Background/Purpose: It is valuable to predict the effectiveness of biologics in the patients with rheumatoid arthritis (RA) to avoid unnecessary side effects and to save medical resource. Few studies have addressed which patients’ baseline characteristics can predict clinical response in Japanese population. The aim of this study was to determine risk factors for abatacept treatment failure in Japanese population.

Methods: Retrospective cohort study was conducted in tertiary referral hospital in Tokyo, Japan. Consecutive 32 patients who had been treated with abatacept between October 2010 and May 2015 were included. We excluded the patients with abatacept treatment for less than 24 weeks. 32 patients were divided into two groups in terms of clinical responsiveness at 24 weeks using disease activity score 28 C-reactive protein (DAS28-CRP). DAS28-CRP more than 2.1 was defined as treatment failure. Candidate variables were age, gender, disease duration, DAS28-CRP, bone erosion, concomitant use of methotrexate (MTX), previous biologics, comorbidities such as other connective tissue diseases (CTDs) and/or interstitial pneumonia (IP), smoking, alcohol consumption, family history of CTDs, laboratory values including rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) antibodies, and antinuclear antibodies (ANA). RF > 45 IU/ml was defined as highly elevated RF. We performed bivariate analyses and logistic regression analysis.

Results:

Mean age (SD) of 32 patients was 64.8 years-old (12.5). 27 (84%) were female. 18 (56%) patients had treatment failure. The median (range) of disease duration was 1783 days (127 to 14379). In bivariate analyses, non-responder were more likely to be female (71.4% vs 94.4%, P value=0.14), have more tender joints (TJ) (median (range) 4 (1 to 13) vs 6.5 (1 to 13), P=value 0.17), and high titer RF (35.7% vs 83.3% P=value 0.01). For clinical response by abatacept, crude odds ratio of age, female gender, number of TJ, highly elevated RF, DAS28-CRP and CCP positivity was 1.05 (95% CI 0.99 to 1.12, P value=0.14), 6.8 (95% CI 0.86 to 143.31, P value=0.07), 1.19 (95% CI 0.96 to 1.53, P value=0.12), 10.5 (95% CI 1.85 to 88.66, P value=0.007), 1.5(95% CI 0.73 to 3.40, P value=0.28), 0.78(95% CI 0.13 to 3.99, P value=0.77) respectively.

In multivariate analysis, adjusted odds ratio of age, female gender, number of TJ, highly elevated RF, DAS28-CRP and CCP positivity was 1.13 (95% CI 1.00 to 1.36, P value=0.05), 18.63 (95% CI 0.45 to 4042.6, P value=0.13), 1.71 (95% CI 0.97 to 4.09, P value=0.06), 14.49 (95% CI 0.98 to 622.01, P value=0.05), 3.09 (95% CI 0.32 to 59.00 P value=0.34), respectively.

Conclusion: In contrast to previous studies, highly elevated RF is a marginally significant risk factor for abatacept treatment failure in Japanese RA patients.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/highly-elevated-rheumatoid-factor-is-a-risk-factor-for-abatacept-treatment-failure-in-japanese-patients-with-rheumatoid-arthritis/