Aim: To estimate the frequency of changes in thyroid function on the background of antiviral therapy in patients with chronic hepatitis C.
Material and methods: The retrospective group was consists of 204 patients (mean age 35.5±8.4 years) with HCV genotype 3a, who took the antiviral therapy course with pegylated interferon and ribavirin during 24 weeks. The patients were divided for two groups: 86.3% (176) had a sustained virological response (SVR), 13.7% (28) did not reach the SVR. SVR was defined as undetectable HCV RNA level at weeks 412. The groups were matched only by sex, because of the mean age of patients with SVR was statistically significant younger (32.3±7.2 years) than patients without SVR (40.63±8.66 years).
Results: Among 204 patients, TSH, fT4, and TPOAb levels were analysed in 66 patients before and after treatment. 92.4% (61) subjects had TSH level between 0.4 and 4.0 mlU/l with normal fT4. 7.6% (5) subjects had subclinical hypothyroidism. Although, absolute levels of TSH, fT4, and TPOAb were not significantly different before and after treatment, however, after course number of people with normal TSH level decreased to 71.2% (47), and in 28.8% (19) patients thyroid dysfunction was diagnosed. Most of them became hypothyroid and Graves disease manifested only in one case. In patients with normal function tests before treatment there was no difference in levels of fT4 in groups with SVR+ and SVR− and there was the significant difference in levels of TSH and TPOAb: the lower the value of TSH and TPOAb was before treatment, the more marked presence of SVR was determined.
Conclusion: Antiviral treatment can caused a statistically significant change in the thyroid function in 21.2% patients. The levels of TSH and TPOAb before treatment may be a predictor of SVR. Another study are necessary for confirming this fact.