Frequency and specificity of red cell antibodies in thalassemia patients in Albania

Abstract

Introduction: Thalassemia major is a common hemoglobinopathy in Albania. However, there are no data available on the frequency of RBC alloimmunization and autoimmunization in transfusion-dependent Albanian patients with thalassemia.

Methods: A total of 118 patients with thalassemia receiving regular transfusions were studied during 5 years with antibody screening. During this period, they were exclusively transfused with blood matched for ABO, Rhesus and Kell system. These patients were previously exposed to unmatched blood because of blood shortages.

Results: Fourteen of 118 (11, 8%) patients developed alloantibodies. Twelve (10, 1%) were already present at the start of the study. Only 2 (1, 7%) were formed after the application of a strict Rh and Kell matching policy. The most common antibody was anti-K, followed by anti-D, anti-C, anti-E, anti-c, anti-e, anti-Jk(b) , and anti-C(w) . Three patients developed anti-D plus anti-C. Anti-K was combined with Rh antibodies in two of five cases. Anti-c was combined with anti-E in two of three cases. The majority of antibodies (10/14) belonged to the Rh blood group system. With the exception of the anti-Jk(b) and the anti-C(w) , all antibodies were already present at the beginning of the follow-up period. During our follow-up, 27 patients (22.8%) developed autoantibodies. A strong coincidence was found between the presence of alloantibodies and autoantibodies. Eleven of 14 (78%) of the patients with alloantibodies had also autoantibodies, whereas autoantibodies were found in 16 of 104 (15%) of patients with thalassemia without autoantibodies. The rate of alloantibody formation dropped from 10.1% to 1.7% after application of a strict Rh and Kell matching policy.

Conclusion: A policy of Rhesus and Kell matching without occasional exceptions greatly reduced the development of new alloantibodies and autoantibodies. Self-sufficiency through regular blood donation is necessary for the full implementation of an extended match policy and the prevention of antibody formation in our patients.

Keywords: Alloimmunization; alloantibodies; thalassemia patients.