmission-blocking interventions. Electronic supplementary material The online version of this article (10.1186/s12936-018-2382-6) contains supplementary material, which is available to authorized users.
Collapse
|
47
|
Collins KA, Wang CY, Adams M, Mitchell H, Rampton M, Elliott S, Reuling IJ, Bousema T, Sauerwein R, Chalon S, Möhrle JJ, McCarthy JS. A controlled human malaria infection model enabling evaluation of transmission-blocking interventions. J Clin Invest 2018; 128:1551-1562. [PMID: 29389671 PMCID: PMC5873858 DOI: 10.1172/jci98012] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/30/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND. Drugs and vaccines that can interrupt the transmission of Plasmodium falciparum will be important for malaria control and elimination. However, models for early clinical evaluation of candidate transmission-blocking interventions are currently unavailable. Here, we describe a new model for evaluating malaria transmission from humans to Anopheles mosquitoes using controlled human malaria infection (CHMI). METHODS. Seventeen healthy malaria-naive volunteers underwent CHMI by intravenous inoculation of P. falciparum–infected erythrocytes to initiate blood-stage infection. Seven to eight days after inoculation, participants received piperaquine (480 mg) to attenuate asexual parasite replication while allowing gametocytes to develop and mature. Primary end points were development of gametocytemia, the transmissibility of gametocytes from humans to mosquitoes, and the safety and tolerability of the CHMI transmission model. To investigate in vivo gametocytocidal drug activity in this model, participants were either given an experimental antimalarial, artefenomel (500 mg), or a known gametocytocidal drug, primaquine (15 mg), or remained untreated during the period of gametocyte carriage. RESULTS. Male and female gametocytes were detected in all participants, and transmission to mosquitoes was achieved from 8 of 11 (73%) participants evaluated. Compared with results in untreated controls (n = 7), primaquine (15 mg, n = 5) significantly reduced gametocyte burden (P = 0.01), while artefenomel (500 mg, n = 4) had no effect. Adverse events (AEs) were mostly mild or moderate. Three AEs were assessed as severe — fatigue, elevated alanine aminotransferase, and elevated aspartate aminotransferase — and were attributed to malaria infection. Transaminase elevations were transient, asymptomatic, and resolved without intervention. CONCLUSION. We report the safe and reproducible induction of P. falciparum gametocytes in healthy malaria-naive volunteers at densities infectious to mosquitoes, thereby demonstrating the potential for evaluating transmission-blocking interventions in this model. TRIAL REGISTRATION. ClinicalTrials.gov NCT02431637 and NCT02431650. FUNDING. Bill & Melinda Gates Foundation.
Collapse
Affiliation(s)
| | - Claire Yt Wang
- Queensland Paediatric Infectious Diseases (QPID) Laboratory, Centre for Children's Health Research, Brisbane, Queensland, Australia
| | - Matthew Adams
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Hayley Mitchell
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Melanie Rampton
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | | | - Isaie J Reuling
- Radboud Institute for Health Science, Radboud University Medical Center, Nijmegen, Netherlands
| | - Teun Bousema
- Radboud Institute for Health Science, Radboud University Medical Center, Nijmegen, Netherlands
| | - Robert Sauerwein
- Radboud Institute for Health Science, Radboud University Medical Center, Nijmegen, Netherlands
| | | | | | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| |
Collapse
|
48
|
Ng SS, Souza-Fonseca-Guimaraes F, Rivera FDL, Amante FH, Kumar R, Gao Y, Sheel M, Beattie L, Montes de Oca M, Guillerey C, Edwards CL, Faleiro RJ, Frame T, Bunn PT, Vivier E, Godfrey DI, Pellicci DG, Lopez JA, Andrews KT, Huntington ND, Smyth MJ, McCarthy J, Engwerda CR. Rapid loss of group 1 innate lymphoid cells during blood stage Plasmodium infection. Clin Transl Immunology 2018; 7:e1003. [PMID: 29484181 PMCID: PMC5822408 DOI: 10.1002/cti2.1003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/09/2017] [Accepted: 12/05/2017] [Indexed: 12/20/2022] Open
Abstract
Objectives Innate lymphoid cells (ILCs) share many characteristics with CD4+ T cells, and group 1 ILCs share a requirement for T‐bet and the ability to produce IFNγ with T helper 1 (Th1) cells. Given this similarity, and the importance of Th1 cells for protection against intracellular protozoan parasites, we aimed to characterise the role of group 1 ILCs during Plasmodium infection. Methods We quantified group 1 ILCs in peripheral blood collected from subjects infected with with Plasmodium falciparum 3D7 as part of a controlled human malaria infection study, and in the liver and spleens of PcAS‐infected mice. We used genetically‐modified mouse models, as well as cell‐depletion methods in mice to characterise the role of group 1 ILCs during PcAS infection. Results In a controlled human malaria infection study, we found that the frequencies of circulating ILC1s and NK cells decreased as infection progressed but recovered after volunteers were treated with antiparasitic drug. A similar observation was made for liver and splenic ILC1s in P. chabaudi chabaudi AS (PcAS)‐infected mice. The decrease in mouse liver ILC1 frequencies was associated with increased apoptosis. We also identified a population of cells within the liver and spleen that expressed both ILC1 and NK cell markers, indicative of plasticity between these two cell lineages. Studies using genetic and cell‐depletion approaches indicated that group 1 ILCs have a limited role in antiparasitic immunity during PcAS infection in mice. Discussion Our results are consistent with a previous study indicating a limited role for natural killer (NK) cells during Plasmodium chabaudi infection in mice. Additionally, a recent study reported the redundancy of ILCs in humans with competent B and T cells. Nonetheless, our results do not rule out a role for group 1 ILCs in human malaria in endemic settings given that blood stage infection was initiated intravenously in our experimental models, and thus bypassed the liver stage of infection, which may influence the immune response during the blood stage. Conclusion Our results show that ILC1s are lost early during mouse and human malaria, and this observation may help to explain the limited role for these cells in controlling blood stage infection.
Collapse
Affiliation(s)
- Susanna S Ng
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia.,School of Natural Sciences Griffith University Nathan QLD Australia
| | - Fernando Souza-Fonseca-Guimaraes
- Faculty of Medicine, Dentistry and Health Sciences University of Melbourne Melbourne VIC Australia.,Molecular Immunology Division The Walter and Eliza Hall Institute of Medical Research Parkville VIC Australia
| | | | - Fiona H Amante
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Rajiv Kumar
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia.,Department of Biochemistry Banaras Hindu University Varanasi India
| | - Yulong Gao
- Immunology in Cancer and Infection QIMR Berghofer Medical Research Institute Herston QLD Australia.,School of Medicine University of Queensland Herston QLD Australia
| | - Meru Sheel
- National Centre for Immunisation Research and Surveillance Westmead NSW Australia
| | - Lynette Beattie
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Marcela Montes de Oca
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Camille Guillerey
- Immunology in Cancer and Infection QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Chelsea L Edwards
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia.,School of Medicine University of Queensland Herston QLD Australia
| | - Rebecca J Faleiro
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Teija Frame
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Patrick T Bunn
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Eric Vivier
- Aix Marseille Université, CNRS, INSERM, CIML Marseille France.,Service d'Immunologie APHM, Hôpital de la Conception Marseille France
| | - Dale I Godfrey
- Department of Microbiology and Immunology Peter Doherty Institute for Infection and Immunity University of Melbourne Melbourne VIC Australia.,Australian Research Council Centre of Excellence for Advanced Molecular Imaging University of Melbourne Melbourne VIC Australia
| | - Daniel G Pellicci
- Department of Microbiology and Immunology Peter Doherty Institute for Infection and Immunity University of Melbourne Melbourne VIC Australia.,Australian Research Council Centre of Excellence for Advanced Molecular Imaging University of Melbourne Melbourne VIC Australia
| | | | | | - Nicholas D Huntington
- Molecular Immunology Division The Walter and Eliza Hall Institute of Medical Research Parkville VIC Australia.,Department of Medical Biology The University of Melbourne Melbourne VIC Australia
| | - Mark J Smyth
- Immunology in Cancer and Infection QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - James McCarthy
- Clinical Tropical Medicine QIMR Berghofer Medical Research Institute Herston QLD Australia
| | - Christian R Engwerda
- Immunology and Infection Laboratory QIMR Berghofer Medical Research Institute Herston QLD Australia
| |
Collapse
|
49
|
Wockner LF, Hoffmann I, O'Rourke P, McCarthy JS, Marquart L. Comparison of statistical models to estimate parasite growth rate in the induced blood stage malaria model. Malar J 2017; 16:352. [PMID: 28841864 PMCID: PMC5574106 DOI: 10.1186/s12936-017-1999-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/20/2017] [Indexed: 11/28/2022] Open
Abstract
Background The efficacy of vaccines aimed at inhibiting the growth of malaria parasites in the blood can be assessed by comparing the growth rate of parasitaemia in the blood of subjects treated with a test vaccine compared to controls. In studies using induced blood stage malaria (IBSM), a type of controlled human malaria infection, parasite growth rate has been measured using models with the intercept on the y-axis fixed to the inoculum size. A set of statistical models was evaluated to determine an optimal methodology to estimate parasite growth rate in IBSM studies. Methods Parasite growth rates were estimated using data from 40 subjects published in three IBSM studies. Data was fitted using 12 statistical models: log-linear, sine-wave with the period either fixed to 48 h or not fixed; these models were fitted with the intercept either fixed to the inoculum size or not fixed. All models were fitted by individual, and overall by study using a mixed effects model with a random effect for the individual. Results Log-linear models and sine-wave models, with the period fixed or not fixed, resulted in similar parasite growth rate estimates (within 0.05 log10 parasites per mL/day). Average parasite growth rate estimates for models fitted by individual with the intercept fixed to the inoculum size were substantially lower by an average of 0.17 log10 parasites per mL/day (range 0.06–0.24) compared with non-fixed intercept models. Variability of parasite growth rate estimates across the three studies analysed was substantially higher (3.5 times) for fixed-intercept models compared with non-fixed intercept models. The same tendency was observed in models fitted overall by study. Modelling data by individual or overall by study had minimal effect on parasite growth estimates. Conclusions The analyses presented in this report confirm that fixing the intercept to the inoculum size influences parasite growth estimates. The most appropriate statistical model to estimate the growth rate of blood-stage parasites in IBSM studies appears to be a log-linear model fitted by individual and with the intercept estimated in the log-linear regression. Future studies should use this model to estimate parasite growth rates. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1999-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Leesa F Wockner
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - Isabell Hoffmann
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia.,Institute of Medical Biostatistics, Epidemiology and Informatics, Medical Center of Johannes Gutenberg University, 55101, Mainz, Germany
| | - Peter O'Rourke
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia. .,School of Medicine, University of Queensland, Brisbane, QLD, 4072, Australia. .,Q-Pharm Pty Ltd, Brisbane, QLD, 4006, Australia.
| | - Louise Marquart
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, 4006, Australia
| |
Collapse
|
50
|
Burel JG, Apte SH, Groves PL, Boyle MJ, Langer C, Beeson JG, McCarthy JS, Doolan DL. Dichotomous miR expression and immune responses following primary blood-stage malaria. JCI Insight 2017; 2:93434. [PMID: 28768914 DOI: 10.1172/jci.insight.93434] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 06/29/2017] [Indexed: 01/12/2023] Open
Abstract
Clinical responses to infection or vaccination and the development of effective immunity are characterized in humans by a marked interindividual variability. To gain an insight into the factors affecting this variability, we used a controlled human infection system to study early immune events following primary infection of healthy human volunteers with blood-stage Plasmodium falciparum malaria. By day 4 of infection, a dichotomous pattern of high or low expression of a defined set of microRNAs (miRs) emerged in volunteers that correlated with variation in parasite growth rate. Moreover, high-miR responders had higher numbers of activated CD4+ T cells, and developed significantly enhanced antimalarial antibody responses. Notably, a set of 17 miRs was identified in the whole blood of low-miR responders prior to infection that differentiated them from high-miR responders. These data implicate preexisting host factors as major determinants in the ability to effectively respond to primary malaria infection.
Collapse
Affiliation(s)
- Julie G Burel
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,The University of Queensland, Brisbane, Queensland, Australia
| | - Simon H Apte
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Penny L Groves
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Michelle J Boyle
- Menzies School of Health Research, Darwin, Northern Territory, Australia.,Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Christine Langer
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.,Department of Microbiology, Monash University, Victoria, Australia
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,The University of Queensland, Brisbane, Queensland, Australia
| | - Denise L Doolan
- QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,Centre for Biosecurity and Tropical Infectious Diseases, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| |
Collapse
|