Background Several environmental factors were found to be associated with rheumatoid arthritis (RA), such as tobacco, silica, or atmospheric pollutants. These factors are characterized by a first contact with the respiratory tract, suggesting that the lung could be a candidate site of RA initiation or preclinical phase of RA. Most studies on lung disorders during RA have been performed with long evolution affected RA patients.
Objectives The aim of this study was to describe the pulmonary manifestations associated with early RA.
Methods Inclusion criteria were as follow: patients presenting RA according to ACR/EULAR 2010 criteria and with less than 2 years of evolution. Patients presenting a respiratory disorder already identified or another autoimmune disease were excluded.
The respiratory check-up included a non-contrast high resolution computed tomography-scan (HRCT), lung function tests with carbon monoxide diffusion and capillary gases values.
Results Twenty-four patients were included, with a mean age of 54,2±11,1 years old, a 58% female proportion (n=14/24), and 76% (n=18/24) were active or past smokers. 67% (n=11/15) of active or past smokers were ACPA-positive vs. 60% (n=3/5) for the non-smokers group. The mean DAS28-VS were about 3,15±1,61 at inclusion with 58% of patients (n=14/24) with a low disease activity, and a mean duration of disease about 10±8 months.
35% of patients (n=7/20) presented pulmonary symptoms: cough, dyspnea, or sputums. The pulmonary examination was found abnormal for 10% of patients (n=2/20).
Lung function tests identified a bronchial obstruction for 19% (n=4/21) and a restrictive ventilatory disorder for 10% of patients (n=2/21), and an abnormal level of DLCO for 7 patients (33%).
HRCT-scan identified 13 elementary lesions for 10 patients: nodules (n=5), reticulations (n=2), thickening of the bronchial walls (n=3), condensations (n=1), bronchiectasis (n=1) and ground glass opacities (n=1).
Description of HRCT-scan results allowed finding 2 cases of interstitial lung disease (with restrictive ventilatory disorder), a bronchodilation for 2 patients and emphysema for 4 patients.
50% (n=8/16) of seropositive patients (ACPA and/or RF) were found to have pulmonary lesions, vs. 33% (n=2/6) for the seronegatives ones (p=0,646). Finally, abnormalities in lung function tests were highlighted for 31% (n=5/16) of seropositive patients vs. 14% (n=1/7) for seronegative patients (p=0,621).
Conclusions This pilot study allowed the identification of early respiratory disorders in early RA affected patients, suggesting the putative role of lung in RA physiopathology.
Further inclusions are needed to confirm the aetiology of several autoimmune and environmental factors in pulmonary lesions for RA patients.
Disclosure of Interest None declared