Matrix metalloproteinase-9 expression is associated with the presence of Chlamydia pneumoniae in human coronary atherosclerotic plaques
- Correspondence to:
Department of Cardiological Sciences, St Georges Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK;
- Accepted 25 October 2004
Objective: To investigate the association between Chlamydia pneumoniae and matrix metalloproteinase-9 (MMP-9) in atherosclerotic plaques.
Design: 31 coronary atherosclerotic plaque specimens were studied by immunohistochemistry, polymerase chain reaction (PCR), and reverse transcription PCR for the presence of C pneumoniae antigen and genomic DNA, and of MMP-9 protein and transcripts.
Results: Immunohistochemical analysis identified a strong association between the presence of C pneumoniae antigen and production of MMP-9 in coronary atherosclerotic plaques (p = 0.001). Furthermore, analysis of the intralesional amount of C pneumoniae and MMP-9 indicated an increased number of cells positive for MMP-9 in arterial sections that had increased C pneumoniae positivity (p < 0.05).
Conclusions: This study provides evidence of an association between expression of MMP-9 and the intravascular presence of C pneumoniae and may suggest a potential pathological mechanism whereby C pneumoniae may contribute to the progression of coronary atherosclerosis.
- MMP, matrix metalloproteinase
- PCR, polymerase chain reaction
- RT-PCR, reverse transcription polymerase chain reaction
- Chlamydia pneumoniae
- matrix metalloproteinase
- polymerase chain reaction