Collagenase activity in the gingival crevicular fluid of periodontal patients

A total of 51 gingival crevicular fluid (GCF) samples were collected, and their associated gingival index (GI) and probing pocket depth (PD) were recorded. The active and latent collagenase activities in the GCF were determined by an assay measuring the intact alpha 1 chain of collagen after sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography with 3H-collagen (type I) as an enzyme substrate. The collagen digestion patterns showed that GCF samples generated predominantly 3/4 alpha and 1/4 alpha collagen fragments, typical of vertebrate collagenase. The active collagenase activity was significantly associated with the severity of the measured GI. Active enzyme activity was also elevated in sites with attachment loss (PD > 4mm). However, the enzyme activity in the group with a 7-10 mm probing depth was not greater than that of those with a 4-6 mm pocket depth. The elevation of active collagenase activity was found to be highly correlated with GI, while it was low with respect to the probing depth. The latent collagenase activity increased with the GI score, but not with the pocket depth. These results suggest that most collagenase present in GCF is derived from polymorphonuclear leukocytes which are markedly increased in more severe cases of periodontal disease. Thus, the measurement of active collagenase in GCF samples of patients is a scientifically reliable and sensitive method of assessing disease activity possibly associated with tissue destruction.