Antigen matching for transfusion support in Brazilian female patients with sickle cell disease to reduce RBC alloimmunization.

Abstract

Red blood cell (RBC) alloimmunization is a complication of patients with sickle cell disease (SCD) and it has a greater impact on pregnancy, leading to a risk of hemolytic disease of the newborn and reducing blood availability for pregnant women. This study proposed to evaluate antigen matching transfusion protocols, aiming to reduce RBC alloimmunization in Brazilian female patients with SCD. Samples from female patients with SCD (153) and self-declared Afro-Brazilian donors (307) were genotyped for RBC antigens and RH variants were investigated. The transfusion needs of patients during 1-year period and the number of compatible donors were assessed using three antigen-matching transfusion protocols: prophylactic CEK antigen-matched RBCs, prophylactic extended antigen-matched RBCs, and extended-matched red blood cells (RBCs) only for alloimmunized patients. In addition, RH molecular matching has been proposed for patients carrying variant RHCE. Provision of CEK antigen-matched donors would have been possible in 92.4% of transfusion events while provision of prophylactic extended antigen-matched RBCs would cover 88.7% of the transfusion events. Extended antigen matching for alloimmunized patients would be efficient in 99% of the cases. The presence of partial D in 10 patients increased the need of D-negative donors. Compatible donors could be enough for four of the five patients with altered RHCE genotypes in both alleles. In Brazilians, screening African descent donors allows the implementation of prophylactic CEK and extended antigen-matching transfusion protocols to female patients with SCD to reduce RBC alloimmunization; however, the supply of compatible blood can be impaired for patients with Rh variants.