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Hope
Springs Eternal …As Do Allergies
Excerpt
By
Colette Bouchez,
HealthScoutNews
While most people are happy to bid
farewell to the cold and snow of winter, not everyone is equally
excited to see spring and summer arrive.
The reason: Seasonal allergies, a problem that plagues some
35 million Americans beginning as early as March and often lasting
clear through the first frost.
"Spring and summer allergies are extremely common, mostly because
there are so many different allergens that come into bloom this
time of the year," says Dr. Clifford Bassett, an allergy and asthma
specialist at New York University Medical Center.
Whether it be trees, grass, flowers or weeds, when the small,
dry, light pollen becomes airborne, simply taking a deep breath
outdoors can leave you sneezing, wheezing, tearing and itching
for up to six months of the year.
New Weapon in Anti-Allergy Arsenal
To heighten awareness of the problem and educate people about
treatments new and old, May is designated Asthma and Allergy Awareness
Month.
While some relief from allergies can be found through practical
means — such as keeping windows closed and staying indoors
when pollen counts are high — for many people spring and
summer survival is made possible by any number of medications
designed to stifle allergic reactions.
These include antihistamines, nasal decongestants and anti-inflammatory
nasal sprays — many of those now available over-the-counter,
as well as by prescription.
However, a brand new class of prescription drugs is posed to
join the anti-allergy arsenal. Known as Anti-IgE, it just may
revolutionize not only the way seasonal allergies are treated,
but also the treatment of asthma as well as food and drug sensitivities.
"It is the first phase of a new kind of treatment for allergy
disease — and it holds some very exciting promise," says
Dr. Lanny Rosenwasser, president of the American Academy of Allergy,
Asthma and Immunology and a researcher and allergist at the National
Jewish Medical and Research Center in Denver.
Immune System Antibody Is Key
Regardless of what you are allergic to, the cascade of biochemical
events that make up an allergic reaction are remarkably similar.
Key to the process is an immune system antibody known as IgE —
or immunoglobulin E.
With a seasonal allergy, airborne pathogens — particularly
pollen — are inhaled, and as they enter the body they bind
to the IgE antibodies. These antibodies, in turn, bind to nearby
mast cells and basophils — immune system molecules that
line your lungs, skin and mucous membranes.
As this occurs, the mast cells and basophils become inflamed
and irritated, which then sparks the release of a wide range of
biochemicals. The end result is one particular chemical known
as histamine, which floods your tissues. When it does, blood vessels
and tissues in your nose begin to dilate and swell, while sensitive
nerve endings become highly irritated. And then, quite quickly,
you have an "allergy attack."
"In the case of seasonal allergies, histamine would initiate
the classic sneezing, wheezing and stuffy nose, along with itchy,
red, watery eyes," Bassett says.
Preventing Reaction in the First Place
For many years, the treatment of seasonal allergies relied on
preventing or reducing histamine production, as well as mast cell
inflammation. While the treatments worked well, to get optimum
relief they had to be administered before exposure because, once
histamine production began it could not really be reversed.
However, the new anti-IgE treatments take an entirely different
approach, working to help prevent the body from reacting to an
allergen in the first place.
"An anti-IgE binds to IgE and ties it up, preventing it from
activating and inflaming the mast cells," Rosenwasser says. The
body is "tricked" into believing there is no allergen present.
So, it responds as if there were no allergy.
More importantly, anti-IgEs are not "allergen-specific." Theoretically,
they can work to block almost any type of allergic reaction. "It
has promise in all allergic diseases," says Rosenwasser, "including
drug and food allergies."
The good news is that the first anti-IgE medication — a
drug known as Xolair (omalizumab-RhuMAb-E25), manufactured by
Genetech — is expected to be approved by the U.S. Food and
Drug Administration in time for the spring-summer allergy season.
The discouraging news is that it must be administered by your
doctor, via injection, once or twice a month, which is expected
to be costly. And since it was tested primarily in asthma patients,
it's true effectiveness with seasonal allergies has not yet been
fully determined.
New Treatment May Not Be Cost-Effective
With that in mind, unless your seasonal allergies are severe,
doctors say you may want to wait a bit before you rush out and
get that anti-IgE treatment.
"For those who have standard hay fever, which can be easily controlled
by nasal steroids or an antihistamine, anti-IgE medication may
not be economically feasible — at least in the beginning,"
Rosenwasser says.
If, however, your allergies are severe, and particularly if you
haven't found relief from available treatments, Xolair may be
worth a try. Should it turn out to be extremely effective, it
may become one of the "big guns" in allergy care, Rosenwasser
says.
Besides Xolair, other IgE drugs are in development to help treat
various types of allergies. Earlier this year, studies published
in The New England Journal of Medicine showed how one anti-IgE
medication reduced the life-threatening affects of a peanut allergy.
In addition, Rosenwasser and colleagues at the National Jewish
Medical and Research Center are developing yet another allergy
treatment called Anti CD23. It works by thwarting the connection
between allergens and the immune system at an even earlier stage
than the anti-IgE drugs, and similarly disrupting the sequence
of allergic responses. This treatment could be available within
several years.
More information
To learn more about all available treatments for allergies, visit
The American Academy of Allergy, Asthma and Immunology (http://www.AAAAI.org).
Or you can check with the National Library of Medicine (http://www.nlm.nih.gov/medlineplus/ency/article/000812.htm).
Reference
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