Blood Test for Alzheimer's?

Professor Naomi Cahn, the incoming chair of the AALS section on Aging & Law, sent me this recent article,  The Hunt for a Blood Test for Alzheimer’s Disease wherein "[r]esearchers hope circulating biomarkers will enable earlier detection and better monitoring of the neurodegenerative disorder—and perhaps help usher in new treatments." The article identifies updates in research and summarizes some blood tests being tried to help with diagnosis.

A number of questions and issues remain to be resolved before many of the biomarkers found in the blood are ready for use in trials, much less for clinical care... [with] [o]ne issue that researchers must account for is individual variability....  “People are so different [and] there’s a lot of things we still don’t know how to even control for in terms of statistical analyses.” Age and APOE4 carrier status, for example, can change the levels of some AD biomarkers independently of whether an individual has the disease.

The story also notes the existence of technical challenges and challenges of consistency. So far scientists haven't found the definitive diagnosis, nor the cure, but they are surely working hard to do so.