SALIVARY PAF LEVELS CORRELATE WITH THE SEVERITY OF PERIODONTAL INFLAMMATION

Platelet-activating factor (PAF), a potent phospholipid mediator of in flammation, has been previously identified in inflamed gingival tissue s and gingival crevicular fluid. However, the role of PAF in oral path obiology remains unknown. The purpose of the present study was to eval uate the relationship between salivary PAF levels and the severity of periodontal inflammation. PAF activity in lipid extracts of whole (mix ed) saliva collected from 69 untreated subjects immediately prior to r outine oral evaluation was determined by platelet bioassay. Significan t positive correlations were observed between the level of PAF in sali va and measures of periodontal inflammation, i.e., the percentage of p eriodontal probing depths greater than 4 mm, the number of periodontal bleeding sites, and the number of histologically identified polymorph onuclear neutrophilic leukocytes (PMN) in saliva. Moreover, when subje cts were subdivided into groups on the basis of periodontal probing de pths, a significant correlation was observed between salivary PAF leve ls and the extent of periodontal disease, i.e., PAF levels in saliva p rogressively increased from the healthiest group to the most severely affected group. Thus, salivary PAF levels correlate with the severity of periodontal inflammation. These results support the hypothesis that this pro-inflammatory phospholipid autacoid may participate in the pa thogenesis of periodontal tissue injury and disease.