COVID-19 Convalescent Plasma (CCP) - When to Transfuse

Background/Case Studies: CCP is a new product emergently approved by the FDA for treatment of COVID-19 based on clinical indications The rationale is that CCP provides anti-SARS-CoV-2 antibodiesimproving the recipient's immune response Ideally, transfusion decisions should be based on the clinical status in conjunction with the patient's blood component level requiring supplementation Thus, we measured the antibody levels of the donors and recipients Study Design/Methods: Between 4/16 and 5/9/2020, 18 CCPs were transfused based on clinical indication CCP was purchased from a regional blood product provider Qualitative determination of anti-Spike protein IgG was performed in the recipient's pretransfusion plasma and in the CCP using the EuroImmun ELISA (Luebeck, Germany) for 16 of the patients Results/Findings: Of the 16 patients, 11 were positive for IgG prior to the transfusion, questioning the utility of CCP administration Patients 1-7, 10 and 11 are deceased All other patients have been discharged All patients receiving CCP were critically ill and on ventilation support, although the disease progressed at different paces The patients who died showed a more rapid decline during the disease, thus there were a higher number of seronegative patients amongst those who died (3/7 of expired vs 2/9 of living patients) There was no statistically significant difference between the surviving versus the deceased group regarding the time from admission to CCP transfusion but there was a statistically significant difference related to the total length of stay (mean of 39 surviving vs 10 days expired group) Overall survival in our cohort was 50% Two patients developed fever and hypotension during transfusion, raising the question of a transfusion reaction Conclusions: Developing transfusion guidelines will help manage utilization and may reduce the risk to the patients and optimize outcomes Based on these limited observations and the unknown therapeutic effect of the CCP, we propose to restrict CCP to IgG negative patients considering that the presence of IgG in the recipient indicates an active immune response, especially since the amount of IgG provided by the CCP is minimal compared to the total amount of patient IgG due to the high difference in volume between the CCP (200 ml) and the patient's plasma volume (3000 ml or more) The IgG detection is qualitative The inhibitory capacity of the IgG was not assessed, although it is recognized that the anti-Spike protein antibodies have neutralization capacity In our cohort rapid clinical decline within 5-6 days of symptom onset was associated with seronegativity