Association of Plasma miRNA-7-5p and miRNA-214-5p With Rheumatoid Arthritis Associated Interstitial Lung Disease

Objective: Rheumatoid arthritis–associated interstitial lung disease (RA-ILD) is a major extra-articular complication contributing to increased morbidity and mortality. Circulating microRNAs (miRNAs) have emerged as potential non-invasive biomarkers in autoimmune diseases. This study aimed to evaluate whether plasma miRNA-7-5p and miRNA-214-5p are associated with the presence of RA-ILD and with radiological and functional indicators of pulmonary involvement. Methods: In this cross-sectional study, 58 RA patients (29 RA-ILD, 29 without ILD) and 30 matched healthy controls were included. RA-ILD was diagnosed by multidisciplinary assessment (HRCT and pulmonary function tests). Plasma miRNA levels were measured by qRT-PCR and analyzed using the 2^−ΔΔCT method. Diagnostic performance was evaluated by ROC analysis. Results: Plasma miRNA-7-5p and miRNA-214-5p levels were significantly higher in RA patients compared with healthy controls (p < 0.05 for both). Among RA patients, both miRNAs were significantly lower in those with ILD (p < 0.05). miRNA-7-5p demonstrated promising discriminatory performance for identifying RA-ILD (AUC = 0.87, 95% CI: 0.760–0.947; p < 0.001), whereas miRNA-214-5p showed modest accuracy (AUC = 0.676, 95% CI: 0.539–0.794; p = 0.01). In multivariable analysis, ILD presence was independently associated with decreased levels of both miRNAs. Neither miRNA correlated significantly with DAS28-CRP, disease duration, nor with radiological or functional severity parameters. Conclusion: Circulating miRNA-7-5p and miRNA-214-5p are associated with the presence of RA-ILD but do not reflect disease severity in this cohort. Larger prospective studies are required to validate their potential role as adjunctive biomarkers for RA-ILD detection and risk stratification.