Endothelial progenitor cells in patients on extracorporeal maintenance dialysis therapy.
BACKGROUND
Chronic renal failure patients have a high cardiovascular disease burden, low numbers and impaired function of endothelial progenitor cells (EPCs). We hypothesized that enhanced uraemic toxin removal restores EPCs in haemodialysis patients.


METHODS
In a prospective, randomized, cross-over trial, 18 patients were subjected to 4 weeks of each low-flux haemodialysis, high-flux haemodialysis and haemodiafiltration differing in uraemic toxin removal. EPCs were determined at baseline and at the end of each 4-week period. A cohort of 16 healthy volunteers served as control. EPCs were studied after culture on fibronectin (CFU-Hill) and collagen-1 (ECFC).


RESULTS
Dialysis patients had a lower number of ECFCs than in healthy controls (P < 0.001) and a reduced fraction of vital ECFCs (P < 0.05), whereas the formation of endothelial cell colonies (ECCs) was increased (P < 0.05). Different middle molecular uraemic toxin removal had no effects on EPC numbers. The number of prototypical EPCs (CD34( +)/VEGFR2-KDR( +)/CD45( -) ECFCs) was similar between patients and controls. Correlations of plasma C-reactive protein with ECC count, CFU-Hill colony count and CD34( +)/VEGFR2-KDR( +)/CD45( -) subpopulation of both ECFC and CFU-Hill cells were observed.


CONCLUSIONS
Different middle molecule removal has no effect on EPCs. Reduced vitality and enhanced ECC formation suggest growth induction of impaired EPCs in chronic renal failure and are associated with inflammation.
Krieter
Detlef H
DH
Division of Nephrology, Department of Medicine, University of Würzburg, Würzburg, Germany. krieter_d@medizin.uni-wuerzburg.de
Fischer
Regina
R
Merget
Karin
K
Lemke
Horst-Dieter
HD
Morgenroth
Andreas
A
Canaud
Bernard
B
Wanner
Christoph
C
D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D002452:Cell Count; D018592:Cross-Over Studies; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D017583:Hemodiafiltration / Q000379:methods; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods*; D013234:Stem Cells / Q000473:pathology*; D016896:Treatment Outcome
D002097:C-Reactive Protein