Serum miRNA-21, miRNA-146a and plasma cell free DNA as novel biomarkers for assessing systemic lupus erythematosus activity

BACKGROUND: MicroRNA and cell-free DNA have shown significant correlations with several autoimmune disorders including systemic lupus erythematosus (SLE). SLE has been associated with challenges in determining its activity, so that the need for biomarkers contributing to assessing its activity is emerging. The current study investigated miRNA-21, miRNA-146a and plasma cf-DNA in determination of SLE activity, in addition their association with clinical data including complement factor 3 (C3), complement factor(C4), anti-dsDNA, and other disease activity indices. METHODS AND RESULTS: Eighty subjects divided into; twenty active patients (with SLE-DAI2K score of 16–18) twenty inactive patients (with SLE-DAI2K score of 1–3), and forty healthy control participants) were included in this study. Serum miR-21, miR-146a, and plasma cf-DNA were quantified by real time PCR and their correlation with clinical data was statistically analyzed. The results demonstrated that active cases have significant upregulation of serum miRNA-21 and plasma cf-DNA. Moreover, miR-21 showed a negative, significant pertaining to C3, C4 and was positively related to Systemic Lupus Erythematosus Disease Activity Index 2 K score (SLE-DAI Index2K score) and Systemic-Lupus-Erythematosus-Disease Activity-Index 2 K activity (SLE-DAI 2 K activity). Also, Active group miRNA-146a was negatively, significantly correlated with C3, as well as a positive significant relationship with SLE-DAI2K score and SLEDAI 2 K activity, in addition to anti DNA Autoantibodies. Furthermore, miR-21 and cf-DNA demonstrated a differential value through Receiver Operating Characteristic (ROC) curve’s study. CONCLUSIONS: the present study illustrated miR-21, miR-146a, and cf-DNA relationship with SLE clinical data. In addition to their potential value in SLE diagnosis, and activity determination.