The therapeutic efficacy of intravenous immunoglobulin in anti-neutrophilic cytoplasmic antibody-associated vasculitis: a meta-analysis

Objectives The therapeutic effects of IVIG in patients with ANCA-associated vasculitis (AAV) have not been established so far. This study aims to estimate the effects of IVIG on AAV by conducting a systematic review and meta-analysis. Methods A comprehensive systematic review was conducted in accordance with the guidelines of PRISMA (Preferred Reporting Items for Systematic Reviews And Meta-analyses). PubMed and Google Scholar were used to search for original studies on AAV and collect clinical data before and after IVIG treatment. A meta-analysis of each clinical parameter was performed, and standardized mean difference (SMD) and 95% CI were calculated using the random effects model. Results A total of 220 studies were identified, and nine met the selection criteria for the meta-analysis. IVIG was administered to active AAV patients as an immunomodulatory therapy in the nine studies selected. Significant reductions in BVAS (SMD –1.7; 95% CI [–2.66, –0.73]; P = 0.0006), ANCA (SMD –0.72; 95% CI [–1.13, –0.31]; P = 0.0006) and CRP (SMD –0.92; 95% CI [–1.49, –0.35]; P = 0.002) were noted within 6 months after administration of IVIG. Subgroup analysis in the unmodified immunotherapy population showed reductions in BVAS (SMD –1.39; 95% CI [–2.31, –0.48]; P = 0.003) and CRP (SMD –0.56; 95% CI [–0.93, –0.19]; P = 0.002) within half a month after IVIG treatment. Conclusion IVIG was associated with rapid improvements in disease activity and the related biomarkers in patients with active AAV.