Baylor Innovations Fort Worth — Spring Vol 2 No 2
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Air Force
Matt Windsor

Asthama is a battle, and anyone who has seen a person with, asthma fighting for breath has witnessed the struggle. Scientists, however, finally believe the tide is turning in their favor. Experts say better education, enhanced medications and innovative therapies will continue to improve the lives of the more than 22 million Americans with this airway disease.

In 2007, the National Heart, Lung, and Blood Institute (NHLBI) released the first major revision of its asthma treatment guidelines in a decade, highlighting the importance of controlling environmental triggers – along with regular assessment and monitoring, and increased patient education – to keep asthma in check.

“The good news is that with current medications, asthma can be well controlled or adequately controlled in 80 to 85 percent of patients,” says Mark Millard, M.D., medical director of the Baylor Martha Foster Lung Care Center and physician on the medical staff at Baylor University Medical Center at Dallas. “But trigger avoidance is very important.

Is it reflux that’s causing nighttime asthma? Is it dust mites in the pillow and mattress? The NHLBI guidelines say very clearly that if you can reduce the triggering of asthma symptoms you can reduce the overall severity of asthma symptoms and potentially the amount of medication required for good control.”

Relatively simple changes can have a big impact, particularly for the more than 50 percent of asthma cases that are caused by allergies. These steps include vacuuming often to remove dust and dander, changing bed sheets frequently, keeping kitchens clean and foods sealed to deter cockroaches and avoiding smoking in homes and cars. The National Institutes of Health conducted a large study involving pediatric asthma patients, and participants who practiced similar measures for a year had an average of 21 fewer days of symptoms compared to a control group – as much of an improvement as what can be achieved with inhalers. (For tips on avoiding springtime asthma triggers, see “Spring [Pollen] Break” on page 22.)

On the horizon
The current standard for determining allergic asthma triggers is the skin test, Dr. Millard says. And now, scientists at the Georgia Tech Research Institute have designed a portable meter that patients can take home to monitor daily exposure to a range of allergens and irritants, such as ozone, that are implicated in asthma attacks. Although the sensor cannot currently detect all triggers or offer real-time feedback, it has future promise, says Dr. Millard. When marketed, this option could be useful for some patients with multiple allergies who want to pinpoint the ones giving them the most trouble.

Not all advances rely on high-tech hardware. Researchers at Baylor Dallas and Southern Methodist University have begun an NIH-sponsored three-year study to determine whether simple breathing exercises can improve asthma control. “The hypothesis is that in asthma, people hyperventilate – they breathe faster and deeper than they’re supposed to, and that can aggravate airway inflammation,” says Dr. Millard.

Using a monitor, patients are being taught to breathe more shallowly; in theory, this should raise carbon dioxide levels just enough to ease inflammation – and patients’ dependence on medication.

Improved drug therapies
Despite efforts such as these, medications will continue to be a necessity for most patients with asthma. But the drugs are getting better, says Fred Hsieh, M. D., a staff physician at the Cleveland Clinic Respiratory Institute. Within the next five years, for example, ultralong- acting beta-agonist drugs such as indacaterol should be available, he says. These airway-opening medications are designed to last 24 hours, unlike current drugs that must be taken twice per day. Used in combination with existing 24-hour inhaled corticosteroids, the new medications “would give good control throughout the day,” says Dr. Hsieh. “And certainly with once-a-day therapy we’d see better patient adherence.”

Even further in the future, Dr. Hsieh notes the potential of so-called dissociated corticosteroids. Trials are under way to perfect versions of these highly effective anti-inflammatory Drugs that have been stripped of their troublesome side effects, including weight gain and an increased risk of cataracts and osteoporosis. “The first drug of this kind on the market would be a blockbuster, especially for the pediatric age group,” says Dr. Hsieh.

Bugs in the system
Beyond improving current medications, better understanding of the biological problems underlying airway inflammation may lead to new treatments, says Geoffrey Chupp, M.D., director of the Yale Center for Asthma and Airways Disease. Cellular pathways that were first identified as targets for cancer and heart disease are now providing inspiration for asthma medications – including FLAP- and JNK-inhibitors.

Dr. Chupp and fellow Yale researchers have made a breakthrough in another direction. They have been investigating an asthma-triggering role for chitinases, substances the human body produces in reaction to chitin, a hard material found in the bodies of dust mites, cockroaches and fungus – all of which are known triggers of allergic asthma.

“If you inhale a dust mite that has chitin in it, there is an increased production of chitinases to deal with that,” says Dr. Chupp. “But at the same time they’re combating that organism those chitinases are probably also driving an inflammatory response, so the lungs and airways get inflamed, too.” The Yale team found that chitinase levels were higher in people with asthma than in the rest of the population, and that patients with severe asthma had the highest levels of all.

Dr. Chupp says his team’s working hypothesis is that patients with certain types of asthma overexpress these chitinases. Measuring chitinase levels in the blood could identify people with this subgroup of disease, and further research may lead to therapies that specifically block the chitinase response.

“It’s the whole concept of personalized medicine,” says Dr. Chupp. “I think we’re heading into that era for asthma, where we’re going to be able to personalize therapy at a new level.”
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