Efficacy of IVIG (intravenous immunoglobulin) for corona virus disease 2019 (COVID-19): A meta-analysis

Background: The benefit of IVIG (Intravenous Immunoglobulin) therapy for COVID-19 remains controversial. We performed a meta-analysis to investigate the efficacy of IVIG treatment in patients with COVID-19. Methods: We searched articles from Web of Science, PubMed, Embase, the Cochrane Library, MedRxiv between 1 January 2020 and February 17, 2021. We selected randomized clinical trials and observational studies with a control group to assess the efficiency of IVIG in treating patients with COVID-19. Subjects were divided into 'nonsevere', 'severe' and 'critical' three subgroups based on the information of the study and the World Health Organization (WHO) definition of severity. We pooled the data of mortality and other outcomes using either a fixed-effect model or a random-effects model. Results: Our meta-analysis retrieved 4 clinical trials and 3 cohort studies including 825 hospitalized patients. The severity of COVID-19 is associated with the efficiency of IVIG. In critical subgroup, IVIG could reduce the mortality compared with the control group [RR = 0.57 (0.42-0.79, I2 = 025%). But there was no significant difference in the severe or non-severe subgroups. Conclusion: IVIG has demonstrated clinical efficacy on critical ill patients with COVID-19. There may be a relationship between the efficacy of IVIG and the COVID-19 disease severity. Well-designed clinical trials to identify the clinical and biochemical characteristics in COVID-19 patients' population that could benefit from IVIG are warranted in the future.