Relationship between gingival crevicular fluid levels of aspartate aminotransferase and active tissue destruction in treated chronic periodontitis patients

Abstract

Data from several sources demonstrate the disease-active and disease-inactive periodontal pockets exist, and that disease progression occurs in bursts of activity. Currently used diagnostic procedures do not distinguish between disease-active and disease-inactive sites at any given point in time. We report the results of studies aimed at determining whether levels of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) are associated with disease activity as assessed by the level of gingival inflammation and probing attachment loss. 25 previously treated periodontitis patients participating in a quarterly recall maintenance program, who had experienced recurrent periodonal deterioration, served as experimental subjects. Patients were evaluated at 3-month intervals for 2 years. Values for plaque index, gingival index, and probing attachment level were recorded, and 30-second samples of gingival fluid harvested from the mesiobuccal aspect of the 4 first molars and the distal of the 4 lateral incisors. GCF volume was measured using a Periotron 6000, and AST activity was measured by a standard method. Sites were ranked in a hierarchy based on the degree of certainty of attachment loss as well as the severity of gingival inflammation, and the relationship of the values to AST levels was determined. Three models were used to analyze the resulting data, and all led to the same conclusion. Maximum enzyme level was significantly elevated at sites with confirmed disease activity as assessed by attachment loss, with maximum AST levels 725 units higher at these sites, on average, than at other sites (p < 0.0001). Maximum AST values were also associated with severe gingival inflammation (p < 0.005) where values were about 600 units higher than at sites with mild or with no gingival inflammation. Our data support the idea that an ojective diagnostic test, based on levels of AST in GCF, that distinguishes between disease-active and disease-inactive sites may be possible.