Thrombotic thrombocytopenic purpura associated with pegylated-interferon alpha-2a by an ADAMTS13 inhibitor in a patient with chronic hepatitis C.

Abstract

A deficiency of ADAMTS13 leads to platelet clumping and/or thrombi formation, finally resulting in thrombotic thrombocytopenic purpura (TTP). In this study, a 62-year-old male with chronic hepatitis C developed TTP a month after long-term pegylated-interferon (PEG-IFN) treatment. The observed low level of activity of plasma ADAMTS13 following PEG-IFN treatment was shown to gradually increase with the improvement of TTP, while the titer of an inhibitory anti- ADAMTS13 IgG antibody decreased concomitant with the increase in ADAMTS13 activity. Serial determination of ADAMTS13 activity and its inhibitor may provide useful information for the diagnosis and treatment of IFN-associated TTP, as well as its pathogenesis.