title: Reduced number of endothelial progenitor cells is predictive of early relapse in anti-neutrophil cytoplasmic antibody-associated vasculitis.
abstract: OBJECTIVE
  ANCA-associated vasculitis (AAV) is an inflammatory disorder of small- to medium-sized vessels with relapsing/remitting progression. Microvascular endothelial injury is a major feature of AAV. Circulating endothelial progenitor cells (EPCs) may provide an endogenous repair mechanism to counteract ongoing endothelial damage. We hypothesized that decreased capacity for endothelial regeneration paralleled by low EPC numbers could increase the risk of relapse in patients with AAV.
  
  
  METHODS
  The number of circulating EPCs was determined by a colony-forming assay in a cohort of 41 patients with AAV. The patients were stratified into three subgroups according to the initial EPC count (low, medium and high) and prospectively followed. The primary goal was to determine the association between baseline EPC level and the time to the first relapse of the disease.
  
  
  RESULTS
  A total of 19 (46%) patients relapsed during the study period. The cumulative relapse-free survival increased stepwise across three increasing baseline levels of EPCs (P = 0.013). EPC levels were not predictive of progression of renal disease, number of organs involved or death from any cause.
  
  
  CONCLUSIONS
  Low numbers of EPCs are associated with increased propensity for early relapse of AAV.
authors.affiliation: Department of Nephrology, Charles University in Prague, Czech Republic. zavada@revma.cz
authors.forename: Jakub
authors.initials: J
authors.lastname: Závada
authors.forename: Lindy
authors.initials: L
authors.lastname: Kideryová
authors.forename: Robert
authors.initials: R
authors.lastname: Pytlík
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Hrusková
authors.forename: Vladimír
authors.initials: V
authors.lastname: Tesar
mesh_terms: D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D001327:Autoimmune Diseases / Q000097:blood* / Q000276:immunology; D002452:Cell Count; D003404:Creatinine / Q000097:blood; D042783:Endothelial Cells / Q000473:pathology*; D004812:Epidemiologic Methods; D005260:Female; D005921:Glomerulonephritis / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D013234:Stem Cells / Q000473:pathology*; D014657:Vasculitis / Q000097:blood* / Q000276:immunology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D003404:Creatinine