Smokers and people with chronic obstructive pulmonary disease are at hugely increased risk of severe Covid-19 infection because of high levels of one enzyme, researchers warn today.
The research is published in the European Respiratory Journal by Dr Janice Leung of the University of British Columbia, Canada, and colleagues.
This ‘entry point’ enzyme in lungs is angiotensin converting enzyme II. It sits on the surface of lung cells and allows Covid-19 to enter and cause infection.
The researchers examined samples from 21 chronic obstructive pulmonary disease patients and 21 people without the disease. Higher levels of angiotensin converting enzyme II were found in chronic obstructive pulmonary disease patients, and in participants who smoked. Levels were lower in former smokers than current smokers.
“The data emerging from China suggested that patients with chronic obstructive pulmonary disease were at higher risk of having worse outcomes from Covid-19,” said Dr Leung.
“We hypothesised that this could be because the levels of angiotensin converting enzyme II in their airways might be increased compared to people without chronic obstructive pulmonary disease, which could possibly make it easier for the virus to infect the airway.”
She added: “This suggests that there has never been a better time to quit smoking to protect yourself from Covid-19.”
Professor Tobias Welte of the national German Covid-19 task force commented: “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 angiotensin converting enzyme II levels to improve survival in patients infected with Covid-19 or whether this would make a difference in chronic obstructive pulmonary disease patients who contract the infection.”
Leung, J. M. et al. ACE-2 Expression in the Small Airway Epithelia of Smokers and COPD Patients: Implications for Covid-19. European Respiratory Journal 9 April 2020; doi: 10.1183/13993003.00688-2020
https://doi.org/10.1183/13993003.00688-2020
* New-born babies infected with Covid-19 tend to experience only mild symptoms and are at low risk, according to a Chinese study reported in the journal.
Dr Zhi-Jiang Zhang and colleagues at Wuhan University in China report on four babies born to mothers with Covid-19. The babies caught the infection but none required intensive care or mechanical ventilation.
“Covid-19 is highly contagious and our study suggests that intrauterine transmission cannot be ruled out, but that the prognosis is good for both pregnant women and new-born babies,” said Dr Zhang.
All of the babies in the report were delivered by caesarean section, and three of the four were separated from their mothers at birth.
The cases are described in the European Respiratory Journal today (9 April).
The authors write: “Two of the four new-born babies had fever, one had shortness of breath, one had cough and one had no syndromes. None had any severe complications.
“Three of the babies recovered by the end of this study and had been discharged with 16, 23, and 30 days of hospital stay.
”In summary, new-born babies are susceptible to Covid-19 infection. The symptoms in new-born babies were milder and outcomes were less severe as compared to adults.”
Commenting on the report, Professor Tobias Welte of the national German Covid-19 task force said: “It’s important to protect pregnant women and new-born babies against infection. It’s also important that any cases of Covid-19 in new-borns are picked up, monitored and treated quickly and carefully.”
He added: “At this stage we still do not know whether there are any longer-term consequences of infection.”
Zhang, Z-J, et al. Novel Coronavirus Infection in Newborn Babies Under 28 Days in China. European Respiratory Journal 9 April 2020; doi: 10.1183/13993003.00697-2020
Leave a Reply