The association between serological markers for Chlamydophila pneumoniae and the development of abdominal aortic aneurysm

Ann Vasc Surg. 2011 Apr;25(3):322-6. doi: 10.1016/j.avsg.2010.09.001. Epub 2010 Dec 3.


Background: To investigate the association between serological markers for Chlamydophila pneumoniae (Cpn) and the development of abdominal aortic aneurysm (AAA) in a population-based case-control study.

Methods: A screening for AAA among 65-75-year-old men and women was performed in a population with high prevalence of disease. Most of the subjects had undergone previous testing at the age of 60, including blood sampling. A total of 42 patients with AAA were compared with 100 age- and gender-matched controls with normal aortas. Cpn immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies present in plasma samples obtained at the time of screening (current) and in the past 5-15 (mean, 12) years (historical) were analyzed. Cpn antibody titers (<1/64, 1/64, 1/264, and 1/1024) were analyzed using the microimmunofluorescence technique.

Results: No differences in current Cpn immunoglobulin A and IgG antibodies titers (p = 0.111 and 0.659), historical titers (p = 0.449 and 0.228), or titer change (delta) (p = 0.794 and 0.172) were observed between patients with AAA and controls. In all, 82% of the patients with AAA had a current Cpn IgG titer of 1/1024 as compared with the 70% of the control group. All 11 patients who had an aortic diameter of >40 mm reported having high current Cpn IgG titers. The fact that such a large proportion of the healthy population demonstrated an immune response against Cpn made it difficult to demonstrate possible effects of Cpn infection on AAA formation in a case-control study.

Conclusion: No significant associations were found between AAA detected by screening and Cpn antibody titer levels at the time of screening or during past screening at the age of 60.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antibodies, Bacterial / blood*
  • Aortic Aneurysm, Abdominal / diagnostic imaging
  • Aortic Aneurysm, Abdominal / microbiology*
  • Case-Control Studies
  • Chi-Square Distribution
  • Chlamydophila Infections / complications
  • Chlamydophila Infections / microbiology*
  • Chlamydophila pneumoniae / immunology*
  • Female
  • Fluorescent Antibody Technique
  • Humans
  • Immunoglobulin A / blood*
  • Immunoglobulin G / blood*
  • Male
  • Mass Screening / methods
  • Risk Assessment
  • Risk Factors
  • Serologic Tests
  • Sweden
  • Ultrasonography


  • Antibodies, Bacterial
  • Immunoglobulin A
  • Immunoglobulin G