Red cell alloimmunization in sickle-cell anaemia patients.

This study in King Fahd Hospital of the University, Saudi Arabia, assessed the frequency of alloimmunization to red cell antigens in sickle-cell anaemia patients over 1996-2004 in order to evaluate the risk of alloimmunization and identify the most common alloantibodies. A retrospective analysis of the transfusion history and medical records of 350 patients aged 2 to 75 years who had received at least 1 transfusion found that 48 patients had developed alloantibodies (13.7%). The most common alloantibodies detected were: anti-E alone (18.8%), nonspecific (12.5%), inconclusive (12.5%), anti-K (10.4%) and anti-c 3 (6.3%). Some patients had 1 alloantibody, while others more than 1 and even multiple antibodies. Nine patients had a persistent positive direct antiglobulin test.