New research from Austria suggests that a protein called HSP27 has the potential to be a new blood biomarker for the earlier detection of chronic obstructive pulmonary disease (COPD), thereby increasing the chance of earlier treatment and better outcomes.
Study leader Hendrik Jan Ankersmit and colleagues, from the University Department of Surgery at MedUni Vienna and the Christian Doppler Laboratory for the Diagnosis and Regeneration of Heart and Thorax Diseases, write about their findings in Respiration, the international journal of thoracic medicine. An early edition of their study appeared online in March.
Chronic Obstructive Pulmonary Disease (COPD) is an umbrella term for chronic lung diseases that limit the flow of air in the lungs. Doctors no longer use the more familiar terms ‘chronic bronchitis‘ and ‘emphysema‘, which are now included within a COPD diagnosis.
About 90% of COPD cases result from smoking.
Although the most common symptoms of COPD are breathlessness, excessive sputum, and a chronic cough, it is not simply a “smoker’s cough”, but an under-diagnosed, life-threatening lung disease that can slowly kill.
According to the World Health Organization (WHO), COPD is expected to be the third leading cause of death worldwide by 2030. Latest estimates for 2004 show about 3 million people worldwide died from the disease that year, and 64 million are affected.
Early detection is the key to successful treatment of COPD. As the disease progresses, it causes lung damage, such as air trapping (air that cannot be exhaled due to overinflation of the alveoli) and pulmonary emphysema (holes in the lung filled with air that reduce the lung surface area).
People can feel healthy in the early stages of COPD, and because current lung function tests only detect changes in lung volume, which occur in later stages of the disease, patients and doctors may assume there is no cause for concern.
Now Ankersmit and colleagues suggest high levels of HSP27 in the bloodstream can indicate lung damage in the early stages of COPD, before a lung function test detects the reduction in lung volume.
For their study, they recruited 94 apparently healthy male and female smokers of average age 43, who volunteered to undergo high-resolutions CT scans, lung function tests, and give blood samples.
The scan results showed that 57.5% of them showed signs of air trapping or air trapping with emphysema, even though their lung function test results appeared normal.
From the blood samples, using a special kit called ELISA kit from R&D Systems, the researchers established that levels of HSP27 showed a significant correlation with the lung damage detected in the CT scans.
Ankersmit told the press:
“If there is increased prevalence of the marker HSP27 and risk behaviour, such as smoking, is evident, then this may signify lung damage and, potentially, the early onset of chronic obstructive pulmonary disease.”
Although the majority of cases are due to smoking, certain jobs can also increase risk for COPD. Examples include welding, furnace stoking and jobs that expose workers to smoke and chemical vapours.
Ankersmit hopes one day to see GPs and lung specialists using HSP27 as a screening marker for lung disease.
Written by Catharine Paddock PhD