Effectiveness of Convalescent Plasma Therapy in the Treatment of Moderate to Severe COVID 19 Patients: A Systematic Review and Meta-Analysis

J Assoc Physicians India. 2020 Dec;68(12):35-43.


Though Convalescent plasma therapy (CPT) is being used for management of COVID-19, the evidence is still equivocal. So, we carried out this study to evaluate the currently available data to provide evidence about CPT in COVD-19 patients. RCTs and observational studies with sample size with more than 5 were included in the analysis. Out of 196 studies, 12 studies were selected for systematic review and meta-analysis was carried out for 6 studies having a control arm. For dichotomous values, risk ratio (RR) and 95% confidence interval was expressed.

MAIN OUTCOMES: All-cause mortality, clinical improvement by day 7 and viral detection by day 7 were the defined outcome measures before starting of data extraction.

RESULT: For 6 studies (2 RCTs and 4 observational studies) with 474 patients, the overall pooled RR for all-cause mortality was 0.61 (95%CI: 0.37 to 0.99. P= 0.04). Only RCTs and only observational studies for all-cause mortality showed pooled RR of 0.60 (95% CI: 0.33 to 1.10, P=0.10) and 0.48 (95% CI: 0.17 to 1.36, P= 0.17) respectively. There was risk of bias in the studies due to randomization process and confounding. Sensitivity analysis was carried out only for observational studies. The overall pooled RR for clinical improvement by day 7 and viral detection by day 7 were 1.12 (95%CI: 0.96 to 1.31, P=0.16) and 0.19 (95%CI: 0.09 to 0.60, P < 0.0001).

CONCLUSION AND RELEVANCE: Though the review suggests modest utility of CPT in reducing all-cause mortality, improving clinical outcome, and early viral clearance, it should be interpreted cautiously.