Pulmonary function tests and high resolution computed tomography of the lungs in patients with rheumatoid arthritis

Abstract

Objective: To compare the results of pulmonary function tests (PFTs) and high resolution computed tomography (HRCT) of the lungs in rheumatoid arthritis (RA) patients.

Methods: Sixty eight patients (54 women, 14 men) fulfilling the revised criteria for RA were consecutively included in a transversal prospective study. Their mean age was 58.8 years (range: 35-82) and the mean duration of the disease was 12 years (range: 5-16). Rheumatoid factor was positive in 52 patients (76.5%). Fifty two patients (76.5%) were lifelong non-smokers. Detailed medical and drug histories were obtained. PFTs comprised spirometry and gas transfer measurements. Results for PFTs were expressed as percentage of predicted values for each individual adjusted for age, sex, and height. HRCT was undertaken with a Siemens Somatom Plus.

Results: A significant decrease of FEV1/ FVC, FEF25%, FEF50%, FEF75%, FEF25-75%, and TLCO was observed (p < 0.05) and 13.2% of the patients had a small airways involvement defined by a decrease of FEF25-75% below 1.64 SD. The most frequent HRCT findings were: bronchiectasis (30.5%), pulmonary nodules (28%), and air trapping (25%). The patients with small airways involvement had a high frequency of recurrent bronchitis (75% v 34%, p = 0.05) and bronchiectasis (71% v 23%, p = 0.019). The patients with bronchiectasis were characterised by low values of FEV1, FVC, FEF25-75%, and TLCO (p < 0.01), a high prevalence of small airways involvement (29% v 5%, p = 0.019), and a low prevalence of HLA DQA1 *0501 allele (14% v 33%, p < 0.05).

Conclusion: This study suggests a significant association between small airways involvement on PFTs and bronchiectasis on HRCT in unselected RA patients.