The Role Of Platelet Activating Factor In The Relationship Between Periodontal Inflammation And Coronary Heart Disease

Background & objective: In the recent years, many investigators, unable to attribute a large part of atherosclerotic heart diseases (CHD) the traditional recognized factors, such as hypertension, hypercholesterolemia, dyslipidemia, obesity, diabetes mellitus and smoking, raised the hypothesis that chronic infections, including periodontal inflammation may cause atherosclerosis.Platelet-activating factor (PAF) is one of the most potent and versatile proinflammatory mediators found in mammals. It can be produced and released from a variety of cells, especially activated inflammatory cells, such as macrophages, thrombocytes, and lymphocytes. Many reports support the theory that PAF may play a role in the initiation and progression of coronary artery disease. And PAF may play an important role in the pathogenesis of periodontal disease.Therefore, PAF may become one way to reveal the possible relationship between periodontal inflammation and coronary artery disease. By examining the presence of PAF in gingival crevicular fluid (GCF) and serum in Chinese patients with periodontitis and/or CHD, the aim of the present study was to collect the further evidences about thecorrelation between periodontal disease and coronary artery disease and the possible role of PARMethods: This research included two parts. In Part one, 21 patients with periodontitis, 19 gingivitis patients and 20 perioaorttaily healthy individuals were included. Clinical examinations including probing pocket depth, clinical attachment levels, bleeding on probing, plaque indexes, and sulfide levels, were performed for six sites of each tooth. GCF was collected from all individuals, and blood samples were withdrawn on the time of GCF sampling. PAF levels in GCF and serum samples were investigated by Enzyme-Linked Immunosorbent Assay.In Part two, 19 CHD patients with periodontitis and 19 CHD patients without periodontitis, 21 periodontitis patients without CHD and 20 healthy individuals were included in the study. Clinical examination and sample collection had been down like Part one. The same ELISA kit had been used to investigate the level of PAF.In Part three, Realtime PCR technology was used to detect the expression of Platelet activating factor receptor (PAFR) mRNA in gingival tissues from 4 patients with periodontitis and 3 healthy individuals.Results: In Part one, the periodontitis group had higher PAF levels of serum and GCF compared to the gingivitis patients. And the gingivitis group had higher PAF levels than the healthy control.In Part two, the PAF level in serum and GCF from all patients (including the three groups) was higher compared to healthy subjects. And no difference could be observed among the PAF level in serum of the three groups. No difference was observed between the PAF level inGCF of periodontitis patients with and without CHD. The PAF level in GCF from CHD patients without periodontitis was lower than the level from periodontitis, but significantly higher than the level from healthy controls.And the PAF levels in both serum and GCF of all patients had significantly positive correlations with all periodontal parameters including SULAnd the expression of PAFR mRNA increased in gingival tissues from periodontitis than from healthy.Conclusions: PAF may be an important mediator in the initiation and progression of coronary artery disease or periodontitis, and contribute to the correlation between atherosclerosis and periodontal disease.