Case report: Successful treatment with plasma exchange in life-threatening hyperhemolytic syndrome unrelated to sickle cell disease

IntroductionHyperhemolytic syndrome (HHS) is a severe form of delayed transfusion reaction primarily described in sickle cell anemia patients which is characterized by a hemoglobin decrease to pre-transfusion levels or lower, often with reticulocytopenia and no evidence of auto- or allo-antibodies. Case PresentationWe present two cases of severe HHS in patients without sickle cell anemia refractory to treatment with steroids, immunoglobulins, and rituximab. In one case, temporary relief was achieved with eculizumab. In both cases, plasma exchange resulted in a profound and immediate response allowing for splenectomy and resolution of hemolysis. Discussion/ConclusionWe discuss the pathophysiology of HHS, its presentation and treatment and expand on the possible role of plasma exchange in this setting.