Convalescent plasma titers can now be qualified using the Mount Sinai COVID-19 ELISA IgG Antibody Test
The US Food and Drug Administration (FDA) announced Dec. 1, 2020, that it has reissued the emergency use authorization (EUA) for the use of convalescent plasma for treating COVID-19 in hospitalized patients. This EUA was initially issued in late August 2020, but it had the notable deficit of only permitting the use of a single SARS-CoV-2 antibody test for testing. (See Testing Donated Plasma: Clinical Laboratories Should Be Aware of Overlooked Requirement).
The initial EUA for convalescent plasma states that prior to use, units were required to be “tested by the Ortho VITROS SARS-CoV-2 IgG test and found to have a signal-to-cutoff (S/C) value of 12 or greater.” There were no other allowances made for testing potential units of convalescent plasma using other tests.
The December 2020 reissuance of the convalescent plasma EUA addressed this limitation by permitting a second SARS-CoV-2 antibody test to qualify potential plasma as containing the antibodies needed to treat COVID-19. The FDA announced, “The Letter of Authorization has been revised to add the Mount Sinai COVID-19 ELISA IgG Antibody Test as an acceptable test to be used for the purpose of qualifying high and low titer COVID-19 convalescent plasma in the manufacture of COVID-19 convalescent plasma.”