Abstract: Objective To investigate the gremlin level in peritoneal dialysate effluent and its influence on peritoneal function. Methods A total of 78 cases of continuous ambulatory peritoneal dialysis (CAPD) patients treated in the First Affiliated Hospital of Xinxiang Medical College from Jan. 2010 to Jan. 2015 were enrolled in this study. Gremlin and TGF-β1 in peritoneal dialysate effluent were measured by ELISA, and peritoneal function was assessed by peritoneal equilibrium test. The relationship between gremlin level and peritoneal function was then evaluated. Results ① With the extension of dialysis, peritoneal equilibrium test showed that the proportion of low transport and low average transport were gradually reduced, and some patients transformed into high transport or high average transport. Compared to the baselines, the χ2 values for the peritoneal equilibrium test ratios in the follow- up of 3 years, 4 years, 5 years were 12.219, 9.154 and
10.707, respectively, with the P values of 0.007, 0.027 and 0.013, respectively, indicating that peritoneal solute transport function gradually enhanced. ②In initial stage of peritoneal dialysis (CAPD for one month), gremlin and TGF-β1 in the peritoneal dialysate effluent were 3.54 ± 2.51pg/mL and 4.04 ± 2.58pg/mL, respectively. With the extension of dialysis, gremlin and TGF-β1 levels increased gradually and reached 232.71±55.01pg/mL and 367.25 ± 182.34pg/mL, respectively, in the follow- up of 5 years. The values at the follow- up period of 6 months, one year, 2 years, 3 years, 4 years and 5 years were statistically different from those at the baseline condition (P=0.000). ③Gremlin and TGF-β1 levels in peritoneal dialysate effluent were positively correlated with duration of dialysis, with the correlation coefficient of 0.744 and 0.873, respectively. Conclusions Gremlin may be involved in the pathogenesis of peritoneal fibrosis, resulting in the changes of peritoneal solute transport function. Intervention of gremlin expression may be useful for inhibiting or reversing peritoneal fibrosis.

Key words: Gremlin, peritoneal fibrosis, peritoneal dialysis, peritoneal function