Acute Q Fever Hepatitis Mimicking Autoimmune Hepatitis

Abstract: A 44-year-old previously healthy man presented with 17 days of high-grade fevers, chills, night sweats, nausea, dark urine, and progressive jaundice after returning from a 2-week trip to Mexico during which he had eaten unpasteurized goat cheese daily and had contact with goats, horses, and dogs. Evaluation revealed mixed cholestatic and hepatocellular liver injury, splenomegaly, and significantly elevated inflammatory markers, with negative blood cultures and negative Brucella serologies. Strongly positive antinuclear, anti-smooth muscle, and antimitochondrial antibodies, together with a liver biopsy initially interpreted as autoimmune hepatitis, suggested an autoimmune process. Q fever serologies obtained during the diagnostic workup showed phase II IgM and IgG titers of 1:512, and pathology review demonstrated granulomatous hepatitis compatible with Q fever. Convalescent serology at 6 weeks confirmed phase I seroconversion. The patient was diagnosed with acute Q fever complicated by Q fever hepatitis and was treated with doxycycline-based therapy. Granulomatous hepatitis with prominent autoantibodies should prompt exposure history and phase-specific serologies before the findings are attributed to autoimmune disease.