title: Reproducibility of circulating endothelial cell enumeration and activation in children and adolescents.
abstract: We examined the reproducibility of circulating endothelial cells (CEC) enumeration and activation among youth.
  
  
  
  CECs from 151 youth were measured at baseline and 1 week follow-up. Enumeration of CEC in fresh whole blood was determined by direct assessment of buffy coat smears (CD146+ nucleated cells) and activated CEC (%VCAM-1 expression) was determined after immunomagnetic enrichment and co-staining of nuclei, plus positivity for P1H12 and VCAM-1.
  
  
  
  No statistically significant difference in CEC enumeration (1.2 ± 2.5 vs 1.3 ± 2.2 CEC/milliliter of whole blood, p = 0.745) or activated CEC (57.1 ± 24.4 vs 58.0 ± 21.3 %VCAM-1, p = 0.592) between baseline and 1 week follow-up.
  
  
  
  On a cohort basis, CEC enumeration and activation are reproducible in youth. Relatively high individual biological variability may limit its clinical utility.
authors.affiliation: Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: Justin R
authors.initials: JR
authors.lastname: Ryder
authors.affiliation: Division of Biostatistics, School of Public Health, Minneapolis, MN 55455, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Connell
authors.affiliation: Division of Biostatistics, School of Public Health, Minneapolis, MN 55455, USA.
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Rudser
authors.affiliation: Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: Claudia K
authors.initials: CK
authors.lastname: Fox
authors.affiliation: Vascular Biology Center, Division of Hematology, Oncology & Transplantation, University of Minnesota Medical School, Minneapolis, MN 55455, USA.|Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: Anna N
authors.initials: AN
authors.lastname: Solovey
authors.affiliation: Vascular Biology Center, Division of Hematology, Oncology & Transplantation, University of Minnesota Medical School, Minneapolis, MN 55455, USA.|Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hebbel
authors.affiliation: Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN 55455, USA.|Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Kelly
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood*; D058621:Blood Buffy Coat / Q000166:cytology; D015992:Body Mass Index; D051929:CD146 Antigen / Q000378:metabolism; D002648:Child; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D051929:CD146 Antigen
keywords: biomarkers; cardiovascular disease risk; circulating endothelial cells; obesity; pediatric; reproducibility; youth