Alloimmunization among patients with transfusion-dependent thalassemia in Taiwan.

The development of erythrocyte alloantibodies complicates transfusion therapy in patients with thalassemia. However, no data are available on the frequency of erythrocyte alloimmunization in patients with transfusion-dependent thalassemia in Taiwan. We analysed the clinical and transfusion records of 30 individuals (15 females and 15 males; mean age, 20 years; range, 4-31 years) with thalassemia who had regular transfusions for periods ranging from 0.5 to 20 years. Of the 30 patients, 28 who had beta-thalassemia major and two who had Hb H disease (alpha thalassemia), 11 (37%) were found to carry alloantibodies. All alloantibodies were clinically significant specificities, including four cases of anti-E, two of anti-E + c, two of anti-'Mi(a)', one of anti-'Mi(a)' + E, one of anti-D and one of anti-S. Alloimmunization to erythrocyte antigens is a frequent complication in transfusion-dependent thalassemia.