title: G6PD A-variant influences the antibody responses to Plasmodium falciparum MSP2.
abstract: High antibody levels directed to Plasmodium falciparum merozoite surface proteins (MSP), including MSP2, as well as genetically related red blood cell defects, have previously been found to be associated with protection against malaria. Here, our main objective was to study the changes in MSP2-specific total IgG, IgG1 and IgG3 responses during a malaria transmission season in order to assess the impact of sickle-cell, α(+)-thalassemia and G6PD variants on antibody kinetics. Repeated parasitological assessments of a cohort of children were conducted during an 8-month period. Antibody responses to recombinant MSP2/3D7 and MSP2/FC27 proteins were measured at the beginning and at the end of transmission season. We found that (i) the period of last Plasmodium falciparum infection during the transmission season was associated with IgG3 anti-MSP2 change. Compared to the IgG3 levels of children infected in January 2003 (end of transmission season), the IgG3 level of children decreased with the length of the period without infection, (ii) G6PD A- carriers had a lower increase of IgG3 levels to MSP2/FC27 and MSP2/3D7 during the transmission season than the noncarriers. This latter finding is suggestive of qualitative and/or quantitative reduction of exposure to malarial antigens related to this genetic variant, leading to weaker stimulation of specific antibody responses. We speculate that cell-mediated immune activity may explain the clinical protection afforded by this genetic trait.
authors.affiliation: Institut de Recherche pour le Développement (IRD), Unité Mixte de Recherche (UMR) 216 Mère et enfant face aux infections tropicales, 75006 Paris, France. David.Courtin@ird.fr
authors.forename: David
authors.initials: D
authors.lastname: Courtin
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Milet
authors.forename: Gwladys
authors.initials: G
authors.lastname: Bertin
authors.forename: Manijeh
authors.initials: M
authors.lastname: Vafa
authors.forename: Jean Birame
authors.initials: JB
authors.lastname: Sarr
authors.forename: Laurence
authors.initials: L
authors.lastname: Watier
authors.forename: Philippe
authors.initials: P
authors.lastname: Deloron
authors.forename: Marita
authors.initials: M
authors.lastname: Troye-Blomberg
authors.forename: André
authors.initials: A
authors.lastname: Garcia
authors.forename: Florence
authors.initials: F
authors.lastname: Migot-Nabias
mesh_terms: D000953:Antigens, Protozoan / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D056726:Genetic Association Studies; D014644:Genetic Variation; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics*; D006801:Humans; D056724:Immunity, Humoral / Q000235:genetics*; D007074:Immunoglobulin G / Q000097:blood; D016778:Malaria, Falciparum / Q000150:complications / Q000276:immunology*; D008297:Male; D015999:Multivariate Analysis; D010963:Plasmodium falciparum / Q000235:genetics*; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics*; D017085:alpha-Thalassemia / Q000150:complications* / Q000235:genetics
chemical_list: D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium; D005954:Glucosephosphate Dehydrogenase; C482910:glucose-6-phosphate dehydrogenase A-