Novel microRNA biomarkers of systemic lupus erythematosus in plasma: miR-124-3p and miR-377-3p

Background: To explore the clinical value of miR-124-3p and miR-377-3p in plasma, and to examine whether these microRNAs can serve as biomarkers for systemic lupus erythematosus.Methods: Samples from 50 patients with SLE and 47 healthy individuals were collected from the Rheumatology and Immunology Department at the Second Affiliated Hospital of Chongqing Medical University. The expression of miR-124-3p and miR-377-3p in peripheral blood mononuclear cells (PBMCs) and serum were determined by quantitative reverse-transcription PCR (RT-PCR). We then further analyzed the associations between these microRNAs and clinically relevant indicators. We employed receiver operating characteristic (ROC) curves and the area under the ROC curves (AUCs) to validate the diagnostic value of miR-124-3p and miR-377-3p.Results: The expression of miR-124-3p and miR-377-3p was significantly upregulated in PBMCs and serum from SLE patients compared with the normal control group (P < 0.05). ROC curve analysis indicated that plasma miR124-3p and miR-377-3p were thus candidate diagnostic biomarkers for SLE, with AUCs of 0.714 (95% CI, 0.610 to 0.820, P < 0.05) and 0.705 (95% CI, 0.600 to 0.809, P < 0.05), respectively. Furthermore, the combined diagnostic efficiency of miR-124-3p and miR-377-3p was higher than that for miR-124-3p or miR-377-3p alone, and the AUCs for miR-124-3p and miR-377-3p in plasma were higher than in PBMCs. Plasma miR-124-3p expression was also associated with various clinicopathological parameters such as antiC1q and C3. Binary logistic regression analysis revealed that the expression of miR-377-3p was an independent predictor for SLE, and the plasma miR-124-3p was independently associated with the remission rate of SLE.Conclusion: Circulating miR-124-3p and miR-377-3p may constitute promising biomarkers for the diagnosis of SLE.