title: Levels of interleukin-21 in patients with untreated chronic periodontitis.
abstract: BACKGROUND
  A growing body of evidence suggested that interleukin (IL)-21 enhances the effector phase during T-cell responses. The aim of our study is to determine the levels of IL-21 in periodontal sites from patients with chronic periodontitis and controls.
  
  
  METHODS
  The population studied consisted of 34 patients (15 with chronic periodontitis and 19 healthy patients). Twenty samples (10 gingival crevicular fluid [GCF] and 10 gingival biopsies) were collected from each group before the patients with periodontitis received periodontal treatment. Total protein concentrations were measured in all samples; the presence of IL-21 was confirmed by immunohistochemistry and Western blot, and IL-21 levels were quantified through an enzyme-linked immunosorbent assay. Statistical analyses were performed using statistical software. Data were expressed as patient means ± SDs or medians (interquartile ranges) by using the χ(2), Student t, and Mann-Whitney U tests.
  
  
  RESULTS
  GCF IL-21 was mainly detected in patients with chronic periodontitis (P <0.05). Levels of IL-21 in gingival tissues were significantly higher in patients with chronic periodontitis compared to healthy individuals (P <0.05). The Western blot and immunohistochemical staining confirmed the presence of IL-21 in periodontal tissues and GCF.
  
  
  CONCLUSIONS
  IL-21 was highly expressed in patients with chronic periodontitis, especially in gingival biopsies; therefore, IL-21 might play a role in the T-cell response.
authors.affiliation: Laboratory of Periodontal Biology, Department of Conservative Dentistry, University of Chile, Santiago, Chile.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Dutzan
authors.forename: Catalina
authors.initials: C
authors.lastname: Rivas
authors.forename: Jocelyn
authors.initials: J
authors.lastname: García-Sesnich
authors.forename: Leslie
authors.initials: L
authors.lastname: Henríquez
authors.forename: Oriana
authors.initials: O
authors.lastname: Rivera
authors.forename: Andrea
authors.initials: A
authors.lastname: Dezerega
authors.forename: Marcela
authors.initials: M
authors.lastname: Hernández
authors.forename: Nora
authors.initials: N
authors.lastname: Silva
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Aguillón
authors.forename: Javier
authors.initials: J
authors.lastname: Puente
authors.forename: Rolando
authors.initials: R
authors.lastname: Vernal
authors.forename: Jorge
authors.initials: J
authors.lastname: Gamonal
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D055113:Chronic Periodontitis / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005881:Gingiva / Q000276:immunology* / Q000378:metabolism; D005883:Gingival Crevicular Fluid / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D007378:Interleukins / Q000032:analysis* / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D000098546:Interleukin-21