How the coronavirus short-circuits the immune system

www.seattletimes.com
5 min read
fairly difficult
At the beginning of the pandemic, the coronavirus looked to be another respiratory illness. But the virus has turned out to affect not just the lungs, but the kidneys, the heart and the circulatory system — even, somehow, our senses...
of smell and taste.

Now researchers have discovered yet another unpleasant surprise. In many patients hospitalized with the coronavirus, the immune system is threatened by a depletion of certain essential cells, suggesting eerie parallels with HIV.

The findings suggest that a popular treatment to tamp down the immune system in severely ill patients may help a few, but could harm many others. The research offers clues about why very few children get sick when they are infected, and hints that a cocktail of drugs may be needed to bring the coronavirus under control, as is the case with HIV.

Growing research points to "very complex immunological signatures of the virus," said Dr. John Wherry, an immunologist at the University of Pennsylvania whose lab is taking a detailed look at the immune systems of COVID-19 patients.

In May, Wherry and his colleagues posted online a paper showing a range of immune system defects in severely ill patients, including a loss of virus-fighting T cells in parts of the body.

In a separate study, the investigators identified three patterns of immune defects, and concluded that T cells and B cells, which help orchestrate the immune response, were inactive in roughly 30% of the 71 COVID-19 patients they examined. None of the papers have yet been published or peer reviewed.

Advertising

Researchers in China have reported a similar depletion of T cells in critically ill patients, Wherry noted. But the emerging data could be difficult to interpret, he said — "like a Rorschach test."

Research with severely ill COVID-19 patients is fraught with difficulties, noted Dr. Carl June, an immunologist at the University of Pennsylvania who was not involved with the work.

"It is hard to separate the effects of simply being critically ill and in an ICU, which can cause havoc on your immune system," he said. "What is missing is a control population infected with another severe virus, like influenza."

One of the more detailed studies, published as…
The New York Times, This Story Was Originally Published At Nytimes.Com.
Read full article