Chlamydia pneumoniae, systemic inflammation and the risk of venous thrombosis

Inflammatory mediators are involved in activation of the coagulation system, and elevated plasma concentrations of IL-6 and IL-8 are associated with an increased risk of venous thrombosis. Using serologic and molecular biologic tests, we investigated in a case-control study on patients with recurrent venous thrombosis the association between Chlamydia (C) pneumoniae and venous thrombosis and we evaluated the relation between C. pneumoniae serology and the cytokines IL-6 and IL-8. The presence of C. pneumoniae antibody titers ≥ 1:16 was not associated with an increased risk of venous thrombosis (odds ratio 0.8 95% CI, 0.4-1.7). Circulating C. pneumoniae-DNA was detected in only one patient and two control subjects. IgG antibody titers against C. pneumoniae were not correlated with the concentrations of IL-6 and IL-8. These results indicate that the inflammatory process shown in patients with venous thrombosis is not related to C. pneumoniae.