A 28-year-old woman presents with a 3-week history of facial redness over both cheeks, joint pain in her hands and knees, and sharp chest pain that worsens with deep breathing. She spent several days at the beach approximately 4 weeks ago and noticed the rash developing a few days after returning. Over the past week she has noticed foamy urine. Her temperature is 37.8°C, blood pressure 132/84 mmHg. Urinalysis shows 3+ protein and RBC casts. Hand radiographs show periarticular soft tissue swelling without bony erosions.
Laboratory results:
| Test | Value | Reference Range |
|------|-------|----------------|
| ANA | 1:640 | <1:40 |
| Anti-dsDNA | Positive | Negative |
| C3 | 52 mg/dL | 90–180 mg/dL |
| C4 | 8 mg/dL | 16–47 mg/dL |
| Anti-CCP | Negative | Negative |
Which of the following best describes the mechanism responsible for the multi-organ findings in this patient?