This study will evaluate subjects with thrombotic thrombocytopenic purpura (TTP), a rare blood condition that cases blood clots to form in small blood vessels through the body, not known to be due to another disorder or drug, treated with plasma exchange.
The primary study objective is to determine if treatment with Rituximab increases the probability of Early Treatment Response in patient with TTP who are also being treated with Plasma Exchange and corticosteroids.