The Management of IgG4-Related Disease in Children: A Systematic Review

Background/Objectives: IgG4-related disease (IgG4-RD) is a multi-organ disease with greatly varying therapeutic approaches and a lack of specific treatment algorithms. This systematic review aimed to determine the therapeutic approaches for pediatric IgG4-RD in real-word practice. Methods: We searched PubMed and Google Scholar for articles on pediatric IgG4-RD cases published in English from 2012 to August 2024, focusing on treatments and outcomes. Study type, treatment(s), dose/regimen, age and sex, organ(s) involved, and treatment outcomes were manually extracted from each study. Results: Of the 219 studies identified, we analyzed 81 studies, including 114 pediatric IgG4-RD cases. Fifty-seven percent of patients suffered from multi-organ disease and required several treatment schemes. Around 75% received steroids, alone or in combination, regardless of the organ affected. The treatment outcomes were positive in most cases, although relapses occurred in approximately 30% of patients, usually upon steroid tapering. Other common therapeutic approaches included immunosuppressants, often used as steroid-sparing agents, with azathioprine and mycophenolate mofetil being the most common; surgery for localized disease; and biologics, mainly rituximab, used in more severe/refractory cases. Uncommon but effective therapies included adalimumab and ruxolitinib. Drug combinations seemed to be more efficacious than monotherapies across studies. Patients > 10 years old more frequently received aggressive approaches (surgery and rituximab) and more often experienced relapses. Relapse rates were higher among females. Conclusions: This review highlights the use of systemic steroids as an effective first-line treatment for pediatric IgG4-RD, but also underscores the use of non-steroid-based alternatives in combination with steroids or other immunosuppressants for the effective management of IgG4-RD.