Alloimmunization and erythrocyte autoimmunization in transfusion-dependent egyptian thalassemic patients

Background: Alloimmunization to red blood cells (RBCs) antigens and formation of autoantibodies against RBCs is a frequent complication among immunocompetent transfusion-dependent patients. Autoantibodies can result in clinical hemolysis and difficulty in cross-matching blood. The objective of this study was to evaluate the presence of alloantibodies and autoantibodies in regularly transfused β-thalassemic patients and the factors influencing the development of alloantibodies. Materials and Methods: The clinical and transfusion records of 95 Egyptian β-thalassemic patients, with a mean age of 17.07 years, presenting to the National Blood Transfusion Centre for regular blood transfusion were evaluated for alloimmunization and antibody formation. Results: Alloantibodies were encountered in 27 patients (28.4%). The most frequent alloantibodies encountered were anti-Kell (23.6%) and anti-E (23.6%). Patients with blood group O were the highest in developing antibodies (37.9%). Patients with blood phenotypes R2r Kell negative developed more alloantibodies. Autoantibodies were encountered in only 1 patient. Conclusions: Alloimmunization to RBCs antigens is a frequent finding among Egyptian transfusion-dependent thalassemic patients, with the majority of patients being transfused with blood matched for ABO and D antigens only. Absence of phenotypically matched donors, except for a limited number of patients, may have contributed to this problem. Copyright © 2011 by Lippincott Williams & Wilkins.