De-novo autoimmune hepatitis after liver transplantation.

BACKGROUND

Late graft dysfunction that does not result from recognised causes, such as rejection, infection, or vascular or biliary complications, can occur after liver transplantation. We investigated a particular type of unexplained graft dysfunction that is associated with autoimmune features in children who underwent transplantation at our unit between 1991 and 1996.

METHODS

Seven (4%) of 180 liver-transplant recipients developed an unexplained but characteristic form of graft dysfunction (five boys, two girls; median age at presentation 10.3 years, range 2.0-19.4). The median period after surgery was 24 months (6-45). The indications for transplantation had been extrahepatic biliary atresia (four patients), Alagille's syndrome (one), drug-induced acute liver failure (one), and alpha1-antitrypsin deficiency (one). Four patients were on triple immunosuppression with cyclosporin, azathioprine, and prednisolone; and three were on tacrolimus. Immunoglobulin measurements, autoantibody studies, serological studies, and HLA typing were undertaken. Liver-biopsy samples were taken.

FINDINGS

Infectious and surgical complications were excluded. Liver-biopsy samples showed the histological changes of chronic hepatitis, including portal and periportal hepatitis with lymphocytes and plasma cells, bridging collapse, and perivenular-cell necrosis without changes typical of acute or chronic rejection. All patients had high concentrations of IgG (median 22 g/L [range 17.2-34.4]) and high titres of autoantibodies. All but one patient responded to prednisolone 2 mg/kg daily and an increase in or addition of azathioprine (1.5 mg/kg daily) within a median of 32 days (7-316). One responder relapsed owing to poor compliance but went into remission after treatment was restored. All six respondents remain in remission on a reduced dose of prednisolone (5-10 mg/day) and 1.5 mg/kg daily azathioprine at a median of 283 days (range 108-730) follow-up.

INTERPRETATION

Our data show that symptoms of autoimmune hepatitis, which are responsive to the classical treatment for this condition, can appear in liver-transplant patients while they are on anti-rejection immunosuppression. Whether the liver damage in these patients is a form of rejection or the consequence of autoimmune attack has yet to be established.