ABO blood groups and malaria related clinical outcom

Objectives: The study was undertaken to correlate the blood groups and clinical presentations in malaria patientsand to understand the differential host susceptibility in malaria.Methods: From October 2007 to September 2008, malaria positive patients’ samples were evaluated in thisstudy. Hemoglobin, total leukocyte count, and platelet count of each patient were done on an automated cellcounter. After determining the blood groups, malarial species and the severity of clinical course were correlated.Results: A total of 100 patients were included in the study, of which 63 cases were positive for Plasmodiumfalciparum and 37 cases were positive for P. vivax infection and 11 patients had mixed infection. The results ofthe blood groups showed 22 – ‘A’ group, 42 – ‘B’ group, 35 – ‘O’ group and 1 was ‘AB’ group. When the clinicalcourses between different groups were compared using the following parameters for severe infection—a parasiticload of >10/1000 RBCs, severe anemia with hemoglobin < 6 g%, platelet count of <10,000/mm3, hepato orsplenomegaly or clinical signs of severe malaria such as fever >101oF and other organ involvement, it wasobserved that ‘O’ group had an advantage over other the groups. The difference in rosetting ability between redblood cells of different ‘ABO’ blood groups with a diminished rosetting potential in blood group ‘O’ red bloodcells was due to the differential host susceptibility.Conclusion: ‘O’ group had an advantage over the other three blood groups. Based on literature and the results ofthis study, the diminished rosetting potential in blood group ‘O’ red blood cells is suggested as the basis for thedifferential host susceptibility.