Immunologic burden links periodontitis to acute coronary syndrome

Periodontitis, a common polymicrobial inflammatory disease in the tooth supporting tissues, is a risk factor for coronary artery disease. One of the proposed underlying mechanisms is the systemic immune response to periodontal infection. We studied how serum antibodies against seven periodontal pathogens and their subgingival levels associate with each other, periodontitis, and coronary artery disease.

The Parogene cohort included 505 Finnish patients (mean age 63 y) who underwent coronary angiography, and clinical and radiographic oral examinations. Coronary diagnosis was defined as no significant coronary artery disease (<50% stenosis, n = 152), stable coronary artery disease (≥50% stenosis, n = 184) and acute coronary syndrome (n = 169). Levels of subgingival Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Tannerella forsythia, Campylobacter rectus, and Fusobacterium nucleatum were determined by checkerboard DNA-DNA hybridization. Serum antibody (IgA/IgG) levels were analyzed with enzyme-linked immunosorbent assay (ELISA). Aggregate IgA/IgG burdens were calculated by summing and standardizing the serum antibody levels.

Patients with active periodontitis were characterized by higher levels of subgingival bacteria and corresponding IgA/IgG response. Quartiles 2-4 of serum IgA/IgG burden indicated higher risk for acute coronary syndrome (OR 1.84, 95%CI 1.01-3.35 for IgA; OR 1.87, 95%CI 1.01-3.46 for IgG) independently of established cardiovascular risk factors, body mass index, number of teeth, subgingival bacterial levels and periodontal diagnosis.

Our findings support the hypothesis that the association between periodontitis and cardiovascular diseases is partly mediated by the immunologic response for periodontal pathogens.