Unmasking alloimmunization: A prevalence study in modern transfusion practice

Background: Alloimmunization against non-ABO red cell antigens remains a significant clinical concern, potentially leading to hemolytic transfusion reactions and complications in pregnant women. Aim: To assess and compare the prevalence and types of irregular red cell antibodies in transfusion recipients. Study Design and Setting: This was a prospective study conducted over one year at a tertiary care hospital blood center in Mumbai. A total of 9756 blood samples were analyzed—3243 from patients and 6513 from healthy donors. Materials and Methods: Antibody screening was performed using a commercially available three-cell panel. Samples testing positive underwent further identification using a 14-cell panel in low-ionic strength saline, with and without enzyme treatment. Statistical Analysis: Chi-square test was applied to evaluate the association between antigen exposure and antibody formation. Results: Irregular antibodies were detected in 65 of 3243 patient samples (2%). Anti-c (21%) was the most prevalent, followed by pan-reactive antibodies (20%) and anti-D (16%). Among males, pan-reactive antibodies were most common (36%), while anti-D (28%) was predominant among females. The prevalence among healthy donors was 0.72%. Conclusion: Alloimmunization is significantly higher in transfusion-exposed patients, particularly females. Routine antibody screening should be prioritized in patients requiring multiple transfusions.