Washington University School of Medicine in St. Louis will receive $5.9 million over the course of five years to begin an ambitious and potentially decades-long search for the earliest signs that a seemingly normal person may someday develop Alzheimer’s disease.
“The brain changes that cause Alzheimer’s disease begin many years before they culminate in dementia, the symptom that brings most patients in for diagnosis,” says John C. Morris, M.D., director of the Alzheimer’s Disease Research Center (ADRC) at the University and principal investigator for the new grant from the National Institute on Aging. “By the time of diagnosis there has already been so much brain damage that any treatment we start is unlikely to be effective at restoring patients.”
To make it possible to detect Alzheimer’s disease before it progresses to the level of dementia, ADRC scientists are using the grant to fund the Adult Children Study. Scientists plan to conduct comprehensive health assessments every 3 years of two groups each comprised of 120 participants: people with at least one parent with Alzheimer’s, and a control group of people whose parents never had Alzheimer’s. Volunteers in both groups will be cognitively normal and between the ages of 45 and 74.
“Ninety-three percent of patients who have Alzheimer’s disease are 75 or older, so we’re going to go back thirty years before that to look for all the possible early indicators of the disease,” Morris says. “We’ve made a commitment as a center to be in this study for the foreseeable future to look at how closely these indicators are associated with eventual onset of clinical Alzheimer’s disease.”
Two such potential indicators were recently correlated to Alzheimer’s disease in a study from researchers at the ADRC (http://mednews.wustl.edu/news/page/normal/6161.html): brain scans with a new imaging agent that lets scientists detect the amyloid plaques characteristic of Alzheimer’s, and analyses of cerebrospinal fluid levels of amyloid beta 42, a protein that is a primary component of the plaques.
While the recent study’s results are intriguing, Alzheimer’s experts aren’t ready to put all their early diagnosis eggs in one basket and probably won’t be for some time to come, Morris says.
“We’re planning an intense and diverse battery of tests for our volunteers, who are very committed,” says Morris. “We will evaluate not only clinical symptoms such as memory changes and personality changes, but also genetic factors, neuropsychiatric performance and several different kinds of brain imaging. We will also look at the levels of various proteins that are suspected to be linked to Alzheimer’s in the blood and the cerebrospinal fluid.”
The short-term goal of the study, likely to be completed in the initial five-year funding period, will be to determine whether the adult children of parents with Alzheimer’s have more of the potential early indicators of Alzheimer’s disease than the control group.
Over the long term, researchers hope to develop a battery of tests that clinicians can use to weigh the chances that a patient will eventually develop Alzheimer’s.
Currently, the best treatments for Alzheimer’s can only slow the progress of the disease. However, Morris notes that clinical trials are underway at the ADRC of new agents that may be able to stop the brain mechanisms that cause Alzheimer’s disease.
“Ideally, we’d one day like to identify patients many years before clinical onset and put them on treatments that can stop the disease,” he says.
If any volunteers develop Alzheimer’s disease during the study, they will be switched to yearly evaluations at the ADRC.
“As far as I know, this is the only comprehensive study of clinically normal middle-aged people to evaluate potential indicators of Alzheimer’s disease,” Morris says. “There are other studies of adult children of Alzheimer’s patients, but none with such a really comprehensive assessment of potential risk factors.”
Scientists began recruitment and initial evaluations of participants in October 2005. They are close to meeting their goals for adult children of Alzheimer’s, but are still looking for participants for the control group whose parents did not develop Alzheimer’s.
Washington University School of Medicine’s full-time and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.