Immune Response Links Periodontitis and Acute Coronary Syndrome

Objectives: Periodontitis is known to induce a systemic humoral immune response, which in turn is thought to exacerbate the progression of atherosclerosis. We studied how periodontal serology associates with corresponding bacterial prevalence, periodontal status and coronary artery disease (CAD) diagnosis.

Methods: The Finnish Parogene population consists of 492 patients. Based on the coronary angiography, 164 subjects had acute coronary syndrome (ACS), 181 stable CAD, and 120 no significant CAD. Based on periodontal examination, 45 were healthy (no alveolar bone loss [ABL] and bleeding on probing [BOP] <25%), 61 had gingivitis (no ABL and BOP≥25%), 81 had history of periodontitis (mild-severe ABL and BOP<25%) and 265 had active periodontitis (mild-severe ABL, BOP≥25%). Serum IgA and IgG antibody levels against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Porphyromonas endodontalis, Tannerella forsythia, Campylobacter rectus and Prevotella intermedia were determined by ELISA. Subgingival bacterial level of these species was analyzed with checkerboard DNA-DNA hybridization. The antibody and subgingival bacterial levels were standardized and combined within each parameter to receive three “burden” values. Differences between groups were analyzed with Mann-Whitney U-, linear regression- and logistic regression tests as appropriate.

Results: The subgingival bacterial burden associated significantly with the IgA- and IgG-burden. All three burden values distinguished active periodontitis from other groups. Compared to the patients without CAD, the IgA-burden was higher in the ACS patients (p=0.048). In the multivariate analysis, the highest tertile of IgA-burden associated with ACS (OR 3.2, 95%CI 1.2-9.0, p=0.025) in women. Subgingival bacterial or IgG-burden did not associate with ACS.

Conclusions: Active periodontitis associates with subgingival bacterial burden and IgA- and IgG-response against it, but only IgA-burden associates with ACS. The repeated or recent immunological response in active periodontitis links the periodontal microbiome to increased risk of acute cardiac events.