RESUMO
OBJECTIVE: To investigate the frequency of thyroid disorders (TD) in patients with chronic hepatitis C before and during interferon-alpha (IFN-α) and ribavirin (RIB) treatment. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: We prospectively studied 65 anti-HCV and viral RNA positive patients. Free thyroxine, thyroid-stimulating hormone, and thyroid peroxidase antibodies (TPO-Ab) were systematically tested at entry (m0), week 12 (m3) and week 24 (m6) of treatment. RESULTS: Mean age of the 65 patients (38 females and 27 males) was 49.61 ± 11.83 years. Seven (10.76 percent) patients presented baseline thyroid disorders (m0), three had thyroid dysfunction, and four were TPO-Ab positive. Thyroid disorders occurred in the first 12 weeks of treatment in 11 (16.92 percent) patients, four with thyroid dysfunction, and seven with TPO-Ab positive (m3). A total of 18 patients (27.69 percent) developed TD after 24 weeks of treatment, 7 with thyroid dysfunction, and 11 with TPO-Ab positive (m6). The relative risk of developing hypothyroidism found in this study was 1.3 (95 percent CI: 1.1 to 1.6), hyperthyroidism 1.2 (95 percent CI: 1.1 to 1.4), and TPO-Ab positivity 7.6 (95 percent CI: 3.9 to 14.5). The study showed a significant association between female sex and thyroid disease (p = 0.009). CONCLUSION: Thyroid dysfunction and autoimmune TD were observed during IFN-α and RIB therapy.