Autoimmune thyroiditis and myelosuppression following treatment with interferon-alpha for hepatitis C

Case: We describe the case of a 48-year-old woman from Thailand diagnosed w ith chronic hepatitis C, who experienced a suppression of all blood cell co unts accompanied by a newly developed clinically manifested autoimmune thyr oid disorder after treatment with interferon alpha-2b (INF-alpha) 46 days a fter beginning of therapy a decrease of platelet, red and white blood cell counts became obvious. Concomitantly we observed an increase of FT4 and FT3 with a totally depressed TSH level 80 days after starting INF-alpha admini stration. Antibody assessment resulted in detection of high numbers of anti thyroid-microsomal antibodies and antithyroglobulin antibodies. Thyroid hor mone levels normalized under treatment with methimazole/propylthiouracil wi thin 4.5 months. However, two months after cessation of antithyroid therapy increasing TSH levels and decreasing FT4 levels indicated a new tendency t owards a hypothyroid state. Conclusion: We classify this case as an interfe ron-alpha-induced disorder of thyroid function accompanied by myelosuppress ion. A close monitoring for thyroid dysfunction, e.g. evaluation of TSH-lev els before and after administration of INF-a is mandatory.