[Autoimmune dysthyroidism induced by alpha interferon in two female patients with chronic non-A, non-B hepatitis]

We report two cases of autoimmune thyroid disorders which appeared after 6 months of recombinant alpha interferon therapy given for chronic non-A, non-B hepatitis. There was no family or personal history of thyroid disease, or had the patients taken any hepatic or thyroid toxic drugs. The other causes of hepatic and thyroid diseases were ruled out. The first case concerned a 33-year-old woman with sporadic hepatitis C. Therapy was complicated by the appearance of antimicrosomal thyroid antibodies and hypothyroidism. At 22 months, substitutive therapy was still necessary in one case. The second case involved a 37-year-old woman with post-transfusional non-A, non-B hepatitis which was complicated by transient hypothyroidism preceding thyrotoxicosis (with TSH-receptor antibodies). We observed a return to euthyroidism and loss of associated antibodies after withdrawal of interferon and institution of hormonal therapy.