Quantification and location of Chlamydia pneumoniae-specific antigen in the walls of abdominal aortic aneurysms.

摘要

BACKGROUND: To evaluate the prevalence and quantity of Chlamydia pneumoniae-specific antigen in the three layers (intima, media, and adventitia) of abdominal aortic aneurysms (AAAs), so as to further investigate the pathogenesis of AAAs. METHODS: Aortic walls were collected from 20 patients with AAA and 11 healthy organ donors. Immunohistochemistry was used to identify the C pneumoniae-specific antigen, and image analysis system was used to quantify and locate it. RESULTS: The positive rate of C pneumoniae-specific antigen was higher in the AAA group than in the control group (100% vs. 54.54%, p = 0.003), positive intensity decreased from the tunica intima to the adventitia in the AAA group (16.32% +/- 2.13%, 14.84% +/- 1.80%, and 14.25% +/- 1.67%, respectively, p = 0.003). In the control group, positive cells were mainly found in focal lesion areas. CONCLUSION: We have demonstrated the presence and differentiation of C pneumoniae-specific antigen in the three layers of AAAs, which are in accordance with pathology, thus suggesting a pathogenic role of the antigen.