Restrictive Lung Disease USMLE Step 1 Practice Question

A 58-year-old man with a 10-year history of systemic lupus erythematosus presents to the emergency department with acute-onset dyspnea and pleuritic chest pain. He reports hemoptysis this morning. Vital signs: BP 128/82 mmHg, HR 98 bpm, RR 22 breaths/min, SpO2 92% on room air. Physical examination reveals bilateral crackles at the lung bases and no cardiac murmurs. Laboratory studies show: Hgb 8.2 g/dL (previously 11.5), platelet count 95,000/μL, positive ANA (1:640, homogeneous), positive anti-dsDNA antibodies, BUN 28 mg/dL, creatinine 1.8 mg/dL. Pulmonary function testing shows FEV1 65% predicted, FVC 72% predicted (FEV1/FVC 0.90), and DLCO 48% predicted. Chest radiograph demonstrates bilateral patchy ground-glass opacities with no pulmonary edema pattern. Which of the following is the most likely diagnosis?