Hepatitis C has become one of the major epidemics afflicting young people in both the developed and developing countries in the late 20th century. This peculiar infection has been associated with many extrahepatic manifestations, including renal glomerular and autoimmune diseases. The most common endocrine disorder, especially after treatment with interferon-␣ (IFN-␣)-based therapy, is autoimmune thyroid disease. Although the pathophysiology of this condition is generally understood to be related to the immunomodulating properties of the hepatitis C virus particles, accentuated by exogenous IFN-␣ when treated, not every patient undergoing treatment encounters autoimmune thyroid disease, indicating there are other factors at play. This is particularly applicable to primary hypothyroidism. A surveillance program for thyroid diseases is proposed for patients undergoing IFN-␣-based treatment.
Learning Objectives• Outline the ways in which hepatitis C virus infection and its treatment may contribute to the development of autoimmune thyroid disease and consequent thyroid dysfunction. • Identify relationships among human immunodeficiency virus infection, interferon therapy, and both thyrotoxicosis and hypothyroidism.