Role of B-Cell Inhibition in Autoimmune Hepatitis: Lessons Learnt From Systemic Lupus Erythematosus.

Autoimmune hepatitis (AIH) is a chronic liver disease characterized by histological, clinical, and laboratory findings, including elevated liver enzymes, immunoglobulin G (IgG), and autoantibodies. Belimumab, a monoclonal antibody targeting B-lymphocyte stimulator (BLyS), is primarily approved for systemic lupus erythematosus (SLE) but shows promise in improving liver function tests (LFTs) in patients with concurrent AIH and SLE. We present the case of a 24-year-old female diagnosed with AIH and SLE, whose elevated LFTs initially resisted standard azathioprine therapy. Upon switching to mycophenolate and belimumab, a notable reduction in LFTs was observed. This case highlights belimumab's potential as an adjunct therapy in AIH, especially in patients with overlapping autoimmune conditions, supporting its role in reducing systemic inflammation and autoimmune activity.