Audio Qbank – Q335 – A 44M with dark urine and blood-tinged sputum

A 44-year-old man comes to the physician for a two-month history of dark urine and blood-tinged sputum. A renal biopsy is performed and shown below.

The immunologic mechanism responsible for this patient’s condition is most similar to which of the following?

Anaphylaxis
Contact dermatitis
Heparin-induced thrombocytopenia
Serum sickness