title: Blood levels, apoptosis, and homing of the endothelial progenitor cells after skin burns and escharectomy.
abstract: BACKGROUND
  Skin burns are an acute trauma involving an extensive vascular damage and an intense inflammatory response. Bone marrow-derived circulating endothelial progenitor cells (EPC) are known to migrate to sites of neovascularization in response to mediators (vascular endothelial growth factor and stromal cell-derived factor-1) released after trauma and ischemia, to contribute to wound healing, and to increase neovascularization of animal prefabricated flaps. Recent data showed an increase in EPC number in burned patients and a positive correlation between EPC number and total body surface area (TBSA) burnt, but data were limited to the first 5 days after thermal injury.
  
  
  METHODS
  By using flow cytometry, we studied EPC (CD34, CD133, CD45, and KDR cells) blood levels, apoptosis, and homing (stromal cell-derived factor-1 receptor expression and CXC chemokine receptor 4) in a 1-month follow-up postburn in 25 patients with ≥15% TBSA burnt, at least grade II burns and escharectomy performed at days 5 to 6, with respect to 31 controls.
  
  
  RESULTS
  EPC count at admission showed a positive linear correlation with TBSA burnt. The EPC blood levels of the patients were low (50.7 cells/mL±61.8 cells/mL) immediately after thermal injury, then increased with two peaks, at day 1 (188.3 cells/mL±223.2 cells/mL) and day 12 (253.1 cells/mL±430.7 cells/mL) with respect to controls (95.2 cells/mL±28.5 cells/mL, p<0.05), and then returned to normal levels in 1 month. EPC apoptotic rate and inflammatory parameters paralleled EPC blood count. No significant variations were found in CXC chemokine receptor 4 expression.
  
  
  CONCLUSIONS
  Thermal injury and escharectomy seem to induce an intense response in EPC production. In particular, escharectomy could improve physiologic wound repair by increasing EPC levels.
authors.affiliation: Department of Histology, Microbiology, and Medical Biotechnologies, Center for Male Gamete Cryopreservation, Section of Clinical Pathology, Clinic of Plastic and Reconstructive Surgery, University of Padova, Padova, Italy. carlo.foresta@unipd.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Foresta
authors.forename: Mirko
authors.initials: M
authors.lastname: Schipilliti
authors.forename: Luca
authors.initials: L
authors.lastname: De Toni
authors.forename: Sabina
authors.initials: S
authors.lastname: Magagna
authors.forename: Luca
authors.initials: L
authors.lastname: Lancerotto
authors.forename: Bruno
authors.initials: B
authors.lastname: Azzena
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vindigni
authors.forename: Francesco
authors.initials: F
authors.lastname: Mazzoleni
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000502:physiology*; D002056:Burns / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D002452:Cell Count; D054377:Chemokine CXCL12 / Q000097:blood; D062109:Dermatologic Surgical Procedures; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D019718:Receptors, CXCR4 / Q000097:blood; D012867:Skin / Q000503:physiopathology; D013234:Stem Cells / Q000502:physiology*; D013997:Time Factors
chemical_list: D054377:Chemokine CXCL12; D019718:Receptors, CXCR4