title: Gingival crevicular fluid levels of cathelicidin LL-37 and interleukin-18 in patients with chronic periodontitis.
abstract: BACKGROUND
  Cathelicidin LL-37, an antimicrobial peptide, is part of the host innate immune response in the oral cavity. Interleukin (IL)-18, a proinflammatory cytokine, could play a role in the progression of the inflammatory response. The aim of the present study was to determine the levels of cathelicidin LL-37 and IL-18 in the gingival crevicular fluid (GCF) of patients with gingivitis and chronic periodontitis.
  
  
  METHODS
  Fifty-nine subjects were included in the present study. Probing depth (PD), clinical attachment level (CAL), plaque index (PI), bleeding on probing, and papilla bleeding index (PBI) were assessed in patients with chronic periodontitis or gingivitis and in healthy controls. GCF levels of cathelicidin LL-37 and IL-18 were analyzed by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  GCF levels of cathelicidin LL-37 were significantly elevated in patients with chronic periodontitis compared to the other groups (P <0.05). No significant difference was found in the total amount of GCF IL-18 among the study groups (P >0.05). Spearman correlation analysis revealed a positive relationship between levels of GCF cathelicidin LL-37 and PD, CAL, PI, and PBI at the sampled sites (P <0.01), whereas no correlation was found between the total amount of GCF IL-18 and clinical periodontal parameters at the sampled sites (P >0.05).
  
  
  CONCLUSIONS
  Elevated levels of GCF cathelicidin LL-37 in chronic periodontitis suggest that it may play a role in the host innate immune response during periodontal inflammation.
authors.affiliation: Department of Periodontology, School of Dentistry, Ege University, Izmir, Turkey. oya_t@yahoo.com
authors.forename: Oya
authors.initials: O
authors.lastname: Türkoğlu
authors.forename: Gülnur
authors.initials: G
authors.lastname: Emingil
authors.forename: Necil
authors.initials: N
authors.lastname: Kütükçüler
authors.forename: Gül
authors.initials: G
authors.lastname: Atilla
mesh_terms: D000328:Adult; D023181:Antimicrobial Cationic Peptides / Q000032:analysis*; D054804:Cathelicidins; D055113:Chronic Periodontitis / Q000276:immunology*; D003430:Cross-Sectional Studies; D003774:Dental Plaque Index; D018450:Disease Progression; D005260:Female; D005883:Gingival Crevicular Fluid / Q000737:chemistry* / Q000276:immunology; D005884:Gingival Hemorrhage / Q000276:immunology; D005891:Gingivitis / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology; D018836:Inflammation Mediators / Q000032:analysis; D020382:Interleukin-18 / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000276:immunology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000276:immunology
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D018836:Inflammation Mediators; D020382:Interleukin-18