Interferon-Alpha Induced Severe Hypothyroidism Followed by Graves' Disease in a Patient Infected with Hepatitis C Virus

ABSTRACT

Interferon-alpha (IFN-alpha) is an important therapeutic agent for hepatitis C virus (HCV) infection, but has various side effects including thyroiditis. We report a case of interferon-induced non-autoimmune hypothyroidism followed by autoimmune-medicated Graves' disease. A 59-year-old woman was diagnosed with chronic active hepatitis C; she had been treated with IFN-alpha and ribavirin for 24 weeks. Before starting the IFN-alpha, her thyroid function was normal and she was negative for autoantibodies. Severe hypothyroidism developed 5 weeks after halting the IFN-alpha, with the Graves' disease phase arising at 32 weeks. For accurate diagnosis and appropriate treatment of thyroid dysfunction during treatment with IFN-alpha, we need to understand and consider rare cases of multiphasic disorder involving both non-autoimmune and autoimmune thyroiditis induced by IFN-alpha.