The US Food and Drug Administration (FDA) has approved a new blood-based diagnostic test for Alzheimer’s disease, the first of its kind in the world. The Lumipulse G pTau 217/β-Amyloid 1-42 Plasma Ratio can detect amyloid plaques associated with the disease in people aged 55 and older who show signs and symptoms.
According to the FDA Commissioner Martin Makary, Alzheimer’s disease affects more people than breast cancer and prostate cancer combined. The new test aims to help patients by providing an earlier diagnosis, which can lead to timely treatment options that may slow or even prevent the disease progression.
The blood test measures two biomarkers: phosphorylated tau 217 (p-tau 217) and beta-amyloid 1-42 concentrations in plasma. It calculates a numerical ratio of these two values to identify patients with amyloid pathology, reducing the need for invasive tests like PET scans or cerebrospinal fluid analysis.
A clinical study of 499 individual plasma samples showed that the test resulted in 91.7% positive predictive value and 97.3% negative predictive value. The FDA emphasized that results must be interpreted together with other patient information and are not intended as a standalone diagnostic tool.
The test is designed for patients presenting at specialized care settings, showing signs of cognitive decline. However, it also comes with risks of false positive or false negative results, which can lead to misdiagnosis or delayed treatment.
Over 7 million older adults in the US have Alzheimer’s disease, and the number is expected to grow exponentially. The FDA clearance marks a significant milestone for patients and clinicians, as it allows for earlier diagnosis using a simple blood test, similar to cholesterol testing.
Source: https://www.medpagetoday.com/neurology/alzheimersdisease/115631