COPD in spotlight as HMRI researcher Dr Jemma Mayall and Grace Cooper discover abnormal cells behaving badly may be to blame

Dr Jemma Mayall, a postdoctoral researcher with HMRI and the University of Newcastle, said COPD - or Chronic Obstructive Pulmonary Disease - is permanent, irreversible and progressive, and a "huge burden" on the healthcare system.

In collaboration with Grace Cooper from the University of Southampton, Dr Mayall identified that immune cells that reside in the lungs - also known as "natural killer" cells - were abnormally active in people with COPD, and this may be making them more susceptible to respiratory infections that aggravate their condition further.

"We studied this particular type of immune cell that just lives in the lungs - it doesn't circulate throughout the bloodstream," Dr Mayall said.

"Not much was really known about them, because they are difficult to study - usually people don't like to give you a bit of their lung to look at. But we have a model of COPD, and Grace came over from the UK to use it. What we found was that in people with COPD, this specific type of natural killer cell was altered. They were more active early on during the progression of COPD."

These cells, when exposed to viral infections, became "overactive quickly" and then stopped working. The immune response then becomes dysregulated and the killer cells don't respond to viral infections in the way they should.

"Usually when they do the right thing, they're able to see the cells that are infected and kill the cells that have the virus in them," Dr Mayall said. "But during COPD, the tissue resident natural killer cells weren't doing that function. We think that the dysregulation of these specific cells in COPD could be part of the reason why people with COPD are more susceptible to infection, and get a worse viral infection, because they don't have these normal responses."

The findings were recently published in The American Journal of Respiratory and Critical Care Medicine, and may prove useful in the research and treatment of other respiratory infections.

"COPD is actually a bit of an umbrella term for a group of progressive lung diseases, but they often overlap and occur concurrently," Dr Mayall said.

"So emphysema, chronic bronchitis, and occasionally chronic asthma are part of that.

"A lot of people will associate COPD with being caused by smoking, or passive smoking, which is one of the main causes. But you can also develop COPD from exposure to pollution, or occupational exposures to things like dusts, gases and chemical fumes. It is very prevalent in that occupational exposure sense too."

Dr Mayall said the first step was identifying what wasn't working well in people with COPD.

She said the next step was to identify which particular parts of these "dysfunctional" responses could be targeted with a new or existing drug to improve treatments and the quality of life of people with COPD.