title: Red blood cell complement receptor one level varies with Knops blood group, α(+)thalassaemia and age among Kenyan children.
abstract: Both the invasion of red blood cells (RBCs) by Plasmodium falciparum parasites and the sequestration of parasite-infected RBCs in the microvasculature are mediated in part by complement receptor one (CR1). RBC surface CR1 level can vary between individuals by more than 20-fold and may be associated with the risk of severe malaria. The factors that influence RBC CR1 level variation are poorly understood, particularly in African populations. We studied 3535 child residents of a malaria-endemic region of coastal Kenya and report, for the first time, that the CR1 Knops blood group alleles Sl2 and McC(b), and homozygous HbSS are positively associated with RBC CR1 level. Sickle cell trait and ABO blood group did not influence RBC CR1 level. We also confirm the previous observation that α(+)thalassaemia is associated with reduced RBC CR1 level, possibly due to small RBC volume, and that age-related changes in RBC CR1 expression occur throughout childhood. RBC CR1 level in malaria-endemic African populations is a complex phenotype influenced by multiple factors that should be taken into account in the design and interpretation of future studies on CR1 and malaria susceptibility.
authors: Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.|Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
authors: D H
authors: DH
authors: Opi
authors: Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
authors: S
authors: S
authors: Uyoga
authors: Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
authors: E N
authors: EN
authors: Orori
authors: Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.|Department of Medicine, Imperial College, St Mary's Hospital, London, UK.
authors: T N
authors: TN
authors: Williams
authors: Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
authors: J A
authors: JA
authors: Rowe
mesh_terms: D001789:Blood Group Antigens / Q000235:genetics; D002648:Child; D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D007630:Kenya; D016778:Malaria, Falciparum / Q000235:genetics; D010963:Plasmodium falciparum / Q000276:immunology; D011951:Receptors, Complement / Q000097:blood*; D013789:Thalassemia / Q000378:metabolism
chemical_list: D001789:Blood Group Antigens; D011951:Receptors, Complement