Down-regulation of serum miR-151a-3p is associated with renal tissue activity in class IV lupus nephritis.

Objective The aim of this study was to explore the value of serum miRNA for evaluating renal tissue activity in patients with class IV lupus nephritis (LN). Methods First, we used a microRNA array to identify miRNAs differentially expressed between class IV LN patients and healthy volunteers (n=4/group). Then, we analysed the association between these identified miRNAs and renal tissue activity in class IV LN patients. Finally, to validate the results, 20 class IV LN patients (confirmed by renal biopsy) and 20 healthy control volunteers were further studied. Results We found 23 miRNAs to be significantly differentially expressed between the 2 groups. We selected 5 of these miRNAs (miR-3165, miR-4762-5p, miR-146a-5p, miR-151a-3p, and miR-21-5p) for further experiments. In validation experiments, expression of miRNA-151a-3p was significantly down-regulated in the class IV LN group compared to that in the control group (p<0.01) and was negatively correlated with the activity index (Al) in the class IV LN group(r=-0.526, p=0.017); the internal correlation was described with a linear fitting equation (p<0.01). Conclusion Serum miR-151a-3p expression was decreased in class IV LN patients compared with healthy control volunteers and was negatively correlated with renal tissue activity. Thus, miR-151a-3p may play a employed for diagnosing class IV LN and evaluating renal tissue activity.