Toxoplasma gondii IgG Serointensity Is Positively Associated With Frailty.

BACKGROUND: Persistent inflammation related to aging ("inflammaging") is exacerbated by chronic infections and contributes to frailty in older adults. We hypothesized associations between Toxoplasma gondii (T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and secondarily between T. gondii and previously reported markers of immune activation in frailty. METHODS: We analyzed available demographic, social, and clinical data in Spanish and Portuguese older adults [N = 601; age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was measured with an enzyme-linked immunosorbent assay. The Fried criteria were used to define frailty status. Validated translations of Mini-Mental State Examination, Geriatric Depression Scale, and the Charlson Comorbidity Index were used to evaluate confounders. Previously analyzed biomarkers that were significantly associated with frailty in both prior reports and the current study, and also related to T. gondii serointensity, were further accounted for in multivariable logistic models with frailty as outcome. RESULTS: In T. gondii-seropositives, there was a significant positive association between T. gondii IgG serointensity and frailty, accounting for age (p = .0002), and resisting adjustment for multiple successive confounders. Among biomarkers linked with frailty, kynurenine/tryptophan and soluble tumor necrosis factor receptor II were positively associated with T. gondii serointensity in seropositives (p < .05). Associations with other biomarkers were not significant. CONCLUSIONS: This first reported association between T. gondii and frailty is limited by a cross-sectional design and warrants replication. While certain biomarkers of inflammaging were associated with both T. gondii IgG serointensity and frailty, they did not fully mediate the T. gondii-frailty association.

Relationship between DNA damage measured by the comet-assay and cognitive function.

Recent studies exploring the relationship between DNA damage measured by the comet assay (single-cell gel electrophoresis) and cognitive function in both animal models and humans are reviewed and summarized. This manuscript provides an overview of studies exploring cognitive dysfunction related to DNA damage due to biological ageing process, cancer treatment, adverse environmental or occupational exposures, and prenatal genotoxic exposure. The review confirms the potential of comet assay to further explore the link between DNA damage, as indicative of genomic instability, and cognitive impairment in different research and clinical areas. Analysed studies support, in fact, the significant relationship between DNA damage and cognitive impairment, mainly affecting attention, working memory and executive functions. These cognitive domains are crucial to daily functioning and occupational performance, with important clinical implications. Although evidence support the relationship between DNA damage measured by the comet assay and cognitive function in different settings, further longitudinal research is needed to disentangle the temporal relationship between them over time, and to explore the potential of comet assay-detected DNA lesions to predict response to interventions.