Prevalence of Red Blood Cell Alloimmunization Among Pediatric Patients with Sickle Cell Disease in Saudi Arabia

Purpose: Sickle cell disease (SCD) is a common global hereditary hemoglobin disorder. One of the main treatments of sickle cell patients is the requirement of blood transfusions. Post transfusion alloimmunization of red blood cell antigens continue to be a major risk for SCD patients. The study objective is to determine the rate, nature, and risk factors of red cell alloimmunization among pediatric SCD patients in our center and compare our results to published reports from the KSA, regional and some international countries. Methodology: A retrospective study drsign was adopted with record review of SCD patients at King AbdulAziz Medical City-Jeddah (KAMC-J) between 2008-2019 where blood samples were analyzed for alloimmunization using immunohematological techniques. Demographic characteristics and transfusion history were recorded. Data analysis was conducted by SPSS ver. 26. Data are summarized as frequency distribution and chi square test was used to check significance of the difference in the frequency of alloantibodies among subgroups.   Findings: Out of all examined sickle cell patients (n=112). Alloantibodies were detected in 21 patients (17.4%), and these were mostly single in 15 patients (71.4%) as anti-K (23.7%), anti-E (19.0%), and anti-S (9.5%). The other six patients (28.6%) had multiple alloantibodies, especially the combination of anti-C and anti-K (9.5%) and the combination of anti-C and anti-E (9.5%). Alloantibodies were significantly higher in patients who had been admitted to the hospital > 5 times annually, those who had an exchange blood transfusion, age groups > 3 years, and for those who received a larger number of blood units (p-value < 0.05). Recommendations: The consequences of red blood cell alloimmunization are highly significant and, therefore, extended RBC antigens to include ABO, RH (D, C, c, E, e), K, Fya, Fyb, Jka and Jkb antigens in the screening panel for donors and recipients is highly recommended to ensure better transfusion practices and avoid transfusion related complications. Our rate of alloimmunization post frequent blood transfusion is considered relatively low compared to other nations.