Plasmodium falciparum malaria and ABO blood group:: is there any relationship?

There is increasing evidence that Plasmodium falciparum malaria is influenced by ABO blood group but the extent of association between both is yet to be well defined. Studies that investigated association between P. falciparum malaria and ABO blood group were identified using MEDLINE search and were systematically reviewed. There were apparent discrepancies and contradictions in the studies as some reported significant association between both while others observed no significant association. This outcome may reflect the complex interaction between P. falciparum malaria and the host immune responses. However, findings from all studies reviewed suggested that individuals of blood group O are relatively resistant to severe disease caused by P. falciparum infection. It was established that parasitized erythrocytes form rosettes more readily with red blood cells (RBCs) of A, B, or AB groups than with blood group O and this parasite-triggered RBC rosette formation is associated with the severity of clinical disease and with the development of cerebral malaria. Differences in rosetting ability were based on the P. falciparum strain-specific preference of rosetting with non-O blood groups and not only a phenomenon of laboratory-propagated strains, but also exist in wild clinical isolates from all major malarious areas of the world.