Agranulocytosis during treatment of chronic hepatitis C complicated by hyperthyreosis. Case reports.

Agranulocytosis is a life-threatening disorder characterised by a greatly decreased number of circulating neutrophils below 500/μL. This article presents two cases of agranulocytosis in patients treated with pegylated interferon and ribavirin due to chronic hepatitis C. Interferon induced hyperthyroidism, which required the use of a tyreostatic. Anti-thyroid drugs (ATD) used to treat hyperthyroidism can cause agranulocytosis. The synergistic reaction of ATD and interferon on bone marrow cannot be excluded.