Red blood cell alloimmunization in patients with sickle cell disease in Turkey: a single center retrospective cohort study

Purpose: We aimed to investigate erythrocyte alloimmunization frequency and related factors in our region where SCD is common Material and Methods: This study was planned as a single center, cross-sectional and retrospective cohort study. A total of 216 patients who had been followed up due to SCD [Hemoglobin (Hb) SS, Hb S-beta thalassemia, Hb S-alpha thalassemia] were included in this study. Patients were divided to two groups according to amount of transfusion. The patients who had received less than 6 transfusions per year and who did not have the history of erythropheresis were allocated to Group 1, and the patients who had received 6 or more simple transfusion per year or who had undergone erythrocyte exchange were allocated to Group 2 Results: Of 216 SCD patients included in the study. Alloimmunization was detected in 67 (31.0%) out of 216 patients who underwent transfusion, and in 17 (30.4%) out of 56 patients in Group 1 and in 50 (31.3%) out of 160 patients in Group 2. When the patients were analyzed according to alloimmunization development, our study revealed that neither SCD complications are a risk factor for alloimmunization nor alloimmunization increases mortality rates Conclusion: High alloimmunization frequency found in our study suggests the insufficient adherence of alloimmunization-prevention policies in RBC transfusions performed except experienced institutions. Therefore alloimmunization may be reduced or prevented through performing extended red cell typing among SCD patients