A PROSPECTIVE cohort study has identified serum biomarkers that may predict the risk of progression in rheumatoid arthritis-associated interstitial lung disease (RA-ILD), offering valuable tools for clinical monitoring and early intervention.
Drawing on data from the Korean Rheumatoid Arthritis Interstitial Lung Disease (KORAIL) cohort, researchers analysed 136 patients with RA-ILD over a median of 3 years. Progression was defined using the 2022 international guidelines for progressive pulmonary fibrosis (PPF), encompassing both radiological and physiological changes.
One-third of patients (34.6%) experienced ILD progression during follow-up. Elevated baseline levels of Krebs von den Lungen 6 (KL-6) and human surfactant protein D (hSP-D) were independently associated with greater risk of progression, with adjusted hazard ratios (HR) of 1.37 and 1.51, respectively. Notably, matrix metalloproteinase 7 (MMP-7) was linked to progression only in its highest quartile (HR 2.60).
Among all biomarkers, the strongest predictor was a rising KL-6 level one year after baseline, which doubled the risk of progression (HR 2.00; 95% CI 1.29–3.11), even after adjusting for initial levels.
This is the first prospective study to apply the new PPF criteria to RA-ILD, and its findings suggest that routine serial monitoring of pulmonary biomarkers, particularly KL-6, could support earlier identification of patients at risk and inform more personalised treatment strategies.
Reference
Chang SH et al. Serum Biomarkers of Pulmonary Damage and Risk for Progression of Rheumatoid Arthritis–Associated Interstitial Lung Disease. J Rheumatol. 2025;52(4)323-33.
