Antibodies that attack the protein
believed responsible for Alzheimer's
disease may offer a new way to treat the brain-destroying
illness, U.S. researchers reported.
The infusion of antibodies
seemed to be safe and may have delayed or even halted progression
of the fatal disease in Alzheimer patients, the researchers
said.
But the trial of immunoglobulin,
or IVIg, therapy was done in just eight patients and it
is too early to know much about its promise, the team at
New York-Presbyterian Hospital/Weill Cornell Medical Center
cautioned.
"If these results are confirmed
in larger, controlled trials, we might have a safe Alzheimer's
treatment capable of clearing the amyloid protein away,"
Dr. Marc Weksler, who helped lead the study, said in a statement.
In the Phase I safety trial,
eight Alzheimer's patients were treated with IVIg for six
months and then tested for decline in their mental function.
Cognitive function stopped
worsening in seven patients tested so far and has improved
in six, the researchers told a meeting of the American
Academy of Neurology in Miami.
The antibodies target beta-amyloid,
a protein that is a key feature of the brain-clogging plaques
and tangles that characterize Alzheimer's. It seems to kill
nearby brain cells, robbing patients of memories and eventually
of all ability to function and care for themselves.
Previous studies had shown
that antibodies, which are immune system proteins that recognize
and latch onto germs and abnormal cells, can also pull beta-amyloid
out of the nervous system.
Using infusions of antibodies
from blood is called passive immunization and has been used
to fight diseases such as hepatitis.
"Immune therapy for Alzheimer's
disease has shown tremendous promise in the laboratory but
has been difficult to translate into clinical practice,"
said Dr. Norman Relkin of Weill Cornell Medical College.
Other efforts to make a vaccine
against Alzheimer's have been troubled by complications
-- one vaccine caused fatal encephalitis, a swelling of
the brain, for instance.
But IVIg has been approved
for decades for use in treating immune disorders. It turns
out it contains elements specific for beta-amyloid.
