RT Journal Article
SR Electronic
T1 Eosinophilic granulomatosis with polyangiitis exhibits T cell activation and IgG4 immune response in the tissue; comparison with IgG4-related disease
JF RMD Open
JO RMD Open
FD EULAR
SP e002086
DO 10.1136/rmdopen-2021-002086
VO 8
IS 1
A1 Satoshi Kubo
A1 Ryuichiro Kanda
A1 Aya Nawata
A1 Yusuke Miyazaki
A1 Akio Kawabe
A1 Kentaro Hanami
A1 Keisuke Nakatsuka
A1 Kazuyoshi Saito
A1 Shingo Nakayamada
A1 Yoshiya Tanaka
YR 2022
UL http://rmdopen.bmj.com/content/8/1/e002086.abstract
AB Objective To study the pathophysiological differences of EGPA and IgG4-related disease (RD) by clarifying their clinical, pathological and immunological features.Methods Clinical and pathological findings were compared in patients with EGPA and IgG4-RD. Peripheral blood mononuclear cells were used for comprehensive flow cytometric analysis.Results An elevation of the IgG4 level was found in all EGPA cases, with the accompanying pathological findings of lymphocytic infiltration and fibrosis observed in 30.8% patients, and the elevation of IgG4/IgG ratio in 61.5% patients. However, actual IgG4 levels, as well as the degree of the infiltration of IgG4-positive plasma cells, were still higher in patients with IgG4-RD than patients with EGPA. Examination by ACR/EULAR classification criteria showed only 13.6% of the EGPA patients met entry criteria, while all of them met the exclusion criteria. In regard to the immunophenotyping, EGPA patients had increases in activated CD4 and CD8 T cells compared with the healthy controls. However, no such similar changes occurred in IgG4-RD patients. On the other hand, both the EGPA and IgG4-RD patient groups had correlated increased plasmablasts and Tfh. These results indicate the presence of two axes: namely, the activation of T cells and that of B cells. Both axes are present in EGPA, but the T cell activation axis was not observed in IgG4-RD.Conclusions The elevation of serum IgG4 as well as pathological IgG4 infiltration are not specific. Meanwhile, EGPA and IgG4-RD differ in immunological phenotypes, indicating the possible importance of the predominant activation of T cells in the development of vasculitis.Data are available on reasonable request. Not applicable.