Protein may help detect Alzheimer’s: study

CHICAGO (Reuters) – Sampling spinal fluid for a protein
that makes up the plaques that clog the brains of Alzheimer’s
disease patients may help diagnose the mind-wasting disease,
researchers said on Monday.

As plaques build up in the brain, levels of the protein —
A beta 42 — are thought to decline elsewhere in the body,
including the spinal fluid, according to the study appearing in
the Archives of Neurology.

Other than giving suspected Alzheimer’s patients mental
tests, a diagnosis can only be confirmed after death from the
tell-tale plaques found in the brain.

One hundred eight-four adults averaging 50 years old and
free of Alzheimer’s at the start of the study had their spinal
fluid tested for the protein found in brain plaques.

In subjects with a genetic predisposition to Alzheimer’s
disease, protein levels in the spinal fluid declined slightly
through adulthood and then dropped sharply between age 50 and
60 — presumably as plaque formation in their brains
accelerated.

In people without the genetic predisposition, protein
levels in the spinal fluid rose until age 50, then began
declining slowly.

No direct connection was found between levels of the
protein and Alzheimer’s symptoms, but the mental decline from
Alzheimer’s is thought to progress only after years of plaque
buildup and usually becomes evident in old age, the study said.

“These findings have implications for the preclinical
diagnosis of Alzheimer’s disease, as well as for treatment,”
said study author Elaine Peskind of VA Puget Sound Health Care
System and University of Washington School of Medicine,
Seattle.

“Therapeutic strategies aimed at prevention of Alzheimer’s
disease may need to be applied in early midlife or even younger
ages to have maximal effect on amyloid (plaque) deposition,”
she added.