Article from Stanford

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This is the Article that Carol G found from a link of Dr. Utz's from

Stanford. Carol, this is really interesting, thank you.

Stanford's New Antigen Microarrays Open Window to Better Disease Screening

Source: Stanford University

03/06/2002

STANFORD, Calif. - Your immune system normally protects against disease, but

in some cases - such as with rheumatoid arthritis, lupus, and type-I diabetes

- the immune system actually attacks your body. Until now, these disorders,

called autoimmune diseases, have been difficult to diagnose and treat. But a

new microarray-based technology developed at Stanford University Medical

Center may help solve the problem.

Antigen microarrays, as reported in the March issue of Nature Medicine, give

doctors a glimpse of which molecules (antigens) come under attack in an

autoimmune disease. By identifying these antigens, doctors can pinpoint

diseases and treatment options.

" Right now clinicians test each antigen separately - and each one can take

weeks, " said P.J. Utz, MD, assistant professor of immunology and rheumatology

and senior author on the study. " These arrays could enable a clinician to

diagnose the disease on the first visit. "

The antigen microarrays - developed in collaboration with Lawrence Steinman,

MD, professor of neurology and neurological sciences - consist of glass

slides dotted with thousands of proteins and other molecules that are often

attacked in autoimmune diseases. To use the microarray, doctors draw a blood

sample from the patient and incubate it on the array. Those antibodies that

attack molecules on the array will locate their target and latch on.

Fluorescent molecules are then added to detect the antibodies, creating

colored spots on the slide. From there, it's a matter of counting the spots

to see which antigens the immune system recognized.

In normal people, the antibodies will ignore most antigens on the array.

Diabetics, however, may produce arrays with spots corresponding to pancreas

cell proteins, and people with rheumatoid arthritis produce spots that

correspond to molecules found in the joints.

Utz and , MD, PhD, a fellow in the division of immunology and

rheumatology and lead author on the paper, eventually hope to uncover the

tell-tale patterns of all autoimmune diseases.

Although diagnosing disease may be the microarray's most immediate use, an

array can also help design effective treatment for each patient.

" Prescribing currently available drugs for autoimmune diseases is like taking

a sledgehammer to the immune system, " said. Such drugs cripple the

immune system, preventing it from attacking the body, but also opening

vulnerability to colds and more serious infections.

" One of our primary goals is to use this technology to develop and select

antigen-specific therapies to treat autoimmune diseases, " he added. Such a

treatment could target the immune cells causing tissue damage in an

individual patient, rather than hindering the entire immune system.

" Antigen-specific therapies will leave the global immune system in place, "

said.

Microarrays could also help determine who is at future risk of developing a

disease because auto-antibodies may be formed years before signs of illness.

" Even if the patients don't have the disease now, such microarrays may be

able to predict which patients are most likely to develop the disease in the

next five years, " said. In the future, it may become possible to

identify individuals at higher risk - such as those with a family history of

autoimmune disease - so they can begin preventive therapy.

Doctors also may use the microarray in clinical trials of a new drug. Utz

explained that not all people with a given disease produce the same

antibodies. Instead, they may produce two or three out of five that are

associated with the disease. By analyzing microarrays of those who respond to

a drug and those who don't, doctors can identify patterns that show who is

most likely to benefit from the drug.

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