Latent Toxoplasma gondii infections are associated with elevated biomarkers of inflammation and vascular injury

Andrey I Egorov,Elizabeth Sams,Timothy J Wade,Shannon M Griffin,Edward Hudgens,Reagan R Converse,Jennifer N Styles

doi:10.1186/s12879-021-05882-6

Abstract

BackgroundToxoplasma gondii is a protozoan parasite that infects cats as definitive hosts and 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.MethodsThis 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.ResultsT. gondii seroprevalence rate in this sample was 9.7%. Seropositivity was significantly associated with 11% (95% confidence limits 4, 20%) greater median levels of VCAM-1 (p = 0.003), and marginally significantly with 9% (1, 17%), and 36% (1, 83%) greater median levels of ICAM-1, and CRP, respectively (p = 0.04 for each) after adjusting for sociodemographic and behavioral covariates, while the 23% (− 7, 64%) adjusted effect on SAA was not statistically significant (p = 0.15).ConclusionsLatent 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.

Highlights

Toxoplasma gondii is a protozoan parasite that infects cats as definitive hosts and other warmblooded animals including humans as intermediate hosts
200 samples from this subset have been analyzed for biomarkers of inflammation and endothelial function/vascular injury, and for anti-T. gondii Immunoglobulin G (IgG) responses under previous research projects on urban green spaces and allostatic load [22], and green spaces, T. gondii infections and allostatic load [21]
The seroprevalence rate was significantly higher in the subset of participants recruited at National Institute of Environmental Health Sciences (NIEHS) (12.1%) than in the subset recruited at Environmental Protection Agency (EPA) (7.2%)

Summary

Introduction

Toxoplasma gondii is a protozoan parasite that infects cats as definitive hosts and other warmblooded animals including humans as intermediate hosts. It forms infectious cysts in the brain, muscle and other tissues establishing life-long latent infection. Toxoplasma gondii is a protozoan parasite that infects felines as definitive hosts and other warm-blooded animals as intermediate hosts, including humans as accidental or dead-end hosts [38]. Serum IgG antibodies to this parasite usually peak in 2 to 3 months and gradually decline to a lower but still detectable level characteristic of a chronic infection [46]. Serum IgM and IgG tests are typically used for detecting and differentiating acute and latent T. gondii infections [31, 32]. The latest available national US surveillance shows 13.2% IgG seroprevalence in individuals older than 5 years of age [31]

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