• Painful breathing. Rheumatoid arthritis can cause inflammation of the lining of the lungs (pleurisy). The inflammation can cause sharp pain while breathing.
• Shortness of breath. Fluid due to inflammation of the lining of the lungs may accumulate around the lungs (pleural effusion). This accumulation can cause shortness of breath.
• Lung nodules. Small lumps may form in the lungs (rheumatoid nodules), as well as in other parts of the body. Lung nodules usually cause no signs or symptoms, and they don't pose a risk of lung cancer. In some cases, however, a nodule can rupture and cause a collapsed lung.
• Scarring of the lungs. Rheumatoid arthritis can lead to scarring within the lungs. Signs and symptoms may include shortness of breath, chronic dry cough, fatigue, weakness and loss of appetite.

The one thing I found across the many sites I read suggested one thing over and over. If you have any sort of shortness of breath beyond anything normal for you (I have Asthma severe enough to be considered COPD) inform your Rheumy right away. Smoking, now or in the past is a big consideration in your likelihood to get RA Lung, so if you do smoke, here is yet another great reason to kick the habit! I quit 20 yrs ago myself. 

All in all, I am much more at ease with this new twist to the RA puzzle, just another symptom to manage and keep an eye on. I would stress to all of you that if you do not get a yearly chest xray, ask for one! A baseline xray is a great thing to have in case of future issues. 

Brad