Interleukin-4 as an emerging therapeutic target for IgG4-related disease

We read the manuscript reported by Simpson et al with great interest.1 They showed remarkable effectiveness of dupilumab, a monoclonal antibody targeting the interleukin-4 (IL-4) receptor alpha, in immunoglobulin G4-related disease (IgG4-RD) complicated with retroperitoneal fibrosis for the first time. Considering the frequent relapse in patients with IgG4-RD during glucocorticoid tapering and the difficulty in glucocorticoid withdrawal,2 it is of great value that their patient could discontinue prednisone within 2 months after starting dupilumab and even remain stable without any relapse for 12 months.1 They also showed no significant adverse effects of dupilumab for the duration. We have previously revealed that IL-4 plays an important role in the pathogenesis of IgG4-RD.3–5 In particular, IL-4-producing follicular helper T cells contribute to IgG4 class-switching and plasmablast differentiation in the disease.3–5 The case reported by Simpson et al connects the basic research findings with the translational application and …