Clinical and ultrasound features of difficult-to-treat rheumatoid arthritis: A multicenter RA ultrasound cohort study

Abstract

Objective: The optimal strategy for difficult-to-treat (D2T) rheumatoid arthritis (RA) has not been identified, and the ultrasound characteristics of D2T RA have not been reported. We investigated the clinical characteristics and factors contributing to the outcome in D2T RA in a multicentre RA ultrasound observational cohort.

Method: We reviewed 307 Japanese patients diagnosed with RA who underwent treatment with biological and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs). We compared the differences in patient characteristics between the D2T RA and non-D2T RA groups. We examined the factors contributing to a good response [defined as b/tsDMARD continuation and Clinical Disease Activity Index (CDAI) ≤ 10 at 12 months] in the D2T RA patient group.

Results: Forty-three patients (14%) were categorized as D2T RA and the remaining 264 (86%) as non-D2T RA at baseline. The grey-scale (GS) score, disease duration, and CDAI at the initiation of treatment were significantly higher in the D2T RA group than in the non-D2T RA group. In contrast, the power Doppler (PD) score was not significantly different between the two groups. Of the 43 D2T RA patients, 20 achieved a good response. The introduction of CTLA4-Ig (n = 5) was significantly associated with a good response in analysis based on inverse probability weighting with propensity score. GS and PD scores at baseline were not significantly associated with therapeutic response at 12 months in D2T RA patients.

Conclusions: Patients with D2T RA had high clinical and ultrasound activity and poor responses to treatment with b/tsDMARDs. CTLA4-Ig was associated with a good response at 12 months in D2T RA patients.

Acknowledgements

We thank all of the members of Kyushu Multicenter Rheumatoid Arthritis Ultrasound Prospective Observational Cohort Study (KUDOS) Group for their participation, including Nagasaki University Graduate School of Biomedical Sciences (Shin-ya Kawashiri, Ayako Nishino, Yushiro Endo, Atsushi Kawakami), Sasebo Chuo Hospital (Toshiyuki Aramaki, Yukitaka Ueki), Yoshitama Clinic for Rheumatic Diseases (Tamami Yoshitama), Eiraku Clinic for Rheumatic Diseases (Nobutaka Eiraku), Nagasaki Medical Hospital of Rheumatology (Naoki Matsuoka, Masahiko Tsuboi), Japanese Red Cross Nagasaki Genbaku Hospital (Akitomo Okada, Takahisa Suzuki), Japan Community Health care Organization Isahaya General Hospital (Keita Fujikawa, Akinari Mizokami), Miyazaki University Hospital (Hiroaki Hamada), Aso Iizuka Hospital (Shuji Nagano), Kyushu University Hospital (Yojiro Arinobu), and Saga University Hospital (Syuichi Koarada, Yoshifumi Tada).

Disclosure statement

No potential conflict of interest was reported by the authors.

Authors’ contributions

SYK made substantial contributions to the study’s concept. All authors treated the patients and collected the primary data. SM, a biostatistician, conducted the statistical analyses. TM drafted the manuscript with the assistance of SF and under the supervision of SYK. SYK critically revised the manuscript. SYK and AK supervised the entire study and gave final approval for the article. All authors read and approved the final manuscript.