A systematic review of convalescent plasma treatment for COVID19

BackgroundTransfusion of convalescent immune plasma (CP) is commonly used in epidemics. Several articles now describe clinical report data of CP for treatment of SARS-CoV-2-induced COVID-19 disease. MethodsA systematic literature review was conducted using the NCBI curated COVID-19 related open-resource literature database LitCovid to identify studies using CP as treatment for COVID-19 patients. We retrieved and curated all COVID-19 related patient and treatment characteristics from previously reported studies. A Poisson model was developed to evaluate the association between age of the patients, older age being the most common risk factor for COVID-19 mortality, and recovery time since CP treatment using data extracted from the literature. ResultsFrom 18,293 identified COVID-19 related articles, we included ten studies reporting results of CP treatment for COVID-19 from a total of 61 patients. Decreased symptoms of severe COVID-19 and clearance of SARS-CoV-2 RNA were the most direct observations. We found that patients over the age of sixty who received CP treatment for COVID-19 had a significantly prolonged recovery estimated by viral clearance (from 10 to 29 days since first dose of CP) compared to younger patients, who recovered from the infection in less than a week after receiving CP treatment. ConclusionsLimited published results on plasma transfusion treatment for COVID-19 disease with concomitant treatments suggest that CP therapy for COVID-19 is well tolerated and effective. First randomized clinical trial results, however, revealed no improvements in recovery time for elderly patients with severe COVID-19 between standard treatment alone and added with convalescent plasma. Accordingly, we argue that older patients may need a significantly longer time for recovery. Further randomized clinical trial data for COVID-19 with rigorous ethical standards is urgently needed.