Cathepsins B, H and L activities in gingival crevicular fluid from chronic adult periodontitis patients and experimental gingivitis subjects.

To clarify roles of lysosomal cysteine proteinases cathepsins B, H and L in pathological destructive process of periodontal tissues, levels of their enzymatic activities were determined in gingival crevicular fluid (GCF) from chronic adult periodontitis patients and from experimental gingivitis subjects. In periodontitis patients, higher levels of cathepsins B, H and L activities were found at sites with more serious signs of the disease activity. The total activity of each enzyme (per unit time) was positively correlated with the GCF volume. However, it had little or no correlation with the probing depth (PD). In contrast, the specific activity of each enzyme in GCF (activity units per mg protein), which reflects the selectivity of enzyme exudation, was negatively correlated with the GCF volume. These results suggest that the cysteine proteinases are selectively released into gingival crevices at a relatively mild stage of periodontitis. In experimental gingivitis subjects, no significant activity of each enzyme was detected in GCF, even when the quantity of GCF was comparable to that from periodontitis patients. These data suggest that no significant amounts of these enzymes are released at experimental gingivitis sites or that a homeostatic mechanism, including regulation by protease inhibitors, may control activities of these enzymes in GCF with acute inflammation.