Latent Toxoplasma gondii infections are associated with elevated biomarkers of inflammation and vascular injury
Background: Toxoplasma gondii is a protozoan parasite of cats that infects other warm-blooded animals including humans as intermediate hosts. It forms infectious cysts in the brain, muscle and other tissues establishing life-long latent infection. Approximately 10% of the US population is infected. While latent infections are largely asymptomatic, they are associated with neurological deficits and elevated risks of neuropsychiatric diseases.
Methods: This cross-sectional epidemiological study investigated associations of T. gondii infections with biomarkers of inflammation and vascular injury: soluble intercellular adhesion molecule 1 (ICAM-1), soluble vascular cell adhesion molecule 1 (VCAM-1), C-reactive protein (CRP), and serum amyloid A (SAA). Serum samples from 694 adults in the Raleigh-Durham-Chapel Hill, North Carolina metropolitan area were tested for IgG antibody response to T. gondii, and for the above biomarkers using commercially available assays.
Results: T. gondii seroprevalence rate in this sample was 9.7%. Seropositivity was significantly associated with 11% (4%, 20%), 9% (1%, 17%), and 36% (1%, 83%) greater median levels of VCAM-1, ICAM-1, and CRP, respectively after adjusting for sociodemographic and behavioral covariates, while the 23% (-7%, 64%) adjusted effect on SAA was not statistically significant.
Conclusions: Latent infections with T. gondii are associated with elevated biomarkers of chronic inflammation and vascular injury that are also known to be affected by ambient air pollution. Therefore, infections may increase susceptibility to environmental hazards.