Collagenase activity in gingival crevicular fluid of patients with juvenile periodontitis

The nature and origin of collagenases in gingival crevicular fluid of juvenile periodontitis patients was investigated. Gingival crevicular fluid collected from deep untreated periodontal pockets of juvenile periodontitis patients was found to contain only vertebrate collagenase (EC 3.4.24.7) activity that cleaved soluble type-I and -III collagens into 3/4 and 1/4 length fragments, as analyzed by SDS-polyacrylamide gel electrophoresis. Type II collagen was degraded at a markedly slower rate. This substrate specificity is indicative of collagenases produced by fibroblasts, epithelial cells and macrophages. We have previously found that collagenase in gingival crevicular fluid of adult periodontics patients appears to be mainly derived from polymorphonuclear leukocytes (PMN). The reasons for the apparent difference in collagenase source between the groups were investigated. We examined whether the pathogen characteristic for juvenile periodontitis, Actinobacillus actinomycetemcomitans, can release collagenase from normal human PMNs. All 10 A. actinomycetemcomitans strains tested, freshly isolated from the subgingival plaque of juvenile periodontitis patients, caused release of collagenase from PMNs in vitro. These results suggest that the lack of normally functioning PMNs in the periodontium of juvenile periodontitis patients may result in a colonization of bacteria that activate the resident periodontal cells to produce increased amounts of collagenase.