Abstract
As stated in the comprehensive diagnostic criteria for IgG4-related disease (IgG4-RD), IgG4-RD is characterized by elevated serum IgG4 level and pathological findings, characterized by infiltration of IgG4-positive plasma cells. In addition to fibrotic changes, dysregulated activation of lymphocytes is considered as one of major pathogenic events in IgG4-RD. Among lymphocytes, the importance of plasmablast, T follicular helper (Tfh) cells, T type 2 helper (Th2) cells, T regulatory (Treg) cells, and CD4 positive T cells with cytotoxic activity has been reported. Conversely, comprehensive immunophenotyping in patients with IgG4-RD revealed that there are two different axes consisting plasmablast-Tfh cells and Treg cells. There is need for research to seek out molecules associated with these immunocompetent cell interactions. It is believed that this will contribute to the future application to disease-specific treatment for IgG4-RD.
Conflict of interest
S. Kubo has received speaking fees from Bristol-Myers, Pfizer, Eli Lilly, and Takeda. S. Nakayamada has received speaking fees from Bristol-Myers, Sanofi, Abbvie, Eisai, Eli Lilly, Chugai, Pfizer, Takeda, and also research grants from Mitsubishi-Tanabe, Novartis and MSD. Y. Tanaka has received speaking fees and/or honoraria from Daiichi-Sankyo, Astellas, Eli Lilly, Chugai, Sanofi, Abbvie, YL Biologics, Bristol-Myers, Glaxo-Smithkline, UCB, Mitsubishi-Tanabe, Novartis, Eisai, Takeda, Janssen, Asahi-kasei and has received research grants from Mitsubishi-Tanabe, Bristol-Myers, Eisai, Chugai, Takeda, Abbvie, Astellas, Daiichi-Sankyo, Ono, MSD, Taisho-Toyama.