Plasma exosome lncRNA panel as a non-invasive biomarker for molecular diagnosis of systemic lupus erythematosus.

Exosome-derived long non-coding RNAs (lncRNAs) have emerged as promising diagnostic biomarkers in various diseases. However, their diagnostic potential in systemic lupus erythematosus (SLE) remains largely unexplored. This study aimed to characterize plasma exosomal lncRNA profiles and identify candidate lncRNAs with diagnostic and disease-monitoring potential in SLE. Plasma exosomes were isolated from SLE patients and healthy controls (HCs), followed by high-throughput sequencing to characterize exosomal lncRNA expression profiles. Differentially expressed lncRNAs were identified and subsequently validated using quantitative real-time PCR (qRT-PCR). Correlations between the validated exosomal lncRNAs and clinical indicators of SLE were assessed. Receiver operating characteristic (ROC) curve and multivariate logistic regression analyses were performed to evaluate the diagnostic performance of the identified lncRNAs. Three plasma-derived exosomal lncRNAs-ENSG00000229882, MIR4713HG, and LINC00620-were significantly upregulated in SLE patients compared with HCs. Logistic regression analysis identified MIR4713HG and LINC00620 as predictors of SLE. A combined diagnostic model incorporating these two lncRNAs demonstrated diagnostic capacity for distinguishing SLE patients from HCs, with an area under the curve (AUC) of 0.759. Notably, exosomal LINC00620 expression was significantly upregulated in patients with active SLE compared with those with inactive disease and showed a positive correlation with SLE Disease Activity Index 2000 (SLEDAI-2 K scores). Plasma exosomal ENSG00000229882, MIR4713HG, and LINC00620 were significantly upregulated in SLE, indicating their potential as non-invasive diagnostic biomarkers. Particularly, LINC00620 showed a positive correlation with disease activity, suggesting its clinical utility for both SLE diagnosis and disease monitoring.