Comparison of pulmonary abnormalities on high-resolution computed tomography in patients with early versus longstanding rheumatoid arthritis

Objective. To identify the predominant radiological abnormalities in the lungs of patients with early rheumatoid arthritis (RA) and in those with longstanding RA. Methods. We performed high-resolution computed tomography (HRCT) on a total of 126 patients with early RA (n = 65) and longstanding RA (n = 61). The most likely diagnosis for each case was made on the basis of the predominant HRCT findings and their extent in the lungs. Pulmonary function tests were done for RA patients with parenchymal abnormalities. Results. The most frequent finding was bronchial dilatation (41.3%), followed by ground-glass attenuation (27.0%), parenchymal micronodules (15.1%), subpleural micronodules (15.1%), reticulation (11.9%), bronchial wall thickening (11.9%), nodules (10.3%), honeycombing (8.7%), and airspace consolidation (4%). Parenchymal micronodules and bronchial wall thickening, indicative of small airway diseases, were more prominent in the patients with longstanding RA. There were no significant differences in the frequency of interstitial abnormalities such as ground-glass attenuation, reticulation, honeycombing, or consolidation between the 2 groups. We identified 10 patients with bronchiolitis pattern, 11 with nonspecific interstitial pneumonia (NSIP) pattern, 2 with usual interstitial pneumonia (UIP) pattern, and 2 with organizing pneumonia (OP) pattern. Mean values of FEV1/FVC ratio and FEV25-75 were lower in the patients with the bronchiolitis pattern, and DLCO was decreased in the patients with the NSIP or UIP pattern. Conclusion. Interstitial abnormalities were frequently observed even in patients with early RA, although most of them had no respiratory symptoms. Bronchiolar abnormalities were associated with the duration of RA.