Blood plasma from recovered COVID-19 patients does not appear to improve the health outcomes of other critically ill COVID patients, according to research involving UPMC physician-scientists published Monday.

In a paper published in the Journal of the American Medical Association, researchers with the REMAP-CAP — the Randomised, Embedded, Multifactorial, Adaptive Platform Trial for Community-Acquired Pneumonia — wrote that the use of convalescent plasma in critically ill patients was “futile.”

Dr. Bryan McVerry, a co-author of the paper and associate professor of pulmonary, allergy and critical care medicine at the University of Pittsburgh, said in a press release the results should titer the treatment of critical COVID patients away from convalescent plasma.

“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,” he said. “... 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 addition to the futility of plasma treatment in critically ill patients, REMAP-CAP has also found the utility of steroids such as dexamethasone in critically ill patients, and blood thinners help treat the moderately ill.

The paper, which was based on the treatment and outcomes of 2,011 critically ill patients across four countries, specifically found that 37.3% of plasma recipients died in hospital, while 38.4% of those who hadn’t received plasma died.

There was also no statistically significant change in the number of days patients lived without “organ support” — which includes high-dose oxygen therapy, life support and mechanical ventilation — with plasma recipients and non-recipients both averaging 14 days.

Succinctly, the study found convalescent plasma treatment “had a low likelihood of providing improvement in the number of organ support-free days” and it is more than 99% certain convalescent plasma does not help critically ill patients.

The study, however, did not rule out the usefulness of convalescent plasma in immunocompromised patients. While researchers were not able to find a statistically significant link, a group of 126 immunocompromised, plasma-receiving patients appeared to have slightly better outcomes than those with weakened immune systems who didn’t receive such therapy.

Dr. Lise Estcourt, corresponding author of the paper and director of the United Kingdom’s National Health Service Blood and Transplant Critical Trials Unit, said it may be a path for future research.

“It could be that patients with an impaired immune system, who are unable to mount an effective immune response, could still benefit from the antibodies present in blood plasma from COVID-recovered patients, especially early on in the illness,” Estcourt said. “This is something that definitely warrants investigation.”