Effects of Achieving SDAI Remission on Joint Space Outcomes Progression in Early Rheumatoid Arthritis: an HR-pQCT Study

Objectives:

To elucidate the effects of achieving sustained simple disease activity index (SDAI) remission in the progression of joint space outcomes using high-resolution peripheral quantitative CT (HR-pQCT) in patients with early rheumatoid arthritis (ERA), and what the independent effects of erosion /JSW progression are on patient's function.

Hypothesis to be tested: Effective control of inflammation in ERA patients who can achieve sustained SDAI remission will have less progression of joint damage then patients who cannot achieve sustained SDAI remission.

Design and subjects: 110 consecutive ERA patients will participate in this 1-year prospective, hospital-based, cohort study.

Study instruments Metacarpophalangeal joints 2-4 will be measured using HR-pQCT Interventions All participants will receive 1-year tight-control treatment according to a standardized protocol aiming at SDAI remission. Physical function will be assessed by Health Assessment Questionnaire (HAQ) at each visit. HR-pQCT and radiographs will be performed at baseline, 6 (HR-pQCT only) and 12 months. Quantitative analysis of joint space width (JSW) and volume, erosion number and volume, and marginal osteosclerosis (bone apposition at the base of the erosion) will be evaluated by HR-pQCT. Radiographic progression will be scored using van der Heijde-Sharp (SvdH) score.

Outcome measures: The primary outcome is the change in JSW and volume over a period of 12 months. Main secondary outcomes include changes in the i) number and size of erosion, ii) SvdH score and iii) HAQ over a period of 12 months.

Expected results: Patients who can achieve sustained SDAI remission will have less joint damage and functional loss compared