title: Circulating endothelial cells as a marker of ongoing vascular disease in systemic sclerosis.
abstract: OBJECTIVE
  Circulating endothelial cells (CECs) have been described in different conditions involving vascular injury. Vascular abnormalities play a key role in the pathogenesis of systemic sclerosis (SSc). The aim of this study was to search for the presence of CECs in patients with SSc and to evaluate their clinical associations and possible pathogenic role.
  
  
  METHODS
  The study cohort included 46 patients with SSc and 40 healthy controls. Five-parameter, 3-color flow cytometry was performed with a FACScan. CECs were defined as CD45 negative, CD34 positive, and P1H12 positive, and activated CECs were defined as CD45 negative and P1H12 positive, CD62 positive, or CD106 positive. Progenitors were identified as CD34 positive and CD133 positive.
  
  
  RESULTS
  Total and activated CEC counts were significantly higher in SSc patients compared with healthy controls and were positively correlated with the disease activity score. With respect to visceral involvement, significant correlation was observed between the CEC number and the severity of pulmonary hypertension. High levels of endothelial progenitors were observed in patients with SSc, and the counts were higher in the early stages of disease.
  
  
  CONCLUSIONS
  The presence of CECs in patients with SSc may represent direct evidence of endothelial disease and may be a promising new clinical marker for active SSc. Notably, the association between CECs and pulmonary hypertension and impaired carbon monoxide diffusing capacity was evident in patients with limited cutaneous SSc only, suggesting an important role for CECs in this disease subset with prominent vascular changes. Detection of circulating endothelial progenitors may represent a response to vascular ischemia in early SSc, as an attempt at revascularization.
authors.affiliation: Department of Rheumatology, G. Pini Hospital, University of Milan, Milan, Italy. delpapa@gpini.it
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Del Papa
authors.forename: Gualtiero
authors.initials: G
authors.lastname: Colombo
authors.forename: Nicola
authors.initials: N
authors.lastname: Fracchiolla
authors.forename: Lorenza Mazzeo
authors.initials: LM
authors.lastname: Moronetti
authors.forename: Francesca
authors.initials: F
authors.lastname: Ingegnoli
authors.forename: Wanda
authors.initials: W
authors.lastname: Maglione
authors.forename: Denise P
authors.initials: DP
authors.lastname: Comina
authors.forename: Claudio
authors.initials: C
authors.lastname: Vitali
authors.forename: Flavio
authors.initials: F
authors.lastname: Fantini
authors.forename: Agostino
authors.initials: A
authors.lastname: Cortelezzi
mesh_terms: D000328:Adult; D000368:Aged; D043925:Angiogenesis Inducing Agents / Q000378:metabolism; D015415:Biomarkers; D015331:Cohort Studies; D042783:Endothelial Cells / Q000473:pathology*; D004730:Endothelium, Vascular / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D012595:Scleroderma, Systemic / Q000097:blood* / Q000473:pathology*; D013234:Stem Cells / Q000473:pathology; D014652:Vascular Diseases / Q000097:blood* / Q000473:pathology*
chemical_list: D043925:Angiogenesis Inducing Agents; D015415:Biomarkers