Collagenolytic enzymes in gingival crevicular fluid as diagnostic indicators of periodontitis.

Periodontal diseases are associated with the production of several families of enzymes that are detectable in gingival crevicular fluid and that are released by stromal, epithelial or inflammatory cells. Measurement of collagen degrading enzymes in crevicular fluid could contribute to insights into pathogenesis of periodontal diseases and also provide a rational basis for the development of novel diagnostic tests. However, similar to the development of other diagnostic tests, the appropriate validation of collagenolytic enzymes as diagnostic indicators is dependent on clearcut demonstrations of the identity of the enzyme in the assay, and the reproducibility, diagnostic accuracy, and clinical utility of the test. If collagenolytic enzymes are to be of clinical usefulness, they should be easily measured over a broad range of disease severities and in varied clinical settings. Ideally, the diagnostic test should assay for an essential component of proposed pathogenic mechanisms. Neutrophil collagenase and gelatinase are promising enzymes for diagnostic tests because of (1) their apparently central role in periodontal attachment loss and disease progression; (2) demonstrations of positive associations between enzyme levels and attachment loss and inflammation; and (3) availability of sensitive and specific assays to quantify these enzymes. However, much less data exist on reproducibility, diagnostic accuracy, and clinical use in longitudinal studies. In the future, more emphasis must be placed on the importance of appropriate study design for establishing the efficacy of collagenolytic enzymes as diagnostic tests.