[The serum levels of cytokines in patients with rheumatoid arthritis associated interstitial lung disease and their clinical significance].

Objective: To study the clinical significance of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinases (TIMPs) and transforming growth factor beta 1 (TGF-beta1) in the serum of patients with rheumatoid arthritis (RA) associated interstitial lung disease (ILD).

Methods: Twenty-nine patients with RA only (the RA group) and 28 patients with RA associated ILD (the RA-ILD group) were included in the study. Patients in the RA-ILD group were divided into 2 subgroups, 16 in the early RA-ILD group and 12 in the late RA-ILD group.