DEVELOPMENT OF A SALIVARY ASSAY FOR MEASURING PERIODONTAL DISEASE ACTIVITY

Project Summary / Abstract Periodontal disease (PD) is globally the most common chronic inflammatory disease in humans, which according to the Centers for Disease Control and Prevention (CDC) affect 47% of U.S. adults 30 years of age or older and rt60% of those over 65 years.1 Given that the course of PD is marked by a discontinuous pattern of disease activity and inactivity showing exacerbation and remission of tissue destruction,2-4 a critical challenge for clinicians is not detection of clinical features of periodontal disease, but rather identification of patients who have an elevated risk for expressing active/progressing disease. Unfortunately, current guidelines and classifications rely exclusively on clinical and radiographic measurements to identify existing disease. While these records are a good reflection of a patient’s past history,5, 6 they fail to provide information on the current status of active disease or identify individuals and sites at risk for future disease.4, 5 This is because active disease involves tissue destructive processes (biologic phenotype)6, 8, 9 that precede and subsequently trigger the resulting clinical signs and symptoms (clinical phenotype). A host of salivary biomarkers for PD have been identified7, 10, 11 and multiple commercial assays are currently available for use in the clinic, but most lack specificity for tissue destruction and/or are not amenable to point-of-care (POC) real-time testing. Matrix metalloproteinase-8 is amongst the most widely documented, abundant biomarkers in saliva, and uniquely suited to quantitatively assess the extent and degree of tissue destruction.8, 9, 12-14 As an enzyme, it is present in both active and latent (inactive) forms, the relative expression of which dictate the extent of tissue breakdown during active periods of disease.8, 9 Hence, we hypothesize that the ratio of active and total MMP-8 (MMP-8Active/MMP-8Total) will constitute a more meaningful biological measure of disease activity than total MMP-8. However, measures of disease activity to date have not been possible due to the lack of commercially available antibodies for “active” MMP-8. Building off our team’s success in development of Disease Activity Specific Monoclonal Antibody (DASMAB) against MMP-8, we propose here to leverage these unique assets to develop a targeted molecular assay for quantifying disease activity. In this Phase I proposal, we plan to develop and validate an optimized DASMAB- based ELISA assay through the following aims: (1) identify and select the best mAb pairs (capture and detection) for each MMP-8 form to produce ELISA kit prototypes, and (2) analytical and clinical validation of disease activity of ELISA prototypes. Successful development and validation of the first DASMAB-based disease activity assay will precede a clinical POC diagnostic product that will offer clinicians with not only the means to quantify the extent and estimate the rate of disease progression in real-time, but also assess response to therapy and predict the most likely outcome of future events. These technological innovations will allow clinicians to make more effective outcome-driven decisions and personalize preventive strategies to improve patient care.