Clinical and pathological correlation between urinary exosome miR-223 and IgAN patients.

Objective: To investigate the association between urine exosome miR-223 and clinical markers with pathological severity of IgA nephropathy (IgAN) in order to offer a new perspective for the evaluation of IgAN patients.

Materials and methods: Western blotting and transmission electron microscopy were used to identify the exosomes collected and isolated from subjects' urine. qRT-PCR was then performed to determine the expression level of miR-223. Following that, the relationship between miR-223 expression, clinical markers, and the severity of pathology in IgAN patients was examined.

Results: (1) Urine can be used to isolate exosomes since its marker protein was visible by Western blotting, and its size and structure were observable using transmission electron microscopy. (2) Expression levels of miR-223 in urinary exosomes were much higher in IgAN patients than in healthy subjects, and these were also positively correlated with creatinine (Cr) (rho = 0.396; p = 0.006), blood urea nitrogen (BUN) (rho = 0.371; p = 0.011), 24-hour urinary microalbumin (24hU-mALB) (rho = 0.341; p = 0.036), mesangial cell proliferation (rho = 0.359; p = 0.014), glomerular segmental sclerosis (rho = 0.417; p = 0.004), cell/fibroblast crescents (rho = 0.612; p = 0.000), glomerulosclerosis, and renal interstitial fibrosis (rho = 0.331; p = 0.025).

Conclusion: In urine exosomes, miR-223 might be considered a non-invasive biomarker for the assessment of IgAN disease progression.