Background The Clinical Disease Activity Index 1)(CDAI) is widely used as a new remission criterion, and is said to be stricter than the Disease Activity Score (DAS). However, it has a broader range in the assessment of low disease activity.
Objectives We examined whether therapy should be intensified with the aim of remission in patients who had obtained remission in assessment by DAS28, but not by CDAI.
Methods Subjects were 55 patients who were assessed to be in remission by DAS28 after 1 year, among 127 RA patients who used tocilizumab (TCZ) at hospitals affiliated with the Biologics Treatment Group, Department of Orthopedic Surgery, Nagoya University (Tsurumai Biologics Communication2)).
The need for intensification of treatment was assessed using tender joint count (TJC) + swollen joint count (SJC) ≤ 2 as a standard for intensifying treatment, in light of joint surgery, complications and assessments other than the 28 joints. DAS28 < 2.6 was taken as DAS28 remission, and CDAI ≤ 2.8 was taken as CDAI remission, ≤ 10 as low disease activity (CDAI-LDA) and ≤ 22 as moderate disease activity (CDAI-MDA).
Results CDAI assessment of 55 patients with DAS28 remission showed CDAI remission in 15, CDAI-LDA in 33, and CDAI-MDA in 7. Of these, 28.6% (2/7) of CDAI-MDA and 78.8% (26/33) of CDAI-LDA had TJC+SJC ≤ 2. Of the 28 patients with TJC+SJC ≤ 2, 10 (35.7%) had joint surgery before the introduction of TCZ, and 8 (26.6%) had joint pain in others than those 28 joints.
Conclusions For CDAI-LDA and MDA, there were patients lacking improvement only in Patient Global Assessment who seemed to need care of joint surgery sites or of joints other than the 28, rather than intensification of RA therapy. However, there were also patients with persistent tender joint count and swollen joint count that needed intensified RA treatment. Intensification of RA treatment should be considered when using CDAI assessment, keeping in mind joints other than the 28 joints and history of surgery.
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Disclosure of Interest Y. Yabe Speakers bureau: Eisai Co. Ltd, Abbot Japan Co. Ltd, Mitsubishi Tanabe Pharma Corporation, Pfizer Japan, and Chugai Phamaceutical Co. Ltd., T. Kojima Speakers bureau: Eisai Co. Ltd, Abbot Japan Co. Ltd, Mitsubishi Tanabe Pharma Corporation, Daiichi Sankyo Pharmaceutical, Pfizer Japan, Takeda Pharmaceutical, andChugai Phamaceutical Co. Ltd., A. Kaneko Speakers bureau: Eisai Co. Ltd, Abbot Japan Co. Ltd, Mitsubishi TanabePharma Corporation and Chugai Phamaceutical Co. Ltd., Y. Kanayama: None Declared, Y. Hirano: None Declared, T. Shioura: None Declared, K. Saito: None Declared, N. Asai: None Declared, T. Kobayakawa: None Declared, N. Ishiguro Speakers bureau: EisaiCo. Ltd, Abbot Japan Co. Ltd, Mitsubishi Tanabe Pharma Corporation, Daiichi Sankyo Pharmaceutical, Pfizer Japan, Takeda Pharmaceutical, and Chugai Phamaceutical Co. Ltd.