Hyperhemolysis in a patient with sickle cell disease and recent SARS‐CoV ‐2 infection, with complex auto‐ and alloantibody work‐up, successfully treated with tocilizumab

Background Hyperhemolysis syndrome (HHS) is a severe delayed hemolytic transfusion reaction seen in sickle cell disease (SCD) patients, characterized by destruction of donor and recipient RBCs. It results in a drop in hemoglobin to below pretransfusion levels and frequently reticulocytopenia. Case Report We report a case of a man in his thirties with SCD with a recent hospitalization 2 weeks prior for COVID‐19. His red cell antibody history included anti‐Fy(a) and warm autoantibody. At that time, he was given 2 units of RBC and discharged with a hemoglobin of 10.2 g/dl. He returned to the hospital approximately 1.5 weeks later with hemoglobin 6.0 g/dl and symptoms concerning for acute chest syndrome. Pretransfusion testing now showed 4+ pan‐agglutinin in both gel‐based and tube‐based testing. Alloadsorption identified an anti‐N and a strong cold agglutinin. Three least incompatible units were transfused to this patient over several days, with evidence of hemolysis. Further reference lab work revealed anti‐Fy a , anti‐Fy b , anti‐Le a , anti‐Le b , and an anti‐KN system antibody. The patient's hemoglobin nadired at 4.4 g/dl. The patient was treated with a single dose of tocilizumab, his hemoglobin stabilized, and he was discharged. Discussion We present a case of HHS proximate to recent SARS‐CoV‐2 infection with multiple allo and autoantibodies identified. Information on the relationship between SARS‐CoV‐2 infection and HHS is limited; however, it is possible that inflammation related to COVID‐19 could predispose to HHS. Tocilizumab is an approved treatment for COVID‐19. Additionally, tocilizumab appears to be a promising treatment option for patients with HHS.