How reversible is hepatic functional impairment in autoimmune hepatitis?

We quantifed the short-term effects of immunosuppressive therapy on hepatic metabolic function in autoimmune hepatitis to establish how long it takes to achieve maximum functional improvement.

We studied 14 newly diagnosed patients with autoimmune hepatitis (12 type 1, two type 2) by antipyrine clearance and conventional liver tests, then repeated studies at 3-6 month intervals during the first 18 months of immunosuppressive therapy.

Low values for antipyrine clearance were found in 13 of 14 cases; serum albumin concentration was low in four, bilirubin raised in eight and prothrombin time prolonged in four. Following immunosuppressive treatment for 3 months, antipyrine clearance improved by 98% (standard error of the mean 24%), which was proportionally greater than for serum albumin, bilirubin or prothrombin time. Antipyrine clearance and serum albumin continued to improve after 6-12 months of immunosuppressive treatment in several cases, whereas there were no further improvements in alanine aminotransferase (ALT), bilirubin and prothrombin time.

In the short term, immunosuppressive therapy for autoimmune hepatitis markedly improves hepatic metabolic function, which is particularly striking for the sensitive metabolic test antipyrine clearance, but may also be seen with serum albumin. However, it may take up to 12 months to achieve maximal functional recovery. Management guidelines on autoimmune hepatitis should be extended to emphasize that changes in hepatic metabolic function, as well as ALT and gamma-globulin levels, be taken into consideration in the definition of remission.