Clinical and preclinical pulmonary disease in newly diagnosed rheumatoid arthritis: a two-year follow-up study.

Objective: Pulmonary disease is a major cause of excess mortality among patients with rheumatoid arthritis (RA). Interstitial lung disease (ILD) is a feared complication, but the benefit of screening is unknown. The aim of this study was to assess the frequency of pulmonary disease, including ILD, in early RA.

Method: Patients with newly diagnosed RA were recruited prospectively at a single centre and underwent systematic pulmonary function tests (PFTs) and computed tomography (CT) scans at inclusion and after two years.

Results: The study included 150 patients (mean age 57 years, 63% female; 59% current or former smokers). Of these, 136 underwent baseline PFTs and 137 CT. Mean forced expiratory volume in one second was 99% predicted and forced vital capacity 106%. Mean diffusing capacity of the lungs for carbon monoxide (DL_CO) was 84% predicted. Frequently detected CT abnormalities were pulmonary nodules (42%), bronchiectasis (29%), and emphysema (20%). Two patients had clinically significant ILD and six had mild reticulation suggestive of preclinical ILD. No ILD progression was identified at two-year follow-up. Smoking was associated with DL_CO<80% (p=0.004), combined hyperinflation and diffusion impairment (residual volume>120% and DL_CO<80%) (p=0.004), and visual emphysema on CT (p<0.001).

Conclusion: Emphysema and bronchiectasis were common, but most patients had mild disease with preserved lung function. Preclinical or clinical ILD was seen in a minority in this early phase of RA. These findings suggest symptom-based screening and primary intervention focusing on smoking cessation rather than screening for ILD at the time of RA diagnosis.