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Tan AF, Sakam SSB, Piera K, Rajahram GS, William T, Barber BE, Anstey NM, Grigg MJ, Kho S. Neutrophil activation, acute lung injury and disease severity in Plasmodium knowlesi malaria. PLoS Negl Trop Dis 2024; 18:e0012424. [PMID: 39150978 DOI: 10.1371/journal.pntd.0012424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 08/28/2024] [Accepted: 08/02/2024] [Indexed: 08/18/2024] Open
Abstract
The risk of severe malaria from the zoonotic parasite Plasmodium knowlesi approximates that from P. falciparum. In severe falciparum malaria, neutrophil activation contributes to inflammatory pathogenesis, including acute lung injury (ALI). The role of neutrophil activation in the pathogenesis of severe knowlesi malaria has not been examined. We evaluated 213 patients with P. knowlesi mono-infection (138 non-severe, 75 severe) and 49 Plasmodium-negative controls from Malaysia. Markers of neutrophil activation (soluble neutrophil elastase [NE], citrullinated histone [CitH3] and circulating neutrophil extracellular traps [NETs]) were quantified in peripheral blood by microscopy and immunoassays. Findings were correlated with malaria severity, ALI clinical criteria, biomarkers of parasite biomass, haemolysis, and endothelial activation. Neutrophil activation increased with disease severity, with median levels higher in severe than non-severe malaria and controls for NE (380[IQR:210-930]ng/mL, 236[139-448]ng/mL, 218[134-307]ng/mL, respectively) and CitH3 (8.72[IQR:3.0-23.1]ng/mL, 4.29[1.46-9.49]ng/mL, 1.53[0.6-2.59]ng/mL, respectively)[all p<0.01]. NETs were higher in severe malaria compared to controls (126/μL[IQR:49-323] vs 51[20-75]/μL, p<0.001). In non-severe malaria, neutrophil activation fell significantly upon discharge from hospital (p<0.03). In severe disease, NETs, NE, and CitH3 were correlated with parasitaemia, cell-free haemoglobin and angiopoietin-2 (all Pearson's r>0.24, p<0.05). Plasma NE and angiopoietin-2 were higher in knowlesi patients with ALI than those without (p<0.008); neutrophilia was associated with an increased risk of ALI (aOR 3.27, p<0.01). In conclusion, neutrophil activation is increased in ALI and in proportion to disease severity in knowlesi malaria, is associated with endothelial activation, and may contribute to disease pathogenesis. Trials of adjunctive therapies to regulate neutrophil activation are warranted in severe knowlesi malaria.
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Affiliation(s)
- Angelica F Tan
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Kota Kinabalu Sabah - Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Sitti Saimah Binti Sakam
- Infectious Diseases Society Kota Kinabalu Sabah - Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Kim Piera
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Giri S Rajahram
- Infectious Diseases Society Kota Kinabalu Sabah - Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
- Queen Elizabeth Hospital II, Ministry of Health Malaysia, Kota Kinabalu, Malaysia
- School of Medicine and Health Sciences, Monash University Malaysia, Kuala Lumpur, Malaysia
| | - Timothy William
- Infectious Diseases Society Kota Kinabalu Sabah - Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Bridget E Barber
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Kota Kinabalu Sabah - Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
- Infectious Diseases Society Kota Kinabalu Sabah - Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Steven Kho
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
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2
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Lufele E, Manning L, Lorry L, Warrel J, Aipit S, Robinson LJ, Laman M. The association of intraleucocytic malaria pigment and disease severity in Papua New Guinean children with severe P. falciparum malaria. Trans R Soc Trop Med Hyg 2023; 117:797-803. [PMID: 37334767 PMCID: PMC10629949 DOI: 10.1093/trstmh/trad037] [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: 01/22/2023] [Revised: 04/10/2023] [Accepted: 05/19/2023] [Indexed: 06/20/2023] Open
Abstract
BACKGROUND Plasmodium falciparum pigment-containing leucocytes (PCLs) are associated with adverse clinical manifestations of severe malaria in African children. However, limited data exist on the association of PCLs in settings outside of Africa. METHODS Thin films on peripheral blood slides obtained from children ages 6 months-10 y with severe malaria were examined for PCLs. The intraleucocytic pigment data were correlated with clinical phenotypic data such as severe anaemia, metabolic acidosis and coma to determine the association of PCLs with clinical phenotypes of severe malaria and outcome. RESULTS Of the 169 children with severe P. falciparum malaria confirmed by microscopy, 76% (129/169) had PCLs. Compared with children without PCLs, the presence (adjusted odds ratio [AOR] 3.2 [95% confidence interval {CI} 1.5 to 6.9], p≤0.01) and quantity (AOR 1.0 [95% CI 1.0 to 1.1], p=0.04) of pigment-containing monocytes (PCMs) was significantly associated with severe anaemia, while the quantity of both PCMs (AOR 1.0 [95% CI 1.0 to 1.1], p≤0.01) and pigment-containing neutrophils (AOR 1.0 [95% CI 1.0 to 1.1], p=0.01) was significantly associated with metabolic acidosis. Plasma P. falciparum histidine-rich protein-2 level negatively correlated with the platelet count (r=-0.5, p≤0.01) in patients with PCLs and no PCLs. CONCLUSIONS In Papua New Guinean children with severe P. falciparum malaria, the presence and quantity of PCLs are predictors of disease severity, severe anaemia and metabolic acidosis.
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Affiliation(s)
- Elvin Lufele
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Global Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Laurens Manning
- School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia
| | - Lina Lorry
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Jonathan Warrel
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Susan Aipit
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Paediatrics Division, Modilon Hospital, Madang, Papua New Guinea
| | - Leanne J Robinson
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Vector Borne Diseases and Tropical Public Health Division, Burnet Institute, Melbourne, VIC, Australia
| | - Moses Laman
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Paediatrics Division, Modilon Hospital, Madang, Papua New Guinea
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3
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Biswal D, Mirdha BR. A case of atypical vivax malaria with a global review of reports on myriads of morpho-variations in parasitized red blood cells. Access Microbiol 2023; 5:000461.v3. [PMID: 37223061 PMCID: PMC10202396 DOI: 10.1099/acmi.0.000461.v3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 02/07/2023] [Indexed: 05/25/2023] Open
Abstract
Plasmodium vivax, one of the major species associated with human malaria, continues to be a major public health problem in many parts of the world. Numerous studies related to vivax malaria have described quantitative haematological findings (level of haemoglobin, thrombocytopaenia, haematocrit values), but diverse morphological changes of parasite forms within infected red blood cells (iRBCs) have been mentioned only in few studies. Here we report a case of a 13-year-old boy who presented with fever, significant low platelet counts and hypovolaemia that created a diagnostic dilemma. Detection of microgametocytes by microscopic examinations, further confirmed by multiplex nested PCR assays and response to anti-malarials, helped to make the diagnosis. We present an atypical case of vivax malaria with a review of morpho-variations of iRBCs and have summarized the characteristics that aid in creating increased awareness among laboratory health professionals and public health workers.
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Affiliation(s)
- Debasish Biswal
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Bijay Ranjan Mirdha
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
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4
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Srinamon K, Watson JA, Silamut K, Intharabut B, Phu NH, Diep PT, Lyke KE, Fanello C, von Seidlein L, Chotivanich K, Dondorp AM, Day NPJ, White NJ. The prognostic and diagnostic value of intraleukocytic malaria pigment in patients with severe falciparum malaria. Nat Commun 2022; 13:6882. [PMID: 36371433 PMCID: PMC9653500 DOI: 10.1038/s41467-022-34678-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 11/02/2022] [Indexed: 11/13/2022] Open
Abstract
Severe falciparum malaria is a major cause of death in tropical countries, particularly in African children. Rapid and accurate diagnosis and prognostic assessment are critical to clinical management. In 6027 prospectively studied patients diagnosed with severe malaria we assess the prognostic value of peripheral blood film counts of malaria pigment containing polymorphonuclear leukocytes (PMNs) and monocytes. We combine these results with previously published data and show, in an individual patient data meta-analysis (n = 32,035), that the proportion of pigment containing PMNs is predictive of in-hospital mortality. In African children the proportion of pigment containing PMNs helps distinguish severe malaria from other life-threatening febrile illnesses, and it adds to the prognostic assessment from simple bedside examination, and to the conventional malaria parasite count. Microscopy assessment of pigment containing PMNs is simple and rapid, and should be performed in all patients hospitalised with suspected severe malaria.
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Affiliation(s)
- Ketsanee Srinamon
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand
| | - James A. Watson
- grid.412433.30000 0004 0429 6814Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG UK ,grid.499581.8WorldWide Antimalarial Resistance Network, Oxford, UK
| | - Kamolrat Silamut
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand
| | - Benjamas Intharabut
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand
| | - Nguyen Hoan Phu
- grid.412433.30000 0004 0429 6814Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Pham Thi Diep
- grid.412433.30000 0004 0429 6814Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Kirsten E. Lyke
- grid.411024.20000 0001 2175 4264Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD USA
| | - Caterina Fanello
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG UK
| | - Lorenz von Seidlein
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG UK
| | - Kesinee Chotivanich
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand
| | - Arjen M. Dondorp
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG UK
| | - Nicholas P. J. Day
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG UK
| | - Nicholas J. White
- grid.10223.320000 0004 1937 0490Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400 Thailand ,grid.4991.50000 0004 1936 8948Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford, OX3 7LG UK
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5
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Abstract
Severe malaria is a medical emergency. It is a major cause of preventable childhood death in tropical countries. Severe malaria justifies considerable global investment in malaria control and elimination yet, increasingly, international agencies, funders and policy makers are unfamiliar with it, and so it is overlooked. In sub-Saharan Africa, severe malaria is overdiagnosed in clinical practice. Approximately one third of children diagnosed with severe malaria have another condition, usually sepsis, as the cause of their severe illness. But these children have a high mortality, contributing substantially to the number of deaths attributed to 'severe malaria'. Simple well-established tests, such as examination of the thin blood smear and the full blood count, improve the specificity of diagnosis and provide prognostic information in severe malaria. They should be performed more widely. Early administration of artesunate and broad-spectrum antibiotics to all children with suspected severe malaria would reduce global malaria mortality.
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Affiliation(s)
- Nicholas J White
- Mahidol Oxford 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, UK.
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6
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Wilairatana P, Kwankaew P, Kotepui KU, Kotepui M. Low Interleukin-12 Levels concerning Severe Malaria: A Systematic Review and Meta-Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:9345. [PMID: 35954703 PMCID: PMC9368085 DOI: 10.3390/ijerph19159345] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/23/2022] [Accepted: 07/26/2022] [Indexed: 11/28/2022]
Abstract
Although many studies have investigated the role of interleukin (IL)-12 cytokine in the pathogenesis of severe malaria, these studies were based on a limited number of participants, possibly affecting their outcomes. We analyzed the difference in IL-12 levels between patients with severe and uncomplicated malaria through a meta-analysis. A systematic review was conducted following the Cochrane Handbook for Systematic Reviews of Interventions and was reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. Systematic literature searches were performed between 20 February and 2 March, 2022 in PubMed, Scopus, and Embase to identify studies reporting IL-12 levels in patients with severe and uncomplicated malaria. The quality of included studies was determined using the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. The pooled mean difference (MD) in IL-12 between patients with severe and uncomplicated malaria was estimated using the DerSimonian-Laird method for the random-effects model. Altogether, 1885 potentially relevant articles were identified, and 10 studies enrolling 654 patients with severe malaria and 626 patients with uncomplicated malaria were included in the meta-analysis. Patients with severe malaria had lower mean IL-12 levels than those with uncomplicated malaria (p = 0.01, MD: -33.62, 95% confidence interval [CI]: -58.79 to -8.45, I2: 99.29%, 10 studies). In conclusion, decreased IL-12 levels might significantly contribute to the development of severe malaria. As most published literature demonstrated the role of IL-12 in animal models, human studies are required to understand the mechanisms involved in low IL-12 levels in patients with severe malaria.
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Affiliation(s)
- Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand;
| | - Pattamaporn Kwankaew
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat 80160, Thailand; (P.K.); (K.U.K.)
| | - Kwuntida Uthaisar Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat 80160, Thailand; (P.K.); (K.U.K.)
| | - Manas Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat 80160, Thailand; (P.K.); (K.U.K.)
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7
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Babatunde KA, Adenuga OF. Neutrophils in malaria: A double-edged sword role. Front Immunol 2022; 13:922377. [PMID: 35967409 PMCID: PMC9367684 DOI: 10.3389/fimmu.2022.922377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
Neutrophils are the most abundant leukocytes in human peripheral blood. They form the first line of defense against invading foreign pathogens and might play a crucial role in malaria. According to World Health Organization (WHO), malaria is a globally significant disease caused by protozoan parasites from the Plasmodium genus, and it's responsible for 627,000 deaths in 2020. Neutrophils participate in the defense response against the malaria parasite via phagocytosis and reactive oxygen species (ROS) production. Neutrophils might also be involved in the pathogenesis of malaria by the release of toxic granules and the release of neutrophil extracellular traps (NETs). Intriguingly, malaria parasites inhibit the anti-microbial function of neutrophils, thus making malaria patients more susceptible to secondary opportunistic Salmonella infections. In this review, we will provide a summary of the role of neutrophils during malaria infection, some contradicting mouse model neutrophil data and neutrophil-related mechanisms involved in malaria patients' susceptibility to bacterial infection.
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Affiliation(s)
- Kehinde Adebayo Babatunde
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
- Department of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI, United States
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8
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Fitri LE, Widaningrum T, Endharti AT, Prabowo MH, Winaris N, Nugraha RYB. Malaria diagnostic update: From conventional to advanced method. J Clin Lab Anal 2022; 36:e24314. [PMID: 35247002 PMCID: PMC8993657 DOI: 10.1002/jcla.24314] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/11/2022] [Accepted: 02/16/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Update diagnostic methods play essential roles in dealing with the current global malaria situation and decreasing malaria incidence. AIM Global malaria control programs require the availability of adequate laboratory tests in the quick and convenient field. RESULTS There are several methods to find out the existence of parasites within the blood. The oldest one is by microscopy, which is still a gold standard, although rapid diagnostic tests (RDTs) have rapidly become a primary diagnostic test in many endemic areas. Because of microscopy and RDTs limitation, novel serological and molecular methods have been developed. Many kinds of polymerase chain reaction (PCR) provide rapid results and higher specificity and sensitivity. The loop-mediated isothermal amplification (LAMP) and biosensing-based molecular techniques as point of care tests (POCT) will become a cost-effective approach to advance diagnostic testing. CONCLUSION Despite conventional techniques are still being used in the field, the exploration and field implementation of advanced techniques for the diagnosis of malaria are still being developed rapidly.
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Affiliation(s)
- Loeki Enggar Fitri
- Department of ParasitologyFaculty of Medicine Universitas BrawijayaMalangIndonesia
- Malaria Research GroupFaculty of Medicine Universitas BrawijayaMalangIndonesia
| | - Tarina Widaningrum
- Malaria Research GroupFaculty of Medicine Universitas BrawijayaMalangIndonesia
- Department of PharmacologyFaculty of Medicine Universitas BrawijayaMalangIndonesia
| | | | | | - Nuning Winaris
- Department of ParasitologyFaculty of Medicine Universitas BrawijayaMalangIndonesia
- Malaria Research GroupFaculty of Medicine Universitas BrawijayaMalangIndonesia
| | - Rivo Yudhinata Brian Nugraha
- Department of ParasitologyFaculty of Medicine Universitas BrawijayaMalangIndonesia
- Malaria Research GroupFaculty of Medicine Universitas BrawijayaMalangIndonesia
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9
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Anyona SB, Cheng Q, Raballah E, Hurwitz I, Lambert CG, McMahon BH, Ouma C, Perkins DJ. Ingestion of hemozoin by peripheral blood mononuclear cells alters temporal gene expression of ubiquitination processes. Biochem Biophys Rep 2022; 29:101207. [PMID: 35071802 PMCID: PMC8761598 DOI: 10.1016/j.bbrep.2022.101207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/06/2022] [Accepted: 01/08/2022] [Indexed: 12/21/2022] Open
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10
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Pollenus E, Gouwy M, Van den Steen PE. Neutrophils in malaria: the good, the bad or the ugly? Parasite Immunol 2022; 44:e12912. [PMID: 35175636 DOI: 10.1111/pim.12912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/09/2022] [Accepted: 02/13/2022] [Indexed: 11/30/2022]
Abstract
Neutrophils are the most abundant circulating leukocytes in human peripheral blood. They are often the first cells to respond to an invading pathogen and might therefore play an important role in malaria. Malaria is a globally important disease caused by Plasmodium parasites, responsible for more than 400 000 deaths each year. Most of these deaths are caused by complications, including cerebral malaria, severe malarial anemia, placental malaria, renal injury, metabolic problems and malaria-associated acute respiratory distress syndrome. Neutrophils contribute in the immune defense against malaria, through clearance of parasites via phagocytosis, production of reactive oxygen species and release of neutrophil extracellular traps (NETs). However, Plasmodium parasites diminish antibacterial functions of neutrophils, making patients more susceptible to other infections. Neutrophils might also be involved in the development of malaria complications, for example via the release of toxic granules and NETs. However, technical pitfalls in the determination of the roles of neutrophils have caused contradicting results. Further investigations need to consider these pitfalls, in order to elucidate the role of neutrophils in malaria complications.
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Affiliation(s)
- Emilie Pollenus
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, University of Leuven, Leuven, Belgium
| | - Mieke Gouwy
- Laboratory of Molecular immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, University of Leuven, Leuven, Belgium
| | - Philippe E Van den Steen
- Laboratory of Immunoparasitology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, University of Leuven, Leuven, Belgium
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11
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Orbán Á, Longley RJ, Sripoorote P, Maneechai N, Nguitragool W, Butykai Á, Mueller I, Sattabongkot J, Karl S, Kézsmárki I. Sensitive detection of Plasmodium vivax malaria by the rotating-crystal magneto-optical method in Thailand. Sci Rep 2021; 11:18547. [PMID: 34535695 PMCID: PMC8448879 DOI: 10.1038/s41598-021-97532-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/09/2021] [Indexed: 11/29/2022] Open
Abstract
The rotating-crystal magneto-optical detection (RMOD) method has been developed for the rapid and quantitative diagnosis of malaria and tested systematically on various malaria infection models. Very recently, an extended field trial in a high-transmission region of Papua New Guinea demonstrated its great potential for detecting malaria infections, in particular Plasmodium vivax. In the present small-scale field test, carried out in a low-transmission area of Thailand, RMOD confirmed malaria in all samples found to be infected with Plasmodium vivax by microscopy, our reference method. Moreover, the magneto-optical signal for this sample set was typically 1–3 orders of magnitude higher than the cut-off value of RMOD determined on uninfected samples. Based on the serial dilution of the original patient samples, we expect that the method can detect Plasmodium vivax malaria in blood samples with parasite densities as low as \documentclass[12pt]{minimal}
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\begin{document}$$\sim$$\end{document}∼5–10 parasites per microliter, a limit around the pyrogenic threshold of the infection. In addition, by investigating the correlation between the magnitude of the magneto-optical signal, the parasite density and the erythrocytic stage distribution, we estimate the relative hemozoin production rates of the ring and the trophozoite stages of in vivo Plasmodium vivax infections.
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Affiliation(s)
- Ágnes Orbán
- Department of Physics, Budapest University of Technology and Economics, Budapest, Hungary.
| | - Rhea J Longley
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Mahidol Vivax Research Unit, Mahidol University, Bangkok, Thailand.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia
| | | | | | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, Mahidol University, Bangkok, Thailand
| | - Ádám Butykai
- Department of Physics, Budapest University of Technology and Economics, Budapest, Hungary
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Melbourne, VIC, Australia.,Unité Malaria: Parasites et Hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | | | - Stephan Karl
- Vector-borne Diseases Unit, PNG Institute of Medical Research, Madang, Madang Province 511, Papua New Guinea.,Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | - István Kézsmárki
- Department of Physics, Budapest University of Technology and Economics, Budapest, Hungary.,Experimental Physics 5, Center for Electronic Correlations and Magnetism, University of Augsburg, Augsburg, Germany
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12
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Pack AD, Schwartzhoff PV, Zacharias ZR, Fernandez-Ruiz D, Heath WR, Gurung P, Legge KL, Janse CJ, Butler NS. Hemozoin-mediated inflammasome activation limits long-lived anti-malarial immunity. Cell Rep 2021; 36:109586. [PMID: 34433049 PMCID: PMC8432597 DOI: 10.1016/j.celrep.2021.109586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/21/2021] [Accepted: 07/30/2021] [Indexed: 12/04/2022] Open
Abstract
During acute malaria, most individuals mount robust inflammatory responses that limit parasite burden. However, long-lived sterilizing anti-malarial memory responses are not efficiently induced, even following repeated Plasmodium exposures. Using multiple Plasmodium species, genetically modified parasites, and combinations of host genetic and pharmacologic approaches, we find that the deposition of the malarial pigment hemozoin directly limits the abundance and capacity of conventional type 1 dendritic cells to prime helper T cell responses. Hemozoin-induced dendritic cell dysfunction results in aberrant Plasmodium-specific CD4 T follicular helper cell differentiation, which constrains memory B cell and long-lived plasma cell formation. Mechanistically, we identify that dendritic cell-intrinsic NLRP3 inflammasome activation reduces conventional type 1 dendritic cell abundance, phagocytosis, and T cell priming functions in vivo. These data identify biological consequences of hemozoin deposition during malaria and highlight the capacity of the malarial pigment to program immune evasion during the earliest events following an initial Plasmodium exposure.
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Affiliation(s)
- Angela D Pack
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
| | | | - Zeb R Zacharias
- Department of Pathology, University of Iowa, Iowa City, IA, USA
| | - Daniel Fernandez-Ruiz
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, VIC 3000, Australia
| | - William R Heath
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, VIC 3000, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of Melbourne, Parkville, VIC 3010, Australia
| | - Prajwal Gurung
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, USA
| | - Kevin L Legge
- Department of Pathology, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, USA
| | - Chris J Janse
- Leiden Malaria Research Group, Centre of Infectious Diseases, Leiden University Medical Centre, Leiden 233 ZA, the Netherlands
| | - Noah S Butler
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA, USA.
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13
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Phu NH, Day NPJ, Tuan PQ, Mai NTH, Chau TTH, Van Chuong L, Vinh H, Loc PP, Sinh DX, Hoa NTT, Waller DJ, Wain J, Jeyapant A, Watson JA, Farrar JJ, Hien TT, Parry CM, White NJ. Concomitant Bacteremia in Adults With Severe Falciparum Malaria. Clin Infect Dis 2021; 71:e465-e470. [PMID: 32107527 PMCID: PMC7713686 DOI: 10.1093/cid/ciaa191] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/25/2020] [Indexed: 11/13/2022] Open
Abstract
Background Approximately 6% of children hospitalized with severe falciparum malaria in Africa are also bacteremic. It is therefore recommended that all children with severe malaria should receive broad-spectrum antibiotics in addition to parenteral artesunate. Empirical antibiotics are not recommended currently for adults with severe malaria. Methods Blood cultures were performed on sequential prospectively studied adult patients with strictly defined severe falciparum malaria admitted to a single referral center in Vietnam between 1991 and 2003. Results In 845 Vietnamese adults with severe falciparum malaria admission blood cultures were positive in 9 (1.07%: 95% confidence interval [CI], .37–1.76%); Staphylococcus aureus in 2, Streptococcus pyogenes in 1, Salmonella Typhi in 3, Non-typhoid Salmonella in 1, Klebsiella pneumoniae in 1, and Haemophilus influenzae type b in 1. Bacteremic patients presented usually with a combination of jaundice, acute renal failure, and high malaria parasitemia. Four bacteremic patients died compared with 108 (12.9%) of 836 nonbacteremic severe malaria patients (risk ratio, 3.44; 95% CI, 1.62–7.29). In patients with >20% parasitemia the prevalence of concomitant bacteremia was 5.2% (4/76; 95% CI, .2–10.3%) compared with 0.65% (5/769; 0.08–1.2%) in patients with <20% parasitemia, a risk ratio of 8.1 (2.2–29.5). Conclusions In contrast to children, the prevalence of concomitant bacteremia in adults with severe malaria is low. Administration of empirical antibiotics, in addition to artesunate, is warranted in the small subgroup of patients with very high parasitemias, emphasizing the importance of quantitative blood smear microscopy assessment, but it is not indicated in most adults with severe falciparum malaria.
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Affiliation(s)
- Nguyen Hoan Phu
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Nicholas P J Day
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
| | | | | | | | - Ly Van Chuong
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ha Vinh
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Pham Phu Loc
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Dinh Xuan Sinh
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Deborah J Waller
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - John Wain
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Quadram Institute Bioscience, Norwich, United Kingdom
| | | | - James A Watson
- Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
| | - Jeremy J Farrar
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Tran Tinh Hien
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Christopher M Parry
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.,School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Nicholas J White
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
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14
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The C-type Lectin Receptor CLEC12A Recognizes Plasmodial Hemozoin and Contributes to Cerebral Malaria Development. Cell Rep 2020; 28:30-38.e5. [PMID: 31269448 PMCID: PMC6616648 DOI: 10.1016/j.celrep.2019.06.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 03/15/2019] [Accepted: 06/04/2019] [Indexed: 01/04/2023] Open
Abstract
Malaria represents a major cause of death from infectious disease. Hemozoin is a Plasmodium-derived product that contributes to progression of cerebral malaria. However, there is a gap of knowledge regarding how hemozoin is recognized by innate immunity. Myeloid C-type lectin receptors (CLRs) encompass a family of carbohydrate-binding receptors that act as pattern recognition receptors in innate immunity. In the present study, we identify the CLR CLEC12A as a receptor for hemozoin. Dendritic cell-T cell co-culture assays indicate that the CLEC12A/hemozoin interaction enhances CD8+ T cell cross-priming. Using the Plasmodium berghei Antwerpen-Kasapa (ANKA) mouse model of experimental cerebral malaria (ECM), we find that CLEC12A deficiency protects mice from ECM, illustrated by reduced ECM incidence and ameliorated clinical symptoms. In conclusion, we identify CLEC12A as an innate sensor of plasmodial hemozoin. CLEC12A recognizes plasmodial hemozoin The CLEC12A/hemozoin interaction enhances CD8+ T cell cross-priming in vitro CLEC12A−/− mice are protected from experimental cerebral malaria
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15
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Pádua TA, Souza MC. Heme on Pulmonary Malaria: Friend or Foe? Front Immunol 2020; 11:1835. [PMID: 32983096 PMCID: PMC7477073 DOI: 10.3389/fimmu.2020.01835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022] Open
Abstract
Malaria is a hemolytic disease that, in severe cases, can compromise multiple organs. Pulmonary distress is a common symptom observed in severe malaria caused by Plasmodium vivax or Plasmodium falciparum. However, biological components involved in the development of lung malaria are poorly studied. In experimental models of pulmonary malaria, it was observed that parasitized red blood cell-congested pulmonary capillaries are related to intra-alveolar hemorrhages and inflammatory cell infiltration. Thus, it is very likely that hemolysis participates in malaria-induced acute lung injury. During malaria, heme assumes different biochemical structures such as hemin and hemozoin (biocrystallized structure of heme inside Plasmodium sp.). Each heme-derived structure triggers a different biological effect: on the one hand, hemozoin found in lung tissue is responsible for the infiltration of inflammatory cells and consequent tissue injury; on the other hand, heme stimulates heme oxygenase-1 (HO-1) expression and CO production, which protect mice from severe malaria. In this review, we discuss the biological mechanism involved in the dual role of heme response in experimental malaria-induced acute lung injury.
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Affiliation(s)
- Tatiana Almeida Pádua
- Laboratory of Applied Pharmacology, Institute of Drug Technology (Farmanguinhos), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Mariana Conceição Souza
- Laboratory of Applied Pharmacology, Institute of Drug Technology (Farmanguinhos), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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16
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Dobbs KR, Crabtree JN, Dent AE. Innate immunity to malaria-The role of monocytes. Immunol Rev 2020; 293:8-24. [PMID: 31840836 PMCID: PMC6986449 DOI: 10.1111/imr.12830] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/19/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022]
Abstract
Monocytes are innate immune cells essential for host protection against malaria. Upon activation, monocytes function to help reduce parasite burden through phagocytosis, cytokine production, and antigen presentation. However, monocytes have also been implicated in the pathogenesis of severe disease through production of damaging inflammatory cytokines, resulting in systemic inflammation and vascular dysfunction. Understanding the molecular pathways influencing the balance between protection and pathology is critical. In this review, we discuss recent data regarding the role of monocytes in human malaria, including studies of innate sensing of the parasite, immunometabolism, and innate immune training. Knowledge gained from these studies may guide rational development of novel antimalarial therapies and inform vaccine development.
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Affiliation(s)
- Katherine R. Dobbs
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
- Division of Pediatric Infectious Diseases, University Hospitals Rainbow Babies and Children’s Hospital, Cleveland, OH, USA
| | - Juliet N. Crabtree
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Arlene E. Dent
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
- Division of Pediatric Infectious Diseases, University Hospitals Rainbow Babies and Children’s Hospital, Cleveland, OH, USA
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17
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Abstract
Malaria represents a medical emergency. Without rapid diagnosis and treatment, it can progress and lead to severe complications and, eventually, death. Severe malaria is almost always caused by Plasmodium falciparum. Here, we present an image showing a set of hematological findings associated with severe malaria, highlighting the importance of a correct morphological diagnosis.
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Affiliation(s)
- Marco P Barros Pinto
- Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, EPE, Lisbon, Portugal. .,Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
| | - Guilhermina Marques
- Hospital de Santa Maria, Centro Hospitalar Universitário Lisboa Norte, EPE, Lisbon, Portugal
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18
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Plewes K, Leopold SJ, Kingston HWF, Dondorp AM. Malaria: What's New in the Management of Malaria? Infect Dis Clin North Am 2019; 33:39-60. [PMID: 30712767 DOI: 10.1016/j.idc.2018.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The global burden of malaria remains high, with 216 million cases causing 445,000 deaths in 2016 despite first-line treatment with artemisinin-based combination therapy. Decreasing transmission in Africa shifts the risk for severe malaria to older age groups as premunition wanes. Prompt diagnosis and treatment with intravenous artesunate in addition to appropriate supportive management are critical to reduce deaths from severe malaria. Effective individual management is challenging in settings with limited resources for higher-level care. Adjunctive therapies targeting the underlying pathophysiological pathways have the potential to reduce mortality. Resistance to artemisinin derivatives and their partner drugs threaten malaria management and control.
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Affiliation(s)
- Katherine Plewes
- Malaria Department, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand; Department of Medicine, University of British Columbia, Vancouver General Hospital, 452D Heather Pavilion East, 2733 Heather Street, Vancouver, British Columbia V5Z 3J5, Canada
| | - Stije J Leopold
- Malaria Department, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand
| | - Hugh W F Kingston
- Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Headington, Oxford OX3 7BN, UK; Malaria Department, Mahidol Oxford Research Unit, Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand
| | - Arjen M Dondorp
- Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Headington, Oxford OX3 7BN, UK; Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 3/F 60th, Anniversary Chalermprakiat Building, 420/6 Rajvithi Road, Bangkok 10400, Thailand.
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19
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Kho S, Minigo G, Andries B, Leonardo L, Prayoga P, Poespoprodjo JR, Kenangalem E, Price RN, Woodberry T, Anstey NM, Yeo TW. Circulating Neutrophil Extracellular Traps and Neutrophil Activation Are Increased in Proportion to Disease Severity in Human Malaria. J Infect Dis 2019; 219:1994-2004. [PMID: 30452670 PMCID: PMC6542661 DOI: 10.1093/infdis/jiy661] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 11/11/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Neutrophil activation results in Plasmodium parasite killing in vitro, but neutrophil products including neutrophil extracellular traps (NETs) mediate host organ damage and may contribute to severe malaria. The role of NETs in the pathogenesis of severe malaria has not been examined. METHODS In Papua, Indonesia, we enrolled adults with symptomatic Plasmodium falciparum (n = 47 uncomplicated, n = 8 severe), Plasmodium vivax (n = 37), or Plasmodium malariae (n = 14) malaria; asymptomatic P falciparum (n = 19) or P vivax (n = 21) parasitemia; and healthy adults (n = 23) without parasitemia. Neutrophil activation and NETs were quantified by immunoassays and microscopy and correlated with parasite biomass and disease severity. RESULTS In patients with symptomatic malaria, neutrophil activation and NET counts were increased in all 3 Plasmodium species. In falciparum malaria, neutrophil activation and NET counts positively correlated with parasite biomass (Spearman rho = 0.41, P = .005 and r2 = 0.26, P = .002, respectively) and were significantly increased in severe disease. In contrast, NETs were inversely associated with parasitemia in adults with asymptomatic P falciparum infection (r2 = 0.24, P = .031) but not asymptomatic P vivax infection. CONCLUSIONS Although NETs may inhibit parasite growth in asymptomatic P falciparum infection, neutrophil activation and NET release may contribute to pathogenesis in severe falciparum malaria. Agents with potential to attenuate these processes should be evaluated.
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Affiliation(s)
- Steven Kho
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Gabriela Minigo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Benediktus Andries
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Papua, Indonesia
| | - Leo Leonardo
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Papua, Indonesia
| | - Pak Prayoga
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Papua, Indonesia
| | - Jeanne R Poespoprodjo
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Papua, Indonesia
- Rumah Sakit Umum Daerah Kabupaten Mimika, Timika, Papua, Indonesia
- Department of Child Health, Faculty of Medicine, University of Gadjah Mada, Yogyakarta, Indonesia
| | - Enny Kenangalem
- Timika Malaria Research Programme, Papuan Health and Community Development Foundation, Papua, Indonesia
- Rumah Sakit Umum Daerah Kabupaten Mimika, Timika, Papua, Indonesia
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Tonia Woodberry
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Tsin W Yeo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
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20
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Abstract
Neutrophils are abundant in the circulation and are one of the immune system's first lines of defense against infection. There has been substantial work carried out investigating the role of neutrophils in malaria and it is clear that during infection neutrophils are activated and are capable of clearing malaria parasites by a number of mechanisms. This review focuses on neutrophil responses to human malarias, summarizing evidence which helps us understand where neutrophils are, what they are doing, how they interact with parasites as well as their potential role in vaccine mediated immunity. We also outline future research priorities for these, the most abundant of leukocytes.
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Affiliation(s)
- Elizabeth H Aitken
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Agersew Alemu
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
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21
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Cumming BM, Goldring JPD. Monocyte phagocytosis of malaria β-haematin in the presence of artemisinin, amodiaquine, chloroquine, doxycycline, primaquine, pyrimethamine and quinine. Exp Parasitol 2018; 197:93-102. [PMID: 30562480 DOI: 10.1016/j.exppara.2018.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 11/07/2018] [Accepted: 12/14/2018] [Indexed: 12/14/2022]
Abstract
The intraerythrocytic malaria parasite digests haemoglobin to provide amino acids for metabolism and releases toxic haem that is sequestered into haemozoin, a non-toxic, insoluble, crystalline pigment. Following erythrocyte rupture, haemozoin is released into circulation and phagocytosed by monocytes. Phagocytosed haemozoin and antimalarial drugs have both been reported to modulate monocyte functions. This study determined the effects of therapeutic concentrations of seven antimalarial drugs; amodiaquine, artemisinin, chloroquine, doxycycline, primaquine, pyrimethamine and quinine, on the phagocytosis of β-haematin (synthetic haemozoin) by two monocytic cell lines, J774A.1 and U937, and human peripheral blood mononuclear cells. A novel spectrophotometric method based on the absorbance (O.D 400 nm) of alkali/SDS treated monocytes containing β-haematin was developed to complement counting phagocytosis with microscopy. The method has potential use for the large scale screening of monocyte phagocytic activity. Artemisinin, quinine, primaquine and pyrimethamine activated β-haematin phagocytosis by 12% or more, whereas amodiaquine, chloroquine and doxycyline inhibited β-haematin phagocytosis. In contrast, antimalarial drugs had minimal inhibitory effects on the phagocytosis of latex beads with only quinine resulting in more than 20% inhibition. Antimalarial drugs appear to alter monocyte phagocytic activity which has implications for the treatment, pathogenicity and adjunct therapies for malaria.
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Affiliation(s)
- Bridgette M Cumming
- Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville, 3209, South Africa
| | - J P Dean Goldring
- Department of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville, 3209, South Africa.
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22
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Corbett Y, D'Alessandro S, Parapini S, Scaccabarozzi D, Kalantari P, Zava S, Giavarini F, Caruso D, Colombo I, Egan TJ, Basilico N. Interplay between Plasmodium falciparum haemozoin and L-arginine: implication for nitric oxide production. Malar J 2018; 17:456. [PMID: 30522493 PMCID: PMC6282336 DOI: 10.1186/s12936-018-2602-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 11/29/2018] [Indexed: 01/07/2023] Open
Abstract
Background Plasmodium falciparum haemozoin, a detoxification product of digested haemoglobin from infected erythrocytes, is released into the bloodstream upon schizont rupture and accumulates in leukocytes. High levels of haemozoin correlate with disease severity. Some studies have shown that concentrations of the substrate of inducible nitric oxide synthase (iNOS), l-arginine, as well as nitric oxide are low in patients infected with P. falciparum malaria. The present study investigates, in vitro, the role of P. falciparum haemozoin on nitric oxide production, iNOS expression in macrophages, and the possible interaction between l-arginine and haemozoin. Methods Plasmodium falciparum haemozoin was obtained from in vitro cultures through magnetic isolation. Phagocytosis of haemozoin by immortalized bone marrow derived macrophages was detected by confocal reflection combined with fluorescence microscopy. Nitrite concentrations in the supernatants was evaluated by Griess assay as a standard indication of nitric oxide production, while iNOS expression was detected on cell extracts by western blotting. Detection of l-arginine in haemozoin-treated or untreated media was achieved by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Results Haemozoin synergizes in vitro with interferon-gamma to produce nitric oxide. However, when mouse macrophages were stimulated with haemozoin, a proportional increase of nitric oxide was observed up to 25 μM of haemozoin, followed by a decrease with doses up to 100 μM, when nitric oxide release was completely abrogated. This was not due to reactive oxygen species production, nor to an effect on iNOS activity. Interestingly, when at 24 h, haemozoin-treated macrophages were washed and incubated in fresh medium for further 24 h, the nitric oxide production was restored in a dose–response manner. Similar results were seen when l-arginine-enriched media was used in the stimulation. Moreover, muramyldipeptide, a strong nitric oxide inducer, was unable to activate macrophages to release nitric oxide in the presence of haemozoin-treated medium. By LC–MS/MS a complete depletion of l-arginine was observed in this haemozoin-treated, conditioned medium. Conclusions It is proposed that haemozoin interacts with l-arginine reducing its availability for iNOS, and thus decreasing nitric oxide production. The clinical (or pathological) implications of these results are discussed. Electronic supplementary material The online version of this article (10.1186/s12936-018-2602-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yolanda Corbett
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy. .,Dipartimento di Bioscienze, Università degli Studi di Milano, 20133, Milan, MI, Italy.
| | - Sarah D'Alessandro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy.,Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Silvia Parapini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy.,Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Diletta Scaccabarozzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Parisa Kalantari
- Department of Immunology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Stefania Zava
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Flavio Giavarini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Donatella Caruso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Irma Colombo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133, Milan, MI, Italy
| | - Timothy J Egan
- Department of Chemistry, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Nicoletta Basilico
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, 20133, Milan, MI, Italy
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23
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Shu F, Shi Y. Systematic Overview of Solid Particles and Their Host Responses. Front Immunol 2018; 9:1157. [PMID: 29892295 PMCID: PMC5985299 DOI: 10.3389/fimmu.2018.01157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/08/2018] [Indexed: 12/17/2022] Open
Abstract
Crystalline/particulate substances trigger a plethora of signaling events in host cells. The most prominent consequence is the inflammatory reactions that underlie crystal arthropathies, such as gout and pseudogout. However, their impact on our health was underestimated. Recent work on the role of cholesterol crystal in the development of atherosclerosis and the harm of environmental particulates has set up new frontiers in our defense against their detrimental effects. On the other hand, in the last 100 years, crystalline/particulate substances have been used with increasing frequencies in our daily lives as a part of new industrial manufacturing and engineering. Importantly, they have become a tool in modern medicine, used as vaccine adjuvants and drug delivery vehicles. Their biological effects are also being dissected in great detail, particularly with regard to their inflammatory signaling pathways. Solid structure interaction with host cells is far from being uniform, with outcomes dependent on cell types and chemical/physical properties of the particles involved. In this review, we offer a systematic and broad outlook of this landscape and a sage analysis of the complex nature of this topic.
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Affiliation(s)
- Fei Shu
- Department of Basic Medical Sciences, Institute for Immunology, Center for Life Sciences, Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
- Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Peking University, Beijing, China
| | - Yan Shi
- Department of Basic Medical Sciences, Institute for Immunology, Center for Life Sciences, Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, China
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute, University of Calgary, Calgary, AB, Canada
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Kalantari P. The Emerging Role of Pattern Recognition Receptors in the Pathogenesis of Malaria. Vaccines (Basel) 2018; 6:vaccines6010013. [PMID: 29495555 PMCID: PMC5874654 DOI: 10.3390/vaccines6010013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/19/2018] [Accepted: 02/22/2018] [Indexed: 11/16/2022] Open
Abstract
Despite a global effort to develop an effective vaccine, malaria is still a significant health problem. Much of the pathology of malaria is immune mediated. This suggests that host immune responses have to be finely regulated. The innate immune system initiates and sets the threshold of the acquired immune response and determines the outcome of the disease. Yet, our knowledge of the regulation of innate immune responses during malaria is limited. Theoretically, inadequate activation of the innate immune system could result in unrestrained parasite growth. Conversely, hyperactivation of the innate immune system, is likely to cause excessive production of proinflammatory cytokines and severe pathology. Toll-like receptors (TLRs) have emerged as essential receptors which detect signature molecules and shape the complex host response during malaria infection. This review will highlight the mechanisms by which Plasmodium components are recognized by innate immune receptors with particular emphasis on TLRs. A thorough understanding of the complex roles of TLRs in malaria may allow the delineation of pathological versus protective host responses and enhance the efficacy of anti-malarial treatments and vaccines.
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Affiliation(s)
- Parisa Kalantari
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA.
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Amir A, Cheong FW, De Silva JR, Lau YL. Diagnostic tools in childhood malaria. Parasit Vectors 2018; 11:53. [PMID: 29361963 PMCID: PMC5781272 DOI: 10.1186/s13071-018-2617-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/02/2018] [Indexed: 01/05/2023] Open
Abstract
Every year, millions of people are burdened with malaria. An estimated 429,000 casualties were reported in 2015, with the majority made up of children under five years old. Early and accurate diagnosis of malaria is of paramount importance to ensure appropriate administration of treatment. This minimizes the risk of parasite resistance development, reduces drug wastage and unnecessary adverse reaction to antimalarial drugs. Malaria diagnostic tools have expanded beyond the conventional microscopic examination of Giemsa-stained blood films. Contemporary and innovative techniques have emerged, mainly the rapid diagnostic tests (RDT) and other molecular diagnostic methods such as PCR, qPCR and loop-mediated isothermal amplification (LAMP). Even microscopic diagnosis has gone through a paradigm shift with the development of new techniques such as the quantitative buffy coat (QBC) method and the Partec rapid malaria test. This review explores the different diagnostic tools available for childhood malaria, each with their characteristic strengths and limitations. These tools play an important role in making an accurate malaria diagnosis to ensure that the use of anti-malaria are rationalized and that presumptive diagnosis would only be a thing of the past.
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Affiliation(s)
- Amirah Amir
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Fei-Wen Cheong
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Jeremy R De Silva
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, University Malaya, 50603, Kuala Lumpur, Malaysia.
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Phyo AP, Win KK, Thu AM, Swe LL, Htike H, Beau C, Sriprawat K, Winterberg M, Proux S, Imwong M, Ashley EA, Nosten F. Poor response to artesunate treatment in two patients with severe malaria on the Thai-Myanmar border. Malar J 2018; 17:30. [PMID: 29334942 PMCID: PMC5769511 DOI: 10.1186/s12936-018-2182-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/10/2018] [Indexed: 11/22/2022] Open
Abstract
Background Malaria has declined dramatically along the Thai–Myanmar border in recent years due to malaria control and elimination programmes. However, at the same time, artemisinin resistance has spread, raising concerns about the efficacy of parenteral artesunate for the treatment of severe malaria. Case presentation In November 2015 and April 2017, two patients were treated for severe malaria with parenteral artesunate. Quinine was added within 24 h due to an initial poor response to treatment. The first patient died within 24 h of starting treatment and the second did not clear his peripheral parasitaemia until 11 days later. Genotyping revealed artemisinin resistance Kelch-13 markers. Conclusions Reliable efficacy of artesunate for the treatment of severe malaria may no longer be assured in areas where artemisinin resistance has emerged. Empirical addition of parenteral quinine to artesunate for treatment is recommended as a precautionary measure. Electronic supplementary material The online version of this article (10.1186/s12936-018-2182-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand. .,Myanmar Oxford Clinical Research Unit, Yangon, Myanmar.
| | - Kyaw Kyaw Win
- Mae Tao Clinic, 702, Moo 1, Tha Sai Luad, Mae Sot, Tak, 63110, Thailand
| | - Aung Myint Thu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand
| | - Lei Lei Swe
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand
| | - Htike Htike
- Mae Tao Clinic, 702, Moo 1, Tha Sai Luad, Mae Sot, Tak, 63110, Thailand
| | - Candy Beau
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand
| | - Markus Winterberg
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Stephane Proux
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Elizabeth A Ashley
- 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, UK.,Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, PO Box 46, Mae Sot, Tak, 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Burnett JL, Carns JL, Richards-Kortum R. Towards a needle-free diagnosis of malaria: in vivo identification and classification of red and white blood cells containing haemozoin. Malar J 2017; 16:447. [PMID: 29115957 PMCID: PMC5678583 DOI: 10.1186/s12936-017-2096-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 10/28/2017] [Indexed: 12/02/2022] Open
Abstract
Background Optical detection of circulating haemozoin has been suggested as a needle free method to diagnose malaria using in vivo microscopy. Haemozoin is generated within infected red blood cells by the malaria parasite, serving as a highly specific, endogenous biomarker of malaria. However, phagocytosis of haemozoin by white blood cells which persist after the infection is resolved presents the potential for false positive diagnosis; therefore, the focus of this work is to identify a feature of the haemozoin signal to discriminate between infected red blood cells and haemozoin-containing white blood cells. Methods Conventional brightfield microscopy of thin film blood smears was used to analyse haemozoin absorbance signal in vitro. Cell type and parasite maturity were morphologically determined using colocalized DAPI staining. The ability of features to discriminate between infected red blood cells and haemozoin-containing white blood cells was evaluated using images of smears from subjects infected with two species of Plasmodium, Plasmodium yoelii and Plasmodium falciparum. Discriminating features identified by blood smear microscopy were characterized in vivo in P. yoelii-infected mice. Results Two features of the haemozoin signal, haemozoin diameter and normalized intensity difference, were identified as potential parameters to differentiate infected red blood cells and haemozoin-containing white blood cells. Classification performance was evaluated using the area under the receiver operating characteristic curve, with area under the curve values of 0.89 for the diameter parameter and 0.85 for the intensity parameter when assessed in P. yoelii samples. Similar results were obtained from P. falciparum blood smears, showing an AUC of 0.93 or greater for both classification features. For in vivo investigations, the intensity-based metric was the best classifier, with an AUC of 0.91. Conclusions This work demonstrates that size and intensity features of haemozoin absorbance signal collected by in vivo microscopy are effective classification metrics to discriminate infected red blood cells from haemozoin-containing white blood cells. This reduces the potential for false positive results associated with optical imaging strategies for in vivo diagnosis of malaria based on the endogenous biomarker haemozoin. Electronic supplementary material The online version of this article (10.1186/s12936-017-2096-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jennifer L Burnett
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX, 77005, USA.
| | - Jennifer L Carns
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX, 77005, USA
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Arese P, Schwarzer E. Malarial pigment (haemozoin): a very active ‘inert’ substance. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2016. [DOI: 10.1080/00034983.1997.11813168] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Lalloo DG, Shingadia D, Bell DJ, Beeching NJ, Whitty CJM, Chiodini PL. UK malaria treatment guidelines 2016. J Infect 2016; 72:635-649. [PMID: 26880088 PMCID: PMC7132403 DOI: 10.1016/j.jinf.2016.02.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 02/06/2016] [Indexed: 12/15/2022]
Abstract
1.Malaria is the tropical disease most commonly imported into the UK, with 1300-1800 cases reported each year, and 2-11 deaths. 2. Approximately three quarters of reported malaria cases in the UK are caused by Plasmodium falciparum, which is capable of invading a high proportion of red blood cells and rapidly leading to severe or life-threatening multi-organ disease. 3. Most non-falciparum malaria cases are caused by Plasmodium vivax; a few cases are caused by the other species of plasmodium: Plasmodium ovale, Plasmodium malariae or Plasmodium knowlesi. 4. Mixed infections with more than one species of parasite can occur; they commonly involve P. falciparum with the attendant risks of severe malaria. 5. There are no typical clinical features of malaria; even fever is not invariably present. Malaria in children (and sometimes in adults) may present with misleading symptoms such as gastrointestinal features, sore throat or lower respiratory complaints. 6. A diagnosis of malaria must always be sought in a feverish or sick child or adult who has visited malaria-endemic areas. Specific country information on malaria can be found at http://travelhealthpro.org.uk/. P. falciparum infection rarely presents more than six months after exposure but presentation of other species can occur more than a year after exposure. 7. Management of malaria depends on awareness of the diagnosis and on performing the correct diagnostic tests: the diagnosis cannot be excluded until more than one blood specimen has been examined. Other travel related infections, especially viral haemorrhagic fevers, should also be considered. 8. The optimum diagnostic procedure is examination of thick and thin blood films by an expert to detect and speciate the malarial parasites. P. falciparum and P. vivax (depending upon the product) malaria can be diagnosed almost as accurately using rapid diagnostic tests (RDTs) which detect plasmodial antigens. RDTs for other Plasmodium species are not as reliable. 9. Most patients treated for P. falciparum malaria should be admitted to hospital for at least 24 h as patients can deteriorate suddenly, especially early in the course of treatment. In specialised units seeing large numbers of patients, outpatient treatment may be considered if specific protocols for patient selection and follow up are in place. 10. Uncomplicated P. falciparum malaria should be treated with an artemisinin combination therapy (Grade 1A). Artemether-lumefantrine (Riamet(®)) is the drug of choice (Grade 2C) and dihydroartemisinin-piperaquine (Eurartesim(®)) is an alternative. Quinine or atovaquone-proguanil (Malarone(®)) can be used if an ACT is not available. Quinine is highly effective but poorly-tolerated in prolonged treatment and should be used in combination with an additional drug, usually oral doxycycline. 11. Severe falciparum malaria, or infections complicated by a relatively high parasite count (more than 2% of red blood cells parasitized) should be treated with intravenous therapy until the patient is well enough to continue with oral treatment. Severe malaria is a rare complication of P. vivax or P. knowlesi infection and also requires parenteral therapy. 12. The treatment of choice for severe or complicated malaria in adults and children is intravenous artesunate (Grade 1A). Intravenous artesunate is unlicensed in the EU but is available in many centres. The alternative is intravenous quinine, which should be started immediately if artesunate is not available (Grade 1A). Patients treated with intravenous quinine require careful monitoring for hypoglycemia. 13. Patients with severe or complicated malaria should be managed in a high-dependency or intensive care environment. They may require haemodynamic support and management of: acute respiratory distress syndrome, disseminated intravascular coagulation, acute kidney injury, seizures, and severe intercurrent infections including Gram-negative bacteraemia/septicaemia. 14. Children with severe malaria should also be treated with empirical broad spectrum antibiotics until bacterial infection can be excluded (Grade 1B). 15. Haemolysis occurs in approximately 10-15% patients following intravenous artesunate treatment. Haemoglobin concentrations should be checked approximately 14 days following treatment in those treated with IV artemisinins (Grade 2C). 16. Falciparum malaria in pregnancy is more likely to be complicated: the placenta contains high levels of parasites, stillbirth or early delivery may occur and diagnosis can be difficult if parasites are concentrated in the placenta and scanty in the blood. 17. Uncomplicated falciparum malaria in the second and third trimester of pregnancy should be treated with artemether-lumefantrine (Grade 2B). Uncomplicated falciparum malaria in the first trimester of pregnancy should usually be treated with quinine and clindamycin but specialist advice should be sought. Severe malaria in any trimester of pregnancy should be treated as for any other patient with artesunate preferred over quinine (Grade 1C). 18. Children with uncomplicated malaria should be treated with an ACT (artemether-lumefantrine or dihydroartemisinin-piperaquine) as first line treatment (Grade 1A). Quinine with doxycycline or clindamycin, or atovaquone-proguanil at appropriate doses for weight can also be used. Doxycycline should not be given to children under 12 years. 19. Either an oral ACT or chloroquine can be used for the treatment of non-falciparum malaria. An oral ACT is preferred for a mixed infection, if there is uncertainty about the infecting species, or for P. vivax infection from areas where chloroquine resistance is common (Grade 1B). 20. Dormant parasites (hypnozoites) persist in the liver after treatment of P. vivax or P. ovale infection: the only currently effective drug for eradication of hypnozoites is primaquine (1A). Primaquine is more effective at preventing relapse if taken at the same time as chloroquine (Grade 1C). 21. Primaquine should be avoided or given with caution under expert supervision in patients with Glucose-6-phosphate dehydrogenase deficiency (G6PD), in whom it may cause severe haemolysis. 22. Primaquine (for eradication of P. vivax or P. ovale hypnozoites) is contraindicated in pregnancy and when breastfeeding (until the G6PD status of child is known); after initial treatment for these infections a pregnant woman should take weekly chloroquine prophylaxis until after delivery or cessation of breastfeeding when hypnozoite eradication can be considered. 23. An acute attack of malaria does not confer protection from future attacks: individuals who have had malaria should take effective anti-mosquito precautions and chemoprophylaxis during future visits to endemic areas.
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Affiliation(s)
- David G Lalloo
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
| | - Delane Shingadia
- Department of Infectious Diseases, Great Ormond Street Hospital, Great Ormond Street, London WC1N 3JH, UK
| | - David J Bell
- Department of Infectious Diseases, Queen Elizabeth University Hospital, Glasgow G51 4TF, UK
| | - Nicholas J Beeching
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Christopher J M Whitty
- Hospital for Tropical Diseases, Mortimer Market Centre, Capper Street off Tottenham Court Road, London WC1E 6AU, UK
| | - Peter L Chiodini
- Malaria Reference Laboratory, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
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Denic S, Narchi H, Al Mekaini LA, Al-Hammadi S, Al Jabri ON, Souid AK. Prevalence of neutropenia in children by nationality. BMC HEMATOLOGY 2016; 16:15. [PMID: 27213048 PMCID: PMC4875641 DOI: 10.1186/s12878-016-0054-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/14/2016] [Indexed: 01/15/2023]
Abstract
Background A high prevalence of neutropenia has been reported in several ethnic groups amongst whom many healthy individuals with low neutrophil counts undergo unnecessary investigations. This study aims to ascertain the prevalence of neutropenia (NP) in a large cohort of children from North African, Middle Eastern, and Asian countries residing in the United Arab Emirates. Methods Neutrophil counts of 26,542 children (one day to six years of age) from 86 countries were analyzed. The subjects were enrolled in the Well-Child-Care program of Ambulatory Health Services of Emirate of Abu Dhabi, United Arab Emirates. NP was defined as a neutrophil count <1.5 × 109/L and severe NP <0.5 × 109/L. Results The neutrophil counts reached a nadir in the fourth week of life and changed slightly from the age of six-months to six-years. The frequency of NP was (from West-to-East): North African Arabs 15.4 %, Green Crescent Arabs 9.8 %, Peninsular Arabs 10.9 %, Iranians 3.1 %, Afghanis 2.5 %, Pakistanis 5.6 %, Indians 10.2 %, and Filipinos 7.3 %. The frequency of severe NP in North African Arabs (Sudanese) was 2.8 %, Green Crescent and Peninsular Arabs ≤1 %, Indians 1.5 %, and Filipinos 1.8 %. In 12,703 Emirati children, the frequency of NP was 10.6 % similar to their adult counterparts. Conclusion The prevalence of childhood NP varied considerably by geoethnicity. Measures to prevent the inappropriate investigations of healthy children with benign neutropenia are proposed. Electronic supplementary material The online version of this article (doi:10.1186/s12878-016-0054-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Srdjan Denic
- Department of Medicine, College of Medicine and Health Sciences, United Arab Emirates University, PO Box 17666, Al-Ain, United Arab of Emirates
| | - Hassib Narchi
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab of Emirates
| | - Lolowa A Al Mekaini
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab of Emirates
| | - Suleiman Al-Hammadi
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab of Emirates
| | - Omar N Al Jabri
- Ambulatory Healthcare Services, Abu Dhabi, United Arab of Emirates
| | - Abdul-Kader Souid
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab of Emirates
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Kotepui M, Uthaisar K, PhunPhuech B, Phiwklam N. Prevalence and hematological indicators of G6PD deficiency in malaria-infected patients. Infect Dis Poverty 2016; 5:36. [PMID: 27109515 PMCID: PMC4843198 DOI: 10.1186/s40249-016-0130-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/12/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aimed to evaluate the prevalence and alteration of hematological parameters in malaria patients with a glucose-6-phosphate dehydrogenase (G6PD) deficiency, in the western region of Thailand, an endemic region for malaria. METHODS Data about patients with malaria hospitalized between 2013 and 2015 were collected. Clinical and sociodemographic characteristics such as age and gender, diagnosis on admission, and parasitological results were mined from medical records of the laboratory unit of the Phop Phra Hospital in Tak Province, Thailand. Venous blood samples were collected at the time of admission to hospital to determine G6PD deficiency by fluorescence spot test and detect malaria parasites by thick and thin film examination. Other data such as complete blood count and parasite density were also collected and analyzed. RESULTS Among the 245 malaria cases, 28 (11.4 %) were diagnosed as Plasmodium falciparum infections and 217 cases (88.6 %) were diagnosed as P. vivax infections. Seventeen (6.9 %) patients had a G6PD deficiency and 228 (93.1 %) patients did not have a G6PD deficiency. Prevalence of male patients with G6PD deficiency was higher than that of female patients (P < 0.05, OR = 5.167). Among the patients with a G6PD deficiency, two (11.8 %) were infected with P. falciparum, while the remaining were infected with P. vivax. Malaria patients with a G6PD deficiency have higher monocyte counts (0.6 × 10(3)/μL) than those without a G6PD deficiency (0.33 × 10(3)/μL) (P < 0.05, OR = 5.167). Univariate and multivariate analyses also confirmed that malaria patients with a G6PD deficiency have high monocyte counts. The association between G6PD status and monocyte counts was independent of age, gender, nationality, Plasmodium species, and parasite density (P < 0.005). CONCLUSION This study showed a prevalence of G6PD deficiency in a malaria-endemic area. This study also supported the assertion that patients with G6PD-deficient red blood cells had no protection against the P. falciparum infection. In addition, malaria patients with a G6PD deficiency had higher monocyte counts than those without a G6PD deficiency. These findings will help to recognize and diagnose malaria patients with a G6PD deficiency, as well as to identify the risks and protective factors against malaria in endemic areas.
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Affiliation(s)
- Manas Kotepui
- Medical Technology Program, School of Allied Health Sciences and Public Health, Walailak University, Nakhon Si Thammarat, 80161, Thailand.
| | - Kwuntida Uthaisar
- Medical Technology Program, School of Allied Health Sciences and Public Health, Walailak University, Nakhon Si Thammarat, 80161, Thailand
| | - Bhukdee PhunPhuech
- Medical Technology Laboratory, Phop Phra Hospital, Phop Phra District, Tak Province, 63160, Thailand
| | - Nuoil Phiwklam
- Medical Technology Laboratory, Phop Phra Hospital, Phop Phra District, Tak Province, 63160, Thailand
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Abstract
Lung involvement in malaria has been recognized for more than 200 hundred years, yet our knowledge of its pathogenesis and management is limited. Pulmonary edema is the most severe form of lung involvement. Increased alveolar capillary permeability leading to intravascular fluid loss into the lungs is the main pathophysiologic mechanism. This defines malaria as another cause of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).Pulmonary edema has been described most often in non-immune individuals with Plasmodium falciparum infections as part of a severe systemic illness or as the main feature of acute malaria. P.vivax and P.ovale have also rarely caused pulmonary edema.Clinically, patients usually present with acute breathlessness that can rapidly progress to respiratory failure either at disease presentation or, interestingly, after treatment when clinical improvement is taking place and the parasitemia is falling. Pregnant women are particularly prone to developing pulmonary edema. Optimal management of malaria-induced ALI/ARDS includes early recognition and diagnosis. Malaria must always be suspected in a returning traveler or a visitor from a malaria-endemic country with an acute febrile illness. Slide microscopy and/or the use of rapid antigen tests are standard diagnostic tools. Malaria must be treated with effective drugs, but current choices are few: e.g. parenteral artemisinins, intravenous quinine or quinidine (in the US only). A recent trial in adults has shown that intravenous artesunate reduces severe malaria mortality by a third compared with adults treated with intravenous quinine. Respiratory compromise should be managed on its merits and may require mechanical ventilation.Patients should be managed in an intensive care unit and particular attention should be paid to the energetic management of other severe malaria complications, notably coma and acute renal failure. ALI/ARDS may also be related to a coincidental bacterial sepsis that may not be clinically obvious. Clinicians should employ a low threshold for starting broad spectrum antibacterials in such patients, after taking pertinent microbiologic specimens. Despite optimal management, the prognosis of severe malaria with ARDS is poor.ALI/ARDS in pediatric malaria appears to be rare. However, falciparum malaria with severe metabolic acidosis or acute pulmonary edema may present with a clinical picture of pneumonia, i.e. with tachypnea, intercostal recession, wheeze or inspiratory crepitations. This results in diagnostic confusion and suboptimal treatment. Whilst this is increasingly being recognized in malaria-endemic countries, clinicians in temperate zones should be aware that malaria may be a possible cause of 'pneumonia' in a visiting or returning child.
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Affiliation(s)
- Walter R J Taylor
- Travel and Migration Medicine Unit, Department of Community Medicine, Geneva University Hospital, Geneva, Switzerland
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Deroost K, Pham TT, Opdenakker G, Van den Steen PE. The immunological balance between host and parasite in malaria. FEMS Microbiol Rev 2015; 40:208-57. [PMID: 26657789 DOI: 10.1093/femsre/fuv046] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 12/16/2022] Open
Abstract
Coevolution of humans and malaria parasites has generated an intricate balance between the immune system of the host and virulence factors of the parasite, equilibrating maximal parasite transmission with limited host damage. Focusing on the blood stage of the disease, we discuss how the balance between anti-parasite immunity versus immunomodulatory and evasion mechanisms of the parasite may result in parasite clearance or chronic infection without major symptoms, whereas imbalances characterized by excessive parasite growth, exaggerated immune reactions or a combination of both cause severe pathology and death, which is detrimental for both parasite and host. A thorough understanding of the immunological balance of malaria and its relation to other physiological balances in the body is of crucial importance for developing effective interventions to reduce malaria-related morbidity and to diminish fatal outcomes due to severe complications. Therefore, we discuss in this review the detailed mechanisms of anti-malarial immunity, parasite virulence factors including immune evasion mechanisms and pathogenesis. Furthermore, we propose a comprehensive classification of malaria complications according to the different types of imbalances.
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Affiliation(s)
- Katrien Deroost
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium The Francis Crick Institute, Mill Hill Laboratory, London, NW71AA, UK
| | - Thao-Thy Pham
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Ghislain Opdenakker
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Philippe E Van den Steen
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
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Rebelo M, Tempera C, Bispo C, Andrade C, Gardner R, Shapiro HM, Hänscheid T. Light depolarization measurements in malaria: A new job for an old friend. Cytometry A 2015; 87:437-45. [PMID: 25808846 DOI: 10.1002/cyto.a.22659] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/28/2015] [Accepted: 02/27/2015] [Indexed: 12/15/2022]
Abstract
The use of flow cytometry in malaria research has increased over the last decade. Most approaches use nucleic acid stains to detect parasite DNA and RNA and require complex multi-color, multi-parameter analysis to reliably detect infected red blood cells (iRBCs). We recently described a novel and simpler approach to parasite detection based on flow cytometric measurement of scattered light depolarization caused by hemozoin (Hz), a pigment formed by parasite digestion of hemoglobin in iRBCs. Depolarization measurement by flow cytometry was described in 1987; however, patent issues restricted its use to a single manufacturer's hematology analyzers until 2009. Although we recently demonstrated that depolarization measurement of Hz, easily implemented on a bench top flow cytometer (Cyflow), provided useful information for malaria work, doubts regarding its application and utility remain in both the flow cytometry and malaria communities, at least in part because instrument manufacturers do not offer the option of measuring depolarized scatter. Under such circumstances, providing other researchers with guidance as to how to do this seemed to offer the most expeditious way to resolve the issue. We accordingly examined how several commercially available flow cytometers (CyFlow SL, MoFLo, Attune and Accuri C6) could be modified to detect depolarization due to the presence of free Hz on solution, or of Hz in leukocytes or erythrocytes from rodent or human blood. All were readily adapted, with substantially equivalent results obtained with lasers emitting over a wide wavelength range. Other instruments now available may also be modifiable for Hz measurement. Cytometric detection of Hz using depolarization is useful to study different aspects of malaria. Adding additional parameters, such as DNA content and base composition and RNA content, can demonstrably provide improved accuracy and sensitivity of parasite detection and characterization, allowing malaria researchers and eventually clinicians to benefit from cytometric technology.
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Affiliation(s)
- Maria Rebelo
- Molecular Microbiology and Infection Unit, Instituto De Medicina Molecular, Faculdade De Medicina, Lisbon, Portugal
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Chua CLL, Robinson LJ, Baiwog F, Stanisic DI, Hamilton JA, Brown GV, Rogerson SJ, Boeuf P. High numbers of circulating pigmented polymorphonuclear neutrophils as a prognostic marker for decreased birth weight during malaria in pregnancy. Int J Parasitol 2014; 45:107-11. [PMID: 25555554 DOI: 10.1016/j.ijpara.2014.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 12/01/2014] [Accepted: 12/02/2014] [Indexed: 11/25/2022]
Abstract
During gestational malaria, Plasmodium falciparum-infected erythrocytes can sequester within the placenta, contributing to poor pregnancy outcomes, especially low birth weight. In children and non-pregnant adults, pigmented leukocytes may serve as markers of sequestered parasite burden and predict clinical outcomes. Here, we investigated circulating pigmented leukocyte numbers as predictors of clinical outcomes in pregnant women presenting with malaria at enrolment. The number of circulating pigmented neutrophils at enrolment negatively correlated with birth weight (Rho=-25, P=.04), suggesting these cells may have a pathogenic role in, and could serve as prognostic markers for, malaria-associated low birth weight.
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Affiliation(s)
- Caroline Lin Lin Chua
- Department of Medicine, The Doherty Institute, The University of Melbourne, Australia
| | - Leanne J Robinson
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Papua New Guinea; Infection and Immunity Division, Walter and Eliza Hall Institute, Australia; Department of Medical Biology, The University of Melbourne, Australia
| | - Francesca Baiwog
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Papua New Guinea
| | - Danielle I Stanisic
- Vector Borne Disease Unit, Papua New Guinea Institute of Medical Research, Papua New Guinea; Infection and Immunity Division, Walter and Eliza Hall Institute, Australia; Department of Medical Biology, The University of Melbourne, Australia
| | - John A Hamilton
- Department of Medicine, The Doherty Institute, The University of Melbourne, Australia
| | - Graham V Brown
- Department of Medicine, The Doherty Institute, The University of Melbourne, Australia; The Nossal Institute for Global Health, The University of Melbourne, Australia
| | - Stephen J Rogerson
- Department of Medicine, The Doherty Institute, The University of Melbourne, Australia; Victorian Infectious Diseases Service, The Doherty Institute, Australia
| | - Philippe Boeuf
- Department of Medicine, The Doherty Institute, The University of Melbourne, Australia; Victorian Infectious Diseases Service, The Doherty Institute, Australia.
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Gazzinelli RT, Kalantari P, Fitzgerald KA, Golenbock DT. Innate sensing of malaria parasites. Nat Rev Immunol 2014; 14:744-57. [PMID: 25324127 DOI: 10.1038/nri3742] [Citation(s) in RCA: 207] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Innate immune receptors have a key role in immune surveillance by sensing microorganisms and initiating protective immune responses. However, the innate immune system is a classic 'double-edged sword' that can overreact to pathogens, which can have deleterious effects and lead to clinical manifestations. Recent studies have unveiled the complexity of innate immune receptors that function as sensors of Plasmodium spp. in the vertebrate host. This Review highlights the cellular and molecular mechanisms by which Plasmodium infection is sensed by different families of innate immune receptors. We also discuss how these events mediate both host resistance to infection and the pathogenesis of malaria.
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Affiliation(s)
- Ricardo T Gazzinelli
- 1] Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 01605-02324 Worcester, Massachusetts, USA. [2] Laboratório de Imunopatologia, Centro de Pesquisa René Rachou, Fundação Oswaldo Cruz, 30190-002 Belo Horizonte, Minas Gerais, Brazil. [3] Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Parisa Kalantari
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 01605-02324 Worcester, Massachusetts, USA
| | - Katherine A Fitzgerald
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 01605-02324 Worcester, Massachusetts, USA
| | - Douglas T Golenbock
- 1] Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, 01605-02324 Worcester, Massachusetts, USA. [2] Laboratório de Imunopatologia, Centro de Pesquisa René Rachou, Fundação Oswaldo Cruz, 30190-002 Belo Horizonte, Minas Gerais, Brazil
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Mohapatra S, Sharma D, Gupta K, Deb M, Gaind R. A simple and rapid staining method for detection of hemozoin pigment by methylene blue stain. Trop Parasitol 2014; 4:59-62. [PMID: 24754033 PMCID: PMC3992809 DOI: 10.4103/2229-5070.129190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 03/20/2014] [Indexed: 12/02/2022] Open
Affiliation(s)
- Sarita Mohapatra
- Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. E-mail:
| | - Daisy Sharma
- Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. E-mail:
| | - Kavita Gupta
- Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. E-mail:
| | - Manorama Deb
- Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. E-mail:
| | - Rajni Gaind
- Department of Microbiology, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. E-mail:
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Hemozoin inhibition and control of clinical malaria. Adv Pharmacol Sci 2014; 2014:984150. [PMID: 24669217 PMCID: PMC3941158 DOI: 10.1155/2014/984150] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 12/24/2013] [Indexed: 11/17/2022] Open
Abstract
Malaria has a negative impact on health and social and economic life of residents of endemic countries. The ultimate goals of designing new treatment for malaria are to prevent clinical infection, reduce morbidity, and decrease mortality. There are great advances in the understanding of the parasite-host interaction through studies by various scientists. In some of these studies, attempts were made to evaluate the roles of malaria pigment or toxins in the pathogenesis of malaria. Hemozoin is a key metabolite associated with severe malaria anemia (SMA), immunosuppression, and cytokine dysfunction. Targeting of this pigment may be necessary in the design of new therapeutic products against malaria. In this review, the roles of hemozoin in the morbidity and mortality of malaria are highlighted as an essential target in the quest for effective control of clinical malaria.
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Olivier M, Van Den Ham K, Shio MT, Kassa FA, Fougeray S. Malarial pigment hemozoin and the innate inflammatory response. Front Immunol 2014; 5:25. [PMID: 24550911 PMCID: PMC3913902 DOI: 10.3389/fimmu.2014.00025] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/16/2014] [Indexed: 12/28/2022] Open
Abstract
Malaria is a deadly infectious disease caused by the intraerythrocytic protozoan parasite Plasmodium. The four species of Plasmodium known to affect humans all produce an inorganic crystal called hemozoin (HZ) during the heme detoxification process. HZ is released from the food vacuole into circulation during erythrocyte lysis, while the released parasites further infect additional naive red blood cells. Once in circulation, HZ is rapidly taken up by circulating monocytes and tissue macrophages, inducing the production of pro-inflammatory mediators, such as interleukin-1β (IL-1β). Over the last few years, it has been reported that HZ, similar to uric acid crystals, asbestos, and silica, is able to trigger IL-1β production via the activation of the NOD-like receptor containing pyrin domain 3 (NLRP3) inflammasome complex. Additionally, recent findings have shown that host factors, such as fibrinogen, have the ability to adhere to free HZ and modify its capacity to activate host immune cells. Although much has been discovered regarding NLRP3 inflammasome induction, the mechanism through which this intracellular multimolecular complex is activated remains unclear. In the present review, the most recent discoveries regarding the capacity of HZ to trigger this innate immune complex as well as the impact of HZ on several other inflammatory signaling pathways will be discussed.
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Affiliation(s)
- Martin Olivier
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Kristin Van Den Ham
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Marina Tiemi Shio
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Fikregabrail Aberra Kassa
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Sophie Fougeray
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
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Boura M, Frita R, Góis A, Carvalho T, Hänscheid T. The hemozoin conundrum: is malaria pigment immune-activating, inhibiting, or simply a bystander? Trends Parasitol 2013; 29:469-76. [DOI: 10.1016/j.pt.2013.07.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 11/25/2022]
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Newton PN, Stepniewska K, Dondorp A, Silamut K, Chierakul W, Krishna S, Davis TME, Suputtamongkol Y, Angus B, Pukrittayakamee S, Ruangveerayuth R, Hanson J, Day NPJ, White NJ. Prognostic indicators in adults hospitalized with falciparum malaria in Western Thailand. Malar J 2013; 12:229. [PMID: 23829311 PMCID: PMC3711784 DOI: 10.1186/1475-2875-12-229] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Accepted: 06/23/2013] [Indexed: 11/17/2022] Open
Abstract
Background Severe malaria remains a major cause of death and morbidity amongst adults in the Asiatic tropics. Methods A retrospective analysis of the clinical and laboratory data of 988 adult patients, hospitalized with Plasmodium falciparum malaria and prospectively recruited to malaria studies in western Thailand between 1986 and 2002, was performed to assess the factors associated with a fatal outcome. Different severity scores and classifications for defining severe malaria were compared and, using multiple logistic regression, simple models for predicting mortality developed. Results The proportion of patients fulfilling the WHO 2000 definition of severe malaria was 78.1%, and their mortality was 10%. Mortality in patients given parenteral artesunate or artemether (16/317, 5%) was lower than in those given parenteral quinine (59/442, 13%) (P < 0.001). Models using parameter sets based on WHO 1990, 2000 and Adapted AQ criteria plus blood smear parasite-stage assessment gave the best mortality prediction. A malaria prognostic index (MPI), derived from the dataset using five clinical or laboratory variables gave similar prognostic accuracy. Conclusions The mortality of severe malaria in adults has fallen and the switch from quinine to artesunate has probably been an important contributor. Prognostic indices based on WHO 2000 definitions, and other simpler indices based on fewer variables, provide clinically useful predictions of outcome in Asian adults with severe malaria.
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Affiliation(s)
- Paul N Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR.
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Manning L, Davis TME. The mechanistic, diagnostic and prognostic utility of biomarkers in severe malaria. Biomark Med 2013; 7:363-80. [DOI: 10.2217/bmm.13.50] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Malaria remains an important global cause of severe illness and mortality. This literature review summarizes available data on how biomarkers might be applied to diagnose, prognosticate and provide mechanistic insights in patients with severe malaria. Of the large number of candidate biomarkers, only PfHRP2 has consistently demonstrated clinical utility and, when incorporated into rapid antigen detection tests, has shown diagnostic sensitivity above 95%, which is at least as good as light microscopy. As a quantitative test, PfHRP2 also shows some promise in differentiating severe malarial from non-malarial disease in areas where asymptomatic carriage of malaria parasites is common, and possibly as a tool to estimate sequestered parasite burden and subsequent mortality. Biomarkers such as pLDH and panmalarial antigen have lower sensitivity for non-falciparum malaria in rapid antigen detection tests. There is an urgent need to discover and validate better biomarkers for incorporation into rapid antigen detection tests in countries where Plasmodium vivax is a common cause of severe disease. A large number of host-derived acute-phase reactants, markers of endothelial dysfunction and immune mediators have been proposed as biomarkers. Although they have provided mechanistic insights into the immunopathology of severe malaria, their roles as clinical tools remain uncertain.
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Affiliation(s)
- Laurens Manning
- School of Medicine & Pharmacology, Fremantle Hospital & Health Service, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Timothy Mark Earls Davis
- School of Medicine & Pharmacology, Fremantle Hospital & Health Service, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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Deroost K, Tyberghein A, Lays N, Noppen S, Schwarzer E, Vanstreels E, Komuta M, Prato M, Lin JW, Pamplona A, Janse CJ, Arese P, Roskams T, Daelemans D, Opdenakker G, Van den Steen PE. Hemozoin Induces Lung Inflammation and Correlates with Malaria-Associated Acute Respiratory Distress Syndrome. Am J Respir Cell Mol Biol 2013; 48:589-600. [DOI: 10.1165/rcmb.2012-0450oc] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Polimeni M, Valente E, Aldieri E, Khadjavi A, Giribaldi G, Prato M. Role of 15-hydroxyeicosatetraenoic acid in hemozoin-induced lysozyme release from human adherent monocytes. Biofactors 2013; 39:304-14. [PMID: 23355332 DOI: 10.1002/biof.1071] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 11/02/2012] [Indexed: 11/09/2022]
Abstract
Natural hemozoin (nHZ), a lipid-bound ferriprotoporphyrin IX crystal produced by Plasmodium parasites after hemoglobin catabolism, seriously compromises the functions of human monocytes, and 15-hydroxyeicosatetraenoic acid (15-HETE) and 4-hydroxynonenal (4-HNE), two nHZ lipoperoxidation products, have been related to such a functional impairment. nHZ was recently shown to promote inflammation-mediated lysozyme release from human monocytes through p38 mitogen-activated protein kinase- (MAPK)- and nuclear factor (NF)-κB-dependent mechanisms. This study aimed at identifying the molecule of nHZ lipid moiety that was responsible for these effects. Results showed that 15-HETE mimicked nHZ effects on lysozyme release, whereas 4-HNE did not. 15-HETE-enhanced lysozyme release was abrogated by anti-TNF-α and anti-IL-1β-blocking antibodies and mimicked by recombinant cytokines; on the contrary, MIP-1α/CCL3 was not involved as a soluble mediator of 15-HETE effects. Moreover, 15-HETE early activated p38 MAPK and NF-κB pathways by inducing p38 MAPK phosphorylation; cytosolic I-κBα phosphorylation and degradation; NF-κB nuclear translocation and DNA-binding. Inhibition of both routes through chemical inhibitors (SB203580, quercetin, artemisinin, and parthenolide) prevented 15-HETE-dependent lysozyme release. Collectively, these data suggest that 15-HETE plays a major role in nHZ-enhanced monocyte degranulation.
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Affiliation(s)
- Manuela Polimeni
- Dipartimento di Genetica, Biologia e Biochimica, Facoltà di Medicina e Chirurgia, Università degli studi di Torino, Torino, Italy
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Plasmodium coatneyi in rhesus macaques replicates the multisystemic dysfunction of severe malaria in humans. Infect Immun 2013; 81:1889-904. [PMID: 23509137 DOI: 10.1128/iai.00027-13] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Severe malaria, a leading cause of mortality among children and nonimmune adults, is a multisystemic disorder characterized by complex clinical syndromes that are mechanistically poorly understood. The interplay of various parasite and host factors is critical in the pathophysiology of severe malaria. However, knowledge regarding the pathophysiological mechanisms and pathways leading to the multisystemic disorders of severe malaria in humans is limited. Here, we systematically investigate infections with Plasmodium coatneyi, a simian malaria parasite that closely mimics the biological characteristics of P. falciparum, and develop baseline data and protocols for studying erythrocyte turnover and severe malaria in greater depth. We show that rhesus macaques (Macaca mulatta) experimentally infected with P. coatneyi develop anemia, coagulopathy, and renal and metabolic dysfunction. The clinical course of acute infections required suppressive antimalaria chemotherapy, fluid support, and whole-blood transfusion, mimicking the standard of care for the management of severe malaria cases in humans. Subsequent infections in the same animals progressed with a mild illness in comparison, suggesting that immunity played a role in reducing the severity of the disease. Our results demonstrate that P. coatneyi infection in rhesus macaques can serve as a highly relevant model to investigate the physiological pathways and molecular mechanisms of malaria pathogenesis in naïve and immune individuals. Together with high-throughput postgenomic technologies, such investigations hold promise for the identification of new clinical interventions and adjunctive therapies.
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Carme B, Demar M. Hyperparasitaemia during bouts of malaria in French Guiana. Malar J 2013; 12:20. [PMID: 23324618 PMCID: PMC3554481 DOI: 10.1186/1475-2875-12-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 01/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND High circulating parasite load is one of the WHO criteria for severe falciparum malaria. During a period of 11 years (2000-2010), the frequency of hyperparasitaemia (HP) (≥4% infected erythrocytes) during bouts of malaria due to Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae in patients referred to Cayenne General Hospital (CGH) in French Guiana and the frequency of their admission to the Intensive Care Unit (ICU) were evaluated. METHODS A mean of 1,150 malaria cases were referred to the Parasitology Laboratory of CGH each year over the last decade. During this period, malaria diagnostic (microscopy) and parasitaemia evaluation have remained unchanged: determination of the parasitized erythrocytes percentage with asexual forms on thin blood smears for all cases of parasitaemia exceeding 0.1%. Patients admitted to the ICU can be counted by origin of the request for malaria testing. All the data collected retrospectively were anonymized in a standardized case report form and in database. RESULTS Between 2000 and 2010, 12,254 bouts of malaria were confirmed at the Parasitology Laboratory of CHG: P. vivax: 56.2%, P. falciparum: 39.5%, co-infection with both species: 3.4%, P. malariae: 0.9%. HP was observed in 262 cases, at a frequency of 4.9% for P. falciparum and only 0.041% for P. vivax, with no recorded cases for P. malariae. The need for intensive care was correlated with P. falciparum parasite load: 12.3% of cases for parasitaemia of 4-9%, 21.2% for parasitaemia 10-19%, 50% for parasitaemia 20-29% and 77.8% for parasitaemia ≥30% (n=9). The patient with the highest parasitaemia (75% infected erythrocytes with asexual form) presented a major concomitant lupus flare-up treated with corticoids. He survived without obvious sequelae. CONCLUSIONS In French Guiana during bouts of malaria, HP was observed at a frequency of ~ 5% for P. falciparum and two orders of magnitude less frequent for P. vivax. HP is a severity criterion for falciparum malaria in this endemic area. However, two of the patients with HP ≥30% were not admitted to the ICU and sequel-free cure in malaria patients with 75% parasitaemia is, therefore, possible.
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Affiliation(s)
- Bernard Carme
- Laboratory of Parasitology and Mycology, Research team EA 3593, Faculty of Medicine, University Antilles Guyane, and Centre Hospitalier de Cayenne, Rue des Flamboyants, Cayenne, BP 6006, F- 97354, French Guiana
- Centre d’Investigation Clinique - Epidémiologie Clinique Antilles Guyane (CIC-EC INSERM CIE 802), Cayenne General Hospital, Cayenne, French Guiana
| | - Magalie Demar
- Centre d’Investigation Clinique - Epidémiologie Clinique Antilles Guyane (CIC-EC INSERM CIE 802), Cayenne General Hospital, Cayenne, French Guiana
- Unit of Infectious and Tropical Diseases, Cayenne Hospital, Cayenne, French Guiana
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Willmann M, Ahmed A, Siner A, Wong IT, Woon LC, Singh B, Krishna S, Cox-Singh J. Laboratory markers of disease severity in Plasmodium knowlesi infection: a case control study. Malar J 2012; 11:363. [PMID: 23110615 PMCID: PMC3533741 DOI: 10.1186/1475-2875-11-363] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 10/18/2012] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium knowlesi malaria causes severe disease in up to 10% of cases in Malaysian Borneo and has a mortality rate of 1 - 2%. However, laboratory markers with the ability to identify patients at risk of developing complications have not yet been assessed as they have for other species of Plasmodium. Methods A case control study was undertaken in two hospitals in Sarikei and Sibu, Malaysian Borneo. One hundred and ten patients with uncomplicated (n = 93) and severe (n = 17) P. knowlesi malaria were studied. Standardized pigment-containing neutrophil (PCN) count, parasite density and platelet counts were determined and analysed by logistic regression and receiver operating characteristic (ROC) analysis. Results The PCN count was strongly associated with risk of disease severity. Patients with high parasite density (≥ 35,000/μl) or with thrombocytopaenia (≤ 45,000/μl) were also more likely to develop complications (odds ratio (OR) = 9.93 and OR = 5.27, respectively). The PCN count yielded the highest area under the ROC curve (AUC) estimate among all markers of severity (AUC = 0.8561, 95% confidence interval: 0.7328, 0.9794). However, the difference between all parameter AUC estimates was not statistically significant (Wald test, p = 0.73). Conclusion Counting PCN is labour-intensive and not superior in predicting severity over parasitaemia and platelet counts. Parasite and platelet counts are simpler tests with an acceptable degree of precision. Any adult patient diagnosed with P. knowlesi malaria and having a parasite count ≥35,000/μl or ≥1% or a platelet count ≤45,000/μl can be regarded at risk of developing complications and should be managed according to current WHO guidelines for the treatment of severe malaria.
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Affiliation(s)
- Matthias Willmann
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
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Dasari P, Bhakdi S. Pathogenesis of malaria revisited. Med Microbiol Immunol 2012; 201:599-604. [PMID: 22955244 DOI: 10.1007/s00430-012-0265-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 08/24/2012] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum malaria claims 1 million lives around the globe every year. Parasitemia can reach remarkably high levels. The developing parasite digests hemoglobin and converts the waste product to hemozoin alias malaria pigment. These processes occur in a vesicular compartment named the digestive vacuole (DV). Each parasitized cell releases one DV upon rupture. Myriads of DVs thus gain entry into the blood, but whether they trigger pathobiological events has never been investigated. We recently discovered that the DV membrane simultaneously activates the two major enzyme cascades in blood, complement and coagulation. Activation of both is known to occur in patients with severe malaria, so discovery of the common trigger has large consequences. The DV membrane but not the merozoite has the capacity to spontaneously activate the alternative complement and intrinsic clotting pathway. Ejection of merozoites and the DV into the bloodstream, therefore, results in selective opsonization and phagocytosis of the DV, leaving merozoites free to invade new cells. The DV membrane furthermore has the capacity to assemble prothrombinase, the key convertase of the intrinsic clotting pathway. The dual capacity of the DV to activate both complement and coagulation can be suppressed by low-molecular-weight dextran sulfate. This agent protects experimental animals from the detrimental consequences, resulting from intravenous application of purified DVs. Phagocytosis of DVs not only deploys PMN away from merozoites, but also drives the cells into a state of functional exhaustion. This may be one reason for the enhanced susceptibility of patients with severe malaria toward systemic bacterial infections. Together, these findings indicate that the DV may represent a hitherto unrecognized, important determinant of parasite pathogenicity.
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Affiliation(s)
- Prasad Dasari
- Institute of Medical Microbiology and Hygiene, University Medical Center, Johannes Gutenberg University Mainz, Hochhaus Augustusplatz, 55101 Mainz, Germany
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Role of polymorphisms of toll-like receptor (TLR) 4, TLR9, toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) and FCGR2A genes in malaria susceptibility and severity in Burundian children. Malar J 2012; 11:196. [PMID: 22691414 PMCID: PMC3411399 DOI: 10.1186/1475-2875-11-196] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 06/12/2012] [Indexed: 01/17/2023] Open
Abstract
Background Malaria caused by Plasmodium falciparum is one of the leading causes of human morbidity and mortality from infectious diseases, predominantly in tropical and sub-tropical countries. As genetic variations in the toll-like receptors (TLRs)-signalling pathway have been associated with either susceptibility or resistance to several infectious and inflammatory diseases, the supposition is that single nucleotide polymorphisms (SNPs) of TLR2, TLR4, TLR9, Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP) and FCGR2A could modulate malaria susceptibility and severity. Methods This study was planned to make a further contribution to solving the problem of the real role of the most common polymorphisms of TLR4, TLR9, TIRAP and FCGR2A genes in modulating the risk of malaria and disease severity in children from Burundi, Central Africa. All the paediatric patients aged six months to 10 years admitted to the hospital of Kiremba, Burundi, between February 2011 and September 2011, for fever and suspicion of acute malaria were screened for malaria parasitaemia by light microscopy of thick and thin blood smears. In children with malaria and in uninfected controls enrolled during the study period in the same hospital, blood samples were obtained on filter paper and TLR4 Asp299Gly rs4986790, TLR9 G1174A rs352139, T-1486 C rs187084 TLR9 T-1237 C rs5743836, TIRAP Ser180Leu rs8177374 and the FCGR2A His131Arg rs1801274 polymorphisms were studied using an ABI PRISM 7900 HT Fast Real-time instrument. Results A total of 602 patients and 337 controls were enrolled. Among the malaria cases, 553 (91.9 %) were considered as suffering from uncomplicated and 49 (8.1 %) from severe malaria. TLR9 T1237C rs5743836CC was associated with an increased risk of developing malaria (p = 0.03), although it was found with the same frequency in uncomplicated and severe malaria cases. No other differences were found in all alleles studied and in genotype frequencies between malaria cases and uninfected controls as well as between uncomplicated and severe malaria cases. Conclusions TLR9 T1237C seems to condition susceptibility to malaria in Burundian children but not its severity, whereas none of the assessed SNPs of TLR4, TIRAP and FCGR2A seem to influence susceptibility to malaria and disease severity in this population.
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