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

• Published in: Egyptian rheumatologist Vol. 38; no. 2; pp. 77 - 83
• Main Authors: Affara, Nasr K., Refaat, Alaa M., Elgawish, Mohamed H., Zakaria, Mohammad A., Dashti, Khaledah A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-04-2016
• Subjects: Kuwait; Methotrexate; Rheumatoid arthritis; Subclinical interstitial lung disease; Subclinical interstitial lung disease; Methotrexate; Kuwait; Rheumatoid arthritis
• ISSN: 1110-1164; 2090-2433
• DOI: 10.1016/j.ejr.2015.06.003

Interstitial lung disease (ILD) is a frequent extra-articular manifestation of RA and can cause significant morbidity and mortality.
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.
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.
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 >50months 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.
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.