Retrospective Epidemiological Study of Patients in the National Cohort of the French TMA Center

Immune thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening disorder characterized by microangiopathic hemolytic anemia, severe thrombocytopenia, and ischemic organ damage due to microvascular thrombosis. It results from a severe deficiency in the von Willeband factor (vWF)-cleaving protease ADAMTS13, primarily caused by autoantibodies that inhibit its activity. This deficiency leads to accumulation of ultra-large vWF multimers, triggering pathological platelet aggregation and widespread microthrombi. iTTP typically presents with acute neurological symptoms (e.g., confusion, seizures, coma), cardiac events (e.g., myocardial infarction), and multiorgan dysfunction. Without prompt treatment-plasma exchange, immunosuppression, and the vWF inhibitor caplacizumab-mortality exceeds 90%. Survivors face long-term risks, including cardiovascular complications, cognitive impairment, and reduced life expectancy. The TWI-LIGHT protocol is a national retrospective epidemiological study coordinated by the French Reference Center for Thrombotic Microangiopathies (CNR-MAT). It aims to analyze long-term outcome in \>1,200 iTTP patients diagnosed between October 2000 and June 2024. The study leverages pseudonymized data from the CNR-MAT registry, collected via a secure REDCap database. Key Objectives: 1. Primary: Assess the impact of cardiovascular risk factors (e.g., hypertension, diabetes) and ADAMTS13 activity on life expectancy in iTTP survivors. 2. Secondary: * Evaluate disease burden in underrepresented groups (pregnant/postpartum women, children, elderly patients). * Analyze the influence of new therapies (caplacizumab, rituximab, recombinant ADAMTS13) on care pathways. * Identify prognostic factors and treatment practices. * Characterize neurocognitive outcomes and quality of life post-iTTP. Methodology: * Design: Non-interventional, retrospective (MR-004 compliance), using data from standard care. * Inclusion: Patients with confirmed iTTP