The outcome of thyroid disease induced by interferon plus ribavirin in patients with chronic hepatitis C

Objective To explore the long-term outcome of thyroid disease occurred during and after peg-interferon plus ribavirin therapy (PR therapy) in patients with chronic hepatitis C (CHC). Methods CHC patients admitted to Henan People′s Hospital during January 2009 to December 2012 treated with peg-interferon plus ribavirin were included in this study. The thyroid functions were tested before treatment, at week 12, week 24, week 48, week 72 of treatment, and at week 24, week 48, week 96, week 144 after end of treatment. Thyroid function test frequency was increased according to the patients′ test results and medication was registered. Measurement data was analyzed using t test and count data was compared using chi square test or Fisher exact probability test. Results A total of 358 patients was included with mean age of (43±12) years (range 18 to 65 years), of whom 200 were male and 158 were female. There are 300 cases (83.8%) with HCV genotype-1 infection, 56 cases (15.6%) with genotype-2 infection and 2 cases (0.6%) with genotype 3 infection. Eighty out of 358 patients (22.3%) developed thyroid disease, among whom 71 cases (88.75%) were diagnosed with autoimmune thyroiditis and 9 cases (11.25%) were non-autoimmune thyroiditis. At week 144 after end of treatment, 21 (29.6%) cases with autoimmune thyroiditis completely recovered and 9 cases with non-autoimmune thyroiditis fully restored. The comparison between two groups had statistical significance (F=16.69, P=0.00). Patients were divided into non-thyroid disease and thyroid disease groups. The were no significant differences of baseline viral load, HCV genotype, transaminase levels and age between the two group (all P>0.05). The differences of gender, baseline levels of thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb) and treatment outcome were statistically significant (all P<0.05). Conclusions Interferon-induced autoimmune thyroiditis could not be completely reversed. Some patients develop chronic thyroiditis and require long-term drug therapy. Patients with positive TPOAb and TgAb induced by interferon have high risk of developing Hashimoto′s thyroiditis and Graves′disease during follow-up. Appropriate treatment for thethyroid disease induced by interferon does not affect the antiviral treatment. Clinicians should monitor the thyroid function during and after antiviral therapy in patients with CHC. Key words: Hepatitis C, chronic; Thyroid diseases; Interferon; Thyroid Autoantibodies