Kinetics of SARS-CoV-2 antibody responses pre- and post- COVID-19 convalescent plasma transfusion in patients with severe respiratory failure: an observational case-control study

ABSTRACT

OBJECTIVESTo investigate if COVID-19 convalescent plasma (CCP) transfusion in patients with severe respiratory failure will increase plasma levels of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibody titers while improving survival and clinical outcomes. DESIGNObservational, retrospective, control study of anti-Receptor binding domain (RBD) of SARS-CoV-2 IgG and IgM titers from serial plasma samples drawn before and after CCP administration. Clinical improvement in CCP recipients is assessed and compared to COVID-19 control patients. SETTINGPatients hospitalized with severe COVID19, United States, between April 17 and July 19, 2020 PARTICIPANTS34 patients hospitalized with severe or life threatening COVID-19 and who consented and received a CCP transfusion, 95 control patients with COVID-19 not transfused with CCP. 34 out the 95 control patients were matched for age, sex, and the level of respiratory support required. Patients less than 18 years old were excluded. MAIN OUTCOME MEASURESSerial trends of anti-RBD of SARS-CoV-2 IgG and IgM titers in CCP recipients are compared to those in control patients. The primary outcome is survival at 30 days, and the secondary outcomes are length of ventilatory and/or extracorporeal membrane oxygenation (ECMO) support, length of stay (LOS) in the hospital, and LOS in the ICU. RESULTSCCP transfusion occurred in 34 patients at a median of 12 days following COVID-19 symptom onset. Immediately prior to CCP transfusion, patients median anti-RBD SARS-CoV-2 IgG and IgM titers were 13200 (IQR, 150 to 19600) and 1320 (IQR, 140 to 1640) respectively. Following a Loess regression analysis, the kinetics and distribution of anti-RBD of SARS-CoV-2 IgG and IgM in plasma from CCP recipients were comparable to those from a control group of 68 patients who did not receive CCP. CCP recipients presented with similar survival, similar duration on ventilatory and/or ECMO support, as well as ICU and hospital LOS, compared to a matched control group of 34 patients. CONCLUSIONIn the present study, hospitalized COVID-19 patients with severe respiratory failure transfused with CCP presented with high titers of SARS-CoV-2 IgG antibodies before transfusion and did not show improved survival at 30 days.