title: Increased prevalence of regulatory T-cells in the peripheral blood of patients with gastrointestinal cancer.
abstract: BACKGROUND
  Although recent studies have shown that FoxP3 represent the most specific Treg marker only a few studies have reported on the presence of FoxP3(+)Treg in peripheral blood.
  
  
  METHODS
  Peripheral blood mononuclear cells (PBMC) were harvested from 37 healthy volunteers and 94 patients with gastrointestinal cancer. The prevalence of Treg co-expressing CD4(+)FoxP3(+) was analyzed using flow cytometry.
  
  
  RESULTS
  The prevalence of Treg in the peripheral blood of gastrointestinal cancer patients was significantly higher than that in healthy volunteers (p=0.012). In early stage I cancer, Treg levels tended to be higher than those in healthy volunteers (p=0.069); these levels were significantly reduced after tumor resection (p=0.0027).
  
  
  CONCLUSIONS
  The prevalence of Treg was increased in patients with gastrointestinal cancer, even in the early stages of the disease. Since Treg levels decreased after curative resection, it is possible that tumor cells may have induced and expanded the Treg pool.
authors.affiliation: Department of Digestive Surgery and Surgical Oncology (Department of Surgery II), Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Tokuno
authors.forename: Shoichi
authors.initials: S
authors.lastname: Hazama
authors.forename: Shigefumi
authors.initials: S
authors.lastname: Yoshino
authors.forename: Shin
authors.initials: S
authors.lastname: Yoshida
authors.forename: Masaaki
authors.initials: M
authors.lastname: Oka
mesh_terms: D015415:Biomarkers; D016022:Case-Control Studies; D005434:Flow Cytometry; D005770:Gastrointestinal Neoplasms / Q000097:blood* / Q000276:immunology; D006801:Humans; D050378:T-Lymphocytes, Regulatory / Q000166:cytology*
chemical_list: D015415:Biomarkers