Blood test shows high accuracy in detecting Alzheimer’s disease

Alzheimer’s disease, characterized by memory loss, problems with concentrating and thinking and changes in personality and behavior, patients, their families and loved ones. With new treatments available for people with early signs of Alzheimer’s disease, there is a growing need for accessible and cost -effective tests to diagnose Alzheimer’s disease earlier. In a new study, Mayo Clinic researchers confirmed the accuracy of a blood test approved by the FDA that can be used in outpatient clinics to diagnose the disease in patients with a series of cognitive disorders. The findings are published in Alzheimer and Dementia: The Journal of the Alzheimer’s Association.

Standard ways to measure the build -up of toxic proteins in the brain that indicate that Alzheimer’s disease includes positronemissite domography or PET scans and spinal taps. But these tests can be expensive and invasive. More accessible, non -invasive and cost -effective biomarkers – measurable indicators of a disease – are needed to broadly improve the diagnoses in clinical environments.

Our studies showed that blood tests confirmed the diagnosis of Alzheimer’s disease with a sensitivity of 95% and a specificity of 82%. When they are performed in the outpatient clinical setting, this is comparable to the accuracy of biomarkers of cerebrospinal fluid of the disease and is much more convenient and cost -effective. “

GREGG Day, MD, accompanying author, Mayo Clinic Neurologist, Dementia specialist and clinical researcher

The research team says that their findings are promising in:

• Better identifying research participants with the brain changes of Alzheimer’s disease.
• Screening and selecting patients with Alzheimer’s disease on clinical studies.
• Assess how patients respond to therapy in clinical studies.

More than 500 patients who receive treatment for a series of memory problems in the outpatient clinic of memory disorders in Mayo Clinic in Florida participated in the study. They include patients with early and late cognitive disorders, typical and atypical disease of Alzheimer’s, Lewy body dementia and vascular cognitive impairment.

Patients varied from 32 to 89 years old, with the average age of the start of symptoms 66. Alzheimer’s disease was determined as the underlying cause of the symptoms in 56% of patients. The team has also performed serum tests to measure kidney disease that can influence the concentrations of the plasma biomarker.

Mayo Clinic Laboratories tested on two proteins in blood plasma that are associated with amyloid plaque structure, the characteristic of Alzheimer’s disease: Aβ42/40 and P-TAU217. The researchers discovered that P-TAU217 levels were higher in patients with Alzheimer’s disease versus who without the disease. Higher plasma P-TAU217 concentrations were also associated with reduced kidney function, of which researchers say that it should be taken into account when performing the blood test.

Plasma P-TAU217 concentrations were positive in 267 of the 509 patients, including 233 of 246 patients (95%) with cognitive disorders attributed to Alzheimer’s disease.

The study could be seen at the annual meeting of the American Academy of Neurology in April.

In an earlier study, researchers from the Mayo Clinic Laboratories showed the usefulness of these blood tests compared to amyloid PET scans among research participants.

Dr. Day says that the next steps in this study are to evaluate blood -based tests in more diverse patient populations and people with early Alzheimer’s disease who do not show cognitive symptoms. The team also wants to evaluate disease -specific factors that can change the accuracy of biomarkers into clinical examinations.