Toxoplasma gondii exposure and neurological disorders: An age- and gender-matched case-control pilot study

Abstract

Little is known about the association of Toxoplasma gondii infection and neurological disorders. We performed a case-control study with 344 patients with neurological diseases and 344 neurologically healthy age- and gender-matched subjects. Sera of participants were analyzed for anti-T. gondii IgG and IgM antibodies using commercially available immunoassays. Anti-T. gondii IgG antibodies were detected in 25 (7.3%) cases and in 35 (10.2%) controls (odds ratio [OR] = 0.69; 95% confidence interval [CI]: 0.40–1.18; P = 0.17). Anti-T. gondii IgM antibodies were found in 5 (14.3%) of the 25 IgG seropositive cases and in 13 (37.1°%) of the 35 IgG seropositive controls (P = 0.15). Anti-T. gondii IgG antibodies were found in 8 (3.8%) of 213 female cases and in 23 (10.8%) of 213 female controls (OR = 0.32; 95% CI: 0.14–0.73; P = 0.005); and in 17 (13.0%) of 131 male cases and in 12 (9.2%) of 131 male controls (P = 0.32). No direct association between IgG seropositivity and specific neurological disorders was detected. We found no support for a role of latent T. gondii infection in the risk for neurological disorders in this setting. With respect to specific neurological disorders, further studies using larger patient cohorts will be required.

Neuronal impairment following chronic Toxoplasma gondii infection is aggravated by intestinal nematode challenge in an IFN-γ-dependent manner

“…Produced primarily by CD4 + and CD8 + T cells as well as innate lymphoid cells [26, 27], IFN-γ is an essential factor in host protection against the parasite, as it triggers multiple immune cell mechanisms leading to the elimination of the parasite [28]. Moreover, IFN-γ can activate the choroid plexus endothelium, thereby aiding the migration of leukocytes into the CNS parenchyma [29, 30].…”

“…T. gondii infection has been shown to alter behavior in rodents [29], and in humans, seropositive individuals have been shown to exhibit subclinical behavioral alterations as well as an increased risk for neuropsychiatric disorders [30] such as PD [31], AD [32], or schizophrenia [33]. Conclusively, a recent large-scale study provided compelling evidence for the association between latent T. gondii infection and schizophrenia in humans [18].…”

Pathophysiological Mechanisms of Cognitive Impairment and Neurodegeneration by Toxoplasma gondii Infection

“…Moreover, in clinical studies, Perry et al [ 19 ] reported no differences in anti- Toxoplasma IgG antibodies levels between AD patients and control groups. Similarly, in a recent case-control study (n = 344 patients), Toxoplasma infection (assessed by anti- T. gondii IgM and IgG antibodies) and neurological disorders were not related [ 20 ], and neither was it associated with dementia in older adults in Africa [ 21 ]. However, in two recent meta-analyses, a relative association between Toxoplasma infection and AD was found [ 22 , 23 ].…”

Chronic toxoplasmosis and sleepiness in obstructive sleep apnea: Is there a link?

“…Toxoplasma gondii is an apicomplexan parasite with a worldwide prevalence of 30% that is believed to increase the risk of some psychiatric and neurological disorders in humans [8,9]. After primary infection through consumption of raw or undercooked meat containing parasite tissue cysts or by contaminated vegetables with oocysts, T. gondii disseminates by the bloodstream to encyst in the brain and muscles, causing chronic toxoplasmosis in humans [10,11].…”