ABSTRACT
Currently, there is no availability of any proven specific treatment or prevention strategy to fight against COVID-19. Convalescent plasma (CP) therapy is expected to increase survival rates in COVID-19 as in the case of emerging viral infection (SARS-CoV and MERS-CoV). To collect all the studies relevant to CP therapy in critically ill or severe COVID-19 patients and summarize the findings. The systematic review was conducted according to the PRISMA consensus statement. A systematic search was performed in PubMed, Scopus, Web of Science, and Cochrane databases on April 25, 2020. A total of six studies (28 patients) relevant to CP therapy in severe or critical COVID-19 are considered for inclusion. Two authors extracted the data about study characteristics, demographics, symptoms, co-morbidities, clinical classification of COVID-19, drug therapies, oxygen therapy, laboratory results, chest CT, neutralizing antibody titer, SARS-CoV-2 RNA load, aal outcome. The review findings revealed that CP therapy increases lymphocyte count, reduced s serum inflammatory markers (CRP, IL-6, Procalcitonin) and liver enzyme levels (AST or ALT). There was a rise in serum neutralizing antibody titers in 10 of 14 patients after CP transfusion. In 4 of 14 patients, the titer levels remain unchanged after CP transfusion. All 28 cases (100%) achieved negative to the SARS-CoV-2 RNA after CP transfusion. The convalescent plasma transfusion can improve neutralizing antibody titers and reduces the viral load in severe/critical COVID-19 patients. The review recommends a well-controlled trial design is required to give a definite statement on the safety and efficacy of convalescent plasma therapy in severe/critical COVID-19.