ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Tuesday, May 14, 1996 TAG: 9605140055
SECTION: NATIONAL/INTERNATIONAL PAGE: A-3 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: Associated Press
A new laboratory test of blood and skin cells offers promise for early detection of Alzheimer's disease, a fatal brain disorder that now cannot be positively diagnosed until after death.
The test could provide a way to determine if severe memory loss is caused by Alzheimer's or a treatable disorder, said Dr. Jay H. Robbins, a National Cancer Institute researcher who led a team that developed the test.
``This test could be useful in identifying the disease absolutely in patients who are diagnosed as probable Alzheimer's disease'' sufferers, Robbins said. ``Many people who have blood relatives with the disease might want to know. The decision, for instance, could be important for family planning.''
So far, the test has been conducted only experimentally with frozen cells from a few dozen patients. Much more research is needed before the test could be used generally on patients, Robbins said.
A report on the research is to be published today in the Proceedings of the National Academy of Sciences.
Early diagnosis of Alzheimer's also could boost researchers struggling to develop drugs for the disorder, said Dr. Zaven Khachatuarian, director of the Alzheimer's Association Ronald and Nancy Reagan Research Institute.
Khachatuarian said that drugs including hormones, anti-inflammatories and calcium channel blockers are being studied and all of these could be effectively tested only on people who are confirmed to have Alzheimer's.
``Our ability to detect the disease early will be very important in developing these therapies,'' he said.
Early detection will be even more important once drugs are developed, said Khachatuarian, because ``Alzheimer's may start as early as 40 years before symptoms show up and this means that to slow down the progression of this disease, we need to be able to detect it and treat it early.''
The Alzheimer's Association estimates that at least 4 million Americans, including former President Reagan, suffer from Alzheimer's. Its symptoms include a gradual loss of memory and eventual failure of all other body functions that are directed by the brain, resulting in death.
Although done only in the lab so far, the test does show that the skin and blood cells of Alzheimer's disease patients have fundamental differences that can be detected before symptoms of the disease become apparent. In the experiment, Robbins and his colleagues applied the test to unlabeled cells from 95 patients, some of whom had died of what had been shown in autopsies to have been Alzheimer's disease.
The researchers were able to correctly identify cells from 27 Alzheimer's patients, and to separate out cells from patients suffering from other brain disorders, such as Parkinson's disease and Huntington's disease. There were negative results from 28 of 31 normal cells from healthy donors.
Included in the specimens were cells from patients in rare families whose members have a one in two chance of developing Alzheimer's.
Robbins said the test, using unlabeled, frozen cells, correctly identified specimens from three Alzheimer family members who gave the cells years before they developed symptoms of the disease.
``If we want to [test Alzheimer's drugs], it is important to have tests that will identify people 10 to 15 years before they have symptoms,'' he said.
The test identifies Alzheimer's patients by detecting cells that have lost the ability to repair certain kinds of DNA damage. This inability is a characteristic of the brain cell degeneration found in Alzheimer's patients.
More research must be done to prove the accuracy of the test in identifying people with sporadic Alzheimer's, which strikes randomly and is the most common form of the disease, Robbins said. This could take several years and involve many more patients, he said.
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