Reflections on the development of a host-response diagnostic test for periodontal disease

This manuscript reviews the sequence of events surrounding the development of a proposed diagnostic test for periodontal disease based on analysis of a host mediator in gingival crevicular fluid (GCF). The mediator is lysosomal beta-glucuronidase (beta G), a marker of granule release from polymorphonuclear leukocytes. Preliminary studies were conducted to evaluate the most reproducible method of collecting GCF and analyzing the data. This was followed by analysis of the mediator in GCF in a variety of cross-sectional and short-term longitudinal studies, and eventually by a study of the relationship of beta G in GCF to disease progression (probing attachment loss) in a single center longitudinal trial. Development of an academic-industrial collaboration allowed the project to progress, as a rapid, practical assay system was developed, and a multi-center longitudinal trial was conducted. The multicenter trial indicated that patients with elevated beta G in GCF were at 6 to 14 times higher risk for experiencing probing attachment loss. The technical, regulatory, business and marketing issues surrounding the introduction of a diagnostic test for periodontal disease were considered. While technical and regulatory issues were not major impediments, business and marketing concerns contributed to a decision to halt development of the test. Specifically, there was concern about acceptance of the test by practitioners and third party reimbursement. Underlying these issues were the multifactorial nature of periodontal disease, and the lack of a direct cause and effect relationship of test results to disease outcome. While analysis of beta G in GCF is not currently available as a diagnostic test for periodontal disease, the development process has identified important issues for the introduction of diagnostic tests, including consideration of the relationship of test results to treatment, the need to integrate diagnostic tests into dental practice, and an appreciation of the financial and health care benefits derived by practitioners and patients with use of such tests.