Interstitial lung disease in recent onset rheumatoid arthritis

Interstitial lung disease (ILD) is associated with rheumatoid arthritis (RA); however, the prevalence and natural history are undefined. Our aim was to determine the prevalence of ILD associated with RA using a number of sensitive techniques in patients with joint disease of less than 2-yr duration. Patients who met ARA criteria for RA were recruited from community-based and hospital rheumatologists and assessed using the following measures: clinical, lung physiology, radiology (chest X-ray, high resolution CT [HRCT]), bronchoalveolar ravage (BAL) and Tc-99m-DTPA nuclear scan. Thirty-six patients (25 female and 11 male) of joint disease duration of (mean +/- SD) 13.2 +/- 8.6 mo were studied. Abnormalities consistent with ILD were found in one or more investigations in 21 of 36 (58%), which were in lung physiology in 22%, CXR in 6%, HRCT in 33%, BAL in 52%, and Tc-99m-DTPA nuclear scan in 15%. Based on the results, they were categorized as having clinically significant ILD (Group 1), abnormalities compatible with ILD, but no clinically significant ILD (Group 2) and no abnormalities compatible with ILD (Group 3). Five of 36 (14%) were in Group 1, 16 of 36 (44%) in Group 2, and 15 of 36 (42%) in Group 3. The only risk factor for the presence of abnormalities compatible with ILD was male gender (p < 0.04, Student's t test). In conclusion, changes consistent with ILD in early RA are frequent. The significance of these changes is being determined in a longitudinal study.