Levels of platelet-activating factor in gingival crevicular fluid and gingival tissue in specific periodontal diseases

Background: Platelet-activating factor (PAF), a potent phospholipid mediato r of inflammatory and immune reactions, is involved in a variety of biologi cal responses seen in periodontal diseases. The aim of the present study wa s to examine the role of PAF in the pathogenesis of specific periodontal di seases. Methods: PAF levels were investigated in gingival crevicular fluid (GCF) an d gingival tissue (GT) samples of 12 patients with generalized aggressive p eriodontitis (GAgP), 6 patients with localized aggressive periodontitis (LA gP), 10 patients with chronic periodontitis (CP), 6 with gingivitis (G), an d 6 periodontally healthy subjects (H). Periodontal status was evaluated by measuring probing depth, gingival index, papillary bleeding index, and pla que index. PAF was extracted from GCF samples passing through amberlit resi n columns, purified by high performance liquid chromatographic method, and then analyzed by radioimmunoassay. Results: GAgP, LAgP, and CP groups had significantly higher GCF PAF levels compared to the H group (P<0.005). Although statistically not significant, GCF PAF levels were also higher in the G group than those of the H group (P = 0.0784). GAgP, LAgP, and CP groups had similar GCF PAF levels (P>0.005). These groups had higher levels of GCF PAF than those of the G group, but t he difference was significant only for the GAgP group (P<0.005). When the d ata were expressed as concentration, GAgP, LAgP, and CP groups were found t o have higher concentrations of GCF PAF compared to the H group (P<0.005). GCF PAF concentration was similar in patient groups (P>0.005). All patient groups had significantly higher GT PAF levels compared to the H group (P <0 .005). GAgP, LAgP, and CP groups had similar amounts of GCF and GT PAF (P > 0.005). GAgP, LAgP, and CP groups had higher GT PAF levels than those of th e G group, but the differences were only significant for LAgP and CP groups (P <0.005). No significant correlation was found between GCF and GT PAF le vels and clinical parameters. Conclusions: The results of the present study indicate that PAF is likely t o be an important mediator in regulating inflammatory responses in the huma n periodontal tissues. To our knowledge, this is the first report investiga ting PAF levels in GCF and GT in specific periodontal diseases. We believe that this potent phospholipid mediator may need to be considered in the pat hogenesis of periodontal diseases.