De novo autoimmune hepatitis following liver transplantation for primary biliary cirrhosis.

De novo autoimmune hepatitis (AIH) is a rare disorder first described in 1998. It appears in patients with liver transplants for non-AIH etiology. The few cases in the literature make it a little known entity due to mechanisms that are unclear. We present the case of a woman with a liver transplant whose graft developed de novo AIH. Diagnosed with primary biliary cirrhosis, the patient underwent liver transplantation for refractory pruritus. Sixteen months after transplantation, we detected alterations in the hepatic profile with hypertransaminasemia and elevated alkaline phosphatase, together with elevated antinuclear antibodies. IgG levels were normal. Histological findings indicated AIH. The patient responded rapidly to treatment with prednisolone and azathioprine. De novo AIH in patients transplanted for PBC may cause graft dysfunction. This report also analyzes the case with respect to the other four reported cases, discussing etiologic hypotheses.