Associations between alloantibodies and multiple red blood cell transfusions in patients with sickle cell anemia

Abstract

Alloantibodies are popularly transfusion-related and can be formed against many blood components including the red blood cells, white blood cells, and platelets. The formation of alloantibodies which is a common a sequence for repeated red blood cell transfusion has been reported and are clinically crucial in pregnancies, and to identify risk of future transfusion-related adverse hemolytic reactions. The present study was focused at studying the background clinical factors around red blood cell (RBC) transfusion with respect to alloimmunization, effect of Rh-Kell antigen matching units and its impact on sickle cell anemia (SCA) patients to decrease the incidence of alloantibody development. Methodology – Our retrospective study involved data analysis from SCA patients including pregnant women who had undergone antibody screening from Riyadh, Saudi Arabia. Data from the year 2010 up until 2020 was collected from the King Saud Medical City, the regional laboratory and central blood bank in Riyadh and included a total of 246 patients who matched our criteria. Data from indirect antiglobulin test (IAT) done on each patient at two separate time periods was analysed by appropriate statistical tools in SPSS® software platform. Results – A total of 246 SCA patients with a mean age of 11.9 ± 6.7 years were identified to have obtained blood donation in the study period, and 52.4% transfusion recipients were recorded to have undergone phenotype match: Rh-K. Our study also found 17.9% of the alloimmunized patients to have a record of blood transfusions before alloimmunization. Anti-E (40.9%), anti-Kell (34.1%), anti-D (4.5%) were the most popular specificities of alloantibodies defined. No association was found between gender and production of antibodies, and the backward step binary logistic regression analysis predicted recipients of blood transfusions (>7 units) was 3.66 times more exposed to risk of developing alloantibodies (1.23 – 10.85, 95% CI). While among those in the matching phenotype (Rh-K) group was less likely [OR = 0.012 (0.001–0.11, 95% CI)] to develop alloantibodies. The current study showed that advancing age, and multiple transfusion episodes to increase the risk of developing alloantibodies following blood transfusion among SCA patients.