Antibody Development in Pediatric Sickle Cell Patients Undergoing Erythrocytapheresis: A 10 Year Review

Background: The formation of alloantibodies and/or autoantibodies in multitransfused pediatric sickle cell disease patients undergoing monthly erythrocytapheresis (RBCX) during a 10-year period was evaluated utilizing a retrospective patient chart review.

MATERIALS AND METHODS: Clinical charts and transfusion services serological computer records of 32 patients were reviewed under an IRB approved protocol. All patients were seen in the Pediatric Sickle Cell Clinic, Kosair Children’s Hospital (KCH) between 1998 and 2008. Included in the data review were patient gender, ABO/Rh blood type, interval between RBCX start date and last RBCX, number of RBC components transfused, identity of existing antibody(ies) prior and subsequent to RBCX, and time interval for development of new antibody. All patients received C, E, and K antigen negative RBCs based on their phenotype at the start of their RBCX.

RESULTS: Thirty-two patients received between 8 to 555 RBC transfusions (Table 1). An allo- or autoantibody developed in 5/15 patients (33.3%) receiving C-, E-, K- RBCX; 3/10 patients (33.3%) receiving E-, K- RBCX; 2/4 patients (50%) receiving C-K- RBCX. An autoantibody developed in 3/32 patients (9.4%) as did a low frequency antibody (Low) not otherwise identified. One patient each developed an anti-Kp^a and anti-M. In the two patients receiving K- RBCX, no new antibody was identified. Three patients developed anti-E and one patient developed anti-K after receiving partially matched RBCs on an emergency basis.

Table 1. Antibody (Ab) development following erythrocyapheresis (RBCX) of patients with sickle cell disease (n=32)

Conclusions: Performing RBCX using C, E, K antigen phenotypically matched RBCs prevented development of new alloantibodies in 75% of multitransfused patients. Development of autoantibody or antibody to a low frequency RBC antigen can still occur in any patient receiving RBCX. In this series, all patients, including those who developed RBC antibodies, were able to continue long term RBCX without additional complications. Routine use of C-, E-, K- RBCs is recommended in RBCX to prevent formation of clinically significant antibodies.