A 25-year-old man presents to the emergency department with hemoptysis, hematuria, and fatigue. He reports a recent upper respiratory infection two weeks ago. Physical examination reveals mild pallor and bibasilar crackles on lung auscultation. Chest X-ray shows bilateral alveolar infiltrates, and urinalysis reveals hematuria and proteinuria. Laboratory testing demonstrates: Serum creatinine: 3.2 mg/dL (elevated) Anti-glomerular basement membrane (anti-GBM) antibodies: Positive Renal biopsy: Linear IgG deposits along the glomerular basement membrane on immunofluorescence Which of the following best describes the hypersensitivity reaction responsible for this patient’s condition?
