“Understanding the rampage could help the doctors on the front lines treat the fraction of infected people who become desperately and sometimes mysteriously ill.”
Clinicians trace a ferocious rampage through the body, from brain to toe
Apr. 17, 2020
Science Magazine – As the number of confirmed cases of COVID-19 surges past 2.2 million globally and deaths surpass 150,000, clinicians and pathologists are struggling to understand the damage wrought by the coronavirus as it tears through the body.
They are realizing that although the lungs are ground zero, its reach can extend to many organs including the heart and blood vessels, kidneys, gut, and brain.
“[The disease] can attack almost anything in the body with devastating consequences,” says cardiologist Harlan Krumholz of Yale University and Yale-New Haven Hospital, who is leading multiple efforts to gather clinical data on COVID-19. “Its ferocity is breathtaking and humbling.”
Understanding the rampage could help the doctors on the front lines treat the fraction of infected people who become desperately and sometimes mysteriously ill –
- Does a dangerous, newly observed tendency to blood clotting transform some mild cases into life-threatening emergencies?
- Is an overzealous immune response behind the worst cases, suggesting treatment with immune-suppressing drugs could help?
- What explains the startlingly low blood oxygen that some physicians are reporting in patients who nonetheless are not gasping for breath?
“Taking a systems approach may be beneficial as we start thinking about therapies,” says Nilam Mangalmurti, a pulmonary intensivist at the Hospital of the University of Pennsylvania (HUP).
What follows is a snapshot of the fast-evolving understanding of how the virus attacks cells around the body, especially in the roughly 5% of patients who become critically ill.
The infection begins
When an infected person expels virus-laden droplets and someone else inhales them, the novel coronavirus, called SARS-CoV-2, enters the nose and throat.
It finds a welcome home in the lining of the nose, according to a preprint from scientists at the Wellcome Sanger Institute and elsewhere.
They found that cells there are rich in a cell-surface receptor called angiotensin-converting enzyme 2 (ACE2).
Throughout the body, the presence of ACE2, which normally helps regulate blood pressure, marks tissues vulnerable to infection, because the virus requires that receptor to enter a cell.
Once inside, the virus hijacks the cell’s machinery, making myriad copies of itself and invading new cells … Read more.