Thyroid Dysfunction Related to Interferon in Turkish Patients with Viral Hepatitis: Incidence and Influencing Factors

Abstract

Objective: Interferon therapy is widely used for patients with chronic viral hepatitis B and C (CHB-C). It is known that thyroid gland dysfunction (TD) may develop secondary to interferon treatment, but different frequencies of TD development are reported in the literature. For this reason, we aimed to investigate the incidence of TD developing secondary to interferon treatment in patients with CHB-C treated in our clinic and possible influence factors. Methods: A total of 93 CHB-C patients treated with interferon were included in this study. Tests of thyroid functions (TSH, FT3, FT4), thyroid auto-antibodies (Anti-Tg, Anti-TPO) were done before starting interferon treatment, during and after treatment. Patients who did not have normal thyroid gland functions were not included in this study. Results: TD was observed to develop in a total of 20 patients (21.5%). TD had developed in the first 6 months after initiation of interferon therapy. In 18.3% of these patients the condition was temporary, while 3.2% patients required treatment for TD. The most frequently seen condition are subclinical types. Age (over 40 years) (OR: 7.25 95% CI = 1.46-35.80, P = 0.015) and gender (female) (OR: 5.83 95% CI = 1.31-25.76, P = 0.020) were found to be statistically significant independent risk factors in TD development. Conclusion: Although TD secondary to interferon treatment in patients with CHB-C may develop in a substantial rate, most of these are temporary and do not require TD treatment. Independent risk factors in TD development were found to be gender and age.