Whole peripheral blood miR-146a and miR-155 expression levels in systemic lupus erythematosus patients

Objective: To evaluate the diagnostic value of peripheral blood microribonucleic acid (miRNA, miR)-146a and miR-155 expression in systemic lupus erythematosus (SLE). Methods: Expression levels of miR-155 and miR-146a in whole peripheral blood samples from 40 SLE patients and 32 healthy controls (HCs) were determined by quantitative reverse transcription-polymerase chain reaction qRT-PCR (SYBR Green technology) and 2-Delta Delta Ct method was used for analysis. SPSS v20 was used for receiver operating characteristic (ROC) curve and Spearman correlation analysis. Results: Whole peripheral blood expression levels of miR-146a and miR-155 were overexpressed in 62.5% and 50%, respectively, of the SLE patients compared to HCs. The ROC curve analysis showed that the expression levels of miR-146a could discriminate SLE patients from HCs with area under the curve (AUC)=0.711 (95% CI: 0.585 divided by 0.837, p=0.002, with 82.5% sensitivity and 56.2% specificity. The diagnostic accuracy of miR-155 was lower with AUC=0.691 (95% CI: 0.566 divided by 0.817, p=0.005, with 77.5% sensitivity and 50.0% specificity. The diagnostic accuracy did improve when combination of the studied miRNAs was used in multimarker ROC curve analysis (AUC=0.716, 95% CI: 0.590 divided by 0.842, p=0.002, 82.5% sensitivity and 56.2% specificity). miR-146a and miR-155 showed correlation with the diagnosis (rs=0.363 and 0.330, respectively) and the age of the patients (rs =0.239 and 0.366, respectively), and miR-155 showed correlation with the presence of secondary Raynaud syndrome (Spearman correlation coefficient=0.250). Conclusions: Our data showed that the expression levels of miR-146a and miR-155 in PB could be used as diagnostic biomarkers for SLE patients but larger study is needed to confirm these results.