Will Alzheimer’s finally be detected early enough?
Timely recognition is crucial for managing Alzheimer’s disease, as there is currently no cure. Researchers at Lund University in Sweden have developed a blood test called PrecivityAD2, which is 90% accurate in identifying Alzheimer’s in people experiencing cognitive symptoms. Early diagnosis is vital as new treatments, such as immunotherapies, are being developed to slow the disease’s progression. Accurate diagnosis also facilitates research into new treatments.
Researchers tested the PrecivityAD2 blood test, which measures two ratios within a blood sample: plasma phosphorylated-tau217 and two types of amyloid-beta. Both tau and amyloid-beta proteins are pathological hallmarks of Alzheimer’s disease. Blood tests offer a less invasive, cost-effective, and accessible alternative to current methods, allowing for early diagnosis and better patient outcomes.
About 1,200 study participants with an average age of 74 years old were tested with the PrecivityAD2 blood test. Of the participants, 23% had subjective cognitive decline, 33% had dementia, and 44% had mild cognitive impairment. About 50% of participants showed Alzheimer’s disease pathology through primary and secondary care testing. Of the 698 participants previously seen at a memory clinic, the PrecivityAD2 test was about 90% accurate in identifying the presence of Alzheimer’s disease, while specialists were only 73% valid. And for the remaining 515 participants originally seen by a primary care doctor, the test was again about 90% accurate in diagnosing Alzheimer’s disease, compared to primary care physicians being 61% correct.
Next steps in testing the PrecivityAD2 blood test include validation of the blood biomarkers in diverse international cohorts, especially those with lower amyloid positivity prevalence, as well as the development and evaluation of fully automated immunoassays for easier implementation in clinical labs.
By reducing brain health diagnosis to lab tests only, and forgoing detailed clinical interviews and human-to-human assessments, physicians run the risk of false positive dementia diagnoses, reducing complex neuropathological processes into one neat diagnosis and, in our present care environment, unnecessary treatments with high risks. Thus, it is important to stress that laboratory tests should not replace human assessment, but should rather be complementary for early diagnosis.
For more information, visit https://alz-journals.onlinelibrary.wiley.com/doi/full/10.1002/alz.13764.
Mena El Gaddafi — Cases101 Team Member