Independent and Joint Effects of Antibodies to Human Heat-Shock Protein 60 and Chlamydia pneumoniae Infection in the Development of Coronary Atherosclerosis

Abstract

Background —Studies have suggested that the prevalence of antibodies against heat-shock proteins (HSPs), Chlamydia pneumoniae ( Cpn ), and cytomegalovirus (CMV) is associated with coronary artery disease (CAD), but the independent or joint effects of human (h) HSP60 antibodies and these pathogens in patients have not been fully elucidated. Methods and Results —A total of 405 subjects (276 patients with CAD and 129 control individuals) were tested for serum antibodies to hHSP60, Cpn , and CMV immediate-early-1 (IE1) antigens. Patients were also assessed for serum cholesterol, triglyceride levels, and smoking habit. Significantly elevated levels of antibodies to hHSP60 and Cpn but not to CMV-IE1 antigens were documented in CAD patients. Multiple logistic regression analysis and subanalyses of selected subjects showed that these associations were independent of age, sex, smoking, and serum lipid levels. Antibodies to hHSP60 and Cpn did not correlate quantitatively; however, the relative risk of disease development was substantially increased in subjects with high antibody levels to both hHSP60 and Cpn , reaching an odds ratio of 82.0 (95% CI 10.6 to 625.0). Conclusions —High levels of antibodies to hHSP60 and Cpn are independent risk factors for coronary atherosclerosis, but their simultaneous presence substantially increases the risk for disease development.