Blood Tests May Help Predict COPD Exacerbations

Chronic Obstructive Pulmonary Disease (COPD) is a respiratory condition with limited airflow in the lungs, making it hard to breathe out. The disease develops and worsens over time. About 12 million adults in the U.S. have been diagnosed with COPD. In the US, COPD is the 4th leading cause of death.

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In addition to slow and steady deterioration of lung function caused by COPD, patients can experience sudden exacerbations, or flareups, commonly triggered by infection or lung irritants.

COPD patients who experience frequent exacerbations tend to decline more rapidly than those who don’t, have shorter lifespans, and worse quality of life. Clearly, prevention of exacerbations is an important goal for the physician, but predicting them can be difficult.

In a recently published study from Denmark (Thomsen M et al. Inflammatory biomarkers and exacerbations in chronic obstructive pulmonary disease. JAMA 2013; 309: 2353-2361), researchers examined spirometry in over 61,000 participants, finding that patients with COPD who have evidence of chronic inflammation in their blood are more likely to have future COPD exacerbations than those who do not.

Specifically, the researchers found that C-reactive protein (CRP), fibrinogen and leukocytes (WBCs), which can increase in response to inflammation or infection, could help predict risk for these flareups. The COPD patients with elevations of CRP, fibrinogen and white blood cells were more likely to experience COPD exacerbations, regardless of the stage or severity of their disease. The risk was worse, however, in those COPD patients in the highest symptom category. In this group, 62% of those with elevations of all three had frequent exacerbations, compared to only 24% in those with no elevations.

Although these blood tests are readily available, not particularly expensive, and appear to be good risk predictors, more research is needed. The study was not able to prove the role of inflammation in causing COPD exacerbations, or that lowering inflammation with medications could prevent future flare-ups.

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 Denmark.

“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.”

 

Where can I learn more?

  1. American Lung Association
  2. Global Initiative for Obstructive Lung Disease (GOLD)
  3. National Institutes of Health (NIH)
  4. COPD International (support group)
  5. American Thoracic Society