Evaluation of Immune Functions in Transfusion-Dependent Thalassemia Patients with Alloimmunization

Abstract

Objective: Regular erythrocyte suspension transfusions are still performed for most patients with beta-thalassemia major to prevent anemia. In recent years, it has been observed that patients are exposed to multiple allogeneic antigens and this leads to changes in the immune system. Understanding the immune regulators responsible for alloantibody development in thalassemia patients will provide appropriate data for the reduction and/or prevention of alloimmunization. We aimed to evaluate the association of alloimmunization and immune functions in these patients. Materials and Methods: Fifty-four patients with thalassemia between the ages of 1 and 24 years were retrospectively analyzed. The frequency and types of alloantibodies and the immune functions and demographic characteristics that affected their formation were examined in these patients. Results: The rate of alloantibody detection was 29.6%. There was a median interval of 13.7 years from the start of transfusions to alloantibody development. The age at initiation of regular transfusions was significantly higher in patients with alloantibody development. We found strong relationships between alloantibody development and both direct Coombs positivity and low C4+ and low CD19+ B-cell numbers. However, no significant difference was found between the groups in terms of serum immunoglobulin (Ig) G, IgA, IgM, and C3 levels; total lymphocyte count; or CD3+, CD4+, CD8+, and natural killer cell counts. Conclusion: Studies at the molecular level should be increased and research should be conducted with larger numbers of patients to clarify the immune pathogenesis of alloimmunization and determine the markers that will enable early recognition.