Alzheimer's blood test a step closer

U.S. scientists say they are a step closer to achieving a blood test for Alzheimer's, after finding a group of markers that hold up in statistical analyses. Dr. William Hu, an assistant professor of neurology at Emory University School of Medicine in Atlanta, and colleagues at the University of Pennsylvania and Washington University at St. Louis, measured the levels of 190 proteins in the blood of 600 study participants. Study participants included healthy volunteers and those who had been diagnosed with Alzheimer's disease or mild cognitive impairment. Mild cognitive impairment often considered a harbinger for Alzheimer's disease, causes a slight but measurable decline in cognitive abilities. A subset of 17 the 190 protein levels were significantly different in people with mild cognitive impairment or Alzheimer's. Changes in levels of these four proteins in blood also correlated with measurements from the same patients of the levels of proteins -- beta-amyloid -- in cerebrospinal fluid that previously have been connected with Alzheimer's, Hu, the study's lead author, said. "Though a blood test to identify underlying Alzheimer's disease is not quite ready for prime time given today's technology, we now have identified ways to make sure that a test will be reliable," Hu said in a statement."In the meantime, the combination of a clinical exam and cerebrospinal fluid analysis remains the best tool for diagnosis in someone with mild memory or cognitive troubles." The findings were published in the journal Neurology.