Rheumatoid arthritis flares and de novo inflammatory arthritis after immune checkpoint inhibitor therapy: a single-center exploratory study of clinical phenotypes
cases, 10 and 31 patients were classified into ICI-RA and ICI-IA, respectively. Six patients with RA experienced flares. At baseline, serum IgA was numerically higher in the RA flare group than in the non-flare group (median 482.5 vs. 266 mg/dL). At onset, the ICI-IA group exhibited higher eosinophil counts than the RA flare group (median 140 vs. 7/µL), although prior glucocorticoid exposure may have influenced these values. At 365 days, cumulative treatment discontinuation rates were 34.1% for ICI-IA, 20.0% for ICI-RA, and 0% for RA flares. These operationally defined subgroups exhibited heterogeneous clinical courses. These hypothesis-generating findings support future prospective cohorts with detailed immunophenotyping.
Authors
- Shion Kachi (ORCID: https://orcid.org/0009-0000-9856-9681)
- Hirokazu Taguchi (ORCID: https://orcid.org/0009-0004-7894-6389)
- Hideaki Tsuji (ORCID: https://orcid.org/0000-0002-2521-246X)
- Yoichi Nakayama (ORCID: https://orcid.org/0000-0002-8130-4350)
- Kosaku Murakami (ORCID: https://orcid.org/0000-0001-5981-4648)
- Hajime Yoshifuji (ORCID: https://orcid.org/0000-0001-7082-4900)
- Ryosuke Hiwa (ORCID: https://orcid.org/0000-0001-6968-5712)
- Ran Nakashima (ORCID: https://orcid.org/0000-0001-6247-0647)
- Motoo Nomura (ORCID: https://orcid.org/0000-0002-5967-0610)
- Akio Morinobu (ORCID: https://orcid.org/0000-0002-4672-638X)
- Akira Ōnishi (ORCID: https://orcid.org/0000-0002-3120-1273)
- Masao Tanaka (ORCID: https://orcid.org/0000-0002-8942-2933)
- Shuji Akizuki (ORCID: https://orcid.org/0000-0001-9670-9206)
- Mirei Shirakashi (ORCID: https://orcid.org/0000-0003-1135-0463)
- Tsuneo Sasai (ORCID: https://orcid.org/0000-0002-6235-8716)
Institutions
- Kyoto University (JP)
- Nippon Medical School Musashi Kosugi Hospital (JP)
- Kyoto University Hospital (JP)
- Kobe City Medical Center General Hospital (JP)
- Organogenesis (United States) (US)
Publication Details
- Journal
- Immunological Medicine
- Published
- 2026-08-28
- DOI
- https://doi.org/10.1080/25785826.2026.2722488
- Primary Topic
- Cancer Immunotherapy and Biomarkers
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Japan Society for the Promotion of Science