Azathioprine for long-term maintenance of remission in autoimmune hepatitis

In most patients with autoimmune hepatitis, remission can be maintained with prednisolone, usually in combination with azathioprine, but the majority of patients have a relapse when treatment is stopped and therefore require long-term therapy. Because prolonged corticosteroid therapy may have serious toxic effects, in 1984 we undertook a controlled trial of maintenance therapy with azathioprine alone. None of the 25 patients in that trial had relapses during the follow-up period of one year. We have now followed these 25 patients for 10 years and have treated an additional 47 patients in a similar manner.

The 72 patients (median age, 47 years; range, 14 to 71) had been in complete remission for at least one year with 5 to 15 mg of prednisolone per day and 1 mg of azathioprine per kilogram per day. The dose of azathioprine was increased to 2 mg per kilogram per day, and the prednisolone was gradually withdrawn. Remission was defined as the absence of symptoms suggestive of a relapse and serum globulin and aspartate aminotransferase concentrations within the normal range, with or without a liver biopsy showing only minimal inflammation.

Sixty patients (83 percent) remained in remission while receiving azathioprine alone for a median of 67 months (range, 12 to 128). Of 48 follow-up liver biopsies in 42 patients, 45 showed inactive or minimal disease, and 3 showed moderate disease (2 after one year of therapy and 1 after eight years). After the prednisolone had been withdrawn, 26 patients lost their cushingoid facies, and 32 patients lost weight (median loss, 6.4 kg; range, 1.5 to 22.3). The most common adverse effect was arthralgia (in 38 patients). With the higher dose of azathioprine, four patients had myelosuppression, defined as a decrease in the leukocyte and platelet counts to less than 4000 and 150,000 per cubic millimeter, respectively. Two of these patients (both with pancytopenia) relapsed when the azathioprine was withdrawn; in the other two, remission was maintained with the resumption of prednisolone. Lymphopenia developed in 32 of 56 patients treated with 2 mg of azathioprine per kilogram per day for more than two years. During follow-up, nine patients died: one of liver failure and eight of causes not directly related to their liver disease.

Many patients with autoimmune hepatitis who have been in complete remission for at least one year with prednisolone and azathioprine can remain in remission with a higher dose of azathioprine alone.