Red blood cell alloimmunization in blood transfusion-dependent β thalassemia major patients in Sana'a City-Yemen.

The development of erythrocyte alloantibodies complicates transfusion therapy in β thalassemia major patients. These antibodies increase the need for blood and intensify transfusion complications. Data on erythrocyte alloimmunization is scarce in Yemeni thalassemia patients. We studied the frequency of alloimmunization in multitransfused β-thalassemia major patients and investigated risk factors that affect antibody formation. Blood samples were taken from 100 β thalassemia major patients who received multitransfused leukodepleted packed red-blood cells. Antibody screening and identification were performed by indirect antiglobulin test using the gel column technique. All patients were tested for autoantibodies using autocontrol and direct antiglobulin test. No adsorption test was done as no autoantibodies were detected in any patient. In our study of 100 β-thalassemia patients, 50 were male and 50 were female with ages ranging from 1 to 30 years. Alloantibodies were present in 6% of patients, while no autoantibodies were detected. Of the 17 alloantibodies identified, the majority were directed against Kell (41.2%) and Rh (29.4%) blood groups. Alloimmunization was significantly associated with age group and sex (p = 0.013, p = 0.030), respectively in β thalassemia major patients. The development of alloantibodies was not significantly associated with duration, total number of transfusions and splenectomy (P = 0.445, P = 0.125, P = 0.647). No autoantibodies found in patients with β thalassemia major. The study found low rates of erythrocyte alloimmunization in multitransfused β-thalassemia major patients, but significant alloantibodies were produced primarily from Kell and Rh blood groups, suggesting the need for providing phenotypically matched cells for selective antigens to improve transfusion efficiency.