Relationship between C-telopeptide pyridinoline cross-links (ICTP) and putative periodontal pathogens in periodontitis

Abstract

Crevicular fluid pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) is predictive for future alveolar bone loss in experimental periodontitis in dogs. The present study sought to relate ICTP to a panel of subgingival species in subjects exhibiting various clinical presentations such as health (n=7), gingivitis (n=8) and periodontitis (n=21). 28 subgingival plaque and GCF samples were taken from mesiobuccal sites in each of 36 subjects. The presence and levels of 40 subgingival taxa were determined in plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. GCF ICTP levels were quantified using radioimmunoassay (RIA). Clinical assessments made at the same sites included: BOP, gingival redness, plaque, pocket depth, and attachment level. Differences among ICTP levels in the 3 subject groups were sought using the Kruskal-Wallis test. Relationships between ICTP levels and clinical parameters as well as subgingival species were determined by regression analysis. The results demonstrated significant differences among disease categories for GCF ICTP levels for healthy (1.1+0.6 pg/site (mean+/-SEM)) gingivitis (14.8+/-6.6 pg/site) and periodontitis subjects (30.3+5.7 pg/site) (p= 0.0017). ICTP levels related modestly to several clinical parameters. Regression analysis indicated that ICTP levels correlated strongly with mean subject levels of several periodontal pathogens including B. forsythus, P. gingivalis, P. intermedia, P. nigrescens and T. denticola (p<0.01). The data indicate that there is a positive relationship between the putative bone resorptive marker ICTP and periodontal pathogens.

Fig. 1

Panel A is a bar chart of mean (±SEM) ICTP levels (pg/site) in healthy, gingivitis and periodontitis subjects. The numbers above the bars represent the number of sites analyzed in each group. ICTP levels were averaged for subject and then across subjects in the three groups. Significance of differences were sought using the Kruskal-Wallis test. Panel B is a scatter plot of mean ICTP levels for each subject in the three subject groups. Each circle represents the mean ICTP level measured at >20 sites in each subject. The horizontal lines represent mean (±SEM) ICTP levels for each group.

Fig. 2

Bar chart of the mean (±SEM) ICTP concentrations (ng/ml) in the healthy, gingivitis and periodontitis groups. Computation of mean values and the statistical analysis were performed as described for Fig. 1. The numbers above the bars represent the number of sites analyzed in each subject group.

Fig. 3

Bar chart of mean (±SEM) ICTP levels (pg/site) at sites with different PDs. Panel A shows mean ICTP levels at shallow sites (<4 mm) in the three subject groups. ICTP levels were averaged for each PD category within a subject and then averaged across subjects for each PD group. Significance of differences was tested using the Kruskal-Wallis test. Panel B is a bar chart of mean ICTP levels at pockets <4 mm, 4–6 mm and >6 mm in the periodontitis subjects. Computation of mean ICTP levels and statistical analysis were as described above.