title: Circulating Endothelial Progenitor Cell Levels Predict Cardiovascular Events in End-Stage Renal Disease Patients on Maintenance Hemodialysis.
abstract: BACKGROUND
  The number of circulating endothelial progenitor cells (EPCs) has been identified as a surrogate biologic marker for vascular function and cumulative cardiovascular (CV) risk in the general population. Patients with end-stage renal disease (ESRD) on hemodialysis (HD) have markedly decreased EPC counts and function. We hypothesized that the number of circulating EPCs predicts death from all causes and CV events in patients with ESRD on HD.
  
  
  METHODS
  We quantified the EPCs in blood samples from 70 patients with ESRD on HD. Circulating EPCs were counted by flow cytometry as the number of CD45(low)CD34(+)VEGFR2(+) cells. Death from all causes and CV events served as outcome variables over a median follow-up period of 20 months.
  
  
  RESULTS
  It has been postulated that the number of circulating EPCs at baseline ranged from 1 to 350 cells/200 μl, with a mean of ± standard deviation (SD) of 26.0 ± 48.2 cells/200 μl. The median, lowest and highest tertiles of EPC counts were 11.0, 9.0, and 17.0 cells/200 μl, respectively. Patients with the lowest tertile EPC counts had significantly higher rates of CV events, but mortality was similar between the two groups. After adjusting for these risk factors, HbA1c and the lowest tertile EPC count remained as independent predictors of CV events. A cutoff value of 9.5 cells/200 μl maximized the power of the EPC count to predict future CV events as determined by ROC curve analysis.
  
  
  CONCLUSIONS
  Reduced circulating EPC counts independently predicted CV events in 70 patients with ESRD on maintenance HD. Circulating EPCs may play a role in vascular repair, thereby affecting the clinical course of CV events.
authors.affiliation: Department of Nephrology, Seoul Red Cross Hospital, Seoul, South Korea.
authors.forename: Hong Joo
authors.initials: HJ
authors.lastname: Lee
authors.forename: Weon
authors.initials: W
authors.lastname: Kim
authors.forename: Woo Shik
authors.initials: WS
authors.lastname: Kim
authors.forename: Jong Shin
authors.initials: JS
authors.lastname: Woo
authors.forename: Yang Gyoon
authors.initials: YG
authors.lastname: Kim
authors.forename: Ju Young
authors.initials: JY
authors.lastname: Moon
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Chun Gyoo
authors.initials: CG
authors.lastname: Ihm
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Lee
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Jeong
mesh_terms: D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood* / Q000209:etiology* / Q000401:mortality; D002452:Cell Count; D066026:Endothelial Progenitor Cells / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications* / Q000401:mortality; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D006435:Renal Dialysis; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D006442:Glycated Hemoglobin; D017493:Leukocyte Common Antigens; D040301:Vascular Endothelial Growth Factor Receptor-2; C000588866:KDR protein, human