FRIDAY, Sept. 9 (HealthDay News) -- Researchers in Australia
have developed a new treatment plan to reduce asthma flare-ups in
pregnancy while minimizing drug exposure to developing fetuses.
This therapy tracks airway inflammation directly by measuring
something known as "the fraction of exhaled nitric oxide" -- a
marker of inflammation abbreviated as FENO -- in an exhaled breath.
By doing so, researchers can identify asthma in pregnant women who
have airway inflammation but no symptoms and tailor drug therapy
accordingly.
In this study, researchers examined 220 non-smoking women with
asthma who were less than 22 weeks pregnant. Half the women were
treated based on their clinical symptoms during monthly visits (the
control group) and compared to the women in the FENO group, who
were tested for airway inflammation. The researchers found the
flare-up rate among the women in the FENO group was roughly half
that of those in the control group.
The reduction in flare-ups was associated with key changes in
the women's asthma medications, including more frequent use of
inhaled corticosteroid -- but at a lower total daily dose -- and
earlier use of other drugs, such as long-lasting B2 agonists, the
study authors said.
Medicating asthma based on a woman's symptoms alone can lead to
either over-treatment or under-treatment of the condition, they
added.
The study is published in the Sept. 9 European respiratory issue
of
The Lancet.
"Asthma management during pregnancy can be improved by the use of measuring FENO concentration and symptoms to adjust treatment. This algorithmic approach might also be beneficial for non-pregnant women with asthma," the authors wrote in a journal news release.
Meanwhile, a separate study in the same journal issue identified
two new gene variants, linked to immune system signaling, that
appear to boost a person's susceptibility for asthma.
By comparing the genetic information of thousands of patients
with asthma with those of people without asthma, researchers from
Australia identified two new genetic variants strongly associated
with asthma risk.
One of the variants was found on the interleukin 6 receptor
gene, which plays a key role in immunity and inflammation and is
involved in the development of diseases such as rheumatoid
arthritis.
The other variant, found on chromosome 11q13.5, was found to be
more common in people with allergic asthma and atopic dermatitis
(skin itching and dryness accompanied by a rash). This led the
researchers to speculate that the variant might be involved in the
development of allergic sensitization, which can increase a
person's risk for allergic asthma.
The researchers pointed out, however, that asthma is a complex
disease, and that many genes likely interact with a number of
environmental risk factors to determine who will develop the
condition.
More information
The U.S. Centers for Disease Control and Prevention provides
more information on
asthma.