Unrecognized hemoglobin variants in the donor blood supply are detectable in the transfused population

Objectives: The US Food and Drug Administration requires donated blood to be tested for various infectious diseases to ensure safety and purity. However, testing for hemoglobin variants is not required, despite reported occurrences of hemoglobin variant transfusion and concerns about the safety of such transfusions. This study aimed to investigate the frequency of hemoglobin variants within the blood supply. Methods: We performed a 2-part study. First, we tested all RBC units in our blood bank by high-performance liquid chromatography for the presence of hemoglobin variants. Second, we performed a retrospective analysis of hemoglobin variant testing completed for routine management of sickle cell disease patients at our institution over a 5-month period to identify cases of hemoglobin variant transfusion. Results: We found that 2 of 476 (0.4%) RBC units in our blood bank contained a hemoglobin variant, and 5 of 563 (0.9%) sickle cell patients seen at our institution in a 5-month period were transfused with RBCs containing a hemoglobin variant. Conclusions: We confirmed that hemoglobin variants are present within the blood supply, and the frequency of hemoglobin variant transfusion is elevated for patients with sickle cell disease given the increased prevalence of hemoglobin variants in the population of matched donors.