ABSTRACT
BACKGROUND: The association between Chlamydia pneumoniae infection and atherosclerosis has gained recognition. However, the nature of this association is controversial. The infective link may not be specific for atherosclerosis and may also exist in other nonatherosclerotic arterial diseases. We investigated patients with nonspecific aortoarteritis for serological evidence of prior Chlamydia pneumoniae infection. METHODS AND RESULTS: Fifty patients each of nonspecific aortoarteritis and coronary artery disease with angiographic evidence of significant (>70%) coronary artery lesions were tested for the presence of IgG antibodies against Chlamydia pneumoniae by micro-immunofluorescence assay and compared with 50 age- and sex-matched normal healthy controls. The number of patients with nonspecific aortoarteritis who tested positive for Chlamydia pneumoniae antibodies (IgG) was not significantly different from controls (8 v. 7, p=ns). The mean titer amongst positive subjects in the two groups was also similar (1:40+/-40 v. 1:50+/-25; p=ns). Patients with coronary artery disease were significantly older than patients with nonspecific aortoarteritis and controls (53.2+/-5.8 v. 21.2+/-9.9 years and 24.5+/-5.2 years, p<0.01 for both) and showed a higher seroprevalence of prior Chlamydia pneumoniae infection (18 v. 8 and 7, p < 0.05 for both). The mean IgG titers of patients with coronary artery disease who tested positive were also significantly higher than the other two groups (1:98+/-34 v. 1:40+/-40, p<0.001 and 1:98+/-34 v. 1:50+/-25, p<0.01, respectively). CONCLUSIONS: In patients with nonspecific aortoarteritis, the seroprevalence of prior Chlamydia pneumnoniae infection is not more than that in healthy individuals of the same age group, but is significantly lesser than that in patients with coronary artery disease. Thus Chlamydia pneumoniae infection may not be associated with all forms of chronic inflammatory arterial lesions.