title: Endothelial progenitor cells and plasma vascular endothelial growth factor and stromal cell-derived factor-1 during ranibizumab treatment for neovascular age-related macular degeneration.
abstract: OBJECTIVE
  To evaluate endothelial progenitor cell [late outgrowth endothelial progenitor cells (OECs)], vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1α (SDF-1α) plasma levels as potential biomarkers before and during ranibizumab (Lucentis(®)) treatment for neovascular age-related macular degeneration (nvAMD).
  
  
  METHODS
  Thirty-one patients with untreated nvAMD presenting for 3 consecutive intravitreal ranibizumab injections and a follow-up visit at 4 weeks intervals were enrolled. Peripheral blood was collected before each injection and at the follow-up visit and OEC clusters were cultured and evaluated according to previously published protocols. VEGF and SDF-1α plasma levels were measured by enzyme-linked immunosorbent assay and compared to values from healthy young and old control.
  
  
  RESULTS
  Patients with a high OEC count before treatment presented significantly more often with a short symptom duration and a smaller choroidal neovascularization size. VEGF plasma levels were significantly higher in nvAMD (282.4±195.2 pg/mL) compared to young (45.5±6.8 pg/mL) and old control (46.1±8.5 pg/mL). OEC levels decreased nonsignificantly during ranibizumab treatment, returning to baseline levels after the third injection. VEGF and SDF-1α plasma levels decreased significantly during treatment toward control values. Patients needing retreatment after 3 ranibizumab injections had significantly higher VEGF plasma levels at pretreatment compared to patients not needing further treatment.
  
  
  CONCLUSIONS
  The results presented here suggest that VEGF plasma levels may warrant further evaluation regarding biological, therapeutical, and predictive implications in nvAMD.
authors.affiliation: Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Grierson
authors.forename: Birthe
authors.initials: B
authors.lastname: Meyer-Rüsenberg
authors.forename: Frank
authors.initials: F
authors.lastname: Kunst
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Berna
authors.forename: Gisbert
authors.initials: G
authors.lastname: Richard
authors.forename: Michelle
authors.initials: M
authors.lastname: Thill
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D002452:Cell Count; D054377:Chemokine CXCL12 / Q000097:blood*; D020256:Choroidal Neovascularization / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D004334:Drug Administration Schedule; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000473:pathology; D005260:Female; D006801:Humans; D058449:Intravitreal Injections; D008268:Macular Degeneration / Q000097:blood / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D000069579:Ranibizumab; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D015415:Biomarkers; D054377:Chemokine CXCL12; D042461:Vascular Endothelial Growth Factor A; D000069579:Ranibizumab