Study sheds light on asthma and respiratory viruses

Researchers try to find out why people with asthma have
more difficulty when contracting a respiratory virus.

People with asthma often have a hard time dealing with respiratory viruses such as the flu or the common cold, and researchers have struggled to explain why.

In a new study that compared people with and without asthma, the answer is becoming clearer. The researchers found no difference in the key immune response to viruses in the lungs and breathing passages.

The work, at Washington University School of Medicine in St. Louis, suggests that a fundamental antiviral defense mechanism is intact in asthma.

This means that another aspect of the immune system must explain the difficulty people with asthma have when they encounter respiratory viruses.

Among researchers who study asthma, there is debate over why patients with this common breathing disorder might have more trouble dealing with airway viruses than people without asthma.

The debate has centered on the role of proteins called interferons, which are released by cells lining the airways and are so named because they "interfere" with an invading virus.

"One school of thought says there is a defect in interferon production — that patients with asthma don't produce enough interferon," said senior author Michael J. Holtzman, MD, the Selma and Herman Seldin Professor of Medicine. "But we couldn't find any significant differences between the two groups. In fact, we were struck by how similar they were."

Holtzman and his colleagues looked at two common airway viruses — influenza A and respiratory syncytial virus (RSV) — and the interferon response they triggered in airway cells sampled from 11 patients with mild to severe asthma and seven control participants without asthma.

Though the study's sample size was small, the researchers performed an elaborate analysis that took into consideration the downstream events triggered by interferon release.

"Even though we showed both groups made similar amounts of interferon, we recognized that there might be a difference in effectiveness, a difference in how well it triggered downstream events necessary to fighting the virus," Holtzman said.

To find out whether the same amount of interferon might be less effective in patients with asthma, the investigators compared the genes activated by interferon in both groups of patients.

"The products of these genes are very effective in their antiviral action," Holtzman said. "But on the other side, the virus has a lot of ways of getting around them. So it's a battlefield. Who will win out? The interferon-stimulated genes or the viral genes?"

Holtzman and his colleagues showed that even in this downstream activation of genes, asthma patients and those without the condition were remarkably similar.

They also measured similar amounts of virus living in the cells at various points of time during the study, indicating that the battles against the viruses progressed similarly in both groups.

"Whatever is causing asthmatics and non-asthmatics to experience differences in how well they recover from these respiratory infections — why patients with asthma are more likely to end up in the hospital, for example — this interferon mechanism is not the deciding factor based on what we've seen so far," Holtzman said.

Given the complexity of the immune system, there are many other possible culprits to investigate. Holtzman and his colleagues are continuing to research these possibilities in similar studies with larger sample sizes and in studies looking at different aspects of the immune system.

One likely possibility that the group has proposed is that viruses have a special means to induce inflammatory airway disease, and the susceptibility to this process may be an essential feature of asthma and related lung diseases such as chronic obstructive pulmonary disease.

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Heat and asthma – a dangerous combination

How to control asthma symptoms when the temperatures soar

Hot weather can trigger asthma symptoms,
doctors say. Tips for being outdoors and inside.

High temperatures during the summer months can make breathing difficult for people with asthma.

Hot weather means more air pollution, doctors say, and the heat and humidity can also be triggers for some asthma patients.

Asthma is a chronic respiratory disease affects almost 26 million Americans, 7 million of which are children. The condition is also widespread among low income and minority populations.

Some tips from the experts:

• Limit the time spent in the heat
• Drink lots of water – signs of dehydration include dizziness, confusion, trouble breathing
• Keep in the shade as much as you can
• Take breaks in cooler areas, if possible. Even short breaks in air conditioned spaces, for example, helps the body deal better with the heat

Remove asthma triggers from your indoor air

While summer heat and outdoor air pollution are great risks for those suffering from asthma, indoor air pollution can also trigger attacks or make breathing difficult.

With source control, good ventilation and air cleaning, anyone can improve their indoor air quality.

The best air purifiers for asthma and allergies feature safe and proven air filters that can remove a wide range of indoor air contaminants, including dust, particles, mold, bacteria, viruses, chemicals, odors and gases. All of these can contribute to the inflammation to airways.

AllerAir’s air purifiers for allergy and asthma include a medical-grade HEPA filter as well as a deep-bed activated carbon filter and optional UV germicidal filtration to remove those pollutants.

Studies have shown that keeping an air purifier in the bedroom can help manage asthma.

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November is COPD Awareness Month: Can Air Purifiers Help People with COPD?

I read an article on the web this morning that said people with COPD should be careful when buying an air purifier, and the truth is, I tend to agree with this statement.

The article stated that COPD is a “serious life threatening health problem that can be aggravated with the use of inferior poor performance air filters.”

First, what is COPD?
According to Wikipedia, Chronic Obstructive Pulmonary Disease (COPD) is a disease of the lungs in which the airways become narrowed. This leads to a limitation of the flow of air to and from the lungs causing shortness of breath. In contrast to asthma, the limitation of airflow is poorly reversible and usually gradually gets worse over time.

So can an air purifier help a person with COPD?
An October 2008 report by the Department of Environmental Health at the Harvard School of Public Health reports that people with COPD “have substantial mortality risks associated with exposure to particles.” According to the study, particles may impair ventilation in COPD patients by causing airway narrowing and increasing the work of breathing.

So while air purifiers are certainly not a cure for COPD, they can provide cleaner air, which according to the Harvard study, is paramount to people with COPD.

A good HEPA filter can remove 99.97% of airborne particles as small as 0.3 microns from indoor air. It’s pretty safe to say that most air purifiers come (or should come) equipped with a HEPA filter— and since there is no such thing as a “better” HEPA filter, then it would be difficult to separate a superior air filter, from a poor performance air filter based simply on its HEPA filter.

While HEPA filters are indeed designed to remove particles, and since any good purifier comes equipped with this filtration method, what then makes one air purifier superior to another?

Not Just Particles—- Chemicals are also Dangerous for People with COPD
Inhaling chemicals such as gas, sulfur dioxide, nitrogen dioxide, or dry particulate chemicals, such as microscopic particles is dangerous for everyone, but can be especially dangerous for people with COPD. In fact the number one cause for COPD is smoking… and one of the main chemicals in smoke is formaldehyde.

But formaldehyde is also emitted from other everyday things, other than cigarettes, like stain-resistant furniture, flame retardant clothing, wood products such as particleboard, fiberboard, and plywood, and even carpeting, upholstery and baby furniture. In fact, formaldehyde is found in many seemingly harmless things, despite it being considered a human carcinogen. A branch of the California Environmental Protection Agency goes so far as to report that there is no safe level of formaldehyde.

Carbon for Chemicals
Activated carbon is one of the most adsorbent materials known to exist. Activated carbon has been processed to create millions of tiny pores, producing a very large surface area available for adsorption of chemicals and gases. Just one gram of activated carbon has a surface area of approximately 500 m².

Carbon is key when it comes to adsorbing chemicals, just as HEPA is key to filtering particles. The difference is, not all air purifiers have carbon. And many that do, feature mere ounces of carbon, or a type of carbon spray—- both of which are equally ineffective in adsorbing chemicals.

An effective chemical-adsorbing air purifier, and an ideal choice for people with COPD, would be an air purifier that contains both a HEPA filter for particles, and pounds of activated carbon to adsorb dangerous airborne chemicals, like formaldehyde.

Can Air Purifiers Cure COPD?
Absolutely not. Air purifiers are not a cure for COPD, but rather devices that can provide cleaner indoor air, with significantly reduced levels of particles and chemicals. Cleaner air is important for everyone, but perhaps most important for people with reduced lung capacity.

Conclusion
Should people with COPD be cautious when purchasing an air purifier? The answer is yes. A HEPA filter is great for particle filtration, but will do nothing to adsorb the dangerous airborne chemicals. Carbon will adsorb chemicals, but only an air purifier with pounds of activated carbon, not ounces, will be truly effective.

About AllerAir
AllerAir manufactures a full line of combination carbon-HEPA air purifiers, and has specific units designed for people with COPD. For more information on AllerAir, please visit the www.allerair.com website, or call 1.888.852.8247 to speak to one of their Indoor Air Quality Experts.