Clinical effectiveness of convalescent plasma in hospitalized patients with COVID-19: a systematic review and meta-analysis

Abstract

Given the variability of previously reported results, this systematic review aims to determine the clinical effectiveness of convalescent plasma employed in the treatment of hospitalized patients with diagnosis of COVID-19.We conducted a systematic review of controlled clinical trials assessing treatment with convalescent plasma for hospitalized patients with a diagnosis of SARS-CoV-2 infection. The outcomes were mortality, clinical improvement, and ventilation requirement.A total of 50 studies were retrieved from the databases. Four articles were finally included in the data extraction, qualitative and quantitative synthesis of results. The meta-analysis suggests that there is no benefit of convalescent plasma compared to standard care or placebo in the reduction of the overall mortality and in the ventilation requirement; but there could be a benefit for the clinical improvement in patients treated with plasma.We can conclude that the convalescent plasma transfusion cannot reduce the mortality or ventilation requirement in hospitalized patients diagnosed with SARS-CoV-2 infection. More controlled clinical trials conducted with methodologies that ensure a low risk of bias are still needed.