Microassay for the detection of elastase activity in the gingival crevice

Background, aims: A new microassay for the detection of elastase activity (EA) in gingival crevicular fluid (GCF) has been established. GCF was collected with Periopaper(R) strips and quantified in a Periotron(R). Methods: Enzyme activity was measured in a microtiter plate reader, using a fluorometric assay. To ensure quality and precision of the assay, recovery rates were determined at different activities with a recovery of >90%. In a 2nd step, stability of the enzyme was investigated during storage at room temperature, +4 degreesC, -22 degreesC, -88 degreesC. GCF samples retained elastase activity of almost 100% after a storage of 3 days at -22 degreesC. In a group of 12 healthy volunteers, elastase activity was assayed throughout an Is day experimental gingivitis protocol. Results: Median activity increased from 481 muU/mul at baseline to 1444 muU/mul at day 18, which was accompanied by the development of the signs of gingivitis. The increase of EA during the experimental phase of the study was highly significant (p<0.001) and correlated well with the increasing severity of gingivitis. Conclusion: The data suggest that elastase activity in GCF is an excellent quantitative measure of gingival inflammation.