Autoimmune and non-autoimmune thyroid dysfunction in HCV infected and HCV–HIV co-infected patients before and after interferon alpha therapy: A prospective study

Abstract

IntroductionAutoimmune thyroid diseases are reported in no treated hepatitis C virus (HCV) infection. The standard interferon alpha (IFNα) treatment is associated with an increase of thyroid damage and dysfunction. The present cohort prospective study compared thyroid function and autoimmunity in HCV patients’ monoinfected and coinfected HCV–HIV at baseline, during and after IFNα therapy. MethodsWe studied 790 HCV infected patients: G1 (monoinfected HCV: N=580) and G2 (HCV–HIV coinfected: N=210). They were evaluated for thyroid function and thyroid tiroperoxidase antibodies (TPOAb) at baseline and 235 patients (G1: 183; G2: 52) post IFNα therapy.If thyroid dysfunction (TD) was diagnosed, they were reevaluated at 12 month after discontinuation to determine whether the TD was transitory or definitive. ResultsNo difference was found in the prevalence of TD at baseline in G1 (7.6%) and G2 (9%). However, monoinfected patients showed a higher prevalence of TPOAb positivity with a women preponderance in this group. There was no difference in TD between both groups during IFNα therapy (G1 23.5% vs G2 19.2%). In G1 the autoimmune TD was higher than in G2 (67.4% vs 30%, p=0.02). Autoimmune TD during IFNα tended to evolve to definitive hypothyroidism and non-autoimmune TD recovered euthyroidism after IFNα discontinuation. The presence of positive TPOAb (RR 3.55) and female gender (RR 2.4) were associated with the development of TD with IFNα therapy. ConclusionOur hypothesis is the importance of HCV in G1 and G2, combined with IFNα in triggering TD and TPOAb positivity, not described in other diseases’ applications.