Analysis of the Correlation Between Toxoplasma gondii Seropositivity and Alzheimer’s Disease

Alzheimer's disease (AD) is a multifactorial brain disorder and infectious diseases are considered as one of the predisposing factors for AD. <i>Toxoplasma gondii</i>, an obligate intracellular parasitic protozoan, is suspected of being associated with AD. Serum samples were collected from 109 AD patients and 114 age-matched healthy controls. ELISA was performed using recombinant <i>T. gondii</i> cyst wall protein 1 (CST1) to detect <i>T. gondii</i> antibodies. A parallel experiment was performed with Toxoplasma gondii tachyzoites lysate protein. To analyze whether factors associated with the onset of AD included chronic <i>T. gondii</i> infection, a multivariate logistic regression model was applied, further validating the correlation between chronic <i>T. gondii</i> infection and AD. AD patients exhibited significantly higher levels of Toxoplasma-specific antibodies in their serum compared to the control group, with statistically significant differences (<i>p</i> < 0.05). Multivariate logistic regression analysis revealed that <i>Toxoplasma</i> infection is a risk factor for AD (<i>p</i> < 0.01), and the CST1 antigen can significantly improve the model's performance in predicting the occurrence of AD. The results indicate that chronic infection with <i>Toxoplasma gondii</i> could be one of the risk factors for the development of AD, potentially predisposing individuals with underlying health conditions to the disease. This further validates the correlation between <i>Toxoplasma gondii</i> and AD.