A new variety of blood tests could easily help doctors diagnose Alzheimer’s disease faster and more accurately, a new study has reported. According to Lund University in Sweden, some tests work quicker and far better than others. Doctors say since it is tricky to tell if memory problems are caused by Alzheimer’s, it is important to confirm a hallmark sign of the disease - a buildup of a sticky protein known as beta-amyloid. Many patients are diagnosed based on symptoms and cognitive exams.

Even though a few labs have started offering a variety of tests to detect many signs of Alzheimer’s in blood, scientists say they are not widely used yet because there is little data to guide doctors about which kind to order and when. The U.S. Food and Drug Administration has not formally approved any of them and there’s little insurance coverage.

Demand for earlier Alzheimer’s diagnosis is increasing.

In the United States, more than six million people, and many across the world suffer from Alzheimer’s, which is the most common form of dementia. Its telltale biomarkers are brain-clogging amyloid plaques and abnormal tau protein that leads to neuron-killing tangles.

A few drugs like Leqembi and Kisunla slow the worsening symptoms by removing gunky amyloid from the brain. However, according to doctors, they only work in the earliest stages of the degenerative disease. According to researchers, measuring amyloid in spinal fluid is invasive, and a special PET scan to spot plaques is considered costly.

Even specialists can struggle to tell if Alzheimer’s or something else is to blame for a patient’s symptoms. “I have patients not infrequently who I am convinced have Alzheimer’s disease and I do test and it is negative,” Schindler said.

The research suggests blood tests for Alzheimer’s can be simpler and faster. Considering the cases of over 1,200 patients, the scientists say these can work in the real-world bustle of doctors’ offices. In the study, patients who visited doctors for memory complaints got an initial diagnosis using traditional exams, gave blood for testing, and were sent for a confirmatory spinal tap or brain scan.

Blood testing was far more accurate, the researchers reported at the Alzheimer’s Association International Conference in Philadelphia on Sunday (July 28). According to the findings, published in the Journal of the American Medical Association, the primary care doctors’ initial diagnosis was 61 per cent accurate and the specialists’ 73 per cent - but the blood test was 91 per cent accurate.

According to doctors, different biomarkers work to prove a greater than 90 per cent accuracy rate. That type of test measures a form of tau protein that correlates with how much plaque buildup someone has. If the level is high, it signals a strong likelihood the person has Alzheimer’s while a low level indicates that is probably not the cause of memory loss.

Several companies are developing p-tau217 tests including ALZpath Inc., Roche, Eli Lilly, and C2N Diagnostics, which supplied the version used in the Swedish study.