Study of Cyclosporine or Corticosteroids as an Adjunct to Plasma Exchange in Thrombotic Thrombocytopenic Purpura (TTP)

Inclusion Criteria: * Patients with a clinical diagnosis of idiopathic TTP as defined by a microangiopathic hemolytic anemia and thrombocytopenia (\<100 x 103) * Additional components of the pentad (fever, renal and neurologic abnormalities) need not be present. * Additional explanations for the microangiopathic changes including DIC and malignancy should be excluded. * Patients with pregnancy associated TTP will be permitted on this therapeutic trial if the child is delivered prior to the initiation of therapy for TTP. However, female patients that are breastfeeding and are unwilling to discontinue breastfeeding at the time of enrollment will be excluded from this study * Patients with a previous diagnosis of TTP are eligible to be enrolled provided they meet eligibility criteria and have not been treated for an TTP in the past 30 days * Given the potential for nephrotoxicity with CSA, all patients must have a serum creatinine of \< 2.5 mg/dl prior to enrollment Exclusion Criteria: * In light of concern for the prompt initiation of PE, all patients with suspected TTP may be enrolled on this trial. If it is subsequently found that the patient does not meet enrollment criteria, they will be removed and their spot replaced for study purposes. Patients removed from the study after enrollment will continue to be followed longitudinally for 6 months to be monitored for safety and will be included in the safety database. * Patients with TTP clinically categorized as secondary to stem cell transplant and solid organ, bloody diarrhea associated, malignancy associated, and drug associated will not be enrolled on this therapeutic study. * Incarcerated patients will be excluded from the study due to the inherent difficulties in maintaining close follow-up for study purposes in patients who are incarcerated. * Any patients already being treated chronically with corticosteroids or cyclosporine and taking these at the time of their presentation will be excluded from this study. * Female patients that are breastfeeding and are unwilling to discontinue breastfeeding at the time of enrollment will be excluded from this study * Patients taking any medications contraindicated in combination with CSA that cannot be safely discontinued will be excluded from this study.