Fact or Fiction: Asthma vs. COPD
COPD is the third leading cause of death in America, claiming the lives of 134,676 Americans in 2010.
Every day we breathe in countless particles: bacteria, viruses, pollution, chemicals and second-hand smoke. The lungs are designed to filter out all of this “debris,” and normally, they are quite efficient at this task.
But for some patients, the inflammatory response mounted by the body to “take out the trash” can go awry. When left unchecked, one particularly aggressive enzyme, neutrophil elastase, can actually start to attack the lungs and lead to permanent damage.
The respiratory police
Luckily for most people, another enzyme – alpha-1 antitrypsin, or AAT – sweeps in to stop neutrophil elastase before it can do any harm. But for those who have AAT deficiency, the consequences can ultimately be devastating.
“If the smoke, pollution, viruses and chemicals you breathe in are the bad guys, alpha-1 antitrypsin (AAT) is the police,” explains Dr. Kyle Hogarth, a pulmonary expert at the University of Chicago*. “For those folks who are missing this protective enzyme, everything in the lung steers toward destruction.”
"Many people who have AATD are missing what may be a vital opportunity to get the proper treatment."
Over a lifetime with AAT deficiency — which is an inherited disease — damage to the lung accumulates and can lead to symptoms that are strikingly similar to two different, but common lung disorders: chronic obstructive pulmonary disease (COPD) and persistent asthma. Symptoms of all three diseases are the same: wheezing, coughing and shortness of breath.
AAT deficient patients look like regular COPD or asthma patients. They present symptoms like COPD and asthma patients, and take many of the same medications. That is why AATD is often misdiagnosed as COPD or chronic asthma; and as a result, the incorrect treatment is prescribed. In other words, many people who have AATD are missing what may be a vital opportunity to get the proper treatment.
AAT deficiency screening
Several medical societies, including the American Thoracic Society and the European Respiratory Society, have called for all COPD patients and severe asthma patients to be screened for AAT deficiency.
“This disease is horribly under diagnosed,” Hogarth says. “We think there are 100,000 people with the severest form and possibly 80,000 to 100,000 with less severe forms. But only a couple of thousand have been found.”
“Where are the rest of them?” he asks. “They’re out there, but no one has tested all the COPD and severe asthma patients. So they are literally hiding in the clinic.”
Hope with treatment
Researchers have estimated that 1 to 3 percent of all COPD patients may have AAT deficiency. Getting these patients the right diagnosis could lead them to more effective treatment, Hogarth says.
The test is quick and simple: a drop of blood can help doctors to determine if there are insufficient levels of AAT. Further analysis of that single blood sample can reveal the genetics of the disease. Patients with two faulty copies of the gene have the condition, while those with one copy are carriers and can pass the disease on to their children, even if they have no symptoms themselves.
AAT deficiency can be treated with augmentation therapy, which involves getting weekly infusions of the missing protein. This may help further alleviate symptoms of lung disease.
“If you’re deficient in AAT, we can simply replace it, just like we do for hemophilia patients or anemia patients,” Hogarth says, explaining that hemophiliacs get infusions of the missing protein that forces their blood to clot and some anemia patients get blood transfusions.
Hogarth says screening could be vitally important as deaths from COPD are on the rise.
“While rates of death from heart disease, cancer and stroke have been declining, COPD deaths are rising; and it is now the third leading cause of death in the U.S.,” Hogarth explains. “It’s suffering a major lack of proper management.”
Testing for AAT deficiency, he says, could help change that.