Efficacy of intravenous immunoglobulins (IVIG) in COVID-19 patients: a systematic review and meta-analysis

Background and purpose: Though controversial, many clinical trials have been conducted to evaluate the efficacy of intravenous immunoglobulins (IVIG) in COVID-19 cases. Therefore, a systematic review and meta-analysis have been performed to evaluate the efficacy of IVIG in the treatment of COVID-19 patients.Experimental approach: A systematic search was performed in electronic databases and preprint servers up to November 20, 2021. Since substantial heterogeneity was expected, a random-effects model was applied to pool effect size from included studies to calculate the standardized mean differences (SMDs) for the continuous variables and relative risks (RRs) for the dichotomous variable with 95% confidence intervals (CIs).Findings/Results: Five randomized clinical trials and seven cohort studies were analyzed among the 12 eligible studies with a total of 2,156 patients. The pooled RR of mortality was 0.77 (CI 0.59-1.01, P-value = 0.06), and of mechanical ventilation was 1.50 (CI 0.29-7.83; P-value = 0.63) in the IVIG group compared with the standard care group. The pooled SMD of hospital length of stay was 0.84 (CI -0.43-2.11; P-value = 0.20) and of ICU length of stay was -0.07 (CI -0.92-0.78; P-value = 0.86) in the IVIG group compared with the standard care group. Conclusion and implications: This meta-analysis found that the IVIG therapy was not statistically different from the standard care group. Mortality, ICU admission, mechanical ventilation, length of hospital stay, and length of ICU stay were not significantly improved among IVIG recipients. However, statistical indifference is not equal to clinical indifference.