2 CASES OF TRANSIENTLY TSBAB-POSITIVE HYPOTHYROIDISM INDUCED BY INTERFERON-ALPHA THERAPY FOR CHRONIC HEPATITIS-C

A 34-year-old woman and a 54-year-old woman were treated with interfer on-alpha (IFN-a) for chronic hepatitis C. Three months after the cessa tion of the IFN-alpha therapy, each patient developed hypothyroidism w ith the presence of thyroid-stimulation-blocking antibody (TSBAb) and TSH-binding inhibitor immunoglobulin (TBII). These two patients were t reated with thyroxine, and both TSBAb and TBII activities gradually de creased. Although both TSBAb and TBII became negative several months a fter the start of the replacement therapy, the replacement dosage of L -thyroxine could not be reduced. Thyroid biopsies showed that the foll icular epitheliums were flattened in both cases with lymphocytic infil tration. These findings suggest that IFN-cr may induce hypothyroidism and the transient emergence of TSBAb and TBII.