Non < i > -O < /i > ABO blood group genotypes differ in their associations with < i > Plasmodium falciparum < /i > rosetting and severe malaria

by D. Herbert Opi, Carolyne M. Ndila, Sophie Uyoga, Alex W. Macharia, Clare Fennell, Lucy B. Ochola, Gideon Nyutu, Bethseba R. Siddondo, John Ojal, Mohammed Shebe, Kennedy O. Awuondo, Neema Mturi, Norbert Peshu, Benjamin Tsofa, Gavin Band, Kathryn Maitland, Dominic P. Kwiatkowski, Kirk A. Rockett, Thomas N. Williams, J. Alexandra Rowe Blood group O is associated with protection against severe malaria and reduced size and stability ofP.falciparum-host red blood cell (RBC) rosettes compared to non-O blood groups. Whether the non-O blood groups encoded by the specificABO genotypesAO,BO,AA,BB andAB differ in their associations with severe malaria and rosetting is unknown. The A and B antigens are host RBC receptors for rosetting, hence we hypothesized that the higher levels of A and/or B antigen on RBCs fromAA,BB andAB genotypes compared toAO/BO genotypes could lead to larger rosettes, increased microvascular obstruction and higher risk of malaria pathology. We used a case-control study of Kenyan children andin vitro adhesion assays to test the hypothesis that “double dose” non-O genotypes (AA,BB,AB) are associated with increased risk of severe malaria and larger rosettes than “single dose” heterozygotes (AO,BO). In the case-control study, compared toOO, the double dose genotypes consistently had higher odds ratios (OR) for severe malaria than single dose genotypes, withAB (OR 1.93) andAO (OR 1.27) showing most marked difference (p = 0.02, Wald test).In vitro experiments...
Source: PLoS Genetics - Category: Genetics & Stem Cells Authors: Source Type: research