Association of latent Toxoplasma gondii infection with neuroinflammatory biomarkers and cognitive impairment
Abstract
Latent Toxoplasma gondii infection has been implicated in chronic neuroinflammation and altered neurotrophic signaling, potentially contributing to cognitive dysfunction. This study aimed to investigate the association of latent T. gondii infection with neuroinflammatory biomarkers and cognitive impairment compared with healthy controls. A cross-sectional case–control study was conducted between February 2025 and April 2026, including 100 individuals with latent T. gondii infection and 50 age- and sex-matched healthy controls. Latent infection was confirmed by positive anti- Toxoplasma IgG and negative IgM antibodies using ELISA. Serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), S100B protein, high-sensitivity C-reactive protein (hs-CRP), and brain-derived neurotrophic factor (BDNF) were measured using ELISA and immunoturbidimetric assays. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), verbal memory, attention, and executive function tests. Participants with latent T. gondii infection showed significantly higher concentrations of IL-6, TNF-α, IL-1β, S100B, and hs-CRP than controls. In contrast, BDNF levels were significantly reduced in the infected group. Cognitive assessments demonstrated significantly lower MMSE, MoCA, memory, attention, and executive function scores among infected individuals, accompanied by a higher prevalence of cognitive impairment. MoCA scores correlated negatively with inflammatory biomarkers and positively with BDNF concentrations. Latent T. gondii infection is associated with increased neuroinflammatory activity, reduced neurotrophic support, and impaired cognitive performance, suggesting that persistent asymptomatic infection may contribute to mild cogn i tive dysfunction through chronic low-grade neuroinflammation.References
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