Incidence of thyroid dysfunction during interferon alfa-2b and ribavirin therapy in men with chronic hepatitis C: a prospective cohort study

BACKGROUND: Thyroid dysfunction is a known complication of interferon monotherapy in women with hepatitis C virus (HCV) infection. The aims of this study were to determine the incidence and long-term outcome of thyroid dysfunction in HCV-infected men receiving interferon and ribavirin combination therapy. METHODS: We prospectively studied 225 HCV-infected men with baseline levels of thyrotropin (TSH) within the reference range who were treated with subcutaneous interferon alfa-2b (3 million units 3 times per week) and oral ribavirin (1000-1200 mg/d) for 24 to 48 weeks. Patients underwent screening of TSH levels every 12 weeks during HCV therapy and at weeks 12 and 24 after completion of treatment. Patients with abnormal TSH levels underwent a comprehensive thyroid evaluation. RESULTS: Among the 225 patients, overt thyroid disease developed in 6.7% (95% confidence interval, 3.8%-10.8%), and subclinical thyroid disease was diagnosed in 4.0% (95% confidence interval, 1.8%-7.4%). In the 12 patients with overt hypothyroidism, antithyroglobulin antibodies were present in 11 and antithyroid peroxidase antibodies were present in 10, whereas thyroid-stimulating immunoglobulins were present in 2 of the 3 individuals with overt hyperthyroidism. Most of the patients with thyroid dysfunction completed HCV therapy, and thyroid disease resolved in 10 of the 12 patients with overt hypothyroidism, 2 of the 3 with overt hyperthyroidism, and all 9 with subclinical thyroid disease. CONCLUSIONS: Men with HCV infection treated with interferon and ribavirin should undergo routine screening for thyroid disease. Treatment of HCV can be safely continued in these patients because thyroid disease responds well to treatment and is reversible in most individuals.