WOMEN with prior exposure to human herpes viruses demonstrate a notably steeper rise in blood biomarkers linked to dementia as they age, even with no cognitive symptoms, a new study has found.
Researchers examined repeated blood samples from 167 cognitively unimpaired women aged 26 to 98, yielding 345 samples in total. They measured several key dementia-associated biomarkers, including amyloid beta (Aβ40 and Aβ42), the Aβ42/Aβ40 ratio, and phosphorylated tau proteins (pTau181 and pTau217). In addition, they tested each sample for seroprevalence of six human herpes viruses (HHV1 to 6). While all biomarkers except the Aβ42/Aβ40 ratio increased substantially with age, women who were seropositive for herpes viruses saw the sharpest rises. The most pronounced increases were seen for Aβ40, followed by Aβ42, pTau217, and pTau181, with the effect of viral seropositivity most marked for exposure to HHV4, HHV6, and HHV1. Seropositive women experienced an average rate of biomarker increase with age over twice as high as those without past herpes virus infection (2.15 times higher, P = 0.003). Notably, the presence of the APOE4 genotype, a well recognised genetic risk factor for dementia, did not significantly alter these associations.
These results underline the potential of blood biomarker screening to offer insights into dementia risk among healthy individuals, and suggest clinicians should be aware of a possible viral contribution to dementia pathways, irrespective of genetic background. While blood-based dementia biomarkers are gaining ground in research and screening, these findings highlight the importance of understanding infection history when interpreting results, especially in women.
Reference
James LM et al. Human herpes viruses are associated with steeper age-dependent increases of serum biomarkers for dementia in cognitively unimpaired women. Sci Rep. 2025;15:25475.
