Alloantibody among Thalassemia patients receiving multiple blood transfusions at a tertiary care hospital in India

Regular blood transfusion is a lifesaving treatment for thalassemia patients; however, it exposes them to multiple alloantigens. The present study was designed to assess the frequency of alloantibodies in thalassemia patients receiving multiple blood transfusions. Blood samples were tested by Gel card method for ABO, Rh, Direct Antiglobulin Test (DAT), Indirect Antiglobulin Test (IAT), Auto Control (AC) and presence of alloantibody. Alloantibody screening and identification were performed using commercial 3-cell and 11-cell identification panels. Of a total of 66 thalassemia patients, 37 were male and 29 were female, with a mean age of 15.63 +/- 5.93 years and a range of 4.0 to 29.0 years. The ABO profiles of thalassemia patients were B-33, A-19, O-11, and AB-3, with 63 Rh-D positives and 3 Rh-D negatives. An average of 533.39 +/- 284.95 units were transfused an average of 304 +/- 119.65 times. Positive cases for DAT were 29(43.93%), AC was 26(39.39%) and IAT was 4(6.06%). Nine (13.636%) patients had developed alloantibodies, in which anti-K was seen in 5(27.77%), anti-Kpa in 4(22.22%), anti-C in 3(16.66%), anti-Cw in 3(16.66%), anti-D in 1(5.55%), anti-Lea in 1(5.55%), anti-Luain 1(5.55%). Alloantibodies were single in 4(44.44%) and multiple in 5(55.55%) patients. The rate of alloimmunization and positivity of DAT, AC, ICT, and splenectomy were significantly associated with higher age, the number of units transfused, and also the number of times of transfusion. Every new thalassemia patient needs extended blood group typing prior to the start of a blood transfusion and antigen-matched blood. For patients with alloantibodies, corresponding antigen-negative blood must be selected for cross-matching.