Chlamydia pneumoniae-reactive T lymphocytes in abdominal aortic aneurysms: the smoking gun?

The detection of Chlamydia pneumoniae in aneurysm of abdominal aorta and in normal aortic wall of organ donors

Sixty patients underwent surgery due to abdominal aortic aneurysms; the group included 30 patients with asymptomatic aneurysm and 30 with ruptured aneurysm. A control group comprised 30 organ donors. Surgical specimens derived from aneurysm or aorta fragments were investigated for Chlamydia pneumoniae DNA using PCR. In asymptomatic aneurysms, DNA was found in 9 cases (29%), and in ruptured aneurysms in 14 cases (49%). In the control group, C. pneumoniae DNA was not detected in an aortic wall. These results suggest that healthy aortic wall is not susceptible to chlamydial infection. A large number of aneurysm infections implies C. pneumoniae role in proteolysis and degradation of the aneurysm wall. The biological effect of this process may cause an enlargement of the aneurysm.

Cerebral aneurysms in a child with acquired immune deficiency syndrome during rapid immune reconstitution

A 12-year-old boy with perinatally acquired human immunodeficiency virus infection an d Centers for Disease Control and Prevention class C3 disease presented with acute onset of confusion and a right-sided movement disorder 5 months after beginning a new antiretroviral regimen. His CD4 count had been below 50 cells/microL for 4 years but had abruptly risen to more than 250 cells/microL. Computed tomographic and magnetic resonance imaging scans showed cerebral aneurysms and new cerebral lesions consistent with ischemic strokes. The presentation during immune reconstitution suggests that cerebral aneurysms in pediatric patients with acquired immune deficiency syndrome can result from an immune-mediated response to chronic vascular infection.

The relation between Chlamydia pneumoniae infection and abdominal aortic aneurysm: case-control study

Due to recent interest in the role of Chlamydia pneumoniae as a pathogen of the vascular system, a case-control study was conducted to investigate the association between serological evidence of infection with C. pneumoniae and the occurrence of abdominal aortic aneurysm. Detectable IgG antibody to C. pneumoniae was more common among abdominal aortic aneurysm cases than among control patients (adjusted odds ratio, 5.97; P = .08), as was detectable IgM antibody (10% vs. 0%; P = .02). These findings suggest that infection with C. pneumoniae may play a role in the pathogenesis of abdominal aortic aneurysm; therefore, further research in this area is warranted.