Antibody response to the 60-kDa heat-shock protein of Chlamydia pneumoniae in patients with coronary artery disease.

Serum specimens from 752 individuals undergoing coronary arteriography were examined for antibodies to Chlamydia pneumoniae. Patients with coronary artery disease (CAD) were more likely to have IgG antibodies to C. pneumoniae than were individuals without CAD (60% vs. 52%; P=.007; odds ratio, 1.8; 95% confidence interval, 1. 17-2.77). Antibodies to recombinant hsp60 of C. pneumoniae were found with nearly the same frequency in patients with CAD and individuals without CAD (29% vs. 30%; P=.751). There was no association between chlamydial hsp60 antibodies and the severity of CAD or a previous myocardial infarction. Patient sera reacted most frequently to C. pneumoniae proteins of 17, 38, 40, 58, and 60/62 kDa. Reactivity to these proteins was not different between patients with and without CAD. Study results indicate that neither antibodies to chlamydial hsp60 nor antibodies to other C. pneumoniae proteins are useful for discriminating between seropositive patients with and without CAD.