The association of carotid plaque inflammation and Chlamydia pneumoniae infection with cerebrovascular symptomatology

ObjectiveInflammation and infection have been implicated in the pathogenesis of carotid artery atherosclerosis, but their role in cerebrovascular disease symptomatology is not so well defined. We hypothesized that carotid disease symptomatology was associated with specific serologic markers of inflammation and Chlamydia pneumoniae infection and the presence of the pathogen and concentration of tumor necrosis factor-α (TNF-α) on the atheroma.MethodsIn 2004, 78 patients underwent carotid endarterectomy in our department, 46 of whom were symptomatic (group A) and 32 were asymptomatic (group B). A detailed medical history, the presence of atherosclerosis risk factors, ankle-brachial index and boxy mass index were recorded. We measured preoperatively the levels of C-reactive protein, fibrinogen, TNF-α, and the titers of immunoglobulin (Ig) A and IgG antibodies against C pneumoniae in the serum. Finally, the atherosclerotic plaques of all patients were immunohistochemically examined for the presence of C pneumoniae and their TNF-α concentration was determined.ResultsIsolation of the pathogen on the atheromatous lesion was statistically correlated with several risk factors and some of the variables that were tested. After testing independence of association, using the multiple regression analysis, only male gender (P = .024), hypertension (P = .008), hypercholesterolemia (P = .001), and TNF-α plaque values (P = .008) remained significantly associated. Hypertension, serum levels of fibrinogen and anti-C pneumoniae immunoglobulin A, detection of C. pneumoniae on the plaque, and plaque TNF-α values were significantly correlated with carotid disease symptomatology. After multiple analyses, only the presence of the pathogen on the lesion (P = .008) and atheroma TNF-α levels (P = .025) remained significantly associated with cerebrovascular events.ConclusionsIt seems that hypertensive hypercholesterolemic men are more likely to have C. pneumoniae infected carotid plaques and that these plaques have higher TNF-α concentrations. Cerebrovascular disease symptomatology is strongly correlated with both C. pneumoniae infection and TNF-α concentration of the atheroma