Granulocyte elastase was determined in the gingival crevicular fluid (GCF) of 18 periodontitis patients. They initially had similar severity of disease but had responded differently to 5-yr maintenance, 13 responders and 5 non-responders. A total of 102 sites were investigated and categorized as: i) consistently healthy, ii) healthy after treatment, iii) gingivitis, and iv) periodontitis, according to clinical criteria. GCF elastase activity was determined with a granulocyte-specific substrate. The sites from non-responders had consistently higher elastase levels than the corresponding category of sites from responders, despite similar gingival inflammation and periodontal destruction, with the exception of consistently healthy sites. Within the non-responders, the periodontitis sites had higher elastase levels than the gingivitis sites commensurate with probing depth, while no difference existed between gingivitis sites and sites healthy after treatment, despite a difference in probing depth. In contrast, in the responders similar elastase levels were found at the periodontitis sites and gingivitis sites despite difference in probing depth, while both diseased sites had higher elastase levels than the sites healthy after treatment, commensurate with probing depth. This study suggests that increased granulocyte-specific elastase levels in GCF may serve as a diagnostic marker for refractory periodontitis patients.

In 13 patients with severe destructive periodontitis, the response to periodontal therapy was estimated by granulocyte elastase level in gingival crevicular fluid (GCF). 62 sites were classified according to changes of probing depths (PD) and quantitative bone height (BH%) before and after 5-year regular maintenance treatment: (i) 17 consistently healthy sites with no changes of PD and BH%; (ii) 6 initially healthy sites with deterioration in PD and BH%; (iii) 14 diseased sites with improvement in PD and BH%; (iv) 25 diseased sites with no improvement in PD and BH%. GCF was collected by an intracrevicular washing system. The released elastase in the supernatants (EA-S) and the cell-bound elastase in the pellets (EA-P) were determined with a low molecular weight substrate specific for granulocyte elastase. The ratio of EA-S and EA-P (S/P-ratio) was used as a relative measure of elastase released by the granulocytes present. The sites classified as diseased with no improvement or initially healthy but deteriorating, had significantly higher EA-S, EA-P and S/P-ratios than the consistently healthy sites or diseased but improving sites (p < 0.01). Both EA-S and S/P-ratio showed strongly positive correlations with the current levels of gingival inflammation and periodontal destruction (p < 0.001). The present study suggests that increased elastase level is associated with disease progression, and may be used to monitor the response to longitudinal maintenance therapy.