A Prospective Study on the Long-Term Vascular Burden in Thrombotic Thrombocytopenic Purpura Patients

Inclusion Criteria:

• Adults (=18 years) with a recent diagnosis of their first episode of idiopathic TTP,who have been treated with plasma exchange with or without other therapies, and whoare in remission. Remission is defined as the normalization of platelet counts andlactate dehydrogenase levels with no clinical signs or symptoms of microvascularinjury for more than 30 days. The patients will be included in the study within 30days of remission of their symptoms. The patients will all meet the followingdiagnostic criteria for idiopathic TTP: (1) thrombocytopenia with platelet count <150x 109 /L, (2) microangiopathic hemolytic anaemia (presence of red blood cellfragmentation by peripheral blood smear), (3) elevation of lactate dehydrogenase (LDH)> 1.25 X of the upper limit of normal, and (4) ADAMTS13 Activity < 10%

Exclusion Criteria:

• Patients will be excluded if they have diagnoses of typical HUS (diarrhea-associatedHUS), atypical HUS, and disseminated intravascular coagulation, have abnormalinternational normalized ratio at the time of presentation, have diagnoses ofmalignant hypertension at the time of presentation, are on the following drugs within 90 days prior to their presentation: ticlopidine, clopidogrel, mitomycin C,gemcitabine, cyclosporine, and quinine, have a history of hematopoietic stem celltransplantations prior to their presentation, have a history and/or diagnosis ofvasculitis, systemic lupus erythematosus, scleroderma, rheumatoid arthritis,antiphospholipid antibody syndrome, or HIV/AIDS, have a history of solid organmalignancy within 5 years prior to presentation, i.e. lung, breast, gastric, colon,pancreatic, prostate, or liver, are pregnant at the time of presentation, have severebronchospasm, unstable angina, and severe ischemic heart disease, have advanced kidneyfailure (estimated Glomerular Filtration Rate < 30 mL/min/1.73m2), and have history ofallergic reaction to contrast dye.