Circulating miR-181a and miR-223 expression with the potential value of biomarkers for the diagnosis of systemic lupus erythematosus and predicting lupus nephritis.

Background: MicroRNAs (miRNAs) contribute to the development and progression of systemic lupus erythematosus (SLE) by affecting a wide range of targeted genes and facilitating the development of lupus nephritis (LN). The present study aimed to analyze the serum expression of miR-181a and miR-223 in SLE patients and to assess whether they could serve as novel biomarkers for SLE diagnosis and to distinguish LN.

Methods: The study included 70 control subjects and 116 patients with SLE (67 non-LN and 49 LN groups). Circulating miR-181a and miR-223 expression levels were analyzed among the Egyptian population using a real-time polymerase chain reaction.

Results: Up-regulation of miR-181a was detected among SLE patients compared to healthy controls and higher values were reported among the LN group compared to the non-LN group. Down-regulation of miR-223 was reported among SLE patients compared to controls and lower values were reported among the LN group compared to the non-LN group. The higher miR-181a expression and the lower miR-223 expression were associated with higher stages of LN. SLE disease activity index, proteinuria and serum creatinine were independently correlated with miR-181a and miR-223 among SLE patients by linear regression analysis. Receiver-operating characteristic curve analysis revealed that combined miR-181a and miR-223 expression increased the sensitivity and specificity for the diagnosis of SLE and further distinguished LN from non-LN patients.

Conclusions: miR-181a and miR-223 could play a role in evaluating SLE disease progression and prognosis. Combined miR-181a and miR-223 expression analysis could serve as novel serum-based biomarkers in the diagnosis of SLE and predicting LN among Egyptians.