Correlation of Antiglobulin Reactivity and Severity of Pancytopenia in a Patient with Hemophagocytic Lymphohistiocytosis: A Case Report and Review of Literature.

A 46‑year‑old obese male with a medical history of thalassemia minor presented to the emergency room with complaints of severe fatigue and jaundice worsening over two weeks. On further evaluation, the patient was found to have significant hyperbilirubinemia and transaminitis. The hospital course was further complicated by pancytopenia requiring multiple transfusions, worsening hyperbilirubinemia, severe hyperferritinemia, hypofibrinogenemia, and hypertriglyceridemia. He was also found to have splenomegaly and evidence of hemophagocytosis on bone marrow biopsy. On further testing, the patient was also found to have evidence of hemolysis along with a positive direct Coomb's test consistent with autoimmune hemolytic anemia (AIHA), and elevated soluble IL-2 receptor level. The patient was subsequently diagnosed with hemophagocytic lymphohistiocytosis (HLH). He was treated with HLH-94 protocol along with rituximab for AIHA which resulted in improvement of patient's condition. We present a case of HLH with no prior history of autoimmune disease, associated with Coomb's positive AIHA that resolved after therapy for HLH. Our case also delineates how the intensity of antiglobulin reactivity, if present, may correlate with severity of the disease, its progression, and response to treatment.