This multicenter prospective clinical trial investigates the accuracy of ultrasound to predict relapse after discontinuation of infliximab and the efficacy/safety of readministration of infliximab in patients with rheumatoid arthritis in a low disease activity state.

The objective of this multicenter prospective clinical trial is to determine whether ultrasound predicts relapse after discontinuation of infliximab more accurately than does clinical index and to investigate the efficacy and safety of restarting infliximab after relapse in patients with rheumatoid arthritis in remission or low disease activity on infliximab treatment. Infliximab is discontinued in all enrolled patients. Patients are followed up for 48 weeks for monitoring relapse. If relapse occurs, patients receive readministration of infliximab and are further followed up for 24 weeks to determine the efficacy and safety of infliximab readministration. Primary endpoint is the difference in area under curve (AUC) of receiver operator characteristics (ROC) analysis between total power Doppler score and Disease Activity Score (DAS) 28 at baseline to predict relapse within 48 weeks after discontinuation of infliximab.

Inclusion Criteria:

1. 18 years or older
2. RA patients who fulfill 2010 ACR/EULAR Classification Criteria
3. Patients who have been treated with infliximab (Remicade) for 26 weeks or longer
4. DAS28 (CRP) < 3.2 at screening
5. Patients who give written informed consent after receiving sufficient information -

Exclusion Criteria:

1. Receiving prednisolone > 10 mg/day
2. Receiving biological or molecular-target anti-rheumatic drug
3. Alteration of the dose of corticosteroid or anti-rheumatic drug within 8 weeks prior to screening visit
4. Alteration of the dose of non-steroid anti-inflammatory drug within 4 weeks prior to screening visit
5. History of infusion reaction to infliximab
6. Current infection which requires treatment
7. Current or previous demyelinating disorder
8. Current congestive heart failure which requires treatment
9. Breast-feeding or pregnant/possibly pregnant woman, or woman who does not agree to prevent conception during and 6 months after study period
10. Patients whom investigator or co-investigator consider inappropriate for other reasons -

Investigators were masked for ultrasound results