title: Circulating progenitor and apoptotic progenitor cells in patients with aortic regurgitation.
abstract: BACKGROUND
  Endothelial progenitor cells (EPCs) have a role in the repair of endothelial surfaces after injury. Reduced numbers of EPCs are related to endothelial dysfunction and adverse clinical events, suggesting that endothelial injury in the absence of sufficient repair by circulating EPCs promotes the progression of vascular disease or valvular disorder. The aim of the present study was to assess the number and role of EPCs in patients with aortic valve regurgitation (AR).
  
  
  RESULTS
  We assessed the number of EPCs and apoptotic EPCs in 31 patients with significant AR and compared them with 30 patients who had similar risk factors and no valvular disease. The numbers of EPCs and apoptotic EPCs were assessed by flow cytometry. The 2 groups had similar clinical characteristics. Patients with AR had fewer circulating EPCs and late apoptotic EPCs as compared with the control group (0.054 ± 0.03% vs. 0.079 ± 0.06%, P=0.039 and 0% (0-3.4%) vs. 5% (0-14%), P=0.03, respectively). In patients with AR, circulating EPCs correlated negatively with septal thickness (r=-0.47, P=0.01), whereas late apoptotic EPCs had a negative correlation with left ventricular end-systolic diameter (r=-0.57, P=0.01).
  
  
  CONCLUSIONS
  Patients with AR have fewer EPCs and late apoptotic EPCs. These data suggest an impaired valvular endothelial cell regenerative process in patients with AR.
authors.affiliation: Heart Institute, Kaplan Medical Center, Rehovot, Israel. Sara_s@clalit.org.il
authors.forename: Sara
authors.initials: S
authors.lastname: Shimoni
authors.forename: Iris
authors.initials: I
authors.lastname: Bar
authors.forename: Liaz
authors.initials: L
authors.lastname: Zilberman
authors.forename: Sorel
authors.initials: S
authors.lastname: Goland
authors.forename: Orly
authors.initials: O
authors.lastname: Edri
authors.forename: Gera
authors.initials: G
authors.lastname: Gandelman
authors.forename: Arnon
authors.initials: A
authors.lastname: Afek
authors.forename: Ari
authors.initials: A
authors.lastname: Shamiss
authors.forename: Jacob
authors.initials: J
authors.lastname: George
mesh_terms: D000368:Aged; D001022:Aortic Valve Insufficiency / Q000097:blood* / Q000473:pathology*; D017209:Apoptosis; D016022:Case-Control Studies; D002452:Cell Count; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D013234:Stem Cells / Q000473:pathology*