Association of infections and autoimmune conditions with cognition: a study using self-reported conditions and identifying a novel plasma biomarker

BACKGROUND: Over the past couple of decades, the role of infections, as well as the involvement of the immune system, have been highlighted in the development of dementia. METHOD: Data from the Wisconsin Registry for Alzheimer's Prevention cohort were utilized for the analysis. A history of medical conditions was searched across the cohort, and known infections and autoimmune conditions were recorded for each participant. These conditions were then compared with the diagnosis and cognitive performances of each participant. Furthermore, plasma markers were analyzed using two different protein quantification methods. RESULTS: Our analysis revealed poorer cognitive performances among participants with listed medical conditions. In plasma samples, Ab42/ICAM1 was identified as a protein ratio with significant variation across condition statuses. DISCUSSION: Our study confirmed that infections and autoimmune conditions contribute to cognitive decline. Ab42/ICAM1 was identified as a relevant marker.