Analysis of red cell alloimmunization in multi transfused patients at a Tertiary care teaching hospital

Red blood cell (RBC) alloimmunization is an immune response against foreign RBC antigens; this generally occurs after sensitization due to multiple blood transfusions and pregnancies. Antibody detection plays a critical role in transfusion medicine as it can detect irregular or unexpected antibodies. This study was done to know the frequency and specificity of unexpected red cell antibodies in the multitransfused patients.

This prospective study was done in the Department of Immuno-Haematology and Blood Transfusion. Antibody screening of 100 multitransfused patients with initial negative antibody screen was carried out prior to compatibility testing and followed for a period of 12 months for each transfusion. Depending on the results, patients were given corresponding antigen-negative blood units.

In this study, the rate of alloimmunization was 7%. Total number of samples that were positive for irregular alloantibodies were 4 of 54 cases of thalassemia, that is, 7.4%, whereas 3 of 40, that is, 7.5%, cases of solid malignancies developed alloantibodies. None of the patients of chronic kidney disease formed any alloantibody. Anti-K antibody was the most frequent antibody detected in 3 of 7, that is, 42.8% patients. Anti-E was the second most frequent antibody observed in 2 of 7, that is, 28.57%. However, anti-c and anti-M were detected in one each of 7, that is, in 14.28% each.

It is concluded here that red cell alloimmunization should not be overlooked in multitransfused patients. To avoid the effects of alloimmunization, routine RBC antibody screening at set time intervals after transfusion should be performed.