S5643 Successful Use of Rituximab in Refractory Autoimmune Hepatitis: A Case Report

Introduction: Autoimmune hepatitis (AIH) is a rare, chronic inflammatory liver disease that can lead to significant morbidity and mortality if not appropriately managed. First-line therapy typically involves corticosteroids in combination with azathioprine, which induces remission in most patients. However, approximately up to 30% of patients are either refractory to or intolerant of these treatments and require alternative immunosuppressive agents. Rituximab has emerged as a potential rescue therapy in refractory cases, demonstrating promising clinical outcomes. We present a case of AIH refractory to steroids which displayed good response with rituximab. Case Description/Methods: A 52-year-old woman with no prior medical history presented with a diffuse maculopapular rash and transaminitis. Laboratory evaluation revealed elevated IgG and positive anti-smooth muscle antibody. Skin and liver biopsies confirmed concurrent Anti-neutrophil cytoplasmic autoantibody (ANCA) associated vasculitis and AIH. Liver histology showed plasma cell-rich chronic hepatitis with moderate activity and bridging fibrosis. FibroScan was consistent with F3 fibrosis. The patient was initiated on high dose corticosteroids with an initial favorable response and was started on cyclophosphamide for vasculitis management per Rheumatology recommendations. She declined azathioprine therapy for concern of side effects. Due to persistent transaminitis despite receiving steroids, she was started on rituximab, and cyclophosphamide was subsequently discontinued. She demonstrated significant biochemical improvement, with improvement of liver enzymes and amelioration of clinical symptoms. Discussion: Rituximab, a monoclonal antibody directed against the CD20 antigen on B lymphocytes, is an established treatment for several autoimmune diseases. In the context of AIH, rituximab is emerging as a potential therapeutic option, particularly in patients who are refractory to or intolerant of standard immunosuppressive therapy with corticosteroids and azathioprine. Preliminary studies and case series have demonstrated promising responses with rituximab in this subset of patients. However, despite these encouraging findings, rituximab has not yet received FDA approval for the treatment of AIH. Additional studies are necessary to further evaluate its efficacy and safety profile in this patient population and to support its integration into standard treatment protocols.