Supplementary Material for: Analysis of Innate and Adaptive Immunological Characteristics in Patients with IgG4-Related Disease

<b><i>Background:</i></b> Immunoglobulin G4-related disease (IgG4-RD) is a systemic immunological disorder characterized by fibro-inflammatory conditions; however, the pathobiology of IgG4-RD has not been fully identified. <b><i>Objective:</i></b> This study aimed to analyze systemic differences of innate and adaptive immune cells from healthy controls and patients with IgG4-RD. <b><i>Methods:</i></b> Healthy controls (<i>n</i> = 9) and IgG4-RD patients (<i>n</i> = 7) were recruited with informed consent. Peripheral blood was collected from healthy controls and IgG4-RD patients, and three blood samples from IgG4-RD patients were re-collected two months after the last rituximab (RTX) treatment. The various immune cells and cytokine productions were measured by flow cytometry. <b><i>Results:</i></b> Blood CD14⁺ monocytes and steady-state follicular helper T cells were increased in patients with IgG4-RD. However, there were no changes in other immune cell populations, including B cells, CD4 T cells, CD8 T cells, and innate lymphoid cells. Also, the TGF-β-producing CD14⁺ monocytes were significantly augmented in patients with IgG4-RD. Two months after RTX treatment, total B cells (CD19⁺) were depleted; however, the expressions of TGF-β from CD14⁺ monocytes remained unchanged. <b><i>Conclusion:</i></b> These findings showed that IgG4-RD is related to the increment of CD14⁺ monocytes. Besides, controlling increased TGF-β-producing CD14⁺ monocytes with RTX treatment might be a conducive way to regulate IgG4-RD.