In the earliest days of the COVID-19 pandemic, the medical community turned to a century-old treatment: Take blood from recovered patients and give it to the sick. The hypothesis was that components in the so-called “convalescent plasma” that fought off the disease once could do it again, something that has worked in other diseases, such as Ebola.
“There were biologically plausible reasons to turn to convalescent plasma early in the pandemic when hundreds of thousands of people were getting sick and treatments had yet to be discovered,” said co-lead author Bryan McVerry, M.D., associate professor of pulmonary, allergy and critical care medicine at Pitt and a UPMC intensivist. “Unfortunately, it was either being administered outside of clinical trials or in trials that weren’t focused on critically ill patients, slowing our ability to see if it actually worked. Finally, with these results, we can put an end to using convalescent plasma for our sickest COVID-19 patients and focus on treatments that we know work, as well as developing and testing better ones.”
In the convalescent plasma trial, REMAP-CAP enrolled 2,011 adults hospitalized with severe COVID-19. They were randomized to either receive two units of convalescent plasma or no plasma and followed to see if the likelihood of surviving at least three weeks without needing organ support, such as a ventilator, differed based on whether they were treated or not.
The trial concluded for futility when enough data was collected to say with greater than 99% certainty that convalescent plasma did not help critically ill COVID-19 patients.
However, the results followed a slightly different pattern for the 126 patients who were immunocompromised. This group appeared to do slightly better with the convalescent plasma treatment compared to the standard treatment, but the number of patients was too small to make a definitive statement.
The researchers could not determine why convalescent plasma did not improve outcomes in most critically ill patients.
“We speculate that it could be a combination of too few high-quality antibodies in the plasma and these patients being too far along in their illness with a run-away inflammatory immune response for those antibodies to turn the tide,” said co-senior author Derek Angus, M.D., M.P.H., chief innovation officer at UPMC and chair of the Department of Critical Care Medicine at Pitt. “It is still possible that convalescent plasma helps people in earlier stages of illness, though it is likely not efficient to use given that monoclonal antibodies—which UPMC also is evaluating in our OPTIMISE-C19 adaptive trial—are such an effective treatment for early COVID-19.”
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CAPTION: Bryan McVerry, M.D., associate professor of pulmonary, allergy and critical care medicine, University of Pittsburgh, and UPMC intensivist.
CREDIT: Lise Estcourt
CAPTION: Lise Estcourt, M.D., a associate professor of haematology and transfusion medicine at the Oxford University’s Radcliffe Department of Medicine and director of the U.K.’s National Health Service Blood and Transplant Clinical Trials Unit.
CAPTION: Derek Angus, M.D., M.P.H., chief innovation officer at UPMC and chair of the Department of Critical Care Medicine, University of Pittsburgh.