Mycophenolate mofetil as second line treatment in autoimmune hepatitis - A retrospective single center analysis.

Background: Most patients with autoimmune hepatitis respond to standard treatment with steroids and azathioprine. While the disease is usually fatal if untreated, patients who respond well to therapy have an excellent prognosis. Nevertheless, second-line treatment is necessary in approximately 20% of patients, due to either intolerance or insufficient response to first line treatment.While data for mycophenolate mofetil (MMF) in patients intolerant to azathioprine is encouraging, MMF seems of less benefit in patients with insufficient response to first line treatment, but analyzed data on this issue is limited. Aim: To evaluate the efficacy and safety of MMF as a second-line therapy in patients with AIH. Methods: Retrospective analysis of a monocentric database of AIH patients who received medical care from 2000 to 2022. Clinical, immunological and biochemical parameters were assessed at different time points including last follow-up. Results: Overall, 144 patients with AIH were identified. Fifty out of 144 (35%) AIH patients received MMF. Forty (80%) received MMF due to first line treatment intolerance, while ten (20%) due to insufficient response to first line treatment.Remission with MMF monotherapy was 81.5% in the intolerance group versus 30% in the insufficient response group. Patients switched to MMF because of an insufficient response, more often needed additional prednisolone doses higher than 5 mg/day, a switch to third-line treatment or combination regiments, to achieve disease control. Conclusions: Patients treated with MMF because of intolerance to first line treatment show a good disease control under MMF in the majority of cases. Efficacy is considerably lower in the patients switched to MMF because of an insufficient response to first line treatment.