system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 51-year-old woman comes to the physician because of a 1-day history of right flank pain and bloody urine. Over the past 2 weeks, she has also developed progressive lower extremity swelling and a 3-kg (7-lb) weight gain. She has a history of chronic hepatitis B infection, which was diagnosed 10 years ago. She frequently flies from California to New York for business. She appears fatigued. Her pulse is 98/min, respirations are 18/min, and blood pressure is 135/75 mm Hg. Examination shows periorbital edema, a distended abdomen, and 2+ edema of the lower extremities. The lungs are clear to auscultation. A CT scan of the abdomen shows a nodular liver with ascites, a large right kidney with abundant collateral vessels, and a filling defect in the right renal vein. Urinalysis shows 4+ protein, positive glucose, and fatty casts. Which of the following is the most likely underlying cause of this patient's renal vein findings?
assistant
Loss of antithrombin III