Toxoplasma gondii IgG Serointensity Is Positively Associated With Frailty.

Area of Science:

• Gerontology
• Immunology
• Infectious Diseases

Background:

• Aging is associated with persistent inflammation (inflammaging), which is worsened by chronic infections and contributes to frailty.
• Toxoplasma gondii (T. gondii) is a common parasite causing persistent, often asymptomatic, infections.
• This study investigated the potential link between T. gondii infection and frailty in older adults.

Purpose of the Study:

• To examine the association between T. gondii infection and frailty in older adults.
• To explore the relationship between T. gondii serointensity and known biomarkers of immune activation linked to frailty.

Main Methods:

• Demographic, social, and clinical data were collected from 601 Spanish and Portuguese older adults.
• Plasma T. gondii immunoglobulin G (IgG) serointensity was measured using ELISA.
• Frailty was assessed using Fried criteria, and confounders included cognitive function, depression, and comorbidities.

Main Results:

• A significant positive association was found between T. gondii IgG serointensity and frailty in seropositive individuals, even after adjusting for confounders.
• Kynurenine/tryptophan ratio and soluble tumor necrosis factor receptor II levels were positively associated with T. gondii serointensity in seropositive individuals.
• Other tested biomarkers did not show significant associations with T. gondii serointensity.

Conclusions:

• This study reports the first association between T. gondii infection and frailty in older adults.
• While some inflammaging biomarkers were linked to both T. gondii and frailty, they did not fully explain the observed association.
• The cross-sectional design necessitates further research to confirm these findings.