title: Analysis of YKL-40 acute-phase protein and interleukin-6 levels in periodontal disease.
abstract: BACKGROUND
  YKL-40, a new acute-phase protein, is shown to be elevated in inflammatory diseases, such as rheumatoid arthritis, type 2 diabetes mellitus, and coronary artery diseases. However, there is no data indicating a relationship between YKL-40 and periodontal disease. Interleukin-6 (IL-6) is the major regulator of acute-phase protein synthesis and one of the most studied inflammatory markers in periodontal disease. The purpose of the present study is to evaluate YKL-40 and IL-6 levels in gingival crevicular fluid (GCF) and serum of patients with periodontal disease and healthy individuals.
  
  
  METHODS
  Periodontally healthy individuals (n = 15), patients with gingivitis (n = 15), and patients with severe chronic periodontitis (CP) (n = 15) without any systemic disease were included in the study. Clinical measurements were recorded; GCF and blood samples were obtained from each participant. GCF and serum YKL-40 and IL-6 levels were analyzed by enzyme-linked immunosorbent assay. Statistical analysis was performed by parametric and non-parametric tests.
  
  
  RESULTS
  Total amounts of YKL-40 and IL-6 in GCF as well as serum YKL-40 and IL-6 levels were significantly higher in patients with gingivitis and CP compared with healthy controls (P <0.01). YKL-40 levels in GCF and serum as well as serum IL-6 levels were significantly higher in patients with CP compared with patients with gingivitis (P <0.01).
  
  
  CONCLUSIONS
  YKL-40 levels in GCF as well as serum YKL-40 and IL-6 levels increased from gingivitis to periodontitis. Within the limits of the present study, the YKL-40 molecule might be a potential novel inflammatory marker of periodontal disease.
authors.affiliation: Department of Periodontology, Faculty of Dentistry, Ondokuzmayis University, Samsun, Turkey.
authors.forename: Zeynep Pinar
authors.initials: ZP
authors.lastname: Keles
authors.forename: Gonca Cayir
authors.initials: GC
authors.lastname: Keles
authors.forename: Bahattin
authors.initials: B
authors.lastname: Avci
authors.forename: Burcu Ozkan
authors.initials: BO
authors.lastname: Cetinkaya
authors.forename: Gulnur
authors.initials: G
authors.lastname: Emingil
mesh_terms: D000209:Acute-Phase Proteins / Q000032:analysis*; D054392:Adipokines / Q000032:analysis* / Q000097:blood; D000328:Adult; D016301:Alveolar Bone Loss / Q000276:immunology; D001324:Autoantigens / Q000032:analysis* / Q000097:blood; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D000071451:Chitinase-3-Like Protein 1; D055113:Chronic Periodontitis / Q000097:blood / Q000276:immunology*; D003774:Dental Plaque Index; D005260:Female; D005883:Gingival Crevicular Fluid / Q000276:immunology; D005891:Gingivitis / Q000097:blood / Q000276:immunology*; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis* / Q000097:blood; D037102:Lectins / Q000032:analysis* / Q000097:blood; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000276:immunology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000276:immunology
chemical_list: D000209:Acute-Phase Proteins; D054392:Adipokines; D001324:Autoantigens; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D037102:Lectins
keywords: Acute-phase proteins; CHI3L1 protein, human; YKL 40 protein, human; gingival crevicular fluid; interleukin-6; periodontal diseases; serum