Case Presentation: Hemophagocytic lymphohystiocytosis (HLH) is a rare cause of pancytopenia. Patients with sickle cell disease can present with pancytopenia and recognition of (HLH) in patients with sickle cell disease may be a lifesaving diagnosis.Case presentation:A 39-year-old female with past medical history of sickle cell anemia and moyamoya disease was admitted with sickle cell vaso-occlusive pain crisis. She had been hospitalized multiple times in the past 8 weeks for sickle cell pain occlusive pain crisis, requiring numerous blood transfusions. During a recent hospitalization, she was in excruciating pain despite maximal pain management regimen. She was noted to have pancytopenia with progressive thrombocytopenia (table 1). Patient’s ANC fell below 1000/mm3 one week later, reticulocyte count was less than 1, and severe thrombocytopenia developed. The presence of progressive trilinear cytopenias with severe reticulocytopenia, ferritin around 18,000 with clinical progressive weakness and intractable pain was concerning for HLH. The differential diagnosis also included parvovirus infection (returned negative) and sickle cell crisis causing total body bone marrow infarction with complete ablation of the bone marrow. HLH treatment with etoposide and steroid was started due to high clinical suspicion. Bone marrow biopsy demonstrated increased erythroid precursors with megaloblastic changes, consistent with sickle cell anemia–associated marrow findings and prominent hemophagocytosis, characterized by numerous bland-appearing histiocytes containing phagocytosed erythrocytes within the cytoplasm. The bone marrow biopsy confirmed HLH diagnosis. Her condition deteriorated despite the optimal treatment and supportive care. She developed multi-organ failure, gram- positive and gram -negative sepsis. She initiated on appropriate antibiotic regimen and multiple blood product transfusions. She was transferred to ICU due to acute respiratory failure and required intubation. She developed AKI and needed hemodialysis. After month of hospitalization she died of multi-organ failure.

Discussion: Our patient with sickle cell anemia suffered from multiple complications including multiple vaso- occlusive crisis and renal failure requiring HD. HLH diagnoses was particularly challenging since she had pancytopenia during previous admissions. HLH is caused by a hyperinflammatory response from cytokine storm leading to organ damage. HLH in can be primary in children due to a genetic mutation while adults have secondary HLH ghat is acquired. The etiology of secondary HLH is unknown but can associated with blood transfusion, viral or bacterial infection, drugs, malignancy, and autoimmune disorders. It is unknown what caused HLH in our patient, though she had numerous blood transfusions. The combination of high-dose steroids and etoposide patients with agranulocytosis increases risk for severe infection. The majority of patient with HLH die from infection.

Conclusions: HLH is rare and potentially fatal immune system disorder. HLH diagnosis particularly challenging in adult sickle cell patients since disease often characterized with pancytopenia and elevated ferritin. However, a high index of suspicious is essential for early diagnosis and treatment to prevent life threatening complications.