Bilateral Renal Vein Thrombosis in Membranous Nephropathy: Hypoalbuminemia Predictive of Venous Thromboembolism in Nephrotic Syndrome

Nephrotic syndrome is a known clinical syndrome in which there is increased permeability in the glomerular basement membrane leading to proteinuria, >3.5g/24h, and hypoalbuminemia. The primary causes of nephrotic syndrome include membranous nephropathy, focal segmental glomerulosclerosis, and minimal change disease. Secondary causes include lupus nephritis, diabetes mellitus, multiple myeloma, amyloidosis, and other systemic conditions. Clinically, nephrotic syndrome presents with edema, hyperlipidemia, and increased risk of thromboembolism, the primary focus of this paper. Nephrotic syndrome is often associated with thromboembolic events, especially in patients with membranous nephropathy. It has been shown that hypoalbuminemia is the most significant independent predictor of venous thromboembolic risk. We present the case of a 32-year-old male who first presented with pleuritic chest pain and was found to have multiple bilateral pulmonary emboli treated with oral anticoagulation. On subsequent visits, prompted by either chest pain or edema, he was found to have increasing pulmonary emboli, as well as downtrending serum albumin levels at each visit. Eventually, bilateral non-occlusive renal vein thrombi were discovered. Lab work indicated membranous nephropathy as the most likely etiology secondary to the patient's presentation. Serum anti-phospholipase A2 receptor antibody positivity confirmed the diagnosis, and the patient was treated appropriately.