Salivary PAF levels correlate with the severity of periodontal inflammation.

Platelet-activating factor (PAF), a potent phospholipid mediator of inflammation, has been previously identified in inflamed gingival tissues and gingival crevicular fluid. However, the role of PAF in oral pathobiology remains unknown. The purpose of the present study was to evaluate the relationship between salivary PAF levels and the severity of periodontal inflammation. PAF activity in lipid extracts of whole (mixed) saliva collected from 69 untreated subjects immediately prior to routine oral evaluation was determined by platelet bioassay. Significant positive correlations were observed between the level of PAF in saliva and measures of periodontal inflammation, i.e., the percentage of periodontal probing depths greater than 4 mm, the number of periodontal bleeding sites, and the number of histologically identified polymorphonuclear neutrophilic leukocytes (PMN) in saliva. Moreover, when subjects were subdivided into groups on the basis of periodontal probing depths, a significant correlation was observed between salivary PAF levels and the extent of periodontal disease, i.e., PAF levels in saliva progressively 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 pathogenesis of periodontal tissue injury and disease.