Hyperhemolysis Syndrome in Child with Sickle Cell Disease: Case Report and Literature Review

Abstract Presentation Date: 6/8/2024 Presentation Start Time: 6:00:00 PM Background Worsening anemia in the setting of various sickle cell disease sequelae is often treated with packed red blood cell (pRBC) transfusion. Hyperhemolysis syndrome (HHS) is a rare and life-threatening complication of transfusion. HHS is the destruction of host RBC and transfused RBC in the absence of red cell antibodies. This is evidenced by declining hemoglobin (Hb) and reticulocyte counts following transfusion, with negative antibody testing. The pathophysiology of HHS continues to be investigated. Proposed mechanisms include bystander hemolysis, erythropoiesis suppression, and macrophage mediated destruction. Hyperhemolysis is typically treated with IVIG and steroids. Goals of treatment include improving Hb and reticulocyte count. Objective Describe a case of a 15 year old male with sickle cell SS disease with acute chest syndrome (ACS) complicated by hyperhemolysis syndrome. Methods Single case report and literature review Results 15 year old male with sickle cell disease type SS and history of delayed transfusion reactions who initially presented with right sided chest pain and shortness of breath. Patient found to have acute hypoxic respiratory failure with new infiltrates on chest x-ray consistent with right sided pneumonia progressing to ACS requiring increasing respiratory support and antibiotics. Patient noted to have significant anemia, requiring pRBC transfusions. After PRBC transfusion, he experienced worsening clinical status with increasing oxygen requirements, anemia, reticulocytopenia, thrombocytopenia, and leukocytosis with negative Direct Coombs test, raising concern for acute HHS. Patient demonstrated cyclical pattern of significant anemia necessitating transfusions with expected increase in hemoglobin followed by significant thrombocytopenia, reticulocytopenia, and anemia within 48-72 hours of transfusion. Given history of transfusion reactions and suspected HHS, patient was initiated on IV glucocorticoids with demonstrated resolution of anemia, thrombocytopenia, and reticulocytopenia. Conclusions While the exact underlying cause of this patient’s hyperhemolysis remains unknown, he responded immediately to the administration of IV steroids. Both steroids and IVIG together are standard treatment, however this case supports that IV steroids alone are sufficient to treat HHS. IV steroids are more cost effective than IVIG. Furthermore, there is evidence of IVIG induced hemolytic anemia, which would exacerbate the underlying pathologic process in HHS. Being familiar with the presentation of HHS is important to be able to recognize the condition and provide timely treatment.