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

Abstract

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 (DLCO) 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 DLCO<80% (p=0.004), combined hyperinflation and diffusion impairment (residual volume>120% and DLCO<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.