Antibodies to a wide range of substances that can aggregate to
form plaques, such as those found in Alzheimer's patients, have
been identified in the blood and cerebrospinal fluid of healthy
people. Levels of these antibodies decline with age and, in
Alzheimer's patients, with increasing progression of the
disease. These findings by Stanford University School of
Medicine researchers and outside collaborators, described in a
paper to be published online July 6 in the journal Proceedings
of the National Academy of Sciences, raise the possibility that
many of us are carrying antibodies in our blood that could be
playing a role in staving off or slowing the progression of
Alzheimer's disease. This seems to be true even when we are
young and healthy and would presumably have had little or no
exposure to the substances that build up in the brain to cause
this disorder. Alzheimer's disease is characterized by the
build-up of amyloid plaques in the brain. These are large
aggregations of a protein breakdown product, o