2366 Acute Liver Failure Caused by Hemophagocytic Lymphohistiocytosis Secondary to Aggressive Natural Killer Cell Leukemia and Epstein-Barr Virus Reactivation

Abstract

INTRODUCTION: Acute liver injury is a common presentation of many systemic illnesses, including hematologic malignancies. The present case was an unusual presentation of acute liver failure (ALF) caused by hemophagocytic lymphohistiocytosis (HLH) secondary to aggressive natural killer cell leukemia(ANKL) associated with Epstein-Barr virus(EBV) infection reactivation. CASE DESCRIPTION/METHODS: A 24-year-old female presented with fever and altered mental status. Her physical examination revealed massive hepatosplenomegaly. Complete blood count showed pancytopenia with WBC 460/µL, microcytic anemia Hgb 7.8g/dL with MCV 79, thrombocytes 45,000/µL, AST 170IU/L, ALT 162IU/L, INR 1.5, albumin 1.3g/dl and total bilirubin 11.08mg/dL, triglycerides 1164mg/dL, ferritin 1792ng/ml. CT abdomen showed hepatosplenomegaly with hepatic steatosis. Her liver biopsy showed hepatic necrosis with moderate steatohepatitis and perisinusoidal fibrosis with normal liver copper level. She was initially treated with steroids and N-acetylcysteine. Flow cytometry and bone marrow biopsy revealed CD56+ and CD3+ positive cells with high serum soluble IL-2 receptor consistent with ANKL and HLH. EBV markers were found positive for EBV IgG antibody and EBV nuclear antigen with high EBV PCR and negative for EBV IgM antibody, which is consistent with EBV reactivation. A modified SMILE chemotherapy regimen with rituximab was initiated. Unfortunately, her clinical status continued to decline progressively with worsening acute encephalopathy, acute hypoxic respiratory failure and Pseudomonas septic shock which required vasopressors and IV antibiotics. The patient died on day-30 of hospitalization due to her hematologic malignancy, septic shock, and ALF. DISCUSSION: HLH is a consequence of abnormal immune activation which could be secondary to infections, malignancies, or autoimmune diseases; leading to life-threatening multi-organ inflammatory response, especially in the liver. Natural killer (NK) cells are types of lymphocytes that play an important role as part of innate immune system in fighting tumors and viral cells; NK cells are abundant in the liver. It was shown that NK cells might be involved in the intense immune response causing severe liver damage. ANKL is a rare malignant lymphoproliferative disorder of mature NK cells closely associated with EBV. EBV reactivation can occur in this disease setting. Careful evaluation of patients with ALF and abnormal hematologic profile is essential for early detection and therapy of the primary culprit.