Red blood cell exchange (RBCEx) is frequently used in the management of patients with
sickle cell disease (SCD) and
acute chest syndrome or
stroke, or to maintain target
hemoglobin S (HbS) levels. In these settings, RBCEx is a category I or II recommendation according to guidelines on the use of therapeutic
apheresis published by the American Society for
Apheresis. Matching donor red blood cells (RBCs) to recipient phenotypes (e.g., C, E,
K-antigen negative) can decrease the risk of alloimmunization in patients with multi-transfused SCD. However, this may select for donors with a higher prevalence of RBC disorders for which screening is not performed. This report describes a patient with SCD treated with RBCEx using five units negative for C, E, K, Fya, Fyb (prospectively matched), four of which were from donors with
hemoglobin variants and/or
glucose-6-phosphate dehydrogenase (
G6PD) deficiency. Pre-RBCEx HbS quantification by high performance liquid chromatography (HPLC) demonstrated 49.3% HbS and 2.8%
hemoglobin C, presumably from transfusion of a
hemoglobin C-containing RBC unit during a previous RBCEx. Post-RBCEx HPLC showed the appearance of
hemoglobin G-Philadelphia. Two units were G6PD-deficient. The patient did well, but the consequences of transfusing RBC units that are G6PD-deficient and contain
hemoglobin variants are unknown. Additional studies are needed to investigate effects on storage, in-vivo RBC recovery and survival, and physiological effects following transfusion of these units. Post-RBCEx HPLC can monitor RBCEx efficiency and detect the presence of abnormal transfused units.