A 25-year-old man is brought to the physician because of fatigue, lethargy, and lower leg swelling for 2 weeks. He also noticed that his urine appeared darker than usual and for the last 2 days he has passed only small amounts of urine. His temperature is 37.5°C (98.6°F), pulse is 88/min, respirations are 15/min, and blood pressure is 154/98 mm Hg. Examination shows 2+ pretibial edema bilaterally. A kidney biopsy is performed. Light microscopy reveals cellular proliferation, focal necrosis, and crescent formation of most of the glomeruli. On immunofluorescent microscopy, there are no immunoglobulin or complement deposits. Which of the following additional findings is most likely to be present in this patient?

Question

A 25-year-old man is brought to the physician because of fatigue, lethargy, and lower leg swelling for 2 weeks. He also noticed that his urine appeared darker than usual and for the last 2 days he has passed only small amounts of urine. His temperature is 37.5°C (98.6°F), pulse is 88/min, respirations are 15/min, and blood pressure is 154/98 mm Hg. Examination shows 2+ pretibial edema bilaterally. A kidney biopsy is performed.  Light microscopy reveals cellular proliferation, focal necrosis, and crescent formation of most of the glomeruli.  On immunofluorescent microscopy, there are no immunoglobulin or complement deposits.  Which of the following additional findings is most likely to be present in this patient?

Quizplus · Accepted Answer

Eductional Objective: Pauci-immune rapidly progressive glomerulonephritis frequently occurs as a manifestation of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (eg, granulomatosis with polyangiitis, microscopic polyangiitis).  It is characterized by glomerular crescent formation without immunoglobulin or complement deposits.

A 25-Year-Old Man Is Brought to the Physician Because of Fatigue