Autoimmune hepatitis and overlap syndromes

Autoimmune hepatitis is a well-established chronic liver disease. It primarily affects women, is characterized by circulating autoantibodies and elevated gammaglobulins and is associated with extrahepatic immune-mediated syndromes. Treatment regimens have remained unchanged for a number of years because of the high efficacy of steroid monotherapy, or combination therapy of azathioprine and steroids. In approximately 90% of patients remission of the disease is reached by medical therapy, which is usually administered lifelong because long-term remission after drug withdrawal is achieved in only 17% of patients. In 10% of patients treatment failure is observed. The challenge of remission induction involves the use of transplant immunosuppressants such as cyclosporine, mycophenolate moffetil, and tacrolimus. The challenge of maintenance therapy minimizing steroid side-effects involves the evaluation of topical steroids and the use of azathioprine monotherapy. Overlap syndromes occur in approximately 20% of autoimmune liver diseases. The diagnosis is broadly based on serological, biochemical, clinical and histological parameters. Most common are the overlap of autoimmune hepatitis and primary biliary cirrhosis, as well as autoimmune hepatitis with primary sclerosing cholangitis. These yet incompletely defined syndromes are an important differential diagnosis in the difficult-to-treat patient with autoimmune hepatitis.