New ideas give hope to asthma patients
Erin Allday, Chronicle Staff Writer

Sunday, February 17, 2008

Correction: This story misrepresented the role of probiotics in
asthma. Researchers are looking into whether probiotics might help
prevent asthma in children.

- - -

When Rachel Bierach was pregnant, her asthma got so bad that she had
to move in with her parents in San Francisco and she couldn't leave
the house for the last trimester - just taking a shower or changing
positions in bed could set off a terrifying attack.

Her daughter is 8 months old now, and Bierach's asthma has improved.
She has gone back to school at San Francisco State University, and she
can take care of her child. But asthma is still a daily threat.

"I've got inhalers everywhere, they're in cupboards, every purse,
beside tables. There's a trail of them behind me, wherever I go," said
Bierach, 21.

The good news is that after decades of breathtaking climbs in asthma
rates in the United States, doctors are finally developing theories on
what causes asthma, and how it can be prevented.

"Research for human diseases in general is really taking off. It's an
exciting time," said Dr. Esteban Gonzalez Burchard, an assistant
professor at UCSF who studies the relationship between genetics and
asthma rates, specifically how asthma affects different ethnic groups.
"Asthma is a complex story, meaning that it probably has genetic,
environmental as well as social causes. It's not going to be one
method that identifies all risk factors."

Asthma is one of the most common chronic ailments in the United
States, where it afflicts more than 23 million people. In the Bay
Area, 1 in 7 children has asthma, and the rates are higher in some
communities. In Oakland, for example, it's closer to 1 in 5. Rates are
especially high in low-income communities, including San Francisco's
Bayview-Hunters Point.

The number of new asthma cases in the United States has hit a plateau
after roughly doubling during the past 25 years, but the rates are
still staggering, researchers say.

"It's incredible. Asthma has become an epidemic," said Dr. Kari
Nadeau, a Stanford asthma specialist who has worked with asthma
sufferers for 20 years.

Asthma is a lung disease usually marked by chronic inflammation of the
airways, which leaves them especially sensitive to irritants, ranging
from allergens like dust mites and mold to changes in air temperature.
Even stress or exercise can irritate the inflamed airways.

When the airways that carry oxygen to the lungs react to an irritant
in an asthma sufferer, the muscles surrounding the airways constrict,
inflammation increases, and cells produce extra mucus. These combined
reactions severely narrow the airways, making it difficult to breathe
- asthma sufferers describe it as trying to breathe through a straw.

It was only in the late 1980s that doctors began to fully understand
what asthma does to the body, and while treatments have improved,
there have been few new medications made available for asthmatics
since the early '90s.

There is no cure for asthma, and no one is sure why some people get it
and others don't. But the past five or six years have seen significant
growth in the study of asthma.

Theories on what causes the disease vary widely, and most researchers
believe that a variety of factors play a role. At UCSF alone,
researchers are studying race, genetics, air pollution and probiotics
as possible causes of asthma.

For years, researchers considered air pollution the most likely
explanation for the increased rates of asthma. Pollution undoubtedly
plays a role in how asthma manifests. For example, children who live
near freeways are more likely to get asthma and have worse symptoms
than children in other parts of a community, and some researchers say
that increased levels of carbon dioxide are releasing more allergens
into the air.

But pollution is not the main cause of asthma, researchers now say. In
fact, asthma rates continued to rise as air pollution improved in the
1990s.

One of the more unusual theories on asthma comes from Dr. Homer
Boushey, whose colleagues sometimes roll their eyes when his ideas are
mentioned. Boushey, who runs the UCSF asthma lab, says that many cases
of asthma can be pinned on a common cold virus that if caught during
the first few months after birth upsets the immune system for life,
leaving kids vulnerable to allergens that otherwise wouldn't faze
them.

Even Boushey calls himself a borderline heretic. But his research
falls into the current prevailing theory of why asthma cases have
increased so steadily: the hygiene hypothesis.

Essentially, researchers say, kids are too clean. When children are
not exposed to the allergens that they might find on, say, a farm,
their immune systems never develop the ability to distinguish safe
irritants from unsafe ones. As a result, they become overly sensitive
to harmless irritants.

"In most of our history we were exposed to enormous sources of
microbes. We had large families, we lived with farm animals, we played
in the dirt," Boushey said. "Now maybe we don't have enough
stimulation of the immune system in our development as infants, and so
we're more vulnerable to things that cause asthma."

Thinking along those lines, UCSF is running a five-year clinical trial
on the relationship between asthma and probiotics, or bacteria that
are commonly found in foods like yogurt and that could have health
benefits. In the study, babies who have at least one parent with
asthma are given daily doses of probiotics; they will be followed for
five years to see if they develop asthma.

"We think exposing kids to probiotics bacteria might stimulate their
immune system just enough to prevent development of asthma," said Dr.
Michael Cabana, chief of the division of general pediatrics at UCSF
Children's Hospital, who is leading the trial.

If the trial is successful, one solution to preventing asthma could be
making probiotics widely available, much like fluoride is added to
water and iodine to salt.

Meanwhile, as researchers race to find what causes asthma, doctors and
nurses in primary care struggle to keep up with patient demands.

Asthma is not often fatal, but about 5,000 people die from it
annually. It accounts for nearly 25 percent of all emergency-room
visits every year in the United States, according to the Centers for
Disease Control and Prevention. It is the leading cause of school and
work absenteeism.

At Children's Hospital Oakland, the emergency room gets about 5,000
asthma cases a year and the primary-care clinic sees more than 2,500
patients with asthma, said Mindy Benson, an asthma program manager.
"We're talking staggering numbers," she said.

The biggest problem clinicians face is helping children keep their
asthma under control, she said. No one wants to see a child returning
over and over again to the emergency room when he or she should be
able to control the symptoms with medication.

But it isn't easy. The primary problem is the medication itself. Fast-
acting inhalers provide immediate relief during an asthma attack, but
steroids used every day have the best long-term results.

The problem is that parents are often reluctant to give their kids
daily doses of steroids, especially when the medication doesn't offer
immediate results. Strong oral steroids, such as Prednisone, can have
dangerous side effects, including increased blood pressure, loss of
calcium in bones, weight gain and mood swings. But inhaled steroids,
which were once feared to slow growth rates in children, have been
proved safe in studies.

About six years ago, a program known as Oakland Kicks Asthma, funded
by the CDC, began teaching kids and parents, along with doctors, how
to better manage asthma and trust the medications. Children get
lessons in school, and doctors and nurses do home visits to help
families learn about medications and what household allergens trigger
an asthma attack.

Results of the program will be made available in a study to be
released later this year, said Adam Davis, director of Oakland Kicks
Asthma and a program director with the American Lung Association.

"It's really interesting with asthma how little people know about it,"
Davis said. "We've had children in some of our classes who don't know
where their lungs are. It's very typical for children and their
parents to not know what the different asthma medications do, and when
to use them.

"Families can get into this cycle where the kids get these asthma
attacks regularly and they go to the ER and they come to think that's
just how it's supposed to be," he said. "They don't have basic
information that they can use to improve their life."

But even when asthma is under control, just knowing it's lingering
under the surface feels like a constant threat, say asthma sufferers.

"I avoid all my triggers - hot air, stuffy air, exercise. We have a
cat at my parents' house, but he's banished to one room, and it's
winter so the plants are dead, which is good," said Bierach. "I've
never done sports or run around or anything like that. After five
minutes of sort of running, my body won't be tired but my lungs are
burning."

Bierach enrolled her daughter, Violet, in the probiotics study before
she was born, because "if there's any chance she could not have
asthma, and help other kids not have asthma, heck yes, I'll do it."

For the first six months of Violet's life she took the daily
supplements. So far, Bierach said, her daughter shows no signs of
asthma, although it's too soon to tell if she's safe. Bierach's asthma
wasn't diagnosed until she was 2 years old.

Bierach said her asthma got so bad during her pregnancy that her life
was at risk. She says it would be irresponsible to have another
child.

"The first time I met with the asthma specialist when I was pregnant,
she told me I was really sick, that I could die," Bierach said. "She
said people don't take asthma seriously. I didn't know."

Want to know more about asthma?
San Francisco Asthma Task Force: links.sfgate.com/ZCLR

CDC National Asthma Control Program: links.sfgate.com/ZCLS

American Asthma Foundation: links.sfgate.com/ZCLT

UCSF Airway Clinical Research Center, including information on ongoing
clinical studies: acrc.ucsf.edu/

Oakland Kicks Asthma: links.sfgate.com/ZCLV

A quick primer on asthma
What is asthma?

Asthma is a lung disease that occurs when the airways are inflamed.
The inflammation causes the airways of a person with asthma to be
sensitive to irritants. An asthma attack occurs when the airways close
up, making breathing difficult.

What are the symptoms?

Asthma can cause wheezing, coughing, chest tightness and difficulty
breathing. Symptoms are often more pronounced at night and in the
morning. Asthma attacks make symptoms especially pronounced, and can
be caused by an allergic reaction, poor air quality, exercise or
stress.

Who has asthma?

About 23 million people in the United States have asthma, including
4.8 million in California. About 986,000 people in the Bay Area have
asthma, or roughly 1 in 7 people, according to the California Health
Interview Survey. African Americans have the highest rates of asthma.

How is asthma treated?

The two most common treatments are anti-inflammatory drugs, or
steroids, that reduce inflammation; and bronchodilators, which provide
immediate relief during an asthma attack by relaxing the muscles that
tighten around the airway. Anti-inflammatory drugs are meant to be
used long-term to keep people from having asthma attacks.

In addition to medications, people with asthma are advised to figure
out what triggers attacks and how to avoid those triggers.

E-mail Erin Allday at eallday@sfchronicle.com.

http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/02/17/MN7LV21N8.DTL

This article appeared on page A - 1 of the San Francisco Chronicle