Antibody Response to Porphyromonas gingivalis Strains in Cardiovascular Patients

Background: Studies have shown an association between periodontal disease and atherosclerosis. Elevated antibody titres to periodontal bacteria have been reported in cardiovascular patients, whilst a recent study has shown that this may be strain dependent.

Aim: To examine serum antibody levels to six strains of Porphyromonas gingivalis in a group of patients with cardiovascular disease and in patients with low cardiovascular risk.

Materials and methods: 293 dentate patients who had experienced a significant cardiovascular event (myocardial infarct or unstable angina) in the preceding 3 years were enrolled and compared with 41 patients classified as low cardiovascular risk. Low cardiovascular risk patients demonstrated no more than one of the classical cardiovascular risk factors. Detailed medical histories, a periodontal assessment and blood samples were collected from all patients. Serum samples were assessed for IgG antibody titres to six strains of P. gingivalis (FDC381, ATCC33277, W50, SPBG, UQD605, Su63) using ELISA.

Results: Cardiovascular patients showed a consistent trend towards higher serum anti-P.gingivalis antibody levels compared with patients with low cardiovascular risk across all strains examined. This occurred even though low risk patients demonstrated a higher frequency of deepened periodontal probing depths (at least 4 sites with probing depths ³ 4mm) than cardiovascular patients (20/41=49% vs 110/293=38%). Cardiovascular patients with deepened probing depths showed significantly higher levels of antibodies to P.gingivalis when compared with cardiovascular patients without deepened probing depths (p<0.009) for all strains except W50. For low risk patients, antibody levels were not higher in patients with deepened probing depths, except for W50 (p<0.043). Conclusion: Patients with low cardiovascular risk tended to have lower levels of anti-P.gingivali antibodies than cardiovascular patients, regardless of periodontal status. In patients with deepened probing depths, cardiovascular patients and low cardiovascular risk patients responded differently to P.gingivalis strains. This study was supported by Colgate Palmolive Company USA.