Evolution and predictive factors of thyroid disorder due to interferon alpha in the treatment of hepatitis C

AIM： To study predictive factors of thyroid dysfunction associated with interferon-alpha （IFNa） therapy in chronic hepatitis C （CHC） and to describe its long-term evolution in a large population without previous thyroid dysfunction. METHODS： We performed a follow-up of thyroid function and detection of thyroid antibodies in 301 patients treated for CHC with IFNα from 1999 to 2004. RESULTS： Thyroid disorder developed in 30/301 （10%） patients with a mean delay of 6 ± 3.75 mo： 13 patients had hyperthyroidism, 11 had hypothyroidism, and 6 had biphasic evolution. During a mean follow-up of 41.59 ± 15.39 mo, 9 patients with hyperthyroidism, 3 with hypothyroidism, and 4 with biphasic evolution normalized thyroid function in 7.88 ± 5.46 mo. Recovery rate of dysthyroidism was not modified by treatment discontinuation, but was better for patients with negative thyroid antibodies before antiviral treatment （P = 0.02）. Women had significantly more dysthyroidism （P = 0.05）. Positive thyroid peroxidase and thyroglobulin antibodies were more frequent before antiviral treatment in patients who developed dysthyroidism （P 〈 0.0003 and P = 0.0003, respectively）. In a multivariate model, low fibrosis was found to be a predictive factor of dysthyroidism （P = 0.039）.CONCLUSION： In this monocentric population of CHC, dysthyroidism, especially hyperthyroidism, developed in 10% of patients, Low fibrosis was found to be a predictive factor of dysthyroidism, Thyroid disorder recovered in 16/30 patients （53%） and recovery was better in the non-autoimrnune form,