title: The sickle cell trait is associated with enhanced immunoglobulin G antibody responses to Plasmodium falciparum variant surface antigens.
abstract: The sickle cell trait (HbAS) protects against severe Plasmodium falciparum malaria in young African children. We investigated the extent of the association between HbAS and antibodies directed to parasite-derived variant surface antigens (VSAs) on the membrane of infected erythrocytes. We measured immunoglobulin G (IgG) responses with specificity for VSAs of 2 heterologous parasite isolates in 458 Gabonese children aged between 6 months and 11 years. Logistic regression analyses showed a highly significant independent association (P<.001) between carriage of HbAS and the presence of IgG anti-VSA responses; this association was related specifically to IgG1 and IgG4 subclasses in the anti-VSA profile. IgG2 and IgG3 anti-VSA responses were both independently associated with older age, consistent with the pattern observed in semi-immune adults. The results imply that enhanced levels of cross-reactive anti-VSA responses in children with HbAS may be intimately associated with the protection they have against malaria.
authors.affiliation: Department of Parasitology, Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Cabrera
authors.forename: Michel
authors.initials: M
authors.lastname: Cot
authors.forename: Florence
authors.initials: F
authors.lastname: Migot-Nabias
authors.forename: Peter G
authors.initials: PG
authors.lastname: Kremsner
authors.forename: Philippe
authors.initials: P
authors.lastname: Deloron
authors.forename: Adrian J F
authors.initials: AJ
authors.lastname: Luty
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D010963:Plasmodium falciparum / Q000276:immunology*; D012805:Sickle Cell Trait / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G