Impact of Convalescent Plasma Transfusion (CCP) In Patients With Previous Circulating Neutralizing Antibodies (nAb) to COVID-19

INTRODUCTION COVID-19 convalescent plasma (CCP) transfusion has emerged in the past months as an alternative approach to treat pneumonia cases of SARS-CoV-2. Current evidence regarding characteristics of the plasma product, the titer of neutralizing antibodies (nAbs) in the transfused units, time to onset of intervention, and impact of nAbs produced by the patient are limited and heterogeneous. MATERIAL AND METHODS We describe the preliminary results of 104 patients with severe pneumonia due to SARS-CoV-2 transfused with CCP at three medical centers in Brazil. All enrolled patients were transfused with doses between 200 mL through 600mL of ABO compatible CCP on days 0-2 after enrolment. Clinical parameters were monitored and nAbs titration was performed using the cytopathic effect-based virus neutralization test with SARS-CoV-2 (GenBank [MT126808.1][1]). RESULTS Forty-one patients achieved clinical improvement on day 14, and multivariable logistic regression showed that nAbs T (from CCP units transfused) (p= 0.001), nAbs P0 (on day of enrolment) (p=0.009) and use of other supportive therapies (p<0.001) were associated with higher odds for this clinical improvement. Considering ICU length of stay (LOS) and length of mechanical ventilation, in our analysis, nAbs P0 were associated with a significant reduction in ICU LOS (p=0.018) and duration of mechanical ventilation (p<0.001). Administration of CCP after 10 days of symptom onset was associated with increases in ICU length of stay (p<0.001). DISCUSSION/CONCLUSION Despite the study limitations, our data have shown an association between patients’ previously acquired nAbs and clinical outcomes. The potential value of timely administration of CCP transfusion before day 10 of disease onset was demonstrated and nAbsP0, but not nAbsT, were associated with ICU LOS, and duration of mechanical ventilation on the improvement of clinical outcomes was also demonstrated. In conclusion, we consider these data are useful parameters to guide future CPP transfusion strategies to COVID-19. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement DBA by Grant 88887.131387/201600 CAPES, RRGM by Grant 2017/247692 FAPESP, and ELD by Grants 2016/200457 and 2020/064091 FAPESP. This project was partially supported by the initiative Todos Pela Saude Fundacao Itau para Educacao e Cultura. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Approved by the Brazilian National Commission for Research Ethics (CONEP), CAAE 30922420.6.2002.0071, and the Ethics Committees of each participating site. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All related data will be available under special requitrement to the corresponding author [1]: /lookup/external-ref?link_type=GEN&access_num=MT126808.1&atom=%2Fmedrxiv%2Fearly%2F2020%2F12%2F11%2F2020.12.08.20246173.atom