The thromboembolic risk is increased during the nephrotic syndrome (NS) with an incidence of deep vein thrombosis 15%, pulmonary embolism of 10-30% and renal vein thrombosis of 25-37%. There is a hemostatic imbalance with urinary leakage of anticoagulant factors and increased hepatic synthesis of procoagulant factors, platelet hyperaggregability and a decrease in fibrinolytic activity. However, the identification of patients requiring anticoagulant prophylaxis remains imprecise.The thromboembolic risk is higher when the NS is related to extramembranous glomerulonephritis comparatively to others glomerulopathies. The reason of this difference is not still known. This risk increase with SN's severity and therefore with the decrease of albuminemia. Moreover, few studies have evaluated anticoagulant treatment efficacy during a NS, which clinical benefit depends also on hemorrhagic risk specific of each patient. Thus, the determination of the thrombotic risk and the modalities of anticoagulation are variable and perfectible during the NS.

We propose to use the thrombin generation test (TGT) to quantify the thromboembolic risk in patients with a NS and to follow its evolution during prophylactic anticoagulation and after remission of NS.

Thrombin generation test will be performed prospectively in nephrotic patients with various diseases (Minimal Change Disease (MCD), Malignant Nephrosclerosis (MN), Focal Segmental GlomeruloSclerosis (FSGS), diabetic glomerulopathy…) at diagnosis, during anticoagulant treatment (D8±3) and after disease remission (M6).

Inclusion Criteria:

• Nephrotic syndrome
• Known cause of nephrotic syndrome (renal biopsy and/or positive anti-PLA2R)

Exclusion Criteria:

- Active anticoagulation treatment before TGT

Patients with nephrotic syndrome defined by albuminemia <3 g/dl and urinary protein/creatinine > 3g/g) admitted in the nephrology department of Tenon hospital; etiological diagnosis available; consenting to research and whose treatment and follow-up will be possible for at least 6 months.