Appropriate steroid therapy for autoimmune pancreatitis based on long-term outcome

Because autoimmune pancreatitis (AIP) responds well to corticosteroids, many AIP patients are given this treatment. However, there is no consensus on the indications, dose, or duration of steroid treatment. The aim of this study was to establish the most appropriate steroid therapy regimen.

We retrospectively reviewed morphological and serological improvement after steroid therapy and long-term outcome including relapse in 41 AIP patients who were given steroid therapy and were prospectively followed-up for more than 1 year.

All patients responded to steroid therapy, which was given because of bile duct stenosis secondary to sclerosing cholangitis in 34 AIP patients. Pancreatic enlargement normalized within one month; however, 13 patients had incomplete resolution of pancreatic duct narrowing, and 14 patients had incomplete resolution of bile duct stenosis. There was no correlation between the degree of morphological improvement and the initial prednisolone dose (30 mg and 40 mg/day). In 58% of 19 patients, serum IgG4 elevation failed to normalize. Glucose intolerance improved in 38% of the 21 patients with diabetes mellitus. Nine patients who had complete morphological and serological resolution, stopped their medication, and none have relapsed. Thirty-two patients continued maintenance therapy, and 4 of these patients suffered relapse.

The indications for steroid therapy in AIP patients include bile duct stenosis caused by sclerosing cholangitis and other systemic diseases, such as retroperitoneal fibrosis and diabetes mellitus. We recommend that oral prednisolone be used at an initial dose of 30 mg/day; maintenance therapy is required in cases without complete morphological and serological resolution.