Resolution of proteinuria secondary to bilateral renal vein thrombosis after treatment with systemic thrombolytic therapy

A case of significant proteinuria occurred as a result of bilateral renal vein thrombosis secondary to dehydration, which resolved after treatment with urokinase. The patient developed nausea and vomiting from viral gastroenteritis with subsequent volume contraction. He later noted the onset of aching lower abdominal and flank pain. On admission, he was noted to have a serum creatinine of 1.7 mg/dL, and 4+ proteinuria on urinalysis. A 24-hour urine collection showed 2.34 g protein. A renal venogram showed bilateral renal vein thrombosis (RVT) without involvement of the inferior vena cava. Therapy was initiated with heparin at 1,000 U/hr, followed by intravenous (IV) urokinase, 4,400 U/kg bolus, followed by 4,400 U/kg/hr with continuous infusion for 12 hours. A repeat renal venogram done at this time showed partial resolution of thrombosis bilaterally. A second 12-hour infusion of urokinase at 5,000 U/kg/hr was performed; at this time, the patient reported resolution of his flank and abdominal pain. A repeat 24-hour urine collection showed 60 mg protein with a normal creatinine clearance. Levels of antithrombin III, protein C, and protein S were all normal. A renal biopsy was performed and showed normal histology on light, immunofluorescent, and electron microscopic evaluation. The patient has done well on no therapy and has had no recurrence of thrombosis or proteinuria after 2.5 years.