James Diaz, MD, MHA, MPH & TM,
Dr PH, Professor and Head of Environmental Health Sciences at LSU Health New
Orleans School of Public Health, has proposed a possible explanation for the
severe lung complications being seen in some people diagnosed with COVID-19.
The manuscript was published by Oxford University Press online in the Journal
of Travel Medicine.
The SARS beta
coronaviruses, SARS-CoV, which caused the SARS (Severe Acute Respiratory
Syndrome) outbreak in 2003 and the new SARS-CoV-2, which causes COVID-19, bind
to angiotensin converting enzyme 2 (ACE2) receptors in the lower respiratory
tracts of infected patients to gain entry into the lungs. Viral pneumonia and
potentially fatal respiratory failure may result in susceptible persons after
10-14 days.
“Angiotensin-converting
enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are highly
recommended medications for patients with cardiovascular diseases including
heart attacks, high blood pressure, diabetes and chronic kidney disease to name
a few,” notes Dr. Diaz. “Many of those who develop these diseases are older
adults. They are prescribed these medications and take them every day.”
Research in
experimental models has shown an increase in the number of ACE2 receptors in
the cardiopulmonary circulation after intravenous infusions of ACE inhibitors.
“Since patients
treated with ACEIs and ARBS will have increased numbers of ACE2 receptors in
their lungs for coronavirus S proteins to bind to, they may be at increased
risk of severe disease outcomes due to SARS-CoV-2infections,” explains Diaz.
Diaz writes,
this hypothesis is supported by a recent descriptive analysis of 1,099 patients
with laboratory-confirmed COVID-19 infections treated in China during the
reporting period, December 11, 2019, to January 29, 2020. This study reported
more severe disease outcomes in patients with hypertension, coronary artery
disease, diabetes and chronic renal disease. All patients with the diagnoses
noted met the recommended indications for treatment with ACEIs or ARBs. Diaz
says that two mechanisms may protect children from COVID-19 infections —
cross-protective antibodies from multiple upper respiratory tract infections
caused by the common cold-causing alpha coronaviruses, and fewer ACE2 receptors
in their lower respiratory tracts to attract the binding S proteins of the beta
coronaviruses.
He recommends
future case-control studies in patients with COVID-19 infections to further
confirm chronic therapy with ACEIs or ARBs may raise the risk for severe
outcomes.
In the meantime
he cautions, “Patients treated with ACEIs and ARBs for cardiovascular diseases
should not stop taking their medicine, but should avoid crowds, mass events,
ocean cruises, prolonged air travel, and all persons with respiratory illnesses
during the current COVID-19 outbreak in order to reduce their risks of
infection.”
No comments:
Post a Comment