Thrombotic thrombocytopenic purpura: combined treatment with plasmapheresis and antiplatelet agents.

Seven of eight patients with thrombotic thrombocytopenic purpura who were treated with both exchange plasmapheresis and antiplatelet agents (aspirin and dipyridamole) achieved complete remission. The eighth patient appeared to fail on this regimen but responded to corticosteroids and splenectomy. A ninth patient attained full remission after therapy with only aspirin and dipyridamole. The antiplatelet agents appeared to play an important role in the response of four patients. Eight patients received maintenance aspirin and dipyridamole. This maintenance therapy may have prevented relapses of thrombotic thrombocytopenic purpura in some patients as evidence of active, subclinical disease persisted for many weeks in most patients. Treatment with maintenance antiplatelet agents was discontinued in five patients after 7 to 18 months and no patient has relapsed. An effective therapeutic regimen for thrombotic throbocytopenic purpura would include initial therapy with exchange plasmapheresis, aspirin, and dipyridamole and maintenance therapy with antiplatelet agents.