Frequency of red cell alloimmunization in patients with sickle cell anemia in an Egyptian referral hospital

IntroductionSickle cell anemia (SCA) is an important public health issue in Tanta, Egypt. Erythrocyte transfusions may reduce the morbidity of SCA, however, they are associated with numerous risks. Among other risk categories, alloimmunization to red cell antigens may result from transfusions. The objective of this study was to explore the frequency of red cell alloantibodies among SCA patients who received regular transfusions.Materials and methodsA total of 42 patients with SCA were included in this study. This work planned to study the presence of alloantibodies to different red cell antigens in multi-transfused SCA patients using the ID card micro-typing system. Clinical and laboratory data were collected and analyzed to find out the frequency, pattern and factors influencing red cell alloimmunization secondary to multiple blood transfusion in these patients.ResultsOf a total of 42 SCA patients included in the study, 21.4% of patients developed alloantibodies. The most common alloantibodies were anti-K, anti-E and anti-C. The rate of incidence of these alloantibodies was 7.1%, 4.8% and 4.8%, respectively. There was significant association between alloantibody and the rate of transfused blood. The mean age of patients with and without alloimmunization was 12.0 and 6.2 years.ConclusionsAlloimmunization to minor erythrocyte antigens of variable clinical significance is a frequent finding in transfused SCA patients. Regular screening for red cell alloantibodies would provide better management of these patients.