A NEW ULTRASENSITIVE CHEMILUMINESCENT ASSAY FOR THE SITE-SPECIFIC QUANTIFICATION OF ALKALINE-PHOSPHATASE IN GINGIVAL CREVICULAR FLUID

The search for markers of periodontal disease activity and progression has accelerated over the last decade, in an effort to replace existin g subjective clinical measures of periodontal health status. Research is being aimed at establishing more objective and quantitative methodo logy, capable of rapid diagnosis prior to the appearance of clinical s igns of destructive disease. Such tests need to be sensitive enough to evaluate individual periodontal sites in health as well as disease st ates. We report the development of a new chemiluminescent assay for th e enzyme alkaline phosphatase, that is capable of quantifying the enzy me in sub-microliter volumes of gingival crevicular fluid and serum. T he technique will measure alkaline phosphatase (ALP) whilst immobilise d on paper strips, without the need for an elution stage. It is simple , versatile and amenable to chair-side use. We discuss in detail the a ssay procedure and have examined levels of ALP in 11 adult volunteers with clinically healthy periodontal tissues. The mean ALP concentratio n was 2135 IU/L for GCF and 183 IU/L for serum, a 12-fold difference. There also appeared to be an ''oral pattern'' of enzyme distribution i n healthy periodontal sites, with levels being higher in the anterior region of the mouth and highest in the lower anterior region.