Abstract
Objectives
Interstitial lung disease sometimes occurs in rheumatoid arthritis patients. Although the underlying immunological mechanisms responsible for interstitial lung disease associated with rheumatoid arthritis have not yet been clarified, some reports have suggested possible roles of B cells. To examine the role of B-cell subsets in interstitial lung disease in rheumatoid arthritis patients, we analyzed peripheral blood B-cell subsets.
Methods
We analyzed the frequencies of the peripheral blood B-cell subsets by flow cytometry in rheumatoid arthritis patients with and without interstitial lung disease (n = 16 and 81, respectively) and in healthy donors (n = 110) by high-resolution computed tomography.
Results
Compared with healthy donors, rheumatoid arthritis patients showed statistically higher frequencies of naive B cells and lower frequencies of memory B cells. Moreover, the frequencies of memory B cells were lower in rheumatoid arthritis patients with interstitial lung disease than in those without. Multivariate analysis showed that the frequency of memory B cells, particularly switched memory B cells, was significantly decreased in rheumatoid arthritis patients with interstitial lung disease, even after adjusting for prednisolone dose.
Conclusions
We suspect memory B cells play important roles in interstitial lung disease associated with rheumatoid arthritis.
Acknowledgements
We thank the patients and healthy volunteers who participated in this research. We also thank all the members of the Department of Allergy and Rheumatology and the Department of Immunotherapy Management for the collection of clinical data.
Conflict of interest
Y. Nagafuchi received financial support or fees from Bristol-Myers Squibb, Chugai, Kissei, Mitsubishi Tanabe, and Pfizer. H. Harada received financial support or fees from Nihon Pharmaceutical and Novartis. S. Tateishi received consulting fees, speaking fees, and/or honoraria from Eisai, Maruho, AbbVie, and Eli Lilly. H. Kanda received consulting fees, speaking fees, and/or honoraria from Astellas, Abbvie, Ayumi, Asahi Kasei, Eisai, BMS, Pfizer, Daiichi-Sankyo, Janssen, Novartis, Nihon Kayaku, and Eli Lilly. S. Sumitomo received financial support or fees from AbbVie, Eisai, Chugai, UCB, Bristol-Myers Squibb, Takeda, AstraZeneca, Pfizer, Mitsubishi Tanabe, Novartis Pharma, Asahi Kasei, and Eli Lilly. H. Shoda receives fees from Pfizer, Bristol-Myers Squibb, Eli Lilly, GlaxoSmithKline, Chugai, UCB, and Daiichi-Sankyo. K. Yamamoto received speaking fees from AbbVie, Astellas, AYUMI, Bristol-Myers Squibb, Chugai, Eisai, Janssen, Mitsubishi Tanabe, Ono, and UCB. K. Fujio has received grants, consulting fees, speaking fees, and/or honoraria from Takeda, Bristol-Myers Squibb, Mitsubishi Tanabe, Asahi Kasei, Sanofi, Eli Lilly, Daiichi-Sankyo, Ono, Janssen, AbbVie, Astellas, Eisai, Pfizer, Chugai, Novartis, UCB, Tsumura, Taisho Toyama, Nihon Kayaku, and Ayumi. All other authors declare no competing financial interest. The Department of Immunotherapy Management, Graduate School of Medicine, University of Tokyo had courses endowed by Mitsubishi Tanabe, Chugai, Ayumi, Taisho Toyama, Nippon Kayaku, UCB, and AbbVie.
Author contributions
TS, YN, HH, SS, HS, KY, and KF conceived, designed, and analyzed the experiments, and contributed to writing the manuscript. YN, YT, HT, and NH collected clinical data and performed the flow cytometric immunophenotyping experiments. ST and HK collected clinical data. TS and HH analyzed chest CT scans.