Thyroid Dysfunction and Long-term Outcome during and after Interferon-alpha Therapy in Patients with Chronic Hepatitis C

Introduction: Thyroid dysfunction (TD) is a well-established adverse effect in chronic hepatitis C virus (HCV)-infected patients, treated with interferon-alpha (IFN-α), with or without ribavirin. However, the long-term outcome is not well-studied. The purpose of this study was to estimate the prevalence and long-term outcome of TD after HCV-therapy. Materials and Methods: Retrospective analysis of 109 HCV-treated patients (for 6 to 12 months, according to HCV genotype), for the period 1996 to 2008. Thyroid function tests were performed every 3 months during therapy and after discontinuation (3 months to 12 years). Routine laboratory tests and virological assessment were performed according to generally accepted practice. Results: TD was observed in 26 patients (23.85%). The positive and negative predictive value for thyroid autoantibodies (ATA) was 80% and 72.7%, respectively. Relative risk for those with positive ATA was 2.9 (95% CI: 1.6 to 5.3, P = 0.014). The median duration of TD was 12.0 months (min: 3; max: 132). The median follow-up period for the patients with TD was 25.5 months (min: 12; max: 144). Finally, 15 patients developed permanent TD (57.69%), compared to 11 with temporary TD (42.31%). Sex is a risk factor for TD, as there were more females than males affected (P = 0.011). Genotype, viral load, time of HCV-exposure prior to therapy, and virological response did not differ between patients with and without TD. Conclusion: TD among HCV-treated patients was more frequent than usually reported, with >50% developing permanent TD. ATA status may play a role in estimating the risk of subsequent TD. Women appear to be more vulnerable to TD than men.