Résumé
BACKGROUND: Chlamydia pneumoniae is an obligate intracellular organism, which can cause respiratory tract infections, exacerbation of asthma, and possibly atherosclerosis. Detection of C. pneumoniae in the atherosclerotic tissue was made using electron microscopy to elucidate the correlation between C. pneumoniae and atherosclerosis. METHODS: Ten cases of paraffin-embedded atherectomy tissue, which were positive in the immunohistochemistry (IHC) were prepared to demonstrate C. pneumoniae on the electron microscope. Two cases of atherosclerotic tissue, which were negative in IHC were processed identically at the same time as negative controls. The tissues were embedded in resin, ultrathin-sectioned, and stained with uranyl acetate and lead citrate, and then observed on electron microscopy. RESULTS: Nine of 10 (90%) atherosclerotic tissue samples were positive for C. pneumoniae on electron microscopy. Negative controls did not show elementary bodies. Elementary bodies of C. pneumoniae were rarely observed in a scattered pattern in the positive specimens. CONCLUSION: Elementary bodies of C. pneumoniae could be demonstrated on electron microscopy in 9 out of 10 atherosclerotic tissue samples with positive IHC for C. pneumoniae. This finding suggests that C. pneumoniae may play an important role in atherogenesis.