The Effect of Convalescent Plasma Therapy on Mortality Among Patients With COVID-19: Systematic Review and Meta-analysis

Abstract

To determine the effect of COVID-19 convalescent plasma on mortality, we aggregated patient outcome data from 10 randomized clinical trials (RCT), 20 matched-control studies, two dose-response studies, and 96 case-reports or case-series. Studies published between January 1, 2020 – January 16, 2021 were identified through a systematic search of online PubMed and MEDLINE databases. Random-effects analyses of RCT and matched-control data demonstrated that COVID-19 patients transfused with convalescent plasma exhibited a lower mortality rate compared to patients receiving standard treatments. Additional analyses showed that early transfusion (within 3 days of hospital admission) of higher-titer plasma is associated with lower patient mortality. These data provide evidence favoring the efficacy of human convalescent plasma as a therapeutic agent in hospitalized COVID-19 patients.

Convalescent Plasma Therapy for COVID-19: A Graphical Mosaic of the Worldwide Evidence

“…Our recent metaanalysis that aggregated data from 20 matched-control studies supports these findings (8). These analyses indicated that patients transfused with convalescent plasma exhibited a 43% relative reduction in mortality compared to patients receiving standard treatments (21 vs. 29% mortality; OR, 0.57; 95% CI, 0.45, 0.72; P < 0.001) (8). The contrasting mortality benefit between matched-control studies and larger multicenter RCTs raises the possibility that locally sourced plasma administered shortly after donation may increase convalescent plasma efficacy against local variants in real time as they emerge (17).…”

“…Combining these available survival data demonstrated an 11% relative improvement in 28day survival associated with convalescent plasma compared to control patients (82 vs. 74%) (Figure 2C). Our recent metaanalysis that aggregated data from 20 matched-control studies supports these findings (8). These analyses indicated that patients transfused with convalescent plasma exhibited a 43% relative reduction in mortality compared to patients receiving standard treatments (21 vs. 29% mortality; OR, 0.57; 95% CI, 0.45, 0.72; P < 0.001) (8).…”

“…Recent reviews and meta-analyses have also generated disharmonious conclusions regarding the effect of convalescent plasma on COVID-19 patient outcomes, such as mortality and clinical improvement. A pragmatic meta-analysis by our group that included data from both RCTs and matched-control studies demonstrated a mortality reduction attributed to convalescent plasma in COVID-19 patients ( 8 ). Conversely, recent reviews that adhered to stricter study inclusion rules and aggregated only RCT data concluded that either convalescent plasma had no effect on mortality or that insufficient evidence exists to determine efficacy ( 9 , 10 ).…”

Therapeutic Use of Convalescent Plasma in COVID-19 Infected Patients with Concomitant Hematological Disorders

“…A recent meta-analysis of randomized clinical trials and matched-control data showed that the use of CP was associated with a lower mortality rate compared to patients treated with standard drugs. Moreover, a lower mortality was demonstrated in patients who were treated with high-titer CP within 3 days of hospital admission [15]. This evidence suggests that COVID-19 patients with mild symptoms and those not yet undergoing noninvasive ventilation may be excellent candidates for passive immunotherapy.…”

Convalescent Plasma the Old Warhorse First to be Inducted in Pandemics is not the Zippy Chippy of Derby

“…Notably, 11 (range, 8–16) patients need to be treated with CP to avoid 1 mortality. [ 4 ]. Further, an article with mathematical modelling, observed an “inverse correlation between CP usage and mortality per admission in the USA, and report that the population level evidence is consistent with the finding that CP reduces mortality in COVID-19.…”