LATENT AUTOIMMUNE HEPATITIS TRIGGERED DURING INTERFERON THERAPY IN PATIENTS WITH CHRONIC HEPATITIS-C

Background/Aims: Interferon can induce autoantibodies and autoimmune r eactions. This study reviewed the clinical, serological, and HLA pheno typical features of patients who developed autoimmune hepatitis during interferon therapy for chronic hepatitis C, analyzing their response to immunosuppressive treatment. Methods: The diagnosis of chronic hepa titis C was based on positivity for viral RNA and a liver biopsy speci men obtained before interferon treatment. Sera were tested for autoant ibodies by indirect immunofluorescence assay. HLA typing was performed by applying a standard microlymphocytotoxicity method. Results: Of 14 4 patients with chronic hepatitis C treated with interferon, 7 women d eteriorated during treatment; serum transaminase, gamma-globulin, and immunoglobulin G levels increased; and serum autoantibodies became pos itive. interferon was interrupted, a diagnosis of autoimmune hepatitis was established, and immunosuppressive therapy was initiated. All pat ients responded to this treatment. The 7 patients had similar HLA typi ng to those with autoimmune hepatitis, with DR4 in 2 patients (67%) wi th type 2 autoimmune hepatitis, and with DR3 and DR52 in 2 (50%) and 4 (100%) patients, respectively, with type 1 autoimmune hepatitis; addi tionally, 5 patients (71%) had DQ2, and 4 (57%) had both DR52 and DQ2. Conclusions: In female patients with chronic hepatitis C, a genetic s usceptibility to autoimmune hepatitis may exist, possibly triggered by immunostimulating effects during interferon therapy. Immunosuppressiv e treatment has been well tolerated and seems to be effective.