title: Relationships among gingival crevicular fluid biomarkers, clinical parameters of periodontal disease, and the subgingival microbiota.
abstract: BACKGROUND
  The objectives of this study were to measure levels of gingival crevicular fluid (GCF) biomarkers and subgingival bacterial species in periodontally healthy subjects and subjects with periodontitis to explore the relationships among these biomarkers, the subgingival microbiota, and the clinical parameters of periodontal disease.
  
  
  METHODS
  Clinical periodontal parameters were measured at six sites per tooth in 20 subjects with periodontitis and 20 periodontally healthy subjects. GCF and subgingival plaque samples were obtained from the mesio-buccal aspect of every tooth. GCF levels of interleukin (IL)-1beta and IL-8 and matrix metalloproteinase 8 were measured using checkerboard immunoblotting, and the levels of 40 bacterial taxa were quantified using checkerboard DNA-DNA hybridization. A subset of "clinically healthy" sites from each group was analyzed separately. The significance of the differences between groups was determined using the unpaired t test or the Mann-Whitney test. Correlations among immunologic, microbiologic, and clinical data were determined using the Spearman rank correlation coefficient.
  
  
  RESULTS
  There were positive correlations among mean clinical parameters, mean levels of the three biomarkers, and the proportions of orange and red complex species (P <0.05). Clinically healthy sites from subjects with periodontitis had higher levels of IL-1beta and IL-8 and higher proportions of orange and red complex species (P <0.05) than clinically healthy sites from periodontally healthy subjects. Red complex species were positively associated with the expression of all biomarkers (P <0.05), whereas purple and yellow complex species had negative correlations with IL-1beta and IL-8 (P <0.05).
  
  
  CONCLUSIONS
  Clinically healthy sites from subjects with periodontitis have higher levels of GCF biomarkers and periodontal pathogens than clinically healthy sites from periodontally healthy subjects. Different microbial complexes demonstrated distinct associations with specific GCF biomarkers.
authors.affiliation: Department of Periodontology, The Forsyth Institute, 140 The Fenway, Boston, MA 02115, USA. rteles@forsyth.org
authors.forename: Ricardo
authors.initials: R
authors.lastname: Teles
authors.forename: Dimitra
authors.initials: D
authors.lastname: Sakellari
authors.forename: Flavia
authors.initials: F
authors.lastname: Teles
authors.forename: Antonis
authors.initials: A
authors.lastname: Konstantinidis
authors.forename: Ralph
authors.initials: R
authors.lastname: Kent
authors.forename: Sigmund
authors.initials: S
authors.lastname: Socransky
authors.forename: Anne
authors.initials: A
authors.lastname: Haffajee
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001419:Bacteria / Q000145:classification; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D003773:Dental Plaque / Q000382:microbiology*; D005260:Female; D005883:Gingival Crevicular Fluid / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D007375:Interleukin-1 / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism*; D008297:Male; D020784:Matrix Metalloproteinase 8 / Q000378:metabolism; D008875:Middle Aged; D012016:Reference Values; D018709:Statistics, Nonparametric; D013357:Subgingival Curettage
chemical_list: D015415:Biomarkers; D004269:DNA, Bacterial; D018836:Inflammation Mediators; D007375:Interleukin-1; D053583:Interleukin-1beta; D020784:Matrix Metalloproteinase 8