[Plasma and urinary antithrombin III in the nephrotic syndrome in adults]. / Antithrombine III plasmatique et urinaire au cours des syndromes néphrotiques de l'adulte.

The occurrence of thromboembolism in nephrotic syndrome has been recently correlated with acquired antithrombin III (AT III) deficiency (and this raised the question of the prevention and treatment of thromboembolism with heparin). We studied AT III levels in plasma and urine in 39 adults with nephrotic syndrome. Three patients have had thromboembolic manifestations (before treatment with heparin). Their albuminemia was less than 18 g/l, their plasmatic AT III levels were normal and one had an elevated urine AT III level. Plasmatic AT III levels and albuminemia were positively correlated (r = 0.34; p less than 0.05) but AT III levels remained in the normal range being moderately diminished in only 3 patients never less than 70 p. 100. There was no correlation between plasmatic AT III level and proteinuria or urinary AT III levels. We conclude that the risk of thromboembolism in adults with nephrotic syndrome is not correlated with plasmatic AT III levels. This suggests that heparin therapy would be effective in preventing thromboembolism in this disorder. Indeed, no such episodes were seen in our patients under heparin.