Interleukin-6 as a Biomarker for Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Retrospective Study

Objective: This study aims to assess the predictive value of interleukin-6 (IL-6) as a biomarker in patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Methods: A total of 361 RA patients (236 RA non-ILD and 125 RA-ILD patients) are included in the study, and stratified analysis is performed according to age and gender. The RA-ILD group is divided into mild ILD, moderate ILD, and severe ILD groups based on HRCT score. Using logistic regression analysis to investigate the risk association between IL-6 and rheumatoid arthritis-associated interstitial lung disease (RA-ILD), and employing receiver operating characteristic (ROC) to determine the value of IL-6 for distinguishing RA-ILD. Pearson's analysis and linear regression are used to analyze the association between IL-6 and RA disease activity, High-Resolution Computed Tomography (HRCT) scores, and Krebs Von den Lungen-6 (KL-6). Results: > 0.05). Pearson correlation analysis and multiple linear regression analysis show that IL-6 is significantly positively correlated with Disease Activity Score-28 (DAS28), but does not significantly correlate with HRCT score and KL-6. Conclusion: IL-6 may be used as a new peripheral blood biomarker to predict RA-ILD.