High-titer convalescent plasma associated with lower risk for death from COVID-19
Among hospitalized patients with COVID-19 who were not on mechanical ventilation, receiving high-titer convalescent plasma was associated with a lower risk for death than receiving plasma with lower antibody levels, researchers reported.
“In response to the coronavirus pandemic, the Mayo Clinic initiated — along with support and direction from the Biomedical Advances Research and Development Authority and the FDA — the U.S. Expanded Access Program for convalescent plasma to provide access to and assess the safety profile of this experimental therapy,” Michael J. Joyner, MD, an anesthesiologist at the Mayo Clinic, explained to Healio.
Joyner and colleagues conducted a retrospective study using the expanded access program registry to determine the anti-SARS-CoV-2 immunoglobulin G antibody levels in convalescent plasma used to treat hospitalized adults with COVID-19. They assessed patients who had measured anti-SARS-CoV-2 antibody levels and 30-day mortality data available through July 4. According to the study, the primary outcome was death within 30 days after plasma transfusion.
Of the 3,082 patients included in their analysis, 115 of 515 patients (22.3%) in the high-titer group, 549 of 2,006 patients (27.4%) in the medium-titer group and 166 of 561 patients (29.6%) in the low-titer group died within 30 days after plasma transfusion, Joyner and colleagues reported.
They observed a lower risk for death within 30 days in the high-titer group vs. the low-titer group among patients who had not received mechanical ventilation before transfusion (RR = 0.66; 95% CI, 0.48-0.91), but no effect among patients who had received mechanical ventilation (RR = 1.02; 95% CI, 0.78-1.32)
“Transfusion of plasma which had higher levels of anti-SARS-CoV-2 IgG antibody was associated with lower mortality than transfusion of plasma with lower levels of antibody,” Joyner said. “Patients who received plasma within 3 days of diagnosis had lower mortality than those transfused later in the disease course.”