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Onyamboko MA, Olupot-Olupot P, Were W, Namayanja C, Onyas P, Titin H, Baseke J, Muhindo R, Kayembe DK, Ndjowo PO, Basara BB, Okalebo CB, Williams TN, Uyoga S, Taya C, Bamisaiye A, Fanello C, Maitland K, Day NPJ, Taylor WRJ, Mukaka M. Factors affecting haemoglobin dynamics in African children with acute uncomplicated Plasmodium falciparum malaria treated with single low-dose primaquine or placebo. BMC Med 2023; 21:397. [PMID: 37858129 PMCID: PMC10588240 DOI: 10.1186/s12916-023-03105-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/05/2023] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Single low-dose primaquine (SLDPQ) effectively blocks the transmission of Plasmodium falciparum malaria, but anxiety remains regarding its haemolytic potential in patients with glucose-6-phopshate dehydrogenase (G6PD) deficiency. We, therefore, examined the independent effects of several factors on haemoglobin (Hb) dynamics in falciparum-infected children with a particular interest in SLDPQ and G6PD status. METHODS This randomised, double-blind, placebo-controlled, safety trial was conducted in Congolese and Ugandan children aged 6 months-11 years with acute uncomplicated P. falciparum and day (D) 0 Hbs ≥ 6 g/dL who were treated with age-dosed SLDPQ/placebo and weight-dosed artemether lumefantrine (AL) or dihydroartemisinin piperaquine (DHAPP). Genotyping defined G6PD (G6PD c.202T allele), haemoglobin S (HbS), and α-thalassaemia status. Multivariable linear and logistic regression assessed factor independence for continuous Hb parameters and Hb recovery (D42 Hb > D0 Hb), respectively. RESULTS One thousand one hundred thirty-seven children, whose median age was 5 years, were randomised to receive: AL + SLDPQ (n = 286), AL + placebo (286), DHAPP + SLDPQ (283), and DHAPP + placebo (282). By G6PD status, 284 were G6PD deficient (239 hemizygous males, 45 homozygous females), 119 were heterozygous females, 418 and 299 were normal males and females, respectively, and 17 were of unknown status. The mean D0 Hb was 10.6 (SD 1.6) g/dL and was lower in younger children with longer illnesses, lower mid-upper arm circumferences, splenomegaly, and α-thalassaemia trait, who were either G6PDd or heterozygous females. The initial fractional fall in Hb was greater in younger children with higher D0 Hbs and D0 parasitaemias and longer illnesses but less in sickle cell trait. Older G6PDd children with lower starting Hbs and greater factional falls were more likely to achieve Hb recovery, whilst lower D42 Hb concentrations were associated with younger G6PD normal children with lower fractional falls, sickle cell disease, α-thalassaemia silent carrier and trait, and late treatment failures. Ten blood transfusions were given in the first week (5 SLDPQ, 5 placebo). CONCLUSIONS In these falciparum-infected African children, posttreatment Hb changes were unaffected by SLDPQ, and G6PDd patients had favourable posttreatment Hb changes and a higher probability of Hb recovery. These reassuring findings support SLDPQ deployment without G6PD screening in Africa. TRIAL REGISTRATION The trial is registered at ISRCTN 11594437.
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Affiliation(s)
- Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | - Peter Olupot-Olupot
- Busitema University, P.O. Box 1460, Mbale, Uganda
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Winifred Were
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Cate Namayanja
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Peter Onyas
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Harriet Titin
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Joy Baseke
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Rita Muhindo
- Mbale Clinical Research Institute (MCRI), P.O. Box 1966, Mbale, Uganda
| | - Daddy K Kayembe
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | - Pauline O Ndjowo
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | - Benjamin B Basara
- Kinshasa School of Public Health, University of Kinshasa, Avenue Tombalbaye 68-78, Kinshasa, Democratic Republic of Congo
| | | | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Institute of Global Health Innovation, Department of Surgery and Cancer, Imperial College London, London, SW7 2AS, UK
| | - Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Chiraporn Taya
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Adeola Bamisaiye
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Caterina Fanello
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Institute of Global Health Innovation, Department of Surgery and Cancer, Imperial College London, London, SW7 2AS, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Walter R J Taylor
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Andolina C, Ramjith J, Rek J, Lanke K, Okoth J, Grignard L, Arinaitwe E, Briggs J, Bailey J, Aydemir O, Kamya MR, Greenhouse B, Dorsey G, Staedke SG, Drakeley C, Jonker M, Bousema T. Plasmodium falciparum gametocyte carriage in longitudinally monitored incident infections is associated with duration of infection and human host factors. Sci Rep 2023; 13:7072. [PMID: 37127688 PMCID: PMC10150352 DOI: 10.1038/s41598-023-33657-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 04/17/2023] [Indexed: 05/03/2023] Open
Abstract
Malaria transmission depends on the presence of Plasmodium gametocytes that are the only parasite life stage that can infect mosquitoes. Gametocyte production varies between infections and over the course of infections. Infection duration is highly important for gametocyte production but poorly quantified. Between 2017 and 2019 an all-age cohort of individuals from Tororo, eastern Uganda was followed by continuous passive and routine assessments. We longitudinally monitored 104 incident infections from 98 individuals who were sampled once every 28 days and on any day of symptoms. Among infections that lasted ≥ 3 months, gametocyte appearance was near-universal with 96% of infections having detectable gametocytes prior to clearance. However, most infections were of much shorter duration; 55.7% of asymptomatic infections were detected only once. When considering all asymptomatic infections, regardless of their duration, only 36.3% had detectable gametocytes on at least one time-point prior to parasite clearance. Infections in individuals with sickle-cell trait (HbAS) were more likely to have gametocytes detected (Hazard Rate (HR) = 2.68, 95% CI 1.12, 6.38; p = 0.0231) and had gametocytes detected at higher densities (Density Ratio (DR) = 9.19, 95% CI 2.79, 30.23; p = 0.0002) compared to infections in wildtype (HbAA) individuals. Our findings suggest that a large proportion of incident infections is too short in duration and of too low density to contribute to onward transmission.
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Affiliation(s)
- Chiara Andolina
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jordache Ramjith
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Joseph Okoth
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Lynn Grignard
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Jessica Briggs
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
| | - Jeffrey Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Ozkan Aydemir
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Bryan Greenhouse
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
| | - Sarah G Staedke
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Marianne Jonker
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.
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Taylor WR, Olupot-Olupot P, Onyamboko MA, Peerawaranun P, Weere W, Namayanja C, Onyas P, Titin H, Baseke J, Muhindo R, Kayembe DK, Ndjowo PO, Basara BB, Bongo GS, Okalebo CB, Abongo G, Uyoga S, Williams TN, Taya C, Dhorda M, Tarning J, Dondorp AM, Waithira N, Fanello C, Maitland K, Mukaka M, Day NJP. Safety of age-dosed, single low-dose primaquine in children with glucose-6-phosphate dehydrogenase deficiency who are infected with Plasmodium falciparum in Uganda and the Democratic Republic of the Congo: a randomised, double-blind, placebo-controlled, non-inferiority trial. THE LANCET. INFECTIOUS DISEASES 2023; 23:471-483. [PMID: 36462528 DOI: 10.1016/s1473-3099(22)00658-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 12/02/2022]
Abstract
BACKGROUND WHO recommends gametocytocidal, single low-dose primaquine for blocking the transmission of Plasmodium falciparum; however, safety concerns have hampered the implementation of this strategy in sub-Saharan Africa. We aimed to investigate the safety of age-dosed, single low-dose primaquine in children from Uganda and the Democratic Republic of the Congo. METHODS We conducted this randomised, double-blind, placebo-controlled, non-inferiority trial at the Mbale Regional Referral Hospital, Mbale, Uganda, and the Kinshasa Mahidol Oxford Research Unit, Kinshasa, Democratic Republic of the Congo. Children aged between 6 months and 11 years with acute uncomplicated P falciparum infection and haemoglobin concentrations of at least 6 g/dL were enrolled. Patients were excluded if they had a comorbid illness requiring inpatient treatment, were taking haemolysing drugs for glucose-6-phosphate dehydrogenase (G6PD) deficiency, were allergic to the study drugs, or were enrolled in another clinical trial. G6PD status was defined by genotyping for the G6PD c.202T allele, the cause of the G6PD-deficient A- variant. Participants were randomly assigned (1:1) to receive single low-dose primaquine combined with either artemether-lumefantrine or dihydroartemisinin-piperaquine, dosed by bodyweight. Randomisation was stratified by age and G6PD status. The primary endpoint was the development of profound (haemoglobin <4 g/dL) or severe (haemoglobin <5 g/dL) anaemia with severity features, within 21 days of treatment. Analysis was by intention to treat. The sample size assumed an incidence of 1·5% in the placebo group and a 3% non-inferiority margin. The trial is registered at ISRCTN, 11594437, and is closed to new participants. FINDINGS Participants were recruited at the Mbale Regional Referral Hospital between Dec 18, 2017, and Oct 7, 2019, and at the Kinshasa Mahidol Oxford Research Unit between July 17, 2017, and Oct 5, 2019. 4620 patients were assessed for eligibility. 3483 participants were excluded, most owing to negative rapid diagnostic test or negative malaria slide (n=2982). 1137 children with a median age of 5 years were enrolled and randomly assigned (286 to the artemether-lumefantrine plus single low-dose primaquine group, 286 to the artemether-lumefantrine plus placebo group, 283 to the dihydroartemisinin-piperaquine plus single low-dose primaquine group, and 282 to the dihydroartemisinin-piperaquine plus placebo group). Genotyping of G6PD identified 239 G6PD-c.202T hemizygous males and 45 G6PD-c.202T homozygous females (defining the G6PD-deficient group), 119 heterozygous females, 418 G6PD-c.202C normal males and 299 G6PD-c.202C normal females (defining the non-G6PD-deficient group), and 17 children of unknown status. 67 patients were lost to follow-up and four patients withdrew during the study-these numbers were similar between groups. No participants developed profound anaemia and three developed severe anaemia: from the G6PD-deficient group, none (0%) of 133 patients who received placebo and one (0·66%) of 151 patients who received primaquine (difference -0·66%, 95% CI -1·96 to 0·63; p=0·35); and from the non-G6PD-deficient group, one (0·23%) of 430 patients who received placebo and one (0·25%) of 407 patients who received primaquine (-0·014%, -0·68 to 0·65; p=0·97). INTERPRETATION Gametocytocidal, age-dosed, single low-dose primaquine was well tolerated in children from Uganda and the Democratic Republic of the Congo who were infected with P falciparum, and the safety profile of this treatment was similar to that of the placebo. These data support the wider implementation of single low-dose primaquine in Africa. FUNDING UK Government Department for International Development, UK Medical Research Council, UK National Institute for Health Research, and the Wellcome Trust Joint Global Health Trials Scheme.
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Affiliation(s)
- Walter R Taylor
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Peter Olupot-Olupot
- Mbale Clinical Research Institute, Mbale, Uganda; Department of Public Health, Busitema University, Mbale, Uganda
| | - Marie A Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Pimnara Peerawaranun
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
| | | | | | - Peter Onyas
- Mbale Clinical Research Institute, Mbale, Uganda
| | | | - Joy Baseke
- Department of Public Health, Busitema University, Mbale, Uganda
| | - Rita Muhindo
- Mbale Clinical Research Institute, Mbale, Uganda
| | - Daddy K Kayembe
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Pauline O Ndjowo
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Benjamin B Basara
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Georgette S Bongo
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | | | - Grace Abongo
- Mbale Clinical Research Institute, Mbale, Uganda
| | - Sophie Uyoga
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Thomas N Williams
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Institute of Global Health Innovation, Imperial College London, London, UK
| | - Chiraporn Taya
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand
| | - Mehul Dhorda
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Joel Tarning
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Naomi Waithira
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Caterina Fanello
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Institute of Global Health Innovation, Imperial College London, London, UK
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J P Day
- Mahidol Oxford Tropical Medicine Clinical Research Unit, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Association between polymorphisms of IL4, IL13, IL10, STAT6 and IFNG genes, cytokines and immunoglobulin E levels with high burden of Schistosoma mansoni in children from schistosomiasis endemic areas of Cameroon. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 111:105416. [PMID: 36889485 PMCID: PMC10167540 DOI: 10.1016/j.meegid.2023.105416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/02/2023] [Accepted: 02/08/2023] [Indexed: 03/08/2023]
Abstract
Eliminating schistosomiasis as a public health problem by 2030 requires a better understanding of the disease transmission, especially the asymmetric distribution of worm burden in individuals living and sharing the same environment. It is in this light that this study was designed to identify human genetic determinants associated with high burden of S. mansoni and also with the plasma concentrations of IgE and four cytokines in children from two schistosomiasis endemic areas of Cameroon. In school-aged children of schistosomiasis endemic areas of Makenene and Nom-Kandi of Cameroon, S. mansoni infections and their infection intensities were evaluated in urine and stool samples using respectively the Point-of-care Circulating Cathodic Antigen test (POC-CCA) and the Kato Katz (KK) test. Thereafter, blood samples were collected in children harbouring high burden of schistosome infections as well as in their parents and siblings. DNA extracts and plasma were obtained from blood. Polymorphisms at 14 loci of five genes were assessed using PCR-restriction fragment length polymorphism and amplification-refractory mutation system. The ELISA test enabled to determine the plasma concentrations of IgE, IL-13, IL-10, IL-4 and IFN-γ. The prevalence of S. mansoni infections was significantly higher (P < 0.0001 for POC-CCA; P = 0.001 for KK) in Makenene (48.6% for POC-CCA and 7.9% for KK) compared to Nom-Kandi (31% for POC-CCA and 4.3% for KK). The infection intensities were also higher (P < 0.0001 for POC-CCA; P = 0.001 for KK) in children from Makenene than those from Nom-Kandi. The allele C of SNP rs3024974 of STAT6 was associated with an increased risk of bearing high burden of S. mansoni both in the additive (p = 0.009) and recessive model (p = 0.01) while the allele C of SNP rs1800871 of IL10 was protective (p = 0.0009) against high burden of S. mansoni. The alleles A of SNP rs2069739 of IL13 and G of SNP rs2243283 of IL4 were associated with an increased risk of having low plasma concentrations of IL-13 (P = 0.04) and IL-10 (P = 0.04), respectively. This study showed that host genetic polymorphisms may influence the outcome (high or low worm burden) of S. mansoni infections and also the plasma concentrations of some cytokines.
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Thiam F, Diop G, Coulonges C, Derbois C, Mbengue B, Thiam A, Nguer CM, Zagury JF, Deleuze JF, Dieye A. G6PD and HBB polymorphisms in the Senegalese population: prevalence, correlation with clinical malaria. PeerJ 2022; 10:e13487. [PMID: 35811813 PMCID: PMC9266585 DOI: 10.7717/peerj.13487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 05/03/2022] [Indexed: 01/24/2023] Open
Abstract
Background Host genetic factors contribute to the variability of malaria phenotypes and can allow a better understanding of mechanisms involved in susceptibility and/or resistance to Plasmodium falciparum infection outcomes. Several genetic polymorphisms were reported to be prevalent among populations living in tropical malaria-endemic regions and induce protection against malaria. The present study aims to investigate the prevalence of HBB (chr11) and G6PD (chrX) deficiencies polymorphisms among Senegalese populations and their associations with the risk for severe Plasmodium falciparum malaria occurrence. Methods We performed a retrospective study with 437 samples, 323 patients recruited in hospitals located in three different endemic areas where malaria episodes were confirmed and 114 free malaria controls. The patients enrolled were classified into two groups: severe malaria (SM) (153 patients) and uncomplicated malaria (UM) (170 patients). PCR and DNA sequencing assessed host genetic polymorphisms in HBB and G6PD. Using a multivariate regression and additive model, estimates of the impact of human HBB and G6PD polymorphisms on malaria incidence were performed. Results Six frequent SNPs with minor allele frequencies (MAF) > 3% were detected in the HBB gene (rs7946748, rs7480526, rs10768683, rs35209591, HbS (rs334) and rs713040) and two in the G6PD gene (rs762515 and rs1050828 (G6PD-202 G > A). Analysis of selected HbS polymorphism showed significant association with protective effect against severe malaria with a significant p-value = 0.033 (OR 0.38, 95% CI [0.16-0.91]) for SM vs. UM comparison. Surprisingly, our study did not identify the protective effect of variant HbC polymorphism against severe malaria. Finally, we found some of the polymorphisms, like HbS (rs334), are associated with age and biological parameters like eosinophils, basophils, lymphocytes etc. Conclusion Our data report HBB and G6PD polymorphisms in the Senegalese population and their correlation with severe/mild malaria and outcome. The G6PD and HBB deficiencies are widespread in West Africa endemic malaria regions such as The Gambia, Mali, and Burkina Faso. The study shows the critical role of genetic factors in malaria outcomes. Indeed, genetic markers could be good tools for malaria endemicity prognosis.
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Affiliation(s)
- Fatou Thiam
- Groupe de Recherche Biotechnologie Appliquée et Bioprocédés Environnementaux (GRBA-BE), Laboratoire Eau, Energie, Environnement et Procédés Industriels (LE3PI), Département de Génie Chimique et Biologie Appliquée, Ecole Supérieure Polytechnique, Université Cheikh Anta DIOP de Dakar, Dakar Fann, Dakar, Sénégal
| | - Gora Diop
- Unité Postulante de Biologie Génétique, Génomique et Bio-informatique (G2B), Département de Biologie Animale, Faculté des Sciences et Techniques, Université Cheikh Anta DIOP, Avenue Cheikh Anta DIOP, Dakar Fann, Dakar, Sénégal,Pole d’Immunophysiopathologie & Maladies Infectieuses (IMI), Institut Pasteur de Dakar, Dakar, Sénégal
| | - Cedric Coulonges
- Equipe GBA «Génomique, Bioinformatique & Applications », Conservatoire National des Arts et Métiers, Paris, France
| | - Céline Derbois
- CEA, Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, Evry, France
| | - Babacar Mbengue
- Service d’Immunologie, Faculté de Médecine, de Pharmacie et d’Odontostomatologie, Université Cheikh Anta DIOP, Dakar, Sénégal
| | - Alassane Thiam
- Pole d’Immunophysiopathologie & Maladies Infectieuses (IMI), Institut Pasteur de Dakar, Dakar, Sénégal
| | - Cheikh Momar Nguer
- Groupe de Recherche Biotechnologie Appliquée et Bioprocédés Environnementaux (GRBA-BE), Laboratoire Eau, Energie, Environnement et Procédés Industriels (LE3PI), Département de Génie Chimique et Biologie Appliquée, Ecole Supérieure Polytechnique, Université Cheikh Anta DIOP de Dakar, Dakar Fann, Dakar, Sénégal
| | - Jean Francois Zagury
- Equipe GBA «Génomique, Bioinformatique & Applications », Conservatoire National des Arts et Métiers, Paris, France
| | - Jean-Francois Deleuze
- CEA, Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, Evry, France
| | - Alioune Dieye
- Service d’Immunologie, Faculté de Médecine, de Pharmacie et d’Odontostomatologie, Université Cheikh Anta DIOP, Dakar, Sénégal
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Zehner N, Adrama H, Kakuru A, Andra T, Kajubi R, Conrad M, Nankya F, Clark TD, Kamya M, Rodriguez-Barraquer I, Dorsey G, Jagannathan P. Age-related Changes in Malaria Clinical Phenotypes During Infancy are Modified by Sickle Cell Trait. Clin Infect Dis 2021; 73:1887-1895. [PMID: 33738485 PMCID: PMC8599196 DOI: 10.1093/cid/ciab245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Indexed: 12/02/2022] Open
Abstract
Background Infants are protected against Plasmodium falciparum malaria. Mechanisms that drive this protection remain unclear due to a poor understanding of malaria clinical phenotypes during infancy. Methods We enrolled a birth cohort of 678 infants in Busia, Uganda, an area of high malaria transmission. We followed infants through 12 months of age and quantified protection against parasitemia and clinical disease. Results Symptomatic malaria incidence increased from 1.2 to 2.6 episodes per person-year between 0 and <6 months and between 6 and 12 months of age, while the monthly probability of asymptomatic parasitemia given infection decreased from 32% to 21%. Sickle cell trait (HbAS) was protective against symptomatic malaria (incidence rate ratio = 0.57 comparing HbAS vs hemoglobin AA (HbAA); 95% confidence interval, 0.44–0.74; P < .001), but age modified this relationship (Pint = <0.001), with nonlinear protection that waned between 0 and 9 months of age before increasing. Increasing age was associated with higher parasite densities at the time of infection and, in infants with HbAS, a reduced ability to tolerate high parasite densities without fever. Conclusions Age-dependent changes in HbAS protective efficacy in infancy were accompanied by differential loss of antiparasite and antidisease protection among HbAS and HbAA infants. This provides a framework for investigating the mechanisms that underlie infant protection against malaria. Clinical Trials Registration NCT02793622.
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Affiliation(s)
| | - Harriet Adrama
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Abel Kakuru
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Teddy Andra
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Richard Kajubi
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Melissa Conrad
- Department of Medicine, University of California, San Francisco, USA
| | | | - Tamara D Clark
- Department of Medicine, University of California, San Francisco, USA
| | - Moses Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda.,Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | | | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, USA
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7
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Tukwasibwe S, Traherne JA, Chazara O, Jayaraman J, Trowsdale J, Moffett A, Jiang W, Nankabirwa JI, Rek J, Arinaitwe E, Nsobya SL, Atuheirwe M, Frank M, Godwin A, Jagannathan P, Cose S, Kamya MR, Dorsey G, Rosenthal PJ, Colucci F, Nakimuli A. Diversity of KIR genes and their HLA-C ligands in Ugandan populations with historically varied malaria transmission intensity. Malar J 2021; 20:111. [PMID: 33632228 PMCID: PMC7908804 DOI: 10.1186/s12936-021-03652-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Malaria is one of the most serious infectious diseases in the world. The malaria burden is greatly affected by human immunity, and immune responses vary between populations. Genetic diversity in KIR and HLA-C genes, which are important in immunity to infectious diseases, is likely to play a role in this heterogeneity. Several studies have shown that KIR and HLA-C genes influence the immune response to viral infections, but few studies have examined the role of KIR and HLA-C in malaria infection, and these have used low-resolution genotyping. The aim of this study was to determine whether genetic variation in KIR and their HLA-C ligands differ in Ugandan populations with historically varied malaria transmission intensity using more comprehensive genotyping approaches. METHODS High throughput multiplex quantitative real-time PCR method was used to genotype KIR genetic variants and copy number variation and a high-throughput real-time PCR method was developed to genotype HLA-C1 and C2 allotypes for 1344 participants, aged 6 months to 10 years, enrolled from Ugandan populations with historically high (Tororo District), medium (Jinja District) and low (Kanungu District) malaria transmission intensity. RESULTS The prevalence of KIR3DS1, KIR2DL5, KIR2DS5, and KIR2DS1 genes was significantly lower in populations from Kanungu compared to Tororo (7.6 vs 13.2%: p = 0.006, 57.2 vs 66.4%: p = 0.005, 33.2 vs 46.6%: p < 0.001, and 19.7 vs 26.7%: p = 0.014, respectively) or Jinja (7.6 vs 18.1%: p < 0.001, 57.2 vs 63.8%: p = 0.048, 33.2 vs 43.5%: p = 0.002, and 19.7 vs 30.4%: p < 0.001, respectively). The prevalence of homozygous HLA-C2 was significantly higher in populations from Kanungu (31.6%) compared to Jinja (21.4%), p = 0.043, with no significant difference between Kanungu and Tororo (26.7%), p = 0.296. CONCLUSIONS The KIR3DS1, KIR2DL5, KIR2DS5 and KIR2DS1 genes may partly explain differences in transmission intensity of malaria since these genes have been positively selected for in places with historically high malaria transmission intensity. The high-throughput, multiplex, real-time HLA-C genotyping PCR method developed will be useful in disease-association studies involving large cohorts.
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Affiliation(s)
- Stephen Tukwasibwe
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | | | - Olympe Chazara
- Department of Pathology, University of Cambridge, Cambridge, UK
- University of Cambridge Centre for Trophoblast Research, Cambridge, UK
| | - Jyothi Jayaraman
- Department of Pathology, University of Cambridge, Cambridge, UK
- University of Cambridge Centre for Trophoblast Research, Cambridge, UK
| | - John Trowsdale
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Ashley Moffett
- Department of Pathology, University of Cambridge, Cambridge, UK
- University of Cambridge Centre for Trophoblast Research, Cambridge, UK
| | - Wei Jiang
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Joaniter I. Nankabirwa
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - John Rek
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Emmanuel Arinaitwe
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Samuel L. Nsobya
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Maxine Atuheirwe
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
| | - Mubiru Frank
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
| | - Anguzu Godwin
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
| | | | - Stephen Cose
- MRC/UVRI and LSHTM Uganda Research Unit, Kampala, Uganda
| | - Moses R. Kamya
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | | | | | - Francesco Colucci
- University of Cambridge Centre for Trophoblast Research, Cambridge, UK
- Department of Obstetrics & Gynaecology, University of Cambridge, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, CB2 0SW UK
| | - Annettee Nakimuli
- Department of Obstetrics and Gynaecology, School of Medicine, Makerere University College of Health Sciences, P.O BOX 7072, Kampala, Uganda
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8
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Kakande E, Greenhouse B, Bajunirwe F, Drakeley C, Nankabirwa JI, Walakira A, Nsobya SL, Katureebe A, Rek J, Arinaitwe E, Rosenthal PJ, Kamya MR, Dorsey G, Rodriguez-Barraquer I. Associations between red blood cell variants and malaria among children and adults from three areas of Uganda: a prospective cohort study. Malar J 2020; 19:21. [PMID: 31941490 PMCID: PMC6964006 DOI: 10.1186/s12936-020-3105-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/07/2020] [Indexed: 02/06/2023] Open
Abstract
Background Multiple red blood cell (RBC) variants appear to offer protection against the most severe forms of Plasmodium falciparum malaria. Associations between these variants and uncomplicated malaria are less clear. Methods Data from a longitudinal cohort study conducted in 3 sub-counties in Uganda was used to quantify associations between three red blood cell variants Hb [AA, AS, S (rs334)], alpha thalassaemia 3.7 kb deletion, and glucose-6-phosphate dehydrogenase deficiency A—(G6PD 202A genotype) and malaria incidence, parasite prevalence, parasite density (a measure of anti-parasite immunity) and body temperature adjusted for parasite density (a measure of anti-disease immunity). All analyses were adjusted for age, average household entomological inoculation rate, and study site. Results for all variants were compared to those for wild type genotypes. Results In children, HbAS was associated, compared to wild type, with a lower incidence of malaria (IRR = 0.78, 95% CI 0.66–0.92, p = 0.003), lower parasite density upon infection (PR = 0.66, 95% CI 0.51–0.85, p = 0.001), and lower body temperature for any given parasite density (− 0.13 ℃, 95% CI − 0.21, − 0.05, p = 0.002). In children, HbSS was associated with a lower incidence of malaria (IRR = 0.17, 95% CI 0.04–0.71, p = 0.02) and lower parasite density upon infection (PR = 0.31, 95% CI 0.18–0.54, p < 0.001). α−/αα thalassaemia, was associated with higher parasite prevalence in both children and adults (RR = 1.23, 95% CI 1.06–1.43, p = 0.008 and RR = 1.52, 95% CI 1.04–2.23, p = 0.03, respectively). G6PD deficiency was associated with lower body temperature for any given parasite density only among male hemizygote children (− 0.19 ℃, 95% CI − 0.31, − 0.06, p = 0.003). Conclusion RBC variants were associated with non-severe malaria outcomes. Elucidation of the mechanisms by which they confer protection will improve understanding of genetic protection against malaria.
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Affiliation(s)
- Elijah Kakande
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda.
| | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, 94110, USA
| | - Francis Bajunirwe
- Department of Community Health, Mbarara University of Science and Technology, Mbarara, Uganda
| | - Chris Drakeley
- Immunity and Infection, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | | | - Andrew Walakira
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Samuel L Nsobya
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Agaba Katureebe
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - John Rek
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Emmanuel Arinaitwe
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Philip J Rosenthal
- Department of Medicine, University of California, San Francisco, CA, 94110, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, 2C Nakasero Hill Road, Kampala, Uganda
| | - Grant Dorsey
- Department of Medicine, University of California, San Francisco, CA, 94110, USA
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9
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Kiyaga C, Hernandez AG, Ssewanyana I, Schaefer BA, McElhinney KE, Ndeezi G, Howard TA, Ndugwa CM, Ware RE, Aceng JR. Sickle cell screening in Uganda: High burden, human immunodeficiency virus comorbidity, and genetic modifiers. Pediatr Blood Cancer 2019; 66:e27807. [PMID: 31094093 DOI: 10.1002/pbc.27807] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/03/2019] [Accepted: 04/23/2019] [Indexed: 12/26/2022]
Abstract
BACKGROUND The Uganda Sickle Surveillance Study provided evidence for a large sickle burden among HIV-exposed infants in Uganda. To date, however, no large scale screening program has been developed for Central or East Africa. METHODS A 3-year targeted sickle cell screening project in Uganda was designed by the Ministry of Health to (1) determine sickle cell trait and disease prevalence within high-burden districts, (2) document the prevalence among HIV-exposed and nonexposed children, (3) confirm previously suggested HIV comorbidity, and (4) estimate the co-inheritance of known genetic modifiers of sickle cell disease. RESULTS A total of 163 334 dried blood spot samples collected between April 2015 and March 2018 were analyzed, including 112 352 samples within the HIV Early Infant Diagnosis program. A high burden with >1% sickle cell disease was found within targeted East Central and Mid-Northern districts, in both HIV-exposed and nonexposed children. Based on crude birth-rate data, 236 905 sickle cell trait births and 16 695 sickle cell disease births will occur annually in Uganda. Compared to sickle cell disease without HIV, the odds ratio of having sickle cell disease plus HIV was 0.50 (95% confidence interval = 0.40-0.64, P < .0001). Alpha-thalassemia trait and G6PD deficiency were common with sickle cell disease, but with different geospatial distribution. CONCLUSIONS High sickle cell burden and potential HIV comorbidity are confirmed in Uganda. Genetic modifiers are common and likely influence laboratory and clinical phenotypes. These prospective data document that targeted sickle cell screening is feasible and effective in Uganda, and support development of district-level comprehensive care programs.
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Affiliation(s)
- Charles Kiyaga
- Central Public Health Laboratories, Ministry of Health, Kampala, Uganda
| | - Arielle G Hernandez
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Global Health Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Isaac Ssewanyana
- Central Public Health Laboratories, Ministry of Health, Kampala, Uganda
| | - Beverly A Schaefer
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Kathryn E McElhinney
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Grace Ndeezi
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Thad A Howard
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Christopher M Ndugwa
- Department of Paediatrics and Child Health, Makerere University College of Health Sciences, Kampala, Uganda
| | - Russell E Ware
- Division of Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Global Health Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
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10
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Associations between erythrocyte polymorphisms and risks of uncomplicated and severe malaria in Ugandan children: A case control study. PLoS One 2018; 13:e0203229. [PMID: 30222732 PMCID: PMC6141089 DOI: 10.1371/journal.pone.0203229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/16/2018] [Indexed: 12/20/2022] Open
Abstract
Background Evidence for association between sickle cell and alpha thalassemia trait and severe malaria is compelling. However, for these polymorphisms associations with uncomplicated malaria, and for G6PD deficiency associations with uncomplicated and severe malaria, findings have been inconsistent. We studied samples from a three-arm case-control study with the objective of determining associations between common host erythrocyte polymorphisms and both uncomplicated and severe malaria, including different severe malaria phenotypes. Method We assessed hemoglobin abnormalities, α-thalassemia, and G6PD deficiency by molecular methods in 325 children with severe malaria age-matched to 325 children with uncomplicated malaria and 325 healthy community controls. Conditional logistic regression was used to measure associations between specified genotypes and malaria outcomes. Results No tested polymorphisms offered significant protection against uncomplicated malaria. α-thalassemia homozygotes (_α/_α) had increased risk of uncomplicated malaria (OR 2.40; 95%CI 1.15, 5.03, p = 0.020). HbAS and α-thalassemia heterozygous (_α/αα) genotypes protected against severe malaria compared to uncomplicated malaria (HbAS OR 0.46; 0.23, 0.95, p = 0.036; _α/αα OR 0.51; 0.24, 0.77; p = 0.001) or community (HbAS OR 0.23; 0.11, 0.50; p<0.001; _α/αα; OR 0.49; 0.32, 0.76; p = 0.002) controls. The α-thalassemia homozygous (_α/_α) genotype protected against severe malaria when compared to uncomplicated malaria controls (OR 0.34; 95%CI 0.156, 0.73, p = 0.005), but not community controls (OR 1.03; 0.46, 2.27, p = 0.935). Stratifying by the severe malaria phenotype, compared to community controls, the protective effect of HbAS was limited to children with severe anemia (OR 0.17; 95%CI 0.04, 0.65; p = 0.009) and that of _α/αα to those with altered consciousness (OR 0.24; 0.09, 0.59; p = 0.002). A negative epistatic effect was seen between HbAS and _α/αα; protection compared to uncomplicated malaria controls was not seen in individuals with both polymorphisms (OR 0.45; 0.11, 1.84; p = 0.269). G6PD deficiency was not protective against severe malaria. Conclusion Associations were complex, with HbAS principally protective against severe anemia, _α/αα against altered consciousness, and negative epistasis between the two polymorphisms.
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11
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Adedokun SA, Seamans BN, Cox NT, Liou G, Akindele AA, Li Y, Ojurongbe O, Thomas BN. Interleukin-4 and STAT6 promoter polymorphisms but not interleukin-10 or 13 are essential for schistosomiasis and associated disease burden among Nigerian children. INFECTION GENETICS AND EVOLUTION 2018; 65:28-34. [PMID: 30010060 DOI: 10.1016/j.meegid.2018.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/09/2018] [Accepted: 07/11/2018] [Indexed: 01/21/2023]
Abstract
Schistosomiasis is endemic in many parts of rural Africa, with previous reports showing interleukin-13 polymorphisms as drivers of infectivity and disease severity in West Africa while IL-13/IL-4 polymorphisms contributes to patterns of reinfection in East Africa. We have shown that there is a genetic delineation in susceptibility to and severity of infectious diseases in Africa, in addition to sub-continental differences in disease pattern. Therefore, which immunoregulatory biomarkers are essential in driving S. haematobium infection or regulate disease burden among Nigerian school children? One hundred and thirty one age and sex-matched schistosome-infected children and 275 uninfected controls, of same ethnicity, recruited from southwestern Nigeria, were screened for variability of cytokine genes, IL-10 (rs1800872), IL-13 (rs7719175), IL-4 (rs2243250) and STAT6 (rs3024974), utilizing a polymerase chain reaction-restriction fragment length polymorphism assay. We found no difference in genotypic or allelic frequencies of IL-10 and IL-13 promoter polymorphisms alone or in association with disease. Contrariwise, we report significant differences in the frequencies of IL-4 and STAT6 variants between groups. For IL-4, the rs2243250 T/T variant was significantly different for genotypes (71.6% versus 51.2%; p < .0004) and alleles (82.6% versus 71.1%; p < .001) between disease and control groups respectively. For STAT6 (rs3024974), the frequencies of genotypes C/C and C/T are 75.4% and 24.6%, both showing an association with disease; none of the infected subjects had the T/T variant. Despite minor differences in disease covariates, we found no association between IL-4 and STAT6 variants with age, gender or anemia. However, mean egg count (indicative of disease burden), was regulated based on IL-4 variants, with highest burden in infected subjects with rs2243250 T/T variant (mean egg count: 207.5 eggs/10 ml of urine) versus rs2243250 C/T heterozygotes (mean egg count: 84.3 eggs/10 ml of urine) versus rs2243250 C/C (mean egg count: 127.9 eggs/10 ml of urine). Comparing rs2243250 C/T versus rs2243250 T/T (p < .008) or rs2243250 C/C + C/T versus rs2243250 T/T (p < .016) reveals an association with disease burden. We conclude that the IL-4 promoter gene is a susceptibility factor for schistosomiasis, and essential to regulate disease burden, with worse disease among carriers of the rs2243250 T/T variant. The absence of the STAT6, rs3024974T/T variant among infected subjects reveal the necessity of the STAT6 promoter gene in driving susceptibility to schistosomiasis in Nigeria.
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Affiliation(s)
- Samuel A Adedokun
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria.
| | - Brooke N Seamans
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States.
| | - Natalya T Cox
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States.
| | - Gialeigh Liou
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States.
| | - Akeem A Akindele
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria; Department of Community Medicine, Ladoke Akintola University of Technology, Osogbo, Nigeria.
| | - Yi Li
- School of Statistics, Shanxi University of Finance & Economics, Shanxi, China.
| | - Olusola Ojurongbe
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria.
| | - Bolaji N Thomas
- Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria; Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States.
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