Infliximab shows drastic efficacy for controlling inflammation in rheumatoid arthritis (RA), though the ideal dose of infliximab to keep suppressing inflammation has not yet been identified. Recently, it has been evidenced that the minimum trough serum infliximab levels required for suppressing inflammation are greater than 1 µg/mL. This cross-sectional study was designed to identify the minimum dosage of infliximab for maintaining serum infliximab levels greater than 1 µg/mL. Thirty seven RA patients were enrolled in this study and they were divided into two groups (high-infliximab vs. low-infliximab) in reference to Remi-check Q