A 32-year-old black woman presents with fatigue, dry cough, and chest pain for 3 months. She reports mild weight loss and intermittent low-grade fever. A chest X-ray reveals bilateral hilar lymphadenopathy. Laboratory testing shows elevated serum calcium and increased angiotensin-converting enzyme (ACE) levels. A biopsy of a lymph node shows noncaseating granulomas. What is the underlying mechanism responsible for her condition?
