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Cystic
Fibrosis: Advances in Treatment
By Thomas Murphy, MD and Dennis Clements, MD, PhD
For
many parents, news that their child might have cystic fibrosis (known
as CF) can be devastating. One of the more common inherited diseases,
affecting over 30,000 American boys and girls, CF results from a
gene mutation which causes infants and children to have excessive
amounts of thick mucus in their bronchial tubes and intestines.
The lung mucus is prone to infections with drug-resistant germs,
while the mucus in the digestive organs prevents nutrient absorption
and normal weight gain and can even cause intestinal blockages.
Fortunately,
the prognosis for children with CF is far more hopeful than it has
been in the past. In the 1960s life expectancy for an infant diagnosed
with CF was only about five years. For children living with CF today,
the average life expectancy has increased to 32 years. For newborn
babies the odds are even greater, with a life expectancy of 45 years
and beyond. While a cure remains elusive, treatment for CF has obviously
improved.
Improving
the odds
The increase in life span can be directly attributed to an organized
system of physician care and support and scientific research into
the underlying medical problems. Until the early 1960s, much of
the care for CF was improvised. Parents were instructed to go to
specialized butcher shops to purchase beef and pork pancreas so
their child could ingest additional digestive enzymes, and told
to keep infants and small children with respiratory congestion in
cribs with tents that provided a personal haze of fine mist (a treatment
later shown to provide absolutely no benefit).
In
1965, concerned parents and physicians unwilling to accept the tragic
outcomes prevalent at the time established the Cystic Fibrosis Foundation.
Multidisciplinary medical teams consisting of doctors, nurses, nutritionists,
respiratory and physical therapists, and social workers were created
at accredited CF treatment centersincluding The Cystic Fibrosis
Center at Duke University, among the first created. Annual scientific
meetings were devoted to CF study and research. Principles of medical
care were standardized by leading physicians of the time.
Thanks
to these efforts, by the year 2010, CF, long known as a disease
of childhood, will be predominantly an adult disease. These days
most CF children cannot be picked out from their school classmates,
and can be found be among the brightest students and even the best
athletes.
Diagnosing
CF
How is CF identified and diagnosed in children? The process begins
with alert parents and doctors who notice these common indicators:
Young
children who are not gaining weight or growing at a standard rate
Babies that taste unusually salty when kissed
Infants and toddlers with repeated episodes of coughing and wheezing
Newborns with an intestinal blockage due to thick stool (some older
children experience a similar intestinal blockage, called distal
intestinal obstruction syndrome, which can be mistaken for appendicitis)
Children with CF symptoms should be referred to an accredited cystic
fibrosis center for confirmation of diagnosis and parental education.
Siblings of children with confirmed CF, who may be entirely without
symptoms early in the course of their own CF, should also be evaluated.
The
primary test that determines whether or not a child has cystic fibrosis
is known simply as the sweat test. The sweat of children with CF
contains an abnormally high salt content (sodium and chloride).
During the test, which takes approximately one hour, the arms are
cleaned and a medicine called pilocarpine is applied. An electric
current that cannot be felt is applied by a battery-driven metal
plate. This allows the medicine to penetrate to the sweat glands
and increase sweat production. The sweat is then collected and analyzed.
If the level of chloride salt in the sweat is too high, then the
child likely has CF.
In
some children, CF can also be diagnosed based on a blood test for
certain genetic markers. For a diagnosis to be made, two CF genes
must be identifiedone from each parent. Over 1,000 such genes
have been identified so far, but only 16 or so are responsible for
the majority of cases.
Treating
CF, now and tomorrow
The discovery of the CF gene and protein responsible for the disease
in 1989 raised hopes that gene therapy could one day be used to
treat the disease. While that day has not yet arrived, there is
still a spirit of optimism among CF researchers. Detailed knowledge
regarding the CF protein CFTR has emerged in the last fifteen years,
creating the potential for pharmaceutical breakthroughs. The secrets
of predisposition to lung infections are being slowly revealed.
Powerful new tools have sped up the production of new drugs, allowing
thousands of potential drugs can be screened in one day. With this
technological progress comes a sense that CF will soon become much
more controllable, if not curable.
Despite
the disappointment that gene therapy has not yet worked, we have
made great progress in quality of life and life expectancy through
hard work and attention to the many demands of CF therapyincreased
meals, enzyme replacements and vitamins that aid digestion, chest
physical therapy and special coughing techniques and medicines to
clear the mucus, antibiotics, exercise, regular trips to the doctor
and countless other requirements. Our children are like the award-winning
bicyclist Lance Armstrongthey are not willing to let the disease
control how they live their lives, and they do not give up. Their
commitment to fighting the disease, a commitment made by each CF
family and our CF Care Center team, will help to keep all children
with CF as healthy as possible so they can benefit as adults from
the therapies of the future.
Thomas
Murphy, MD, is director of the Duke Cystic Fibrosis Center and chief
of the Division of Pediatric Pulmonary Medicine. Dennis Clements,
MD, PhD, is the chief medical officer of Duke Children's Hospital.
For information, visit www.dukehealth.org
The information presented on this site is intended
solely as a general educational aid, and is neither medical nor
healthcare advice for any individual problem, nor a substitute for
medical or other professional advice and services from a qualified
healthcare provider familiar with your unique circumstances. Always
seek the advice of your physician or other qualified healthcare
professional regarding any medical condition and before starting
any new treatment.
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