The objectives of this study were to analyze the high resolution computed tomography (HRCT) findings in rheumatoid arthritis (RA) patients with respiratory symptoms and to evaluate the relation between the extent of HRCT findings and functional impairment as assessed by spirometry.
HRCT examination of the thorax and pulmonary function tests (PFTs) were performed in 34 RA patients with respiratory symptoms. Patients with smoking history or with emphysema evident on HRCT were excluded from the study. CT findings were assessed for the presence and pattern of abnormalities. Extent was scored based on the number of pulmonary segments involved. PFTs included forced expiratory flows (FEFs) and forced vital capacity (FVC).
Bronchial wall thickening was detected in 29 of 34 RA patients (85%), small nodules in 24 patients (71%), and bronchial dilatation in 21 patients (62%). The extent of bronchial wall thickening correlated with FEF25-75, FEF75, and FEF50 (p<0.0001, respectively) (Spearman's rank correlation). Extent of small nodules correlated with FEF25-75, FEF50, and FEF25 (p<0.01, respectively). Stepwise regression analysis showed independent correlations of bronchial wall thickening with decreases in FEF25-75 and FEF75 (p<0.0001, both). Bronchial dilatation was also independently associated with a decrease in FVC (p<0.05).
The most common HRCT findings in RA patients with respiratory symptoms are bronchial wall thickening and small nodules, and the extent of these findings correlates significantly with functional impairment.