A 38-year-old woman with untreated membranous nephropathy presents with sudden left flank pain, gross haematuria, and a rise in creatinine from 1.0 to 2.4 mg/dL. Doppler ultrasound shows absence of flow in the left renal vein. Which feature of her nephrotic syndrome most directly explains this event?

• A Complement-mediated inflammation of the renal vein wall
• B Hypoalbuminaemia causing intravascular volume depletion alone
• C Hypercholesterolaemia causing renal arterial atherosclerosis
• D Urinary loss of antithrombin III and other anticoagulant proteins ✓

Explanation

Nephrotic syndrome produces a thrombophilic state through urinary losses of antithrombin III, protein C, and protein S, along with increased fibrinogen and platelet hyperactivity. Renal vein thrombosis complicates membranous nephropathy more often than any other glomerulopathy. Hypoalbuminaemia contributes to oedema and intravascular depletion but is not the specific mechanism of venous thrombosis that this stem targets.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.