Plasma microRNA signature of patients with IgA nephropathy.

We looked for differentially expressed MicroRNAs (miRNAs) in Immunoglobulin A nephropathy (IgAN). Forty-eight miRNAs were identified through the initial screening phase (2 IgAN pools vs. 1 normal control (NC) pool) using quantitative reverse transcription polymerase chain reaction (qRT-PCR) based Exiqon panel (miRCURY-Ready-to-Use-PCR-Human-panel-I + II-V.M). By qRT-PCR, these miRNAs were further assessed in the training (32 IgAN VS. 31 NCs) and testing stages (51 IgAN VS. 51 NCs). The renal pathological lesions of patients with IgAN were evaluated according to Lee's grading system. We discovered a plasma miRNA signature including four up-regulated miRNAs (miR-148a-3p, miR-150-5p, miR-20a-5p and miR-425-3p) and the areas under the receiver operating characteristic (ROC) curve (AUC) were 0.80 and 0.76 for the training and testing stage, respectively. The expression of the four miRNAs in IgAN grade I-II subgroups (according to Lee's grading system) was obviously higher than that in IgAN grade III-V (P < .05). In summary, the plasma expression of miR-148a-3p, miR-150-5p, miR-20a-5p and miR-425-3p were up-regulated in patients with IgAN, especially the early-stage disease. Further studies are needed to explore the roles of the four miRNAs in the pathogenesis and progression of IgAN.