A 19-year-old woman comes to the physician for a 6-month history of joint pain in her knees and hips. She has no past medical history. Temperature is 100 F. Examination shows warmth and swelling of the knees. Laboratory studies show:
Hemoglobin 10 g/dL
Platelets 120,000/μL
Blood urea nitrogen 38 mg/dL
Creatinine 1.7 mg/dL
Urine blood 1+
Urine protein 1+
Which of the following is most likely to be seen in this patient?
