Use of Rituximab Treatment in Addition to Standard Care for Newly Presenting Thrombotic Thrombocytopenic Purpura

Rituximab will be administered immediately after pheresis to minimize the amount of Rituximab that is removed by the subsequent days pheresis. The guidelines will be that 12 hours must elapse between the end of the first infusion of study drug and the next pheresis. Subsequent infusions would be weekly (plus or minus 2 days) with an attempt made to give study drug infusions after a pheresis that might be the last in a series, i.e. when no pheresis would be scheduled for at least the next day.