Conclusions

This study shows that RBC alloimmunization remains an important transfusion-related complication among patients with thalassemia and SCD at SMC, Bahrain. The alloimmunization rates observed in this study are consistent with rates reported in other Middle Eastern countries. Alloimmunization was substantially more prevalent among patients with SCD than among patients with thalassemia, likely reflecting differences in disease-related immune activation and transfusion protocols. The low rate in patients with thalassemia suggests that current Rh and Kell matching offers adequate protection in this group. In contrast, the rate in patients with SCD remains elevated despite the use of extended phenotypic crossmatching. The absence of comprehensive alloantibody identification data is a notable limitation. Future studies should ensure complete antibody identification for all patients with positive screens. Investigation of Rh variant alleles and consideration of molecular red cell genotyping as a complement to serologic phenotyping, particularly for patients with SCD, are also warranted to improve transfusion safety in this population.