Chlamydia pneumoniae infection and restenosis in patients with coronary heart disease

Background: The aim of this study was to establish whether Chlamydia pneumoniae is implicated in the development of restenosis in patients with coronary heart disease (CHD) after percutaneous transtuminal coronary angioplasty (PTCA). Patients and Methods: 67 patients were selected for study after they underwent control angiography after PTCA. Sera were tested for anti-chlamydial antibodies with a genus-specific ELISA and a species-specific microimmunofluorescence test (MIFT). Oropharyngeal specimens were examined for the presence of antigen with a Chlamydia immunofluorescence test (IFT), C. pneumoniae IFT and semi-nested PCR. In addition, anamnestic findings were also included. To determine the general level of antibodies, an age- and sex-matched control group of 180 persons was also examined for Chlamydia and C. pneumoniae serology. Results: Coronary angiography revealed that 31 of the 67 patients had developed a restenosis. There was no significant correlation between serological and angiographic findings. However, the MIFT showed a higher positive rate, especially in IgA, in the restenosis group. C. pneumoniae was detected in the oropharynx by PCR and/or IFT in 20.8% and 16.0% of the cases in patients with and without a restenosis. PCR found more C. pneumoniae-positive cases in the restenosis patients than IFT. No association was found between the detection of Chlamydia antigen and serology. The women with restenosis were more frequently smokers (p = 0.012). Men with restenosis were significantly older (p = 0.015). C. pneumoniae serology based on the rELISA or the MIFT did not show any correlation with restenosis. Conclusion: No evidence was found to suggest that positive C. pneumoniae serology is a risk factor for the development of restenosis. However, whether the species-specific serological test, especially for IgA-antibodies, and the detection of C. pneumoniae in oropharyngeal specimens by PCR might be reliable diagnostic markers in these cases remains to be determined.