Alzheimer's disease is a life-limiting, progressive neurological condition that affects an estimated one in 14 people over the age of 65, and one in six people over the age of 80, according to the UK’s National Health Service (NHS). Currently, physicians are dramatically underdiagnosing early cognitive decline (ECD), a precursor to Alzheimer’s, due to the similarity between the symptoms of ECD and the normal symptoms of ageing, in addition to disease-specific stigma, and the delays in getting correct diagnostic tests. However, a new blood test has been found that could replace traditional, lengthy processes like lumbar puncture that are commonly used to diagnose Alzheimer’s. The NHS is launching a trial, which if effective means the test could be rolled out across the UK within five years. As research continues to evolve, new treatments that slow down the progression of the disease have been identified but will only work effectively if they are administered promptly after disease onset. So, earlier diagnosis through blood tests would be massively beneficial.
Being of an older age, having a family member with the condition, having untreated depression, or having lifestyle factors associated with cardiovascular disease may increase the risk of developing Alzheimer's. The first stages of Alzheimer’s usually involve minor memory problems, which may be overlooked, but as the condition develops the memory problems become worse. The patient may then experience confusion, difficulty making decisions, problems with speech and language, as well as personality changes, low mood, and hallucinations. Currently, diagnosing Alzheimer’s is challenging, and is often only based on general practitioner (GP) assessment, and tests of memory and thinking skills. Only 2% of people with a dementia diagnosis receive one gold-standard method, such as a positron emission tomography (PET) scan or a lumbar puncture.
People with Alzheimer’s have a buildup of proteins known as amyloid and tau in their brains, which is one of the main ways to detect the disease. Dr Sheona Scales, director of research at Alzheimer’s Research UK, said that more types of blood tests that detect p-tau217, a form of the protein tau, which is a hallmark protein of Alzheimer’s disease, are becoming available. Using blood tests will be much more efficient than the current lumbar punctures, as they are far less invasive and can be administered as part of routine testing, especially among older generations, who are more susceptible to the disease.
Improving diagnosis will be even more vital with the imminent arrival of new Alzheimer’s disease therapies. “Coming down the line are potentially ground-breaking new drugs which can slow the progression of early-stage Alzheimer’s disease,” said Dr Richard Oakley, associate director of research and innovation at Alzheimer’s Society. “But for people to be eligible for them if they’re approved in the UK, they will need an early, accurate diagnosis.”
The test would also be helpful in the development of treatment plans, as healthcare professionals would be able to predict the patient’s outcome more accurately from more precise pathologies that categorize the patient into one of the various disease categories (such as Alzheimer’s vascular dementia, Lewy body dementia, or frontotemporal dementia).
According to GAVI, the vaccine alliance, the NHS will trial the new blood test, as part of a £5m ($6.308m) initiative to investigate the feasibility of using the new blood tests to diagnose Alzheimer’s disease. If the trial is successful, the NHS hopes to roll out the test nationally within five years.
GlobalData epidemiologists currently predict that the diagnosed prevalent cases of Alzheimer’s in the UK in 2024 will be approximately 330,000, which will increase to approximately 350,000 cases in 2028. However, if the NHS rolls out Alzheimer’s blood tests throughout the country, it is likely the number of diagnosed prevalent cases will massively increase. This will be beneficial not only in terms of improving treatment plans for patients, but also will increase disease awareness.
