Patients with memory issues could be checked for Alzheimer's disease with a blood test at their doctor's surgery, a study has suggested.
Researchers in the US measured blood levels of a brain protein called phosphorylated tau 181 (pTau181) which collects in tangles in patients with Alzheimer's and found that it was three-and-a-half times higher in people with the disease compared with those without.
The study, led by University of California San Francisco (UCSF), said that if approved the test could be used in primary care units such as doctors' surgeries to identify people with Alzheimer's or mild cognitive impairment.
The authors said that existing methods for diagnosing Alzheimer's were "expensive" or "invasive" and not easy to perform for large populations.
The blood test could also lead to a jump in the number of Alzheimer's patients enrolling in clinical trials, they added.
Senior author Adam Boxer, of the UCSF Memory and Ageing Centre, said: "Being able to easily diagnose Alzheimer's at early stages may be especially beneficial to patients with mild cognitive impairment, some of whom may have early Alzheimer's disease. Individuals with early Alzheimer's are more likely to respond to many of the new treatments that are being developed."
The study is published in the journal 'Nature Medicine'.