[Case of thrombotic thrombocytopenic purpura associated with clopidogrel]

We reported a Japanese first case of thrombotic thrombocytopenic purpura (TTP) induced by clopidogrel, a newly developed antithrombotic drug, marketed in May 2006 in Japan. This 80 years old woman developed cerebral infarction and suffered from Broca's aphasia and right hemiparesis. Clopidogrel was started on Day 6 after the onset. On Day 10, four days after the administration of clopidogrel, two egg-sized purpura with marked decrease in platelet count was found. The purpura extended over the entire body in next few days. Despite total seven times of plasma exchange, platelet count did not normalize. Twenty four days after the onset of TTP, the patient developed central catheter infection and died of sepsis. TTP will become a lethal side effect of clopidogrel, when diagnosis and treatment are late. Because it is assumed that the mechanism of clopidogrel induced TTP differs from that of ticlopidine, we should establish firm treatment urgently.