Background:Thyroid dysfunction (TD) represents an extra-hepatic manifestation of chronic hepatitis C (CHC) and it may also be a side effect of interferon-alpha (IFN-?) based treatment. However, previous studies have shown a wide variation in the incidence of TD in patients with CHC. Furthermore, the long-term outcomes and the predictive factors of TD in patients who receive IFN-? based treatment have still not been fully studied.
Objectives:The purpose of this study was to describe the incidence and long-term outcomes of TD in Chinese patients with CHC receiving IFN-? based treatment. We also aimed to identify the predictive factors of TD associated with this type of therapy.
Patients and Methods:A retrospective case-series study of 592 consecutive CHC patients with normal baseline thyroid functions, who received IFN-?based therapy, was performed. Thyroid function was assessed at baseline and every three months during treatment, as well as in the follow-up after cessation of therapy. The incidence and long-term outcomes of TD were observed. The prevalence of pretreatment thyroid peroxidase antibodies (TPOAb) were assayed in a sex- and age-matched nested case-control study. Multivariable stepwise regression analysis was used to explore the independent effects of the baseline factors, on the incidence of TD.
Results:At the end of the IFN-?based therapy, 68 patients (11.5%) in the study had developed TD, 58 patients (85.3%) presented with subclinical TD, and only 10 patients (14.7%) developed overt thyroiditis. The thyroid function of 46 patients (67.8%) spontaneously returned to normal in the six months of follow-up and only three patients (4.4%) had persistent overt TD symptoms after the 24 month follow-up period. Multivariate stepwise analysis suggested that gender and pretreatment TPOAb were the independent factors related to the incidence of TD. Both female patients (OR, 4.31; 95%CI, 2.067.31; P = 1.2610-4) and participants with a positive pretreatment TPOAb (OR = 3.9, 95%CI, 1.728.54, P = 0.008) had an increased risk for the development of TD.
Conclusions:The incidence of TD in Chinese patients with CHC during IFN-?based therapy was 11.5%, the majority of which was subclinical, while only a very small group had long-term overt TD requiring ongoing medical therapy. Female gender and pretreatment TPOAb positivity are risk factors for the development of TD during IFN-?based therapy.
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