[Mechanism of renal vein thrombosis in patients with nephrotic syndrome: a prospective study].

One hundred nephrotic patients were routinely examined with renal venography and renal biopsy. Blood platelet (BPC), aggregation (Pag), adhesiveness (Pad), kaolin prothrombin time (KPTT), thrombin time (TT), plasma viscosity (PV) were tested in 50 patients. Also plasma fibrinogen (Fbg), fibrin/fibrinogen degradation product (FDP), antithrombin III (AT III), antiplasmin (PI), plasminogen (Plg) were investigated from the peripheral vein, superior, inferior veno cava, and right, left renal vein. Forty-six nephrotic patients had the complication of renal vein thrombosis (RVT); 4/5 of them were clinically latent. Multivariate regression analysis, showed that the number of 2 renal branches with RVT (RVTn) related to the history of steroid and membranopathy was associated with the tendency of RVT formation. Coagulation-fibrinolysis test showed RVTn = 1.17284 Pag-0.02363 PI + 0.04034 AT III + 3.21141 PV-0.02447 Plg + 2.33538 (P = 0.025). Fbg in renal vein involved with RVT was significantly different from the innocent side (P < 0.05). In addition, correlations were found between AT III and protein in urine (P < 0.01) and between plasma Fbg and albumin (P < 0.02). 46% patients with nephrotic syndrome complicated by RVT were usually clinically latent. Disorders of platelet function, increased PV, steroid and intensive diuretic treatment might promote RVT formation, especially in membranopathy.