(February 18th 2026) Researchers at Tallaght University Hospital (TUH) and the School of Medicine at Trinity College Dublin have identified two blood tests that can help predict which people with Alzheimer’s disease are most likely to experience faster progression of symptoms. Episodes of delirium – a sudden change in thinking, awareness or attention often triggered by illness, infection or certain medications were also linked to more rapid decline.
In one of the largest and most detailed studies of its kind, researchers followed more than 300 people from nine European Countries living with mild-to-moderate Alzheimer’s disease over 18 months. Researchers found that two blood-based biomarkers - p-tau217, which reflects Alzheimer’s disease proteins in the brain, and GFAP, which reflects brain inflammation were strongly associated with faster loss of memory, thinking ability, and independence.
People with higher levels of these markers declined more quickly over time. Importantly, the study showed that these biomarkers were more informative than a panel of other commonly-measured blood inflammation markers, which did not predict disease progression once Alzheimer’s disease was established. Measurement of these biomarkers was possible due the use of advanced technology in the Trinity Translational Medicine Institute (TTMI).
These emerging bloods tests are not currently clinically available, but standardised laboratory assays to measure their use in Alzheimer’s disease diagnosis are currently undergoing review with the European Medicines Agency for clinical use. TUH anticipates that p‑tau217 testing will become available within specialist memory services the Hospital later this year, enabling earlier integration of these advances into clinical pathways. This represents a significant step toward translating research findings into real‑world patient benefit.
The rollout in TUH is being led by Prof Gerard Boran and Eoin Begley, and will play a pivotal role in this rapid translation of innovation into practice. Their commitment to adopting validated biomarker technologies at the earliest opportunity reflects TUH’s strategic focus on delivering cutting‑edge, evidence‑based diagnostics that enhance patient care and support personalised treatment planning.
The current findings extend their known use in the diagnosis of Alzheimer’s disease and show they may also be important in identifying how quickly Alzheimer’s disease progresses.
The study also found that episodes of delirium - a sudden state of confusion often triggered by illness or hospitalisation - were linked to significantly faster disease progression. People who experienced one or more episodes of delirium during the 18-month study declined substantially faster than those who did not. The impact of delirium was considerable, highlighting the importance of preventing, recognising and treating delirium wherever possible. The findings also underline the need to carefully account for delirium in clinical trials of new Alzheimer’s disease treatments, as the impact of delirium was so substantial that it may obscure the clinical effects of potential new treatments.
The study has been published today in the leading international journal eBioMedicine, part of The Lancet group. The article is available via this link. The study was funded by a grant from the Meath Foundation & the Irish Clinical Academic Training (ICAT) Programme.
“One of the most common questions patients and families ask in clinic is how quickly Alzheimer’s disease will progress. Until now, we have lacked reliable ways to predict this. By using samples generously donated by more than 300 patients from across Europe, and advanced laboratory technology at Trinity Translational Medicine Institute (TTMI), our findings move us closer to predicting how the disease may progress in individual patients - enabling a more personalised approach in the care of older adults living with Alzheimer’s disease.”
Dr Adam Dyer, Specialist Registrar (SpR) in Geriatric Medicine at TUH and Clinical Lecturer, School of Medicine at Trinity College Dublin, who led the study.
“One of the big unknowns in Alzheimer’s disease is the biological processes that influence how the disease progresses over time in an individual. This study shows that blood-based biomarkers such as p-tau217 and GFAP are closely linked to disease progression .The fact that they outperform broad panels of inflammatory markers tells us that specific neurodegenerative and neuroinflammatory processes are driving decline, rather than general inflammation in the body.”
Prof Nollaig Bourke, Associate Professor in Inflammaging, TTMI, Trinity College Dublin, Joint Senior Author on the Study.
“What stands out from this research is the clear and clinically important impact of delirium. Delirium is not a benign or transient complication in people living with Alzheimer’s disease- it is associated with a step-change in decline. This reinforces the need to prioritise delirium prevention, early recognition, and proactive management across hospital and community care. It also highlights why delirium must be carefully accounted for in dementia clinical trials if we are to accurately assess the effects of emerging treatments.”
Prof Seán Kennelly, Clinical Associate Professor in Medical Gerontology, Trinity College Dublin & Consultant Geriatrician/Director of the TUH Institute of Memory & Cognition, Joint Senior Author on the Study
