The transfusion of human convalescent plasma as a mitigation and treatment option for patients with coronavirus disease 2019 (COVID-19) is associated with a low rate of serious adverse events (SAEs) in patients hospitalized with the infection, according to study findings published in Mayo Clinic Proceedings.
The study included a large convenience sample of 20,000 hospitalized adult patients with a confirmed infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and a severe or life-threatening case of COVID-19. The study period ran from April 3 to June 11, 2020.
Approximately 200 to 500 mL of convalescent plasma from recently recovered survivors of COVID-19 were intravenously administered to the hospitalized patients. The clinical status of these patients was assessed 4 hours and 7 days after convalescent plasma transfusion. Researchers examined all SAEs that occurred within a 7-day period after transfusion.
In this large cohort, the ages of patients were reported in ranges: 18 to 39 years (7.6%); 40 to 59 years (31.8%); 60 to 69 years (27.1%); 70 to 79 years (20.6%); and ≥80 years (12.8%). The reported SAEs included transfusion reactions, which were reported in <1% of all transfusions within 4 hours after the completion of the COVID-19 convalescent plasma transfusion. A total of 83 nonmortality events were reported, including 37 transfusion-associated circulatory overload (TACO) events, 20 transfusion-related acute lung injury (TRALI) events, and 26 severe allergic transfusion reactions.
The majority of the thromboembolic or thrombotic events (n=55) and cardiac events (n=562) were deemed unrelated to the transfusions. Overall, the 7-day mortality rate was 8.56% (95% CI, 8.18%-8.95%). This rate was higher in patients who were critically ill, particularly in patients who were admitted to intensive care vs not admitted to intensive care (10.5% vs 6.0%, respectively), mechanically ventilated vs nonventilated patients (12.1% vs 6.2%, respectively), and in patients with septic shock or multiple organ dysfunction/failure vs those without (14.0% vs 7.6%, respectively).
A limitation of the study was the rapid recruitment of patients who had recovered from COVID-19 for convalescent plasma donation, which means the plasma may have included high levels of neutralizing antibodies or other bioactive elements.
Nonetheless, the emerging data from this and similar studies offer “early safety indicators of convalescent plasma for COVID-19 treatment and suggest research should shift focus from safety toward determining the efficacy of convalescent plasma,” according to the study authors.
Joyner MJ, Bruno KA, Klassen SA, et al. Safety update: COVID-19 convalescent plasma in 20,000 hospitalized patients [published online July 19, 2020]. Mayo Clin Proc. doi:10.1016/j.mayocp.2020.06.028