Enzyme activity in human gingival crevicular fluid: considerations in data reporting based on analysis of individual crevicular sites.

Using a reproducible approach to collection, processing and analysis of gingival crevicular fluid (GCF), this study examined 284 fluid samples from individual crevicular sites for the presence of the enzymes lactate dehydrogenase (LDH), B-glucuronidase (BG) and arylsulfatase (AS). 88 of the sites were from periodontally healthy individuals (probing depth 1-3 mm), while 98 sites from patients with periodontitis were examined before and 2 weeks after scaling and root planing (probing depths 1-3 mm, 4-6 mm and 7-10 mm). This study demonstrated the sensitivity of the enzyme assays. When GCF was collected with a 30-s insertion of the filter strip, 90% of the sites from the control subjects demonstrated LDH activity, 85% demonstrated BG activity and 73% demonstrated AS activity. For the 1-3 mm sites from the patients with periodontitis, 100% of sites from which fluid was collected demonstrated LDH and BG activity, and 90% of sites had AS activity before therapy. After therapy, 100% of sites demonstrated LDH activity, 90% had BG activity and 83% had AS activity. All sites in the 4-6 mm and 7-10 mm categories demonstrated activity of all 3 enzymes. The data were analyzed in terms of enzyme activity/30-s sample and as concentration of enzyme in a standard volume of GCF. Enzyme activity/30-s sample was a different and possibly more sensitive indicator of periodontal pathology than standard clinical parameters. There was a disassociation between clinical parameters and the data for enzyme analysis when it was reported as concentration.