title: Quantification of circulating endothelial cells in peripheral blood of systemic lupus erythematosus patients: a simple and reproducible method of assessing endothelial injury and repair.
abstract: BACKGROUND
  Quantification of circulating endothelial cells (CECs) in peripheral blood is developing as a novel and reproducible method of assessing endothelial damage/dysfunction. Accordingly, elevated levels of CECs may be a marker of vascular injury in systemic lupus erythaematosus (SLE). This study was undertaken to assess the blood level of CECs in SLE and to correlate its level with the activity of the disease and to find out the possibility that the presence of increased numbers of CECs can be used as a marker of immune-mediated vessel damage.
  
  
  METHODS
  The study included 33 patients with SLE and 20 healthy controls. They were subjected to clinical examination together with laboratory investigations including complete blood count (CBC), erythrocyte sedimentation rate (ESR), urine analysis, renal function test, C3, C4, ANA, anti-ds DNA antibody, antiphospholipid (IgM and IgG) antibodies and quantification of CECs in blood. CECs were calculated using flow cytometry after staining with a mouse anti-human CD45 antibody (pan-leukocyte marker), mouse anti-human CD146 antibody (endothelial cell marker) and 7-amino-actinomycin D (7-AAD) viability marker. CECs were defined as the live cells with 7-AAD negative, CD45 negative and CD146 positive.
  
  
  RESULTS
  The number of CECs was significantly higher in patients with SLE compared with those in healthy control (mean +/- SD 38.6 +/- 21.2 versus 7.4 +/- 3.4). Furthermore, CECs were correlated positively with SLE disease activity index (SLEDAI) score, ESR and anti-ds DNA. CECs from patients with vasculitic skin lesions, renal and central nervous system (CNS) manifestation were significantly higher than patients free from the previous signs.
  
  
  CONCLUSIONS
  An increased number of CECs observed in patients with SLE was associated with the active phase of the disease and may represent a marker of widespread endothelial injury.
authors.affiliation: Department of Molecular Biology, Genetic Engineering and Biotechnology Institute, Minoufiya University, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Elshal
authors.forename: Abeer
authors.initials: A
authors.lastname: Abdelaziz
authors.forename: Ayman
authors.initials: A
authors.lastname: Abbas
authors.forename: Khaled
authors.initials: K
authors.lastname: Mahmoud
authors.forename: Hanan
authors.initials: H
authors.lastname: Fathy
authors.forename: Shaimaa
authors.initials: S
authors.lastname: El Mongy
authors.forename: Shereif
authors.initials: S
authors.lastname: El-Basyuoni
authors.forename: Hamada
authors.initials: H
authors.lastname: Ahmed
authors.forename: Philip
authors.initials: P
authors.lastname: McCoy
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D015415:Biomarkers / Q000097:blood; D051929:CD146 Antigen / Q000097:blood; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000276:immunology / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014652:Vascular Diseases / Q000097:blood* / Q000209:etiology / Q000473:pathology*; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D051929:CD146 Antigen