Stanford researchers have developed a blood test that may help with the early detection of Alzheimer's disease. The test identities changes in the proteins in blood plasma two to six years before the onset of Alzheimer's.

Medical school researchers have found that the test may be 90 percent accurate in predicting the onset of Alzheimer's years before the first symptoms appear.

Alzheimer's is a debilitating disease involving gradual loss of memory. But many elderly people experience mild memory problems that are not indicators of Alzheimer's. More than 5 million Americans suffer from Alzheimer's.

"Our hypothesis is that there may be something wrong with the production of certain blood cells, which may be needed to clear that stuff that accumulates in the brain in Alzheimer's disease," said Tony Wyss-Cory, Stanford associate professor of neurology and neurological sciences and lead author of the study, published today in Nature Medicine.

"Already we have people approaching us at meetings asking if they give us a vial of their grandfather's blood for testing," said Mark Britschgi, a postdoctoral fellow in Wyss-Cory's lab.

The study used 259 achieved blood samples from clinics in the United States, Sweden, Poland and Italy, from individuals who had symptoms ranging from nothing abnormal to full-blown mild cognitive impairment to advanced Alzheimer's.

-- Don Kazak