Urinary miR-16-5p can be used as a potential marker of endocapillary hypercellularity in IgA nephropathy

The most prevalent primary glomerulonephritis and leading cause of end-stage renal disease worldwide is IgA nephropathy (IgAN). More and more studies are describing urinary microRNA (miRNA) as a non-invasive marker for a variety of renal diseases. We screened candidate miRNAs based on data from three published IgAN urinary sediment miRNAs chips. In separate confirmation and validation cohorts, we included 174 IgAN patients, 100 patients with other nephropathies as disease controls (DC), and 97 normal controls (NC) for quantitative real-time PCR. A total of three candidate miRNAs, miR-16-5p, Let-7g-5p, miR-15a-5p were obtained. In both the confirmation and validation cohorts, these miRNAs levels were considerably higher in the IgAN than in NC, with miR-16-5p significantly higher than in DC. The area under the ROC curve for urinary miR-16-5p levels was 0.73. Correlation analysis suggested that miR-16-5p was positively correlated with endocapillary hypercellularity (r = 0.164 p = 0.031). When miR-16-5p was combined with eGFR, proteinuria and C4, the AUC value for predicting endocapillary hypercellularity was 0.726. By following the renal function of patients with IgAN, the levels of miR-16-5p were noticeably higher in the IgAN progressors than in the non- progressors (p = 0.036). Urinary sediment miR-16-5p can be used as noninvasive biomarkers for the assessment of endocapillary hypercellularity and diagnosis of IgA nephropathy. Furthermore, urinary miR-16-5p may be predictors of renal progression.