title: Dialysis modality is independently associated with circulating endothelial progenitor cells in end-stage renal disease patients.
abstract: BACKGROUND
  Numbers of endothelial progenitor cells (EPC) have been shown to be decreased in subjects with end-stage renal disease (ESRD). It is not clear, however, whether dialysis modality affects circulating EPCs in ESRD subjects.
  
  
  METHODS
  We examined the number of circulating EPCs in 67 continuous ambulatory peritoneal dialysis (CAPD) patients and age- and gender-matched 142 haemodialysis (HD) patients, and 78 subjects without chronic kidney disease. Arterial stiffness was analysed as pulse-wave velocity (PWV) for these patients, and their mutual relationship with circulating EPCs was examined. EPCs were measured as CD34(+) CD133(+) CD45(low) VEGFR2(+) cells determined by flow cytometry.
  
  
  RESULTS
  The EPC numbers exhibited a strong correlation (R(2) = 0.866) with endothelial-colony forming units on culture assay. The levels of EPCs in HD or CAPD subjects were significantly lower than those in control subjects. Among ESRD subjects, the levels of EPC were significantly higher in CAPD subjects than those in HD subjects. In ESRD subjects, PWV levels tended to be associated with EPCs (Rs = -0.131, P = 0.058). However, the significant relationship between dialysis modality and circulating EPCs was independent of the levels of PWV. The association of circulating EPCs with dialysis modality was significant even after adjusting for other potential confounders, including age, gender, blood pressure, history of cardiovascular diseases, presence of diabetes, blood haemoglobin level and treatments with angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker or statin.
  
  
  CONCLUSIONS
  CAPD treatment could be a positive regulator of number of circulating EPCs in subjects with ESRD, with the relationship independent of the status of arteriosclerosis.
authors.affiliation: Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueno
authors.forename: Hidenori
authors.initials: H
authors.lastname: Koyama
authors.forename: Shinya
authors.initials: S
authors.lastname: Fukumoto
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Takuhito
authors.initials: T
authors.lastname: Shoji
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Shoji
authors.forename: Masanori
authors.initials: M
authors.lastname: Emoto
authors.forename: Hideki
authors.initials: H
authors.lastname: Tahara
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tsujimoto
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tabata
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nishizawa
mesh_terms: D042783:Endothelial Cells; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D006435:Renal Dialysis; D013234:Stem Cells