Restrictive Lung Disease USMLE Step 1 Practice Question
A 36-year-old bird breeder presents with subacute dyspnea, fever (38.2°C), and malaise after cleaning bird cages. Vital signs show HR 102/min, RR 24/min, BP 118/76 mmHg, SpO2 91% on room air. Chest X-ray reveals diffuse micronodular infiltrates throughout both lung fields. Serum precipitins against avian proteins are positive; CBC shows normal WBC. Symptoms completely resolved after 2 weeks of antigen avoidance. Which immune response best characterizes this patient's condition?
Answer choices
- AType I hypersensitivity with mast cell degranulation
- BType III and IV hypersensitivity with immune complex and T-cell mediated inflammationCorrect answer
- CDirect cytotoxic T-cell mediated injury without antibodies
- DType II hypersensitivity with cytotoxic antibodies
- EIgE-mediated anaphylaxis with airway edema
- FType I hypersensitivity with IgG-mediated airway obstruction
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