[Brett] Breslow was suffering from a massive bout of inflammation — a catch-all description for the damage in many of the sickest patients with COVID-19. In addition to the assault on his lungs, the disease was harming his liver and kidneys, as well as causing him to form abnormal blood clots.
[I]n June, researchers reported that dexamethasone, an inexpensive, generic steroid, improved the odds of survival for COVID-19 patients on ventilators. But steroids are a brute-force approach.
A new pair of studies from the University of Pennsylvania may offer a road map to a more targeted response. Researchers took blood samples from dozens of COVID patients and ran them through a boxy device called a flow cytometer, using laser beams to identify which kinds of immune cells had been activated to fight the disease.
When it was all boiled down, people with COVID seemed to cluster into three broad “immunotypes,” said E. John Wherry, director of Penn’s Institute for Immunology. Loosely speaking, some patients’ immune systems seemed to have overreacted to the virus, while others were slow to react. In a third group, the immune system did not seem to respond much at all.
The findings represent a first step toward identifying which patients might need to have certain inflammatory agents calmed down, and which might need other elements of the immune system dialed up.