the Puzzle of Asthma
By every measure
hospitalizations, emergency room visits, trips to the doctor's office
the chronic lung disease called asthma is on the rise. Since 1980, asthma
rates have increased 75 percent, and the death rate, though low, has doubled.
Asthma is now one of the country's most common and costly diseases, says the
Centers for Disease Control and Prevention (CDC), affecting an estimated 17
million Americans. The reasons for this upsurge remain mysterious.
The National Institute
of Allergy and Infectious Diseases (NIAID) today releases Focus on Asthma,
a Web site feature that explains how NIAID-sponsored researchers are looking
for ways to better understand, prevent and treat asthma. Below are excerpts
from Focus on Asthma, which may be of interest as the school year begins
and fall allergies kick in. For more details and background information, visit
the NIAID Web site at http://www.niaid.nih.gov/spotlight/asthma01.
To pursue these or other
asthma story ideas, please call Jeff Minerd in the NIAID Office of Communications
and Public Liaison at (301) 402-1663.
Nationwide Effort Makes a Difference for Inner-City Kids
Asthma counselors are going to work in 23 community-based health organizations
across the United States to improve the health of inner-city children with
asthma. The counselors, hired with $2.9 million provided by the CDC, will
implement a treatment intervention developed and proven effective by NIAID-supported
research. This research was carried out by the National Cooperative Inner-City
Asthma Study, an NIAID effort launched in 1991 to find out why asthma disproportionately
affects inner-city children and what can be done about it.
Cats May Protect Against
Contrary to popular belief, high levels of cat allergen in the home can sometimes
decrease the risk of a child developing asthma, says grantee Thomas A.
Platts-Mills, M.D., Ph.D., of the University of Virginia. Apparently,
the presence of a cat can alter the immune system in a manner similar to allergy
shots, he reports.
Cockroaches + Kids
Researchers have known for some time about the connection between cockroach
allergen and asthma, especially in inner-city children, but no one knows exactly
how or why exposure to these insects leads to asthma. The work of grantee
Diane Gold, M.D., of Brigham Women's Hospital, and her colleagues gives
us a closer look at this phenomenon.
Everybody's immune system reacts to the allergens that cause asthma, such
as ragweed pollen, by producing antibodies against them. However, only a quarter
of us produce the allergic antibodies that can lead to asthma; the rest of
us somehow manage to suppress or avoid this allergic response, explains Andrea
Keane-Myers, Ph.D., a NIAID researcher specializing in asthma and allergic
"Most scientists are focusing on what 'turns on' the allergic response,
but a better question may be what turns it off in the majority of people,"
she says. "What are some of the 'stop signals' that prevent allergy?
If we understood these, we could use that knowledge to make better treatments."
Diesel Exhaust Aggravates
Diesel exhaust particles can worsen one's asthma symptoms, and the particles
may contribute to the increased prevalence of the disease, according to grantee
Andrew Saxon, M.D., of the University of California, Los Angeles.Specialized
Cells May be Key to Chronic Asthma
Specialized defensive immune system cells called eosinophils have long been
thought to cause the symptoms of late-stage asthma attacks by releasing toxins
in the airway, but a new study shows these cells may play an even more fundamental
role in allergy and asthma. A clearer understanding of how these cells work
could lead to better asthma treatments.
New Technique to Test
A strategy used to prevent rejection of transplanted organs might also help
fight allergy and asthma, according to Calman Prussin, M.D., head of
the clinical allergy and immunology unit at NIAID. Dr. Prussin and colleagues
plan to test whether allergy shots will work better when combined with a tolerizing
drug. Such drugs are currently used to make immune system cells non-reactive,
or "tolerant," toward a transplanted organ.
DNA Could Lead to Three-In-One Drug
Scientists have identified a snippet of DNA that regulates three key immune
system substances involved in asthma, reports NIAID grantee Richard Locksley,
M.D., an investigator at the University of California, San Francisco.
Further understanding of how this regulatory DNA works could lead to drugs
with a "three-in-one punch," lowering the amount of these substances
in the airways and controlling asthma more effectively than do drugs that
target only one substance.NIAID is a component of the National Institutes
of Health (NIH). NIAID supports basic and applied research to prevent, diagnose
and treat infectious and immune-mediated illnesses, including HIV/AIDS and
other sexually transmitted diseases, tuberculosis, malaria, autoimmune disorders,
asthma and allergies.
Press releases, fact sheets and other NIAID-related materials are available
on the NIAID Web site at http://www.niaid.nih.gov.