Effect of the ABO blood group on susceptibility to severe malaria: A systematic review and meta-analysis.

Understanding how ABO blood group interacts with Plasmodium falciparum (P. falciparum) infection may facilitate development of antimalarial treatments and vaccines. This study systematically summarizes information on the relationship of ABO blood group with severe P. falciparum infection, level of parasitemia and haemoglobin. A total of 1923 articles were retrieved from five databases. After removal of duplicates, and two levels of screening, 21 articles were selected for inclusion in the meta-analysis. A meta-analysis of the studies showed an increased odds of severe P. falciparum infection among individuals with blood group A, B, AB or non-O compared with blood group O. However, the difference in the level of P. falciparum parasitemia was not significant among individuals with blood group A or non-O compared with blood group O. The difference in haemoglobin level among P. falciparum infected individuals was also not significant between those with blood group A, B or AB versus those with blood group O.