Renal vein thrombosis and inferior vena cava thrombosis in systemic lupus erythematosus. Frequency and risk factors.

Phlebography of the inferior vena cava with selective study of the renal veins was performed in 43 patients with systemic lupus erythematosus (SLE). Inferior vena cava thrombosis (IVCT) or renal vein thrombosis (RVT) was found in 3 of 11 patients (27%) with nephrotic syndrome, in 8 of 13 (61.5%) with previous thrombophlebitis, and in 3 of 4 (75%) with suggestive acute clinical picture. In contrast, none of the 20 control patients with SLE had IVCT or RVT. These results show that SLE patients with thrombophlebitis have a very high risk of developing IVCT or RVT; patients with nephrotic syndrome have a smaller risk. Neither IVCT nor RVT was found in SLE patients without antecedent thrombophlebitis or nephrotic syndrome.