Anti chlamydia antibodies in patients with thoracic and abdominal aortic aneurysms

BACKGROUND: Chlamydia species are suspected of being involved in the pathogenesis and progression of aortic aneurysms. We investigated serum levels of Chlamydia antibodies in patients with thoracic aortic aneurysms (TAA) and abdominal aortic aneurysms (AAA) compared to levels in healthy individuals. METHODS: We included 35 consecutive patients with TAA, 42 patients with AAA and 42 age- and sex-matched healthy controls in a case control study. Serum antibodies (IgM and IgG) against Chlamydia lipopolysaccharide (LPS), Chlamydia pneumoniae and Chlamydia trachomatis were measured by recombinant ELISA and quantified by measurement of optical density. RESULTS: Patients with TAA exhibited median immunoglobulin levels against Chlamydia LPS (IgM 0.090, IgG 0.266), C. pneumoniae (IgM 0.023, IgG 0.264) and C. trachomatis (IgG 0.247) comparable to those of healthy subjects Chlamydia LPS IgM 0.209 (p = 0.1), IgG 0.301 (p = 0.2); C. pneumoniae IgM 0.051 (p = 0.07), IgG 0.516 (p = 0.1); C. trachomatis IgG 0.153 (p = 0.2)]. Patients with AAA had higher serum levels of IgG against Chlamydia LPS (0.560) compared to healthy individuals 0.301 (p = 0.04)], but no significant elevation of antibodies against C. pneumoniae IgM 0.029 (p = 0.1), IgG 0.545 (p = 0.9)] and C. trachomatis IgG 0.219 (p = 0.3)]. CONCLUSION: Thoracic aortic aneurysms were not associated with signs of Chlamydia infection or immunopathogenicity. In contrast, patients with abdominal aortic aneurysms exhibited elevated levels of immunoglobulin against Chlamydia LPS, reflecting an unspecific Chlamydia immunopathogenicity. However, elevated levels of antibodies against distinct Chlamydia species were also not found in AAA patients.