Pulmonary embolism and renal vein thrombosis in patients with nephrotic syndrome: prospective evaluation of prevalence and risk factors with CT

To prospectively determine the prevalence of pulmonary embolism ( PE pulmonary embolism ) and renal vein thrombosis ( RVT renal vein thrombosis ) with computed tomography (CT) and to identify markers predictive of PE pulmonary embolism and/or RVT renal vein thrombosis in a large consecutive cohort of patients with nephrotic syndrome. This study was approved by the local institutional review board, and all patients or their guardians provided written informed consent. Consecutive patients with nephrotic syndrome (24-hour urine protein > 3.5 g) underwent combined CT pulmonary angiography for PE pulmonary embolism and renal CT venography for RVT renal vein thrombosis . Prevalence of PE pulmonary embolism and/or RVT renal vein thrombosis was estimated for different ages, sexes, and histopathologic types of nephrotic syndrome. Multivariate analysis was used to determine independent predictors for PE pulmonary embolism and/or RVT renal vein thrombosis in patients with nephrotic syndrome. There were 512 patients in the study cohort (331 male patients, 181 female patients; mean age, 37 years ± 17 [standard deviation]; range, 9-81 years), including 80 children. One hundred eighty (35%) of 512 patients had PE pulmonary embolism and/or RVT renal vein thrombosis , with PE pulmonary embolism the more common condition (85% [153 of 180]). PE pulmonary embolism was associated with RVT renal vein thrombosis in 85 (56%) of 153 patients and was isolated in 68 patients (44%). Most patients with PE pulmonary embolism (84% [128 of 153]) were asymptomatic. One hundred twelve (22%) of 505 patients had RVT renal vein thrombosis . PE pulmonary embolism and/or RVT renal vein thrombosis was found in 15 (19%) of 80 children with nephrotic syndrome, while 165 (38%) of 432 adult patients with nephrotic syndrome had PE pulmonary embolism and/or RVT renal vein thrombosis (P = .001). Membranous nephropathy was the most common histopathologic type associated with PE pulmonary embolism and/or RVT renal vein thrombosis (48% [88 of 183]). Membranous nephropathy, age greater than 60 years, high hemoglobin level, long prothrombin time, and high creatinine level were independent predictors of PE pulmonary embolism and/or RVT renal vein thrombosis (P < .05 for all). PE pulmonary embolism and RVT renal vein thrombosis are common in patients with nephrotic syndrome. PE pulmonary embolism is more common than RVT renal vein thrombosis , is most often asymptomatic, and is most frequently found in patie