S5813 Disseminated Bartonella Infection With Hepatic Involvement Leading to Septic Shock: A Case Report

Introduction: Granulomatous hepatitis is most commonly caused by sarcoidosis, viral hepatitis, lymphoma, and HIV. Bartonella henselae is a rare but important cause particularly in immunocompromised individuals. Disseminated B. henselae can lead to rapid clinical decline, including septic shock. We present a case of hepatic B. henselae infiltration in an immunocompromised host, highlighting the diagnostic challenges and therapeutic considerations in the rare but severe presentation. Case Description/Methods: A 21-year-old man with common variable immunodeficiency and prior, partially treated bacillary angiomatosis presented with 2 weeks of anorexia, profound fatigue, jaundice, and hypotension. Examination revealed hepatosplenomegaly. Laboratory studies demonstrated a total bilirubin 18 mg/dL and alkaline phosphatase 1,540 IU/L. Blood cultures were negative. Cross-sectional imaging demonstrated massive splenomegaly and diffuse lymphadenopathy without biliary dilation. The patient developed septic shock requiring vasopressors and renal replacement therapy. Given persistent cholestasis, a trans-jugular liver biopsy was performed, which demonstrated non-caseating granulomas with nodular regenerative hyperplasia. Broad-range 16S rRNA PCR on liver tissue, whole blood, and an axillary lymph node aspirate confirmed disseminated B. henselae. Empiric broad-spectrum antibiotics were narrowed to Bartonella-directed therapy with intravenous doxycycline initiated on day one and rifampin added on day 10. Due to persistent thrombocytopenia, rifampin was replaced with ciprofloxacin and gentamicin; the patient was ultimately maintained on doxycycline and ciprofloxacin. Fevers resolved by day 20, with gradual improvement in liver function tests, allowing discharge on oral therapy with close outpatient follow-up. Discussion: This case highlights that disseminated B. henselae can mimic infiltrative or autoimmune liver disease. In immunoglobulin-deficient patients, serology is unreliable and cultures insensitive; PCR of blood or tissue is essential for diagnosis and should be pursued early when granulomatous hepatitis coexists with hepatosplenomegaly and lymphadenopathy. Prompt, prolonged combination antimicrobials are critical to halt progression and improve outcomes.