Hyperhemolysis in Patients With Hemoglobinopathies: A Single-Center Experience and Review of the Literature.

Hyperhemolysis is a severe and potentially life-threatening complication of transfusion described in numerous case reports and gaining recognition since 2009 via the UK Serious Hazards of Transfusion scheme. Although it is predominantly seen in patients with sickle cell disease, there are several reports of this complication in patients with other hemoglobinopathies as well as patients with a range of other hematologic diagnoses who have blood transfusions as part of their management. Our understanding of the underlying pathophysiology of this subtype of delayed transfusion reaction has increased over the last few years; however, there are still questions, which remain unanswered. In our center alone, we have encountered 9 cases in the last 5 years both in the adult and pediatric population. Here we discuss our experience in the diagnosis and management of this complication, and review other cases reported in the literature and the various existing theories behind the pathophysiology of this process. We also discuss the role of genotyping and using DNA technology to aid selection of the most appropriate blood for this patient group. With an increased awareness of hyperhemolysis, it would be advantageous to finally develop international registries to determine the true incidence of hyperhemolysis, better understand the pathophysiology, identify markers to predict which patients are at risk, and inform management guidelines.