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...