Australian respiratory physician Dr David Darley says something peculiar happens to a small group of COVID-19 patients on day seven of their symptoms. “Up until the end of that first week, they’re stable,” says Darley, a doctor with Sydney’s St Vincent’s Hospital. “And then suddenly, they have this hyper-inflammatory response. The proteins involved in that inflammation start circulating in the body at high levels.”
The Guardian report that in these patients, the lungs begin to struggle. Blood pressure lowers. Other organs, including the kidneys, may begin to shut down. Blood clots form throughout the body. The brain and intestines may also be affected. Some suffer changes to their personality, suggesting brain damage.
“I think what is evolving is a very specific set of stages of disease and for some reason, not everyone goes through all of the stages,” Darley says. “Some go through to the most severe stage and they require breathing support and oxygen. These patients who are severe tend to be older, they are more likely to be men, and also have other medical problems like diabetes, high blood pressure or cardiovascular disease.”
But there is no way of knowing which patients will be affected by the most severe symptoms. Clinicians like Darley hope that a disease biomarker – a unique characteristic in the blood, body fluids, or tissues – will eventually be discovered for each stage. “It would help clinicians predict what stage patients are at and maybe even if they will progress to the next stage of disease,” he said. “It could help us predict who needs to be more closely observed in hospitals and would mean we have all the systems ready to go if they worsen. And it would give us more confidence to have them discharged to home if a biomarker says they are low risk for developing severe illness.”
The report says Darley is one of the researchers working on a long-term St Vincent’s study of patients admitted to the hospital with COVID-19. Patients will be followed for a year after being discharged, receiving tests at regular intervals to see if there are any lasting effects or changes in the body’s immune system and blood. They will also be assessed for any ongoing changes to lung, gut and brain functions.
No one yet knows if the virus causes permanent or long-term harm, the report says.
[link url="https://www.theguardian.com/world/2020/may/01/how-is-this-possible-researchers-grapple-with-covid-19s-mysterious-mechanism"]Full report in The Guardian[/link]