Convalescent plasma transfusion therapy in severe and critical COVID-19 patients: A Systematic Review and Meta-Analysis

Background Convalescent plasma treatment for severe and critically ill Corona Virus Disease 2019 (COVID-19) patients remains controversial. Objective To evaluate the clinical improvement and mortality risk of convalescent plasma treatment in patients with severe and critically ill COVID-19 patients. Methods A literature search was conducted in the electronic databases for the randomized controlled studies about convalescent plasma therapy in severe and critically ill COVID-19 patients. Two reviewers independently extracted relevant data. The primary outcomes were clinical improvement and mortality risk of severe and critically ill COVID-19 patients that were therapied by convalescent plasma. Results A total of 14 randomized controlled trials with 4543 patients were included in this meta-analysis. Compared to control, no significant difference was observed for either clinical improvement (6 studies, RR 1.07, 95% CI 0.97 to 1.17, p = 0.16, moderate certainty) or mortality risk (14 studies, RR 0.94, 95% CI 0.85 to 1.03, p= 0.18, low certainty) in patients of convalescent plasma therapy group. Conclusion Convalescent plasma did not increase the clinical improvement or reduce the mortality risk in the severe and critically ill COVID-19 patients.