Case Report: Acute liver failure in systemic lupus erythematosus with autoimmune hepatitis–primary biliary cholangitis overlap: a belimumab-containing regimen and longitudinal follow-up

Background Severe autoimmune liver injury as the first manifestation of systemic lupus erythematosus (SLE) is rare, and concomitant autoimmune hepatitis–primary biliary cholangitis (AIH–PBC) overlap is uncommon. B-cell-activating factor (BAFF) provides a biological rationale for adjunctive therapy, although clinical evidence remains limited. Case presentation A 72-year-old woman presented with 4 weeks of fatigue and anorexia and developed coagulopathy (international normalized ratio [INR] 1.8), ascites, and hepatic encephalopathy. Autoimmune testing showed antinuclear antibody 1:1280, high-titer anti-double-stranded DNA antibodies with hypocomplementemia, immunoglobulin G (IgG) 30.0 g/L, and antimitochondrial antibody positivity. Hepatitis B surface antigen, hepatitis C antibody, hepatitis E antibody, and Epstein–Barr virus and cytomegalovirus DNA tests were negative. Liver biopsy 42 days after corticosteroid initiation demonstrated interface hepatitis, destructive small-bile-duct injury, plasma cell-rich inflammation, and Batts–Ludwig stage 2 fibrosis without cirrhosis, supporting a clinicopathologic diagnosis of AIH–PBC overlap. Previously unrecognized chronic autoimmune liver disease could not be excluded. Prednisolone was started at 50 mg/day, followed 10 days later by intravenous belimumab, with concomitant ursodeoxycholic acid. Tacrolimus was added during maintenance. By 10 October 2025, liver biochemistry had improved, IgG was 9.42 g/L, and prednisolone had been reduced to 2.5 mg/day. Liver stiffness decreased from 21.5 to 9.7 kPa. Conclusion Sustained biochemical improvement occurred during a belimumab-containing multidrug regimen. This observation does not establish the independent efficacy of belimumab or histological regression of fibrosis.