Learning More About Alzheimer’s

Research on this topic by Nicolas R. Barthélemy, Kanta Horie, Chihiro Sato, and Randall J. Bateman appears in a recent issue of the Journal of Experimental Medicine.

Highlights are summarized by Tamara Bhandari at Futurity.org:

 Two decades or more before symptoms arise, plaques of a sticky protein called amyloid begin forming in the brains of people later diagnosed with Alzheimer’s disease. The new research shows that levels of a specific protein in the blood rise as amyloid plaques form in the brain.

Researchers analyzed blood samples and brain scans from 34 people participating in Alzheimer’s research studies. They were at Washington University’s [in St. Louis] Charles F. and Joanne Knight Alzheimer’s Disease Research Center. Nineteen participants had no amyloid in their brains. Five had amyloid but no cognitive symptoms. And 10 had amyloid and cognitive symptoms.

The researchers used a technique known as mass spectrometry to identify and measure the different forms of tau in the blood samples. They found that levels of phosphorylated tau 217 correlated with the presence of amyloid plaques in the brain. People with amyloid in their brains had two to three times more of the protein in their blood . These high levels were evident even in people with no signs of cognitive decline.

To verify their findings, the researchers repeated the analysis in a separate group of 92 people. Fort-two with no amyloid. Twenty with amyloid but no cognitive symptoms. And 30 with amyloid and symptoms. Levels of phosphorylated tau 217 in the blood correlated with the presence of amyloid in the brain with more than 90% accuracy. “This is just an exploratory study. But we think phosphorylated tau 217 is a promising target for an early diagnostic test,” Barthélemy says.