Melbourne: Smokers, beware! Lung damage due to puffing can last long even after you kick the butt, a new study has claimed.
   
Researchers at University of Sydney have found that smoking fundamentally alters airway tissue in people with chronic obstructive pulmonary disease (COPD), and even while other aspects of health improve, the lung damage lasts long after a smoker quits.
   
COPD is projected to be the third-leading cause of death worldwide by 2020, and is characterised by thickening of the airway wall. The primary cause is chronic exposure to air pollution, most often cigarette smoke.
   
In their study, the researchers found that smoking lays the groundwork for airway thickening and precipitates precancerous changes in cell proliferation that may be self-perpetuating long after cigarette smoke exposure ends.
   
"We have demonstrated for the first time that the extracellular matrix (ECM) produced by fibroblasts following stimulation with cigarette smoke extract is functionally different than non-exposed ECM, and that the cigarette smoke itself may prime the airways in such a way to create an environment whereby airway remodelling is encouraged," lead researcher David Krimmer said.

The researchers examined the response of human lung tissue from donors with and without COPD to cigarette smoke extract (CSE). They found CSE exposure led to changes in the tissue of donors with COPD over the tissue of individuals without COPD.
   
Similarly, they found CSE increased levels of perlecan —a protein associated with tumor growth and angiogenesis — in COPD lung tissue. These findings demonstrate cigarette smoke has the capacity to directly change the make-up of airways.
   
"This will change the way researchers think about the development of fibrosis in COPD. We have known for a long time that development of fibrosis is irreversible in people with COPD. Our findings suggest that cigarette smoking alters the lung composition in such a way that fibrosis becomes self- perpetuating," Krimmer said.
   
The findings have been published in the latest edition of the 'American Journal of Respiratory Cell and Molecular Biology'.

(Agencies)