UK’s largest GP study of Alzheimer’s blood tests launches in Scotland

The BriDGe (Bringing Alzheimer's Disease Biomarkers to General Practice) study is the largest trial of its kind in UK primary care and will involve more than 50 GP practices across central and northern Scotland, as well as up to 500 patients.  Led by Scottish Brain Sciences and supported by Roche Diagnostics, the research will assess whether two blood tests can help GPs identify Alzheimer's disease more quickly and accurately, guide decisions about further investigations and treatment, and enable patients to access support at an earlier stage.

The study comes just weeks after a new blood-based biomarker test for Alzheimer's disease, Elecsys® pTau217, received CE-marking for clinical use in Europe. Researchers hope the trial will demonstrate how the tests perform in real-world GP settings and whether they can improve the current diagnostic pathway.

Ashton Harper, Global Medical Affairs Lead for Neurosciences at Roche Diagnostics, said: “Around 90,000 people in Scotland are living with dementia, and an estimated two-thirds have Alzheimer’s disease. This landmark collaboration between GPs, researchers and patients across Scotland has the potential to transform the way Alzheimer’s disease is diagnosed. By paving the way for earlier detection through primary care, it could help more people access the right treatment, care and support at the earliest possible stage.”

The study will evaluate two blood biomarkers, pTau181 and pTau217, which are strongly linked to Alzheimer’s disease and are showing promise internationally as early, accurate indicators of the disease

Elecsys® pTau181 Plasma is the first In Vitro Diagnostic Regulation (IVDR) certified test to rule out Alzheimer’s associated amyloid pathology, it is minimally invasive and can reduce the need for confirmatory testing with a negative result. The Elecsys® pTau217 test is designed to identify and measure phosphorylated Tau (pTau) 217 protein, an indicator of amyloid pathology and a hallmark of Alzheimer’s disease . A positive result indicates a high likelihood of amyloid pathology, while a negative result suggests it is unlikely, helping clinicians decide on next steps.

Dr Sheelagh Harwell, Senior Associate GP at GP-Plus in Edinburgh and one of the doctors participating in the study, said the introduction of blood-based diagnostics marked an important shift for primary care.

"The BriDGe study heralds an exciting time in general practice as new diagnostic blood tests become available," she said. "Consultations are shifting from physicians discussing dementia risk with patients to discussing brain health. An earlier diagnosis of Alzheimer's can aid patients with lifestyle modifications, allow them to access support sooner, and plan ahead."

For Martin, who previously took part in a Scottish Brain Sciences study after experiencing significant changes to his memory and thinking, the prospect of a simpler diagnostic pathway is welcome. He described receiving conflicting opinions from healthcare professionals, leaving him uncertain about his condition.

"I had tests through my GP and was told it is likely I have Alzheimer's disease, so I was referred to a psychiatrist at my local hospital," he said. "The psychiatrist told me I didn't have Alzheimer's, without carrying out any tests. I was quite shocked. If a blood test was available through my GP that could make the diagnosis process easier - and potentially quicker - I would be very willing to take it"

Professor Craig Ritchie, Chief Investigator of the BriDGe study and Chief Executive and Founder of Scottish Brain Sciences, said blood biomarkers represented one of the biggest advances in dementia research in decades.

"Blood tests for Alzheimer's are one of the most exciting developments in dementia research in a generation," he said. "We now need to understand how they work in real-world healthcare. By partnering with 50 GP practices and up to 500 patients, BriDGe will show how these tests could transform the way we detect, diagnose and ultimately treat Alzheimer's disease.