Pulmonary involvement in rheumatoid arthritis: A cross-sectional study in Iran

Background: Interstitial lung disease (ILD) is a type of pulmonary manifestation in patients with rheumatoid arthritis (RA). Mostly RA-ILD has no symptoms and is only diagnosed by clinical examination, pulmonary function test (PFT), and high-resolution computed tomography (HRCT); hence it seems that the diagnosis of pulmonary involvement in early stages of RA is of great importance. Therefore, we decided to answer this question whether the evaluation of RA patients without pulmonary symptoms using methods such as PFT and HRCT are justifiable and reasonable or not. Methods: We conducted a cross-sectional study in a referral rheumatology clinic in Razi hospital of Rasht, Iran. Forty-four consecutive patients, diagnosed with RA, were enrolled. Physical examination of the joints was performed by an rheumatologist. The activity of RA was evaluated in all patients by Disease Activity Score 28. An expert pulmonologist performed the respiratory examination in all participants. Then, all subjects were referred for chest X-ray, PFT, and HRCT of lungs. Results: Patients included in this study, 9 (20.45%) males and 35 (79.55%) females, were 21-73 years old and their mean age was 49 +/- 13 years. Significant relation between PFT and respiratory complaints was observed (P = 0.016). PFT had significant relation with respiratory examinations (P = 0.009). Our results indicated a significant relation between disease activity rate and PFT (P = 0.038). While HRCT had any significant relation with above items. Conclusion: We concluded, using PFT in the respiratory assessment of RA patients can be limited to persons with high disease activity, respiratory complaints, and positive findings in the clinical respiratory examination.