Expressions of miR-146a and miR-210 in urinary exosomes of patients with IgA nephropathy and its correlation with histological grade

Objective  To explore the expressions of miR-146a and miR-210 in urinary exosomes of patients with IgAN （IgA nephropathy） and examine their correlation with histological grade of IgAN.

Methods  From January 2018 to January 2022, 113 patients were confirmed as IgAN by histopathology after renal biopsy and selected as research group. Another 100 healthy subjects undergoing physical examination during the same period were selected as healthy control group. According to Lee's classification, they were divided into three groups of mild （grade Ⅰ-Ⅱ）, moderate （grade Ⅲ） and severe （grade Ⅳ-Ⅴ）. The expression levels of miR-146a and miR-210 in urinary exosomes of IgAN patients with different histological grades were compared; Spearman’s rank correlation coefficient was utilized for examining the correlation among 24 h urinary protein, serum creatinine, miR-146a and miR-210 expression levels; receiver operating characteristic curve was plotted for evaluating the diagnostic values of miR-146a and miR-210 in urinary exosomes for IgAN.

Results  The expressions of miR-146a in urinary exosomes of IgAN patients were significantly lower than those of healthy control group （3.27 ± 1.59） vs （5.13 ± 0.34） and miR-210 （1.25 ± 0.71） vs （2.33 ± 0.45）（P<0.01）. Histological grade, 24 h urinary protein and serum creatinine were correlated negatively with the expressions of miR-146a and miR-210. That is, the higher the Lee's grade, the lower the expression levels of miR-146a and miR-210. The sensitivity and specificity of miR-146a for diagnosing IgAN were 88.89% and 77.52% and the area under the curve was 0.835; the sensitivity and specificity of miR-210 for diagnosing IgAN were 79.71% and 85.92%, and the area under the curve was 0.842.

Conclusion  The expression levels of miR-146a and miR-210 decline markedly in urinary exosomes of IgAN patients. Detecting the expression levels of miR-146a and miR-210 in urinary exosomes helps to assess the histological grades of IgAN. miR-146a and miR-210 in urinary exosomes are expected to be potential molecular biomarkers for auxiliary diagnosis and monitoring of therapeutic efficacy for IgAN.