New Study May Unlock Mystery Of Alzheimer's Disease And Speed Search For Effective Treatment

CHICAGO, Jul 7, 1999 (BW HealthWire via COMTEX) -- An immunization with the very peptide that initiates accumulation of amyloid plaques in the brains of people with Alzheimer's disease reduces existing plaques and prevents further plaques from developing in mouse models, according to a research study to be published in the July 8 issue of the journal Nature.

"This is an exciting and encouraging study for the prevention and possible treatment of Alzheimer's disease," said Peter Braun, Los Angeles Alzheimer's Association executive director. "For many years, scientists have hypothesized that the presence of amyloid plaques causes cell death and leads to a decline in a person's cognitive functions. Scientists now have an opportunity to test this theory and begin unlocking the mystery behind this devastating disease."

Researchers at Elan Corp. plc. immunized a group of transgenic mice -- mice genetically engineered to develop Alzheimer's disease pathology similar to that which is seen in humans -- with a form of the beta amyloid peptide called AN-1792. The mice were immunized at an age well before they developed amyloid plaque and associated brain damage.

After 13 months, the researchers compared the brains of the immunized mice to three other groups of mice that were left untreated or had been given either shots of a saline solution or a different plaque-associated protein (SAP).

According to the study, the group treated with AN-1792 showed less amyloid plaque and surrounding neuropathology than the other three groups, and virtually all of the mice treated with AN-1792 had no detectable amyloid deposits in their brains. The mice treated with either saline or SAP showed no reduction in the progressive deposition of plaques.

The researchers conclude that immunization with AN-1792 significantly reduced existing amyloid plaque and inhibited further plaque formation in the brains of transgenic mouse models. Researchers also found that prophylactic immunization with AN-1792 prevented the majority of treated mice from developing virtually any amyloid plaques.

Mice that were immunized after the age that amyloid plaques would be expected to develop showed fewer plaques than mice that were not immunized. The study also suggests that this treatment may clear plaques even after they haveformed.

"This is a novel technique that points us in a new direction toward an effective clinical intervention for the treatment of Alzheimer's disease," said Braun. "It is a very rich time for Alzheimer's disease research, and developments like these today are capable of changing the course of research tomorrow."

Alzheimer's is a progressive, degenerative disease of the brian that causes a steady decline in memory and results in dementia -- loss of intellectual functions (thinking, remembering and reasoning) severe enough to interfere with everyday life. Approximately four million Americans have Alzheimer's disease and in just 50 years, about 14 million Americans will have the disease unless a cure or prevention is found.

Founded in 1980, the Alzheimer's Association is the only national voluntary health organization dedicated to conquering Alzheimer's disease through research, and to providing education, support and advocacy for people with Alzheimer's disease, their families and caregivers.

The association is the largest private funder of Alzheimer research, having awarded more than $70 million in research grants. To find a local chapter nearest you, call 800/272-3900 or visit the association Web site at http://www.alz.org.

The Los Angeles Alzheimer's Association serves the 150,000 people with Alzheimer's disease and their families in the Los Angeles area. Some of the programs of the Los Angeles Alzheimer's Association include Telephone Hotline, Support Groups to support Alzheimer sufferers and family members, as well as educational programs for caregivers and professionals.

For more information about Alzheimer's disease, call the Los Angeles Alzheimer's Association at 323/938-3379.

For more information on this release or the Los Angeles Alzheimer's Association, call Jeff Smith at Kratz & Jensen at 310/284-6820.