Red Blood Cell Alloimmunization in Multi-Transfused Patients: A Prospective Study of Antibody Screening and Identification

Abstract

Background: Red blood cell (RBC) transfusion is an indispensable therapeutic intervention for patients with chronic hematological disorders requiring repeated transfusions, including β-thalassemia major, sickle cell disease, aplastic anemia, myelodysplastic syndrome, and chronic kidney disease. Although transfusion improves survival and quality of life, repeated exposure to foreign erythrocyte antigens may result in the development of alloantibodies. Red cell alloimmunization complicates future transfusion therapy by causing delays in locating compatible blood, increasing the risk of hemolytic transfusion reactions, and contributing to transfusion failure. Early antibody screening and identification therefore play an essential role in ensuring safe transfusion practices. Objectives: To determine the prevalence of red blood cell alloimmunization among multi-transfused patients, identify the spectrum of clinically significant alloantibodies, evaluate demographic and clinical factors associated with alloimmunization, and assess the importance of routine antibody screening before transfusion. Materials and Methods: A prospective observational study was conducted among 100 multi-transfused patients attending the Department of Transfusion Medicine over a 24-month period. Patients receiving three or more packed red blood cell transfusions were enrolled. Blood samples were subjected to ABO and Rh typing, antibody screening using the indirect antiglobulin test, and antibody identification with commercially available reagent cell panels whenever screening was positive. Demographic details, underlying diagnoses, transfusion history, and laboratory findings were recorded. Statistical analysis was performed using SPSS version 25, with p < 0.05 considered statistically significant. Results: Among 100 enrolled patients, RBC alloantibodies were detected in 14% of cases. Females demonstrated a higher alloimmunization rate than males. The most frequently identified antibodies belonged to the Rh blood group system, particularly anti-E and anti-c, followed by antibodies against the Kell system. Patients receiving more than 20 transfusions exhibited significantly higher alloimmunization rates than those receiving fewer transfusions (p < 0.05). Increasing transfusion burden and longer duration of transfusion therapy were independently associated with alloantibody formation. Conclusion: Red blood cell alloimmunization remains a significant complication among multi-transfused patients. Routine antibody screening and identification, combined with extended antigen matching for clinically significant blood group antigens, can substantially reduce alloimmunization and improve transfusion safety.