Severe Acute Liver Injury due to Secondary Hemophagocytic Lymphohistiocytosis: A Case Report.

Severe acute liver injury (ALI) is mostly triggered by viral infections and hepatotoxic drugs; however, it can also be seen in systemic diseases. Hemophagocytic lymphohistiocytosis (HLH) is a rare, immune-mediated syndrome that presents as a life-threatening inflammatory disorder affecting multiple organs. Secondary causes occur mainly in the set of malignancy, infection, and autoimmune disease, and are seldom triggered by vaccination. Although liver involvement is common, presentation as severe ALI is rare. We describe a case of a 65-year-old male with history of low-risk chronic lymphocytic leukemia and rheumatoid arthritis treated with prednisolone who presented with persistent fever and jaundice 1 week after COVID-19 vaccination. The diagnosis was challenging given the predominant liver impairment, characterized by hyperbilirubinemia, transaminases over 1,000 U/L, and prolonged INR, which prompted an extensive investigation and exclusion of autoimmune, toxic, and viral causes of hepatitis. Laboratory workup revealed bicytopenia, hyperferritinemia, which together with organ failure and evidence of hemophagocytosis in bone marrow suggested the diagnosis of HLH. After excluding infectious etiologies, flare of rheumatological disease, and the progression of hematological disease, HLH was diagnosed. He was successfully treated with etoposide and corticosteroids, with dramatic improvement of liver tests. After exclusion of other causes of secondary HLH, the recent vaccination for COVID-19 was the likely trigger. We report a case of double rarity of HLH, as it presented with severe liver dysfunction which was probably triggered by vaccination. In this case, the predominant liver involvement urged extensive investigation of liver disease, so a high index of suspicion was required to make an early diagnosis. Clinicians should consider HLH in patients with unexplained signs and symptoms of systemic inflammatory response and multiorgan involvement, including severe liver involvement as the first presentation.