Institute working toward early diagnosis of Alzheimer's

By Abram Katz Register Science Editor

March 4th 2006 - New Haven - The institute for Neurodegenerative Disorders is studying a way to diagnose and follow Alzheimer's disease in living patients so that scientists can test a new generation of drugs to treat the disease.

About 4 million people in the United States are afflicted with the neurological disorder which causes cognitive impairment, memory loss, confusion, disorientation and, ultimately, death.

New treatments are under development, but researchers first need a way to precisely measure an quantify the progression of the disease.

This is why the institute is studying a promising method to track the changes in the brain that accompany Alzheimer's disease.

If the process proves effective, doctors would be able to diagnose Alzheimer's early, before the onset of dementia.  In the future, treatment could then be started before mental deterioration becomes apparent, said Dr. Kenneth Marek, President of the Institute at 60 Temple St., New Haven.

Researchers have long known that the brains of people with Alzheimer's disease contain large amounts of protein called beta-amyloid.  While scientists do not know whether this amyloid plaque is a cause or a result of the disorder, they believe that beta-amyloid is a good indicator of the disease, Marek said.

The Institute for Neurodegenerative Disorders has received about $300,000 from the Alzheimer's Association to study the key molecule, which is abbreviated as IMPY.  Marek said the Institute is seeking 30 subjects for the ongoing study.

"IMPY is a marking ligand that binds to beta-amyloid, so we can detect if there is an excess of beta-amyloid in the brain," Marek said.

The main goal of the study is to show and illuminate the relationship between beta-amyloid and Alzheimer's symptoms, he said.

Several pharmaceutical companies are working on ways to use the patients' own immune system to rid their brains of plaque.  One approach is vaccination with a beta-amyloidd-like protein to stimulate production of antibodies to attack the brain plaque, he said.

Another avenue is to inject patients with bioengineered antibody designed to latch onto and destroy beta-amyloid protein.

First the Institute is testing IMPY, otherwise known as 6-iodo-2-(4'-dimethylamino-) phenylimidazol [1,2-a] pyridine.  The institute will attach iodine-123 to IMPY and inject the material into a subject.  IMPY has a strong affinity of amyloid and rapidly accumulates in the brain, Marek said.

As the iodine-123 decays it emits gamma rays, which can be detected by the three rotating sensors on one of the institute's SPECT scanners.  A computer can then produce an image showing the amount distribution of beta-amyloid plaque.

"We are looking for subjects.  We would like to image people over time to see what is happening in their brains," said Dr. Danna Jennings, clinical research director at IND.

Potential participants must have been recently diagnosed with Alzheimer's disease or who have significant memory problems.

Eventually, IND would like to scan the brains of patients who are receiving either active or passive immunotherapy for Alzheimer's, Jennings said.  This same kind of immunotherapy may ultimately be useful in treating Parkinson's and other neurodegenerative disorders, she said.  For more information about the study, call (203) 401-4345.