Autoimmune thrombocytopenic purpura during pegylated interferon α treatment for chronic hepatitis C.

We describe a 72-year-old woman with chronic hepatitis C and autoimmune thrombocytopenic purpura (AITP) during pegylated interferon (PEG-IFN) alpha. Immunoglobulin G and antinuclear antibody were 2,113 mg/dL and 1,280 at the start, respectively. A liver biopsy negated autoimmune hepatitis. After a 48-week combination therapy with ribavirin, PEG-IFN alpha-2a was administered. At the 30th month, the platelet count was decreased to 1.1 x 10(4)/microL. Bone marrow biopsy disclosed normocellular marrow compatible with AITP. The platelet-associated IgG (PAIgG) titer rose to 500 ng/10(7) cells. Corticosteroid therapy was successful, and the platelet count and PAIgG titer reverted to 6.4 x 10(4)/microL and 57.3 ng/10(7) cells, respectively.