Fig. 2
Diagnostic performance of urinary small EVs derived CCL21 mRNA for DN. A Urinary small EVs derived CCL21 mRNA was positively correlated to the levels of 24-h proteinuria at the time of renal biopsy (r  =  0.8009, p  <  0.0001). B Plots of correlation between urinary small EV derived CCL21 mRNA expression and eGFR calculated by CKD-EPI formula in DN patients (r  =  − 0.5186, p  =  0.0160). C The expression of urinary small EVs derived CCL21 mRNA of DN patients with normal eGFR (eGFR  >  90 ml/min/1.73m2) and T2DM patients, heathy controls. ***p  <  0.001 compared with healthy controls, ###p  <  0.001 compared with T2DM patients. D The expression of urinary small EVs derived CCL21 mRNA were remarkably increased in overt DN patients (ACR  >  300 mg/g creatinine, n  =  16) compared to incipient DN patients (ACR  <  300 mg/g creatinine, n  =  12) (*p  <  0.05). E ROC curve analysis of eGFR, proteinuria level and CCL21 level in urinary small EVs to discriminate DN patients from T2DM patients (AUC: eGFR, 0.225, 95% CI of 0.065–0.385, proteinuria, 0.748, 95% CI of 0.577–0.920, CCL21, 0.888, 95% CI of 0.752–1). F ROC curve analysis of CCL21 expression in urinary small EVs to discriminate DN patients with normal eGFR (eGFR  >  90 ml/min/1.73m2) from T2DM patients (AUC  =  0.888, 95% CI 0.737–0.997). G ROC curve analysis of CCL21 expression in urinary small EVs to discriminate incipient DN patient with overt DN patients (AUC: 1.0, 95% CI 1.0–1.0)