Autoimmune Enteropathy Associated with Cessation of Interferon-Alpha Therapy in Chronic Hepatitis C

Excerpt

Interferon (IFN) was first described in 1957 by Isaacs and Lindenmann as a substance that interfered with intracellular viral replication [1]. Since its discovery, IFN-α has been used in the treatment of multiple sclerosis, myeloproliferative disorders, solid tumors, and chronic viral hepatitis. The current mainstay of treatment for chronic hepatitis C consists of pegylated interferon alpha 2a (PegIFNα 2a) and ribavirin, with a sustained virologic response rate of 42–46% for genotype 1 and 76–82% for genotypes 2 and 3 [2]. IFN-α acts through both antiviral and immunomodulatory mechanisms. It stimulates the immune system by activating immune cells including cytotoxic T cells, natural killer cells, and macrophages as well as promoting antibody production by B lymphocytes [3]. Likely due to these immune-modulating properties, IFN-α has been reported to precipitate or cause exacerbation of autoimmune conditions such as thyroiditis, type 1 diabetes, and systemic lupus erythematosus (SLE)-like syndromes [4‐10]. In fact, up to 6.2% of patients without prior thyroid autoantibodies treated with IFN-α have been reported to develop thyroiditis [4]. Another study of 677 chronic hepatitis C virus (HCV)-infected patients who were treated with IFN-α found that 0.15% of patients developed SLE-like syndrome [5]. However there has never been a reported case of autoimmune enteropathy (AIE) linked to IFN. …