Zhang P, et al. - Through a prospective clinical trial of 30 newly diagnosed immunoglobulin G4-related disease (IgG4-RD, a newly defined chronic fibro-inflammatory disorder identified by high serum IgG4 levels, tumefactive lesions with a dense lymphoplasmacytic infiltration rich in IgG4 positive plasma cells and storiform fibrosis of related organs) patients with no internal organ involvement, the researchers intended to assess the therapeutic effectiveness and safety of iguratimod plus corticosteroid as bridge therapy in the treatment of mild IgG4-RD. Nine patients attained a complete response, 17 patients with partial response, and 4 patients with no response to treatment were observed at week 24. At weeks 12 and 24 after treatment, IgG4-RD RI, serum IgG, and IgG4 levels as well as CD3+ CD8+ T cells, plasmablast/plasma cells and memory B cells, markedly declined. Significant alterations among untreated patients and healthy donors were revealed by the LC-MS-based plasma metabolomic profiles, which became much similar to normal states post-treatment. Hence, for the treatment of mild IgG4-RD, iguratimod plus corticosteroid as bridge therapy was ascertained as efficient as it improved the clinical symptoms and decreased the serum IgG and IgG4 levels, especially plasmablasts/plasma cells and memory B cells. Furthermore, post-treatment, the similarity between the metabolite profiling to normal controls was found.