Red cell Alloimmunization and its Correlation with Clinical Spectrum & Transfusion Profile in Pediatric Thalassemia...

Thalassemia is the most frequent congenital cause of anemia globally, categorized by anomalous hemoglobin production. Lifelong PRBC transfusion with iron chelation therapy is the only therapeutic option available for the majority. Long-term recurrent blood transfusion has its hindrances like RBC alloimmunization. As there is inadequate data on alloimmunization in the pediatric thalassemia major population, our study aims to find out its prevalence and correlation with the clinical spectrum & transfusion profile.

Alloantibody screening was done using 3 cell screening panel that includes antigens D, C, c, E, e, K, k, Fya, Fyb, Jka, Jkb, Lea, Leb, P1, M, N, S, s, Mia, Dia, and Xga. The presence of an unexpected antibody in the patient's serum was considered a positive antibody screen for alloantibody. All samples were further examined to identify antibody specificity using 11 cell identification panels.

6% (5/82) of the included patients demonstrated presence of one or more alloantibodies Alloimmunization was significantly greater in children having their first transfusion after one year of age [OR (95% CI) = 1.42(1.36-1.49), p = 0.02]; receiving > 12 transfusions per year [OR (95% CI) = 1.26(1.12-1.40), p = 0.03] and having > 150 ml/kg/year annual packed RBC consumption [OR (95%CI) = 1.13 (1.08-1.19), p = 0.05]. Total number of transfusions > 100 was also found to be positively associated with alloimmunization [OR (95% CI) = 1.22 (1.14-1.32), p = 0.04].

In the present study, alloimmunization was found to be 6% in multitransfused pediatric thalassemia patients. Our observation re-emphasizes the prerequisite for RBC antigen typing ahead of the first transfusion and early institution of transfusion therapy after diagnosis to decrease alloimmunization.