[Thyroid function abnormalities during interferon therapy]

Abstract

One hundred and twenty patients with chronic hepatitis C were treated with a 6-month course of recombinant alpha-interferon (a daily dose of 6 MU i.m. for the first two weeks and 6 MU or 3 MU i.m. three times weekly thereafter). Serum levels of thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), antithyroglobulin antibody (TGHA) and antimicrosomal antibody (MGHA) were measured before and three month after treatment. Ten of 106 patients with normal thyroid function test before therapy developed thyroid dysfunction; five with hyperthyroidism, four with hypothyroidism and one with positive MCHA. Fourteen patients had thyroid function disorder before treatment. Seven of eight patients with positive MCHA, showed a rise in the titer during the treatment. These data showed that a small proportion of patients treated with interferon developed thyroid dysfunction during the treatment. The interferon-induced thyroid dysfunction appears to be caused via the immune system but also by acting directly on the thyroid gland.