[Frequency of red blood cell alloimmunization in polytransfused patients at the university teaching hospital of Point G, Bamako, Mali]

This prospective study conducted within 9 months period aimed to determine the frequency of red cell alloimmunization among polytransfused patients of the medical Hematology and oncology ward, and the unit of hemodialysis of the Nephrology ward at the Point-G hospital. Irregular red blood cell antibody screening and identification were performed by gel-filtration method using indirect antiglobulin test and enzymatic treated cells. We did not use saline medium. A total of 78 patients were included in this study. The mean age of the patients was 36.78±14.73 years (range: 11 and 77 years). The sex ratio was of 1.11 in favour of the women. The mean blood units transfused were 12.21±9.99 units (range: 4 and 45 units). The Rhesus phenotypes Dccee, DccEe and DCcee were most predominant, with the respective frequencies of 67.9, 15.4 and 10.3%. Kell antigen was found at a frequency of 1.28%. The total rate of red cell alloimmunization was 10.3%. There was no significant difference between the two wards. All the screened agglutinins were warm antibodies belonging to the Rhesus system: anti-E (7.7%), anti-C (1.3%) and anti-D (1.3%). Only Anti-E was present among hematologic patients. We did not find a significant link between the sex, the age, the number of blood units transfused and the positivity of the antibody screening. We conclude that the frequency of post-transfusional alloimmunization is high among polytransfused patients in Mali. A systematic antibody screening among these patients and the selection of red cells with known Rhesus/Kell phenotypes would allow an optimal blood transfusion safety.