Chlamydial heat-shock protein-60 antibody and correlation with Chlamydia pneumoniae in atherosclerotic plaques.

A study was performed to determine whether serum antibody to Chlamydial heat-shock protein-60 (CHSP-60) and C-reactive protein (CRP) were associated with the presence of Chlamydia pneumoniae in atheromatous plaques in 75 patients. The mean (+/-SD) ELISA optical density (OD) of anti-CHSP-60 was 0.19+/-0.15 in 54 patients with detectable C. pneumoniae antigen, versus an OD of 0.11+/-0.08 in 21 patients without detectable C. pneumoniae I antigen (P=.008). Higher anti-CHSP-60 at an OD > or =0.12 was present in 38 (70.4%) of patients with detectable C. pneumoniae in atheromas, compared with 5 (23.8%) of patients without C. pneumoniae antigen (P<.001; 2-tailed test). The mean CRP concentration was 7.4+/-10.3 mg/L in patients with detectable C. pneumoniae antigen, versus 5.7+/-6.1 mg/L in those without (P=.556). Immune response to CHSP-60 may play a role in atherogenesis, but CRP serum levels does not appear to be related to C. pneumoniae infection.