Clinical Outcomes of Convalescent Plasma Transfusion Therapy in Moderate to Critically Ill Covid-19 Patients: A Systematic Review and Meta-Analysis

Background: Currently, Convalescent plasma (CP)is considered a favorable treatment option for moderate to critically ill Covid-19 patients. But there were very few systematic reviews focused on the effect of CP on clinical parameters. As a result, we undertook this systematic review to learn more about the safety and clinical benefits of convalescent plasma therapy over standard treatment (control).

Methodology: We searched Pub Med, Embase and other bibliographic databases to find relevant articles between December 2019 and February 2021 and identified 10 relevant articles which compared CP therapy taken in addition to standard medication with the Control group(who received standard medication). Two independent reviewers examined all full-text articles and extracted the required information intoa predesigned proforma. Forest plots were drawn using RevMan v.5, a statistical tool offered by the Cochrane database to estimate the pooled effect.

Results: The results of meta-analysis using a random effect model indicated a significant reduction in mortality rate in CP (about 27% risk reduction), a reduced length of hospital stay in about 2 days (Weighted Mean Difference: -2.53, 95% CI, -7.20 to -2.14, P<0.0001), less time to improve clinical symptoms in about 4 days (pooled mean; CP:10.82 days vs Control:15.14 days). C-Reactive Protein (CRP) concentration levels (mg/L) were well controlled with the control group than the CP group and significant changes in lymphocytes and D-dimer values were not observed after CP treatment. It was also found that no difference between CP transfusion and control was seen in improving the oxygen saturationlevels.

Conclusion: CP transfusion can be considered safe and showed a significant reduction in mortality and possible benefits in clinical improvement. Patients on CP therapy had no significant benefits in improving inflammatory markers such as CRP, lymphocytes, D-dimer, or oxygen saturation levels over standard drug therapy, according to meta-analysis data.