Acute Chlamydia pneumoniae infection with heat-shock-protein-60-related response in patients with acute coronary syndrome.

Recent evidence has suggested an association between Chlamydia pneumoniae infection and coronary atherosclerosis. A significant association has also been detected between heat shock protein (HSP) 60 antibody and the severity of coronary atherosclerosis. The aim of this study was to define the relationship between instability of ischemic heart disease (IHD) and serum levels of HSP60 and C. pneumoniae antibodies. Blood samples for the measurement of serum antibody titers were obtained from 1131 patients with ischemic heart disease (65+/-9 years; male/female, 828/303) and 127 non-IHD controls with normal coronary arteries (64+/-9 years; male/female, 60/67) on the day of cardiac catheterization. The serum levels of anti-human HSP60 IgG antibody and anti-chlamydial IgM, but not IgG or IgA, antibody were significantly higher in ACS patients than in stable IHD patients or controls. These results suggest that acute C. pneumoniae infection with HSP60-related immunological responses may contribute to the pathophysiology of acute coronary syndromes.