title: The relationship between bone morphogenic protein-7 and peritoneal transport characteristics.
abstract: BACKGROUND
  After prolonged peritoneal dialysis (PD) and exposure to a non-physiological dialysis solution, peritoneal mesothelial cells undergo the epithelial-to-mesenchymal transition. In other biological systems, bone morphogenic protein-7 (BMP-7) is a key factor that controls this process. However, the role of BMP-7 in peritoneal physiology has not been studied.
  
  
  METHODS
  We studied the peritoneal transport characteristics of 50 consecutive new PD patients at 4 and 52 weeks after PD. Peritoneal permeability will be determined by the standard peritoneal equilibration test (PET). BMP-7 in PD effluent (PDE) at mRNA and protein level at 4 weeks was quantified.
  
  
  RESULTS
  At 4 weeks, the mRNA expression of BMP-7 in PDE significantly correlated with peritoneal transport characteristics, including the dialysate-to-plasma creatinine ratio at 4 h (D/P4) (r = 0.422, P = 0.015) and mass transfer area coefficient (MTAC) of creatinine (r = 0.457, P = 0.008). The PDE BMP-7 level by ELISA also had marginal correlation with D/P4 (r = 0.287, P = 0.072) and MTAC creatinine (r = 0.287, P = 0.073), although the result did not reach statistical significance. For the subgroup of patients who remained free of peritonitis, the PDE BMP-7 level by ELISA had significant correlation with the change in D/P4 (r = 0.441, P = 0.017) and MTAC creatinine in 52 weeks (r = 0.415, P = 0.025). The PDE BMP-7 level remained independently associated with the change in peritoneal transport adjusting for age, sex, serum C-reactive protein and PDE transforming growth factor-beta level. In patients who had peritonitis during the study period, the PDE BMP-7 level did not affect the change in peritoneal transport. Conclusion. We find that the peritoneal BMP-7 level correlates with peritoneal transport characteristics, and a high PDE BMP-7 level is associated with a gradual increase in peritoneal transport parameters with time. It remains unclear, however, whether this effect is beneficial, and the therapeutic role of exogenous BMP-7 on peritoneal transport requires a further study.
authors.affiliation: Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China. ccszeto@cuhk.edu.hk
authors.forename: Cheuk-Chun
authors.initials: CC
authors.lastname: Szeto
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chow
authors.forename: Bonnie Ching-Ha
authors.initials: BC
authors.lastname: Kwan
authors.forename: Ka-Bik
authors.initials: KB
authors.lastname: Lai
authors.forename: Kwok-Yi
authors.initials: KY
authors.lastname: Chung
authors.forename: Chi-Bon
authors.initials: CB
authors.lastname: Leung
authors.forename: Philip Kam-Tao
authors.initials: PK
authors.lastname: Li
mesh_terms: D000368:Aged; D055419:Bone Morphogenetic Protein 7 / Q000378:metabolism / Q000502:physiology*; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014462:Ultrafiltration
chemical_list: D055419:Bone Morphogenetic Protein 7; D016212:Transforming Growth Factor beta; D002097:C-Reactive Protein