A Study of Biomarkers in Patients with Periodontal Disease

Objectives: Individual biomarkers have failed to provide useful predictive information for the response of sites to periodontal treatment. Therefore, the aim of this study is to determine whether combinations of enzymes (MMP-8, Elastase, Sialidase) in gingival crevicular fluid (GCF) along with levels of Porphyromonas gingivalis and Tannerella forsythia in subgingival plaque can be used as an improved prognostic “finger print” for the outcome of periodontal treatment.
Methods: 89 subjects participated in a 6-month longitudinal study. Full mouth clinical parameters (probing pocket depth, clinical attachment loss, plaque index and bleeding index) plus GCF and plaque samples were collected from 3 representative sites: healthy (≤ 3mm), deep non-bleeding (DNB) (≥ 6mm) and deep bleeding (DB) (≥ 6mm) at baseline, 3 and 6 months. Patients received standard nonsurgical periodontal treatment. GCF was assayed for each enzyme and plaque for bacteria using colourimetric substrates and qPCR, respectively. Biomarker profiles were analysed by logistic regression on a site-by-site basis for prediction of a 2mm improvement in probing pocket depth.
Results: 50 subjects have completed the 6-month interval to date. Clinical treatment resulted in reduction of mean probing pocket depths (≥6mm) by 2.1mm. However, 33% of DNB and 35% of DB sites did not improve by 2mm in pocket depth. All biomarkers were significantly higher in diseased sites than healthy sites and low levels of these biomarkers at baseline were associated with better treatment outcome. Logistic regression showed that a combination of enzymes at base-line provided accurate predictions of treatment outcome for DNB sites (84.8%) and DB sites (82%). When combined with the levels of bacteria, prediction values were 91% (DNB) and 92% (DB). Each biomarker alone failed to predict >61% of improvements.
Conclusions: Combined profiles of the above biomarkers offer a significantly improved indication of a site’s response to non-surgical periodontal treatment than they do as single biomarkers.