S5876 Legionella Pneumonia Presenting as Hepatitis: A Rare Extrapulmonary Manifestation

Introduction: Inflammation of the liver (hepatitis) can result from numerous insults including infection, alcohol use, autoimmune disorders, and toxin exposure. Hepatitis is classically associated with elevated transaminases. The vast majority of incidences due to infection are related to viral infections (hepatitis A-E). When bacterial infections are implicated, they portend a poorer prognosis and higher mortality rates. Legionella is a rare, atypical pathogen responsible for 1-3% cases of community acquired pneumonia that can have systemic manifestations including liver inflammation. Legionella presents with symptoms of fever, cough, dyspnea, and sometimes diarrhea. This case highlights a case of Legionella pneumonia manifesting as hepatitis. Case Description/Methods: A 36-year-old man presented to the hospital with concerns of generalized weakness, cough, fever, and diarrhea. He presented febrile and tachycardic. Initial labs were significant for moderate hypotonic hyponatremia, leukocytosis, an elevated procalcitonin level, and an elevated aspartate aminotransferase: alanine aminotransferase (AST:ALT) ratio of 2:1. Computed tomography of the chest was notable for a dense consolidation of the right lower lobe. Legionella urine antigen was positive. Antibiotic coverage followed standard community acquired pneumonia protocols. Abdominal ultrasound showed increased hepatic echogenicity. Acetaminophen level, HIV, and hepatitis panel were negative. He was discharged on azithromycin. Discussion: Legionella infection typically presents with fever, cough, and dyspnea. Patients may occasionally have extrapulmonary manifestations, such as nausea, vomiting, diarrhea, and myalgias, which may confound diagnosis and worsen prognosis, especially in the setting of delayed diagnosis. Rarely, patients can have elevation of transaminases, typically occurring in 2:1 AST:ALT ratio. Hepatic dysfunction in the setting of Legionella infection is believed to be a result of direct bacterial invasion or endotoxin release leading to hepatocellular injury. While Legionella is a rare cause of hepatitis, it should remain high on the differential for patients presenting with 2:1 AST:ALT ratio who do not fit the clinical picture for alcoholic liver disease or viral hepatitis. It is imperative for clinicians to maintain a high index of suspicion for atypical causes of hepatitis to ensure appropriate and timely diagnosis and treatment.