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Better allergy, asthma treatments on the way

As anyone with a nose knows, this spring's pollen crop has arrived early and often across much of the country, courtesy of the mild, wet El Nino winter.

Spores from trees, grasses and weeds, with a bonus dollop of molds, are seizing the sinuses and clogging the bronchial tubes from now until fall.

An estimated 35-million Americans suffer from allergic rhinitis or hay fever and about 15-million have asthma, with much overlap between the two groups, because allergic reaction is a major trigger for asthma attacks.

For millions of allergy sufferers, the arsenal of medications available either over-the-counter or by prescription remains less than ideal, with immunotherapy injections that reduce but don't eliminate sensitivity or antihistamines that curtail the sniffles but leave you drowsy or dried out.

The silver lining to this yellowish-green cloud of a season is that an array of improved and new allergy and asthma drugs and treatment techniques are here or on the horizon, experts say.

The approach creating the biggest stir is called anti-Immunoglobin E monoclonal antibody, a genetically engineered artificial switch to the immune system that selectively turns off the body's allergic response before it reaches the point of producing inflammation, itchiness and sneezes.

"These designer antibodies seem to have overcome some of the early obstacles of being themselves attacked by the human immune system, and seem very promising," said Dr. Mark Dykewicz, an allergy specialist and researcher at St. Louis University. "The first round of human trials showed a single injection of anti-IgE (Immunoglobin E) reduced the response to allergic challenges for more than two months."

The antibody, being developed by several biotechnology firms, is undergoing extensive human trials as an asthma treatment and is in the early rounds of human testing for use against allergy symptoms.

Another line of research, carried out by Farhad Imani of Johns Hopkins University, suggests that mild viral infections leading to colds, influenza and mononucleosis may spur IgE production, with repeat infections setting children up for greater allergic sensitivity and asthma.

Still other immunotherapy work is ongoing using peptides, or small fragments of protein, from various allergens, such as cat dander, ragweed, grasses and trees, and with extracts of DNA from the allergy-causing agents to desensitize the immune system to them.

While these approaches have shown some effectiveness in small groups of patients, "I think their practical use is much further off than the anti-IgE," said Dr. Michael Blaiss, associate professor of pediatrics and medicine at the University of Tennessee, Memphis.

In the short run, most of the action in controlling symptoms of allergy is likely to be in the form of better antihistamines, drugs that control the chemical that produces most of the sneezing, inflammation and runny nose effect of allergy.

Several prescription brands _ Allegra, Claritin and Zyrtec among them _ have refined their antihistamines to isolate the active ingredient one stage further through human metabolism to make them both more effective and with fewer sedating and drying side effects. Many other manufacturers are hurrying to produce similar updates of their drugs.

Also recently available, with more to come, are new classes of corticosteroid nasal sprays, nasal antihistamines and leukotriene (inflammatory) inhibitors (such as Accolate and Zyflo) to combat allergic inflammation and asthma.

Blaiss said two other products for asthma are likely to debut within the next year or so: a better refined derivative of the staple drug albuterol that should eliminate most of its stimulative side effects and an inhaled steroid that can be delivered through a nebulizer, allowing treatment for youngsters under age 5 who can't reliably use a metered-dose inhaler.

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