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 collec ted 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 throug hout 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 gi ngivitis. The increase of EA during the experimental phase of the study was highly significant (p<0.001) and correlated well with the increasing sever ity of gingivitis. Conclusion: The data suggest that elastase activity in GCF is an excellent quantitative measure of gingival inflammation.