Efficacy of convalescent plasma in the treatment of coronavirus disease 2019: a systematic review

ABSTRACT

Objective To systematically review the efficacy of convalescent plasma (CP) in the treatment of coronavirus disease 2019 (COVID-19). Methods PubMed, EMbase, The Cochrane Library, VIP, WanFang Data and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) on the efficacy of CP in the treatment of COVID-19 from inception to September 15th, 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies;then, meta-analysis was performed using RevMan 5.4.1 software. Results A total of 16 RCTs involving 15 301 patients were included. The results of meta-analysis showed that CP treatment did not reduce mortality compared with no-placebo (RR=0.99, 95%CI 0.93 to 1.05, P=0.63) or normal saline (RR=1.06, 95%CI 0.60 to 1.86, P=0.84). However, compared with standard plasma, the mortality of CP group was lower (RR=0.59, 95%CI 0.37 to 0.95, P=0.03). In addition, compared with no-placebo or normal saline, CP treatment could not improve the clinical condition at 28-30 days, reduce mortality at early treatment and in patients without invasive mechanical ventilation when randomized. Conclusion Current evidence shows that compared with no-placebo or normal saline, CP does not reduce mortality in patients with COVID-19. However, when the disease progresses to the point where standard plasma is required, CP may reduce mortality. In addition, use of CP in patients with early or noncritical COVID-19 failed to reduce mortality. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusion. © 2022 West China University of Medical Science. All rights reserved.