A Rare Disease With Many Faces: a Multicentre Registry of Igg4-Related Disease in Children

Abstract

Objectives We aimed to report the characteristics of paediatric IgG4-related disease (IgG4-RD) through a multicentre registry, to assess disease clusters, and to evaluate the performances of the 2019 American College of Rheumatology and European League Against Rheumatism (ACR/EULAR) classification criteria and the 2020 revised comprehensive diagnostic (RCD) criteria in this cohort.Methods Data of IgG4-RD patients in 13 paediatric rheumatology centres were recorded to a web-based registration system. The diagnosis of IgG4-RD was made according to the 2011 comprehensive diagnostic criteria.Results Thirty-five children (19 females and 16 males) with IgG4-RD were enrolled. The median age at diagnosis was 13.3 (25p-75p; 9.9-15.2) years. The most common organ involvement was the eye (n = 21, 60%), followed by lymph nodes (n = 12, 34.3%), musculoskeletal system (n = 12, 34.3%), and neurological system (n = 9, 25.7%). We identified three clusters in our study cohort: those with eye involvement (n = 11, 31.4%), those with eye involvement and neurological findings (n = 15, 42.9%), and those with pancreato-hepatobiliary disease and lymph node involvement (n = 9, 25.7%). Serum IgG4 levels were high in 19 out of 28 patients (67.8%). All patients except one received corticosteroid treatment, and azathioprine was the most preferred drug as a steroid-sparing agent. The sensitivities of the 2019 ACR/EULAR classification criteria and the 2020 RCD criteria were 5.7% and 88.5%, respectively.Conclusion IgG4-RD has a wide variety of clinical manifestations; however, in children, the most common presentation was orbital involvement. The 2020 RCD criteria had a better performance whereas the 2019 ACR/EULAR classification criteria performed poorly in paediatric patients.