Influence of intimal Chlamydophila pneumoniae persistence on cardiovascular complications after coronary intervention

Chlamydophila pneumoniae has been implicated in atherosclerosis/restenosis; however, clear evidence is missing. Therefore, the aim of our study was to examine the influence of intimal infection and systemic inflammation on cardiovascular complications after coronary intervention.

45 atheroma specimens from patients with symptomatic coronary artery disease who underwent directional endatherectomy with stent implantation were analyzed by immunohistochemistry to detect chlamydial (c) and human (h) heat shock protein (HSP) 60. The antibodies used against cHSP60 and hHSP60 were characterized by specificity and lack of cross immunoreactivity. In addition, serum Ig antibodies against Chlamydophila pneumoniae and against mycobacterial (m) HSP65 as well as serum CRP levels were measured. At follow-up of 6 months, quantitative coronary angiography was performed and major adverse cardiac events (MACE) were assessed.

Atheroma specimens of all 10 patients with MACE were positive for cHSP60 with overall higher cHSP60 tissue expressions (1.1 ± 0.4 %) and serum CRP levels (2.18 ± 0.85 mg/dl) compared to the remaining 35 patients without MACE (7 of 35 specimens positive for cHSP60, mean cHSP60 expression: 0.4 ± 0.1 %, CRP levels: 0.67 ± 0.16 mg/dl, p < 0.05). Colocalization of both HSP60 homologues was more frequent in the MACE group. Anti-mHSP65 serum titers were significantly higher in MACE (1:510) versus non-MACE patients (1:335) and correlated positively with plaque expressions of cHSP60 and hHSP60 (r = 0.54, p < 0.05; r = 0.46, p < 0.05; resp.).

Intimal presence of cHSP60, systemic CRP and antibodies against mHSP65 are predictors for occurrence of MACE after coronary intervention.