This is a re-print of a May article posted 1 hour ago. Stay focused Elan is much more than Ty. The daily pps means nothing if your long. Patience, a watched pot never boils.
By Amanda Gardner HealthDay ReporterMon May 9,11:47 PM ET
MONDAY, May 9 (HealthDay News) -- The idea of a vaccine against Alzheimer's disease may yet have some life left to it.
Researchers at the University of Michigan have started a new, albeit modified, trial, even while the May 10 issue of Neurology publishes follow-up data to an Alzheimer's vaccine trial that was halted due to safety concerns in 2002.
The earlier trial was halted after about 6 percent of participants developed a dangerous brain inflammation, encephalitis. However, researchers continued to monitor the remaining patients for up to a year after their last injection -- with some encouraging results.
Participants whose immune systems had mounted a high antibody response to beta-amyloid levels in the brain performed better on memory tests than people who had received a placebo, the Michigan team reported.
They also experienced an unexpected decrease in brain size, perhaps linked to clearance of disease-causing proteins from the brain.
"It's really the publication of what was presented at the Alzheimer's Association meeting in July of last year," said Dr. Sam Gandy, vice president of the Alzheimer's Association's Medical and Scientific Advisory Council.
"The trend is in the right direction. There were some statistically significant improvements on some neuropsychological measures, but they were not obviously meaningful at the bedside," he said.
All of this work, including the new trial, are based on the so-called 'amyloid theory' of Alzheimer's disease, which hypothesizes that rising levels of beta-amyloid protein deposited in the brain are at the root of the disease.
"It's a very popular hypothesis, and the only way to prove whether it's right or wrong is to develop an effective anti-amyloid strategy, expunge amyloid from the brain and see if people never get Alzheimer's or get better," Gandy said.
So far, the evidence has remained unclear.
In the halted trial, about 20 percent (59) of the 300 participants who received at least one injection developed significant quantities of antibodies against beta amyloid in their blood.
In general, those who developed antibodies also displayed stabilization of memory and scored better on certain neuropsychological tests evaluating memory than the placebo group. Furthermore, among those patients who did develop antibodies, those who produced relatively high levels achieved better results on memory tests than those who developed lower levels.
"There was a dose response," said Dr. Sid Gilman, director of the Michigan Alzheimer's Disease Research Center in Ann Arbor and head of the Data Safety Monitoring Board for both trials being reported in Neurology. The trials are funded by two drug makers, Elan Corp. and Wyeth Pharmaceuticals.
Compared to those receiving a placebo, patients who developed antibodies also experienced a decline in levels of tau protein in the cerebrospinal fluid. Tau proteins have long been associated with brain cell death in Alzheimer's patients.
"That suggests that fewer brain cells died in people who achieved a good antibody titer," Gilman said.