Higher levels of coronavirus cell entry receptor in lungs of COPD patients and smokers

Higher levels of coronavirus 'entry point' enzyme in lungs of COPD patients and smokers. Credit: © sciencepics - Depositphotos

People with chronic obstructive pulmonary disease (COPD) and people who currently smoke may have higher levels of angiotensin-converting enzyme II (ACE2), in their lungs according to a study published in the European Respiratory Journal.

Previous research has shown that ACE2, which sits on the surface of lung cells, is the ‘entry point’ that allows coronavirus to get into the lung cells and cause an infection.

The new study also shows that levels of ACE2 in former smokers is lower than in current smokers.

The research was led by Dr. Janice Leung at the University of British Columbia and St. Paul’s Hospital, Vancouver, Canada. She said: “The data emerging from China suggested that patients with COPD were at higher risk of having worse outcomes from COVID-19. We hypothesized that this could be because the levels of ACE2 in their airways might be increased compared to people without COPD, which could possibly make it easier for the virus to infect the airway.”

The team studied samples taken from the lungs of 21 COPD patients and 21 people who did not have COPD. They tested the samples to gauge the level of ACE2 and compared this with other factors, such whether they were from people who never smoked, were current smokers or former smokers. Not only did they find higher levels of ACE2 in COPD patients, they also found higher levels in people who were smokers.

The researchers then checked their new findings against two existing study groups, which together contain data on a further 249 people – some non-smokers, some current smokers and some former smokers. Again, they found levels of ACE2 were higher in current smokers but lower in non-smokers and in those who were former smokers.

Dr. Leung said: “We found that patients with COPD and people who are still smoking have higher levels of ACE2 in their airways, which might put them at an increased risk of developing severe COVID-19 infections. Patients with COPD should be counseled to strictly abide by social distancing and proper hand hygiene to prevent infection.

“We also found that former smokers had similar levels of ACE2 to people who had never smoked. This suggests that there has never been a better time to quit smoking to protect yourself from COVID-19.”

Professor Tobias Welte is an infection expert from the European Respiratory Society and is a coordinator for the national German COVID-19 task force and was not involved in the study. He said: “This study gives some interesting insight into why some people may be at risk of more severe COVID-19 symptoms than others. What it does not tell us is whether it’s possible to manipulate ACE2 levels to improve survival in patients infected with COVID-19 or whether this would make a difference in COPD patients who contract the infection.”


Materials provided by the European Lung Foundation. Content may be edited for clarity, style, and length.


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