Peritoneal dialysis effluent miR-21 and miR-589 levels correlate with longitudinal change in peritoneal transport characteristics.

BACKGROUND: The role of microRNA (miRNA) in peritoneal fibrosis and longitudinal change in transport is uncertain.

METHODS: We studied 80 new peritoneal dialysis (PD) patients. Peritoneal transport was determined by standard peritoneal equilibration test (PET) of creatinine at baseline. Based on published literature, PD effluent levels of 10 miRNA targets were quantified. PET and miRNA quantification were repeated one year later in 46 patients.

RESULTS: Baseline PD effluent levels of all targets tested had modest but significant correlation with peritoneal transport parameters. PD effluent miR-21 and miR-589 levels correlated with dialysate-to-plasma creatinine concentration at 4h (D/P4) at baseline (r=0.377, p=0.001 and r=0.237, p=0.037, respectively) and after one year of PD (r=0.362, p=0.014 and r=0.402, p=0.007). The change in PD effluent -21 and miR-589 levels over one year correlated with the corresponding change in D/P4 (r=0.470, p=0.001 and r=0.479, p=0.002). The number of peritonitis episodes during follow up significantly correlated with the change in PD effluent miR-21 (r=0.387, p=0.009) and miR-589 (r=0.336, p=0.027) levels. There was no significant correlation between PD effluent miRNA level and ultrafiltration volume.

CONCLUSION: Amongst the 10 miRNA targets tested, miR-21 and miR-589 showed consistently significant relation with peritoneal transport. Further studies are needed to delineate their mechanisms of regulating peritoneal transport.