New cause of asthma lung damage revealed

Scientists may have uncovered an overlooked factor in why asthma attacks happen, and they say it could open up a whole new avenue for treatments.

In a laboratory study in mice and human tissues, the researchers revealed how asthma attacks kill cells in the airways of the lungs. They found that when the airways constrict during an asthma attack, the thin layer of cells that line these passageways — called epithelial cells — becomes too crowded, causing some cells to be squeezed out of the tissue and die. 

As a result, this protective barrier in the lungs becomes damaged, triggering inflammation and mucus secretion that blocks the airways and hinders breathing, according to the new research, published April 4 in the journal Science.  

"Without this barrier, asthma sufferers are far more likely to get long-term inflammation, wound healing, and infections that cause more attacks," Jody Rosenblatt, co-senior study author and a professor of cell biology at King's College London, said in a statement. That's partly because, without the barrier, allergens and irritants can reach places in the lungs that they might not otherwise be able to get to.

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In their experiments, the researchers also found ways of stopping this chain reaction and keeping cells in their place in the lung tissue. This treatment approach "may have the capacity to break the iNFLaMMAtory cycle and potentially revolutionize how asthma is treated," Dr. Jeffrey Drazen and Jeffrey Fredberg of the Harvard School of Public Health wrote in a commentary of the study.

Current treatments for asthma manage only its symptoms. For instance, the drug albuterol opens up the airways during an attack, while inhaled corticosteroids calm inflammation to reduce the chances of having an attack. The drugs don't prevent attacks by addressing their underlying causes.