Incidence and determinants of red cell alloimmunization and autoimmunization in paediatric thalassaemia: A North...

Thalassaemia requires lifelong red cell support, which increases the risk of alloimmunization and autoimmunization. This prospective study aimed to determine the incidence of red cell sensitization and investigate the factors influencing sensitization in paediatric thalassaemia patients.

A prospective observational study was conducted from April 2024 to March 2025 on 109 paediatric thalassaemia patients. At every transfusion visit, ABO/RhD typing, direct antiglobulin test and antibody screening were performed. Positive screens underwent antibody identification and provision of antigen-negative units. Demographic variables, transfusion history and product characteristics were analysed to identify significant factors influencing sensitization.

Among 109 patients (mean age 6.14 ± 4.98 years), 7.34% (n = 8) developed alloantibodies and 16.51% (n = 18) developed autoantibodies; the overall immune sensitization rate was 23.85%. Rh system antibodies predominated (75%), including anti-D, anti-E, anti-C and anti-Cw. Factors influencing alloimmunization were significantly associated with older age (p = 0.011), RhD negativity (p = 0.02) and age at first transfusion >1 year (p = 0.015). Factors influencing autoimmunization were significantly associated with later initiation of transfusion (p = 0.003). No significant associations were found with gender, ABO group or total transfusion number. Both alloimmunization (18.6 ± 10.5 days) and autoimmunization (21.9 ± 10.8 days) influenced the transfusion intervals.

The factors influencing sensitization in paediatric thalassaemia patients were early initiation of transfusion (<1 year), RhD blood group and overall cumulative red cell exposure. Routine antibody screening at every visit and provision of Rh and Kell-matched red cell units are essential to minimize risk and enhance transfusion safety in paediatric thalassaemia patients on regular transfusion.