(HealthDay News) — A strong inverse correlation exists between convalescent plasma use per admission and mortality for hospitalized COVID-19 patients, according to a study published online June 4 in eLife.
Noting that the U.S. Food and Drug Administration authorized emergency use of convalescent plasma therapy for hospitalized COVID-19 patients, Arturo Casadevall, M.D., Ph.D., from the Johns Hopkins School of Public Health in Baltimore, and colleagues tracked the number of convalescent plasma units dispensed to hospitals by blood banking organizations and correlated use with hospital admission and mortality data.
The researchers found that in the fall of 2020, convalescent plasma usage per admission peaked; between late September and early November 2020, more than 40% of inpatients were estimated to have received convalescent plasma. Convalescent plasma usage declined steadily to a nadir of less than 10% in March 2021 after randomized controlled trials failed to show a reduction in mortality. A strong inverse correlation was observed between convalescent plasma usage per hospital admission and deaths occurring two weeks after admission (r = −0.52); this finding was robust to examination of deaths occurring one, two, or three weeks after admission. Those findings could not be explained by changes in the number of hospital admissions, severe acute respiratory syndrome coronavirus 2 variants, or patient age. From mid-November 2020 to February 2021, the decrease in convalescent plasma usage may have resulted in as many as 29,000 excess deaths.
“Clinical trials of convalescent plasma use in COVID-19 have had mixed results, but other studies, including this one, have been consistent with the idea that it does reduce mortality,” Casadevall said in a statement.
