Background: Atherosclerosis is considered to be an inflammatory disease. Infections are a significant cause of inflammation. Acute infections might precipitate acute coronary syndromes (ACS) whereas chronic infections might be stimuli for the development of atherosclerosis.
Methods: Coronary angiograms were done on 211 of 335 patients with ACS and the percentage of coronary obstruction was determined. Serum antibody levels to Chlamydia pneumoniae, C. pneumoniae heat shock protein 60 (CpnHSP60), human heat shock protein 60 (hHSP60), enterovirus (EV), herpes simplex virus (HSV), cytomegalovirus (CMV), and two major periodontal pathogens, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, were measured in healthy controls (n = 355) and all patients.
Results: Serum antibody levels to periodontal pathogens did not correlate with ACS. However, IgA-class antibody levels to Aggregatibacter actinomycetemcomitans (p = 0.021), CpnHSP60 (p = 0.048) an hHSP60 (p = 0.038) were higher in patients with coronary occlusion or obstruction compared to those without any obstruction. Odds ratios for coronary changes in the highest quartile as compared to the lower quartiles were for A. actinomycetemcomitans IgA 7.84 (95% CI 1.02-60.39, p = 0.048), for CpnHSP60 IgA 8.61 (1.12-65.89, p = 0.038), and for human HSP60 IgA 3.51 (0.79-15.69, p = 0.100).
Conclusions: We have previously reported that EV and HSV titres correlated significantly to acute coronary events. They do not correlate to the degree of coronary obstruction as shown here. However, infection by A. actinomycetemcomitans or C. pneumoniae or host response against them associated with coronary obstruction. Clinical coronary events may arise by the effect of acute infections and obstructing lesions by a chronic inflammatory stimulus.