Plasma biomarker may aid AD diagnosis

In a study published in Nature, Japanese researchers identified a plasma biomarker of brain beta amyloid burden that had an accuracy of about 90% compared against PET imaging, offering the possibility of cheaper and less invasive approach to enrolling patients in Alzheimer’s disease trials.

While levels of beta amyloid in plasma vary widely from person to person, which is one factor that has prevented its use as a biomarker, the authors found that they could produce a more robust signal by normalizing its levels to that of another peptide that is cleaved from amyloid precursor protein (APP) but does not form toxic aggregates -- APP669-711. They also used a mass spectrometry method with higher sensitivity than the ELISA-based methods often used in the past...