OBJECTIVES: Interferon-α (IFN-α) is a gold standard in the therapy of viral chronic hepatitis type C (CHC). However, such treatment might lead to thyroid dysfunction. Patients usually present hypothyroidism, but rarely also hyperthyroidism may develop. The aim of the study is to present two-year clinical follow-up of patients with CHC and IFN-α-induced hyperthyroidism (IIH), with special regard to the methods and efficacy of the therapy.
METHODS: A group of 106 patients with CHC and IIH were analyzed. Subjects were divided into two groups according to etiology: group 1, with Graves' disease (GD) and group 2, with Hashitoxicosis (HT). The diagnosis of GD and HT was based on: clinical signs of hyperthyroidism, hormonal profile (TSH, fT4, fT3), level of thyroid autoantibodies (Tg-Abs, TPO-Abs, TSHRAbs). Treatment of hyperthyroidism was monitored by repeated clinical assessment and laboratory tests. RESULST: 28 patients (26 with GD of which 5 exhibited mild orbitopathy and 2 with HT) were treated with radioiodine [the average dose of was 17 mCi [668 MBq]. In adition 78 out of 80 patients with HT mostly β-blocker therapy was successful (transient hyperthyroidism). At the end of the observation period, in group 1 remission was achieved in 17 (65.4%) cases, 6 (23.1%) patients showed hypothyroidism and 3 (11.5%) presented recurrence of hyperthyroidism.
CONCLUSIONS: Most patients with IIH present Hashitoxicosis, while a minority of them develop Graves' disease. In a majority of patients with HT spontaneous remission of disease occurs. In patients with long-term hyperthyroidism, radioiodine therapy is an effective and well-tolerated.