High-resolution CT and pulmonary function tests in rheumatoid arthritis patients with subclinical interstitial lung disease in Kuwait

摘要

Background Interstitial lung disease (ILD) is a frequent extra-articular manifestation of RA and can cause significant morbidity and mortality. Aim of the work To characterize and define the frequency of radiological and functional abnormalities capable of identifying “subclinical” RA-ILD with particular concern to the effect of methotrexate (MTX) therapy. Patients and methods Sixty patients with RA were recruited with no respiratory manifestations. They were classified into two groups: group 1 included 35 patients receiving MTX and group 2 included 25 patients receiving only nonsteroidal anti-inflammatory drugs. Patients were also classified according to chest high resolution CT (HRCT) as RA-ILD or RA-noILD. Pulmonary function test (PFT) abnormalities were also used to further characterize occult respiratory defects. Results 38.3% of RA patients had subclinical ILD (25% in group 1 and 13.3% in group 2), while 61.7% were RA-no ILD. The percentage of patients with RA-ILD was insignificantly more in group 1 than group 2 (42.9% and 32% respectively). HRCT score revealed minimal to mild involvement in both groups. Long-standing RA with mean articular duration 50 months carries a significant risk for ILD. Other variables as age, gender, smoking, disease activity or rheumatoid factor seropositivity were not significant risk factors for development of RA-ILD. Conclusions Lung involvement should always be considered in patients with RA particularly those on MTX therapy even in the absence of chest symptoms. A tight control by PFTs, chest radiography and/or HRCT is necessary. Further studies evaluating the potential effect of MTX on progressive ILD with RA are needed.