A 55-year-old man presents with recurrent nosebleeds. He complains of persistent runny nose, fever, malaise, and a 20-lb (9-kg) weight loss. Physical examination reveals a “saddle nose” deformity (patient shown in the image). An X-ray film of the chest shows patchy infiltrates. Urinalysis discloses 2+ hematuria. Antibodies directed to which of the following cellular structures would be expected in the serum of this patient?
- Epithelial nuclei
- Mitochondria
- Neutrophil cytoplasm
- Skeletal muscle
- Smooth muscle