Direct-acting antivirals used in HCV-related liver disease do not affect thyroid function and autoimmunity

Purpose It is well known that interferon-alpha (IFN-alpha), used for long time as the main therapy for HCV-related disease, induces thyroid alterations, but the impact of the new direct-acting antivirals (DAAs) on thyroid is not established. Aim of this prospective study was to evaluate if DAAs therapy may induce thyroid alterations. Methods A total of 113 HCV patients, subdivided at the time of the enrollment in naive group (n = 64) and in IFN-alpha group (n = 49) previously treated with pegylated interferon-alpha and ribavirin, were evaluated for thyroid function and autoimmunity before and after 20-32 weeks of DAAs. Results Before starting DAAs, a total of 8/113 (7.1%) patients showed Hashimoto's thyroiditis (HT) all belonging to IFN-alpha group (8/49, 16.3%), while no HT cases were found in the naive group. Overall, 7/113 (6.2%) patients were hypothyroid: 3/64 (4.7%) belonging to naive group and 4/49 (8.2%) to IFN-alpha group. Furthermore, a total of 8/113 patients (7.1%) showed subclinical hyperthyroidism: 2/64 (3.1%) were from naive group and 6/49 (12.2%) from IFN-alpha group. Interestingly, after DAAs therapy, no new cases of HT, hypothyroidism and hyperthyroidism was found in all series, while 6/11 (54.5%) patients with non-autoimmune subclinical thyroid dysfunction became euthyroid. Finally, the only association between viral genotypes and thyroid alterations was genotype 1 and hypothyroidism. Conclusions This study supports evidence that DAAs have a limited or missing influence on thyroid in patients with HCV-related diseases. Moreover, it provides preliminary evidence that subclinical non-autoimmune thyroid dysfunction may improve after HCV infection resolution obtained by DAAs.