Why Are People With COPD More Susceptible To Covid-19? First-Of-Its-Kind Study Gives Answers

In a first, researchers have shown why people with chronic obstructive pulmonary disease (COPD) are at higher risk of developing severe Covid-19. COPD is an inflammatory lung condition.

The COPD airway cells had 24-fold greater infection with SARS-CoV-2 than the healthy cells, the researchers found. | Representative Photo

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New Delhi: In a first, researchers have shown why people with chronic obstructive pulmonary disease (COPD) are at higher risk of developing severe Covid-19. The first-of-its-kind study, conducted by researchers from the Centenary Institute, Camperdown, and the University of Technology Sydney, was recently published in the American Journal of Respiratory and Critical Care Medicine.

The study could lead to the development of new therapeutic interventions that reduce Covid-19 in COPD patients, a statement issued by Centenary Institute said.

COPD is an inflammatory lung condition which causes airway blockage and makes it difficult to breathe. The disease affects around 400 million people globally, and the increased susceptibility of Covid-19 of COPD patients is yet to be fully understood.

The researchers infected differentiated airway cells from COPD patients and healthy people with SARS-CoV-2, as part of the study. 

COPD Airway Cells Have Greater Infection With SARS-CoV-2 Than Healthy Cells

The COPD airway cells had 24-fold greater infection with SARS-CoV-2 than the healthy cells, the researchers found.

Quoting Dr Matt Johansen, the lead author of the study, the statement said that the researchers examined the genetic information of genetic cells through advanced single cell RNA-sequencing analysis. This technique examines the sequence information from individual cells with optimised next-generation sequencing (NGS) technologies, and provides a higher resolution of cellular differences and a better understanding of the function of an individual cell. 

Johansen added that seven days after SARS-CoV-2 infection, there was a 24-fold increase of viral load in the COPD patient airway cells compared to the cells from healthy individuals.

Infected COPD Cells Have Increased Levels Of  Certain Enzymes Used By SARS-CoV-2

According to the study, the infected COPD cells had increased levels of transmembrane protease serine 2 (TMPRSS2) and cathepsin B (CTSB), both of which are enzymes used by SARS-CoV-2 to enter into the host cell. 

Johansen said these two enzymes are increased in COPD patients and favour greater SARS-CoV-2 infection compared to healthy people. Easier and increased cell infection makes it far more likely that individuals with COPD will have more severe disease outcomes, Johansen explained.

Other Reasons For Susceptibility Of COPD Patients To Covid-19

The study also found additional reasons for COPD patient susceptibility to severe Covid-19.

Key antiviral proteins or interferons that protect against infection were largely blunted in the COPD patient airway cells, and this was a likely trigger in causing increased viral production in COPD patients, the study said.

Infected COPD patient airway cells had higher levels of pro-inflammatory cytokines, which are linked to more severe Covid-19 and COPD outcomes, Johansen said.

He explained that COPD is an inflammatory disease with patients having increased inflammation at baseline compared to healthy people, and it is highly likely that SARS-CoV-2 exacerbates this existing high inflammation level which leads to even poorer outcomes.

New Drug Treatments Can Help Reduce Severity Of Covid-19 In COPD Patients

According to the study, initial laboratory drug testing by the researchers, to inhibit the enzymes TMPRSS2 and CTSB, and to target the high inflammation levels, successfully and substantially reduced SARS-CoV-2 viral levels in COPD patients. This ultimately confirms the study's results. 

Professor Phil Hansbro, the study's senior author, said the researchers believe that new drug treatments targeting relevant enzymes and pro-inflammatory responses in SARS-CoV-2 infection could have excellent therapeutic potential in reducing the severity of Covid-19 in patients with COPD. 

According to Professor Hansbro, the research was critical with hundreds of millions of people affected by COPD globally and with Covid-19 likely to be around for many years to come.