<prompt> A 67-year-old man has a long history of symmetrical small joint arthritis with deformities. He now develops shortness of breath on exertion with a dry cough, but no sputum or chest discomfort. His heart sounds have a loud P2, and the lungs have fine bibasilar crackles. Which of the following is the most likely diagnosis of the pulmonary condition associated with his arthritis?pleuritiscavitating lesionsintrapulmonary nodulesinterstitial fibrosis  <response>: In RA, pleural involvement is very common at autopsy but infrequently causes symptoms. Interstitial lung disease ILD is the most common manifestation of rheumatoid lung disease. RA associated interstitial lung disease RA-ILD is usually similar to idiopathic pulmonary fibrosis IPF in terms of its clinical presentation, pathology, disease spectrum, and pathogenesis. Presentation is more common at age 50-60 years, in men M:F2-3:1, and in association with seropositive and erosive joint disease. If pleural fluid is present, glucose levels are very low. 