People with chronic obstructive pulmonary disease (COPD) who have signs of
chronic inflammation in their blood are more likely to have flare-ups of the
lung disease than those who do not, a large new study shows.
In addition to the slow, steady deterioration in lung function caused by
COPD, patients can have sudden, distressing flare-ups. These so-called
"exacerbations" are periods of worsening breathing problems that are typically
triggered by infections or air pollution.
Patients who experience frequent flare-ups decline more quickly than those
who do not; they also tend to have worse quality of life and poorer survival
rates than those whose conditions are more stable, according to background
information in the study.
Preventing flare-ups is a major goal of COPD treatment, but these episodes
can be difficult to predict.
In a study of more than 61 000 people in Denmark, researchers found that COPD
patients who had increased levels of certain proteins and cells in their blood
were at greater risk for frequent flare-ups.
These particular proteins and cells - C-reactive protein, fibrinogen and
leukocytes - increase in response to infections, tissue damage and
People with higher levels of all three of these "markers" were more likely to
experience frequent flare-ups than those with normal levels. That was true
regardless of the stage or severity of their COPD.
But the risk was especially pronounced for patients in the study with the
worst breathing problems. Among patients who had the highest grade of COPD
symptoms, 24% with no elevated markers had frequent flare-ups compared to 62% of
those who had high levels of all three markers.
Patients with frequent exacerbations had two or more flare-ups each year they
were followed for the study.
According to Dr Elizabeth Regan, who is studying the genetics of COPD at
National Jewish Health in Denver, the researchers "give compelling evidence that
those are useful tests." Regan was not involved with the study.
"These are tests that are readily available. The practicing physician kind of
has them at their fingertips. They're not unusual, they're not high-risk," said
Regan. "If I were seeing patients, I'd be strongly attracted to doing it."
The price of each test varies, but in general, they're inexpensive, ranging
between $10 and $40. Insurance often covers the cost. The only trouble with
doing the tests now, Regan said, is that doctors still don't know exactly how to
use the information.
"While these tests look like they're strong predictors, we don't have the
next piece of this clearly in place," she noted.
The study wasn't able to prove that inflammation causes COPD exacerbations,
or that lowering inflammation with medications could head off future flare-ups,
Other studies currently underway are testing whether antibiotics or newer
medications can prevent such attacks, she noted.
Until more is known, the researchers say there is still one good reason for
COPD patients to get the blood tests.
"Many patients with COPD aren't very adherent to their inhalation medication.
Patients don't like to be sick, so they think 'it's doing well now, so let me
stop,'" said study author Dr Borge Nordestgaard, a clinical professor in the
department of diagnostic sciences at the University of Copenhagen in
"But if you're one of these patients with high biomarkers, then you should be
even better at taking your daily inhalation medication," he said. "That's the
best advice at present."
For more on COPD, head to the US
National Heart, Lung, and Blood Institute.