French National Cohort MATRIX "Renal and Systemic Thrombotic Microangiopathy"

Thrombotic microangiopathies (TMAs) are a diverse, rare but serious group of diseases. Progress has been made regarding the epidemiology of TMA (Bayer CJASN 2019). It has been shown that secondary TMAs account for 95% of cases, whereas primary TMAs (atypical hemolytic syndromes (HUS) and thrombotic thrombocytopenic purpura (TTP)) account for only about 5%. However, in many cases, the pathophysiology, optimal management and prognosis of TMA remains unclear and it has been shown that patients with TMA may have renal-limited TMA or renal and hematological TMA (ie. With (mechanical anemia, thrombocytopenia, elevated LDH, decreased haptoglobin, schistocytes). In most studies, kidney biopsies are not performed and the diagnostic workup is uncomplete. As this is a rare disease, only a multicenter approach (\>20 centers) over a long period of time (\>10 years), with adequate diagnostic workup including kidney biopsies can help us to answer these questions (investigators in the present are usually members of the CNR-MAT (a network of the TMA centers in France).