Abstract:

Objective: To investigate the current status of methotrexate (MTX) application in rheumatoid arthritis (RA) patients. Methods: The clinical and laboratory data of RA patients who attended in the Department of Rheumatology and Immunology of Peking University Third Hospital from January 1, 2022 to November 31, 2023 were collected retrospectively. In order to figure out the relationship between MTX use and RA disease control, we recorded information including the starting dose, maximum dose, current dose, reasons of discontinuation of MTX, etc. The t test, Mann-Whitney U test, Chi-square test, Fisher' s exact probability and multivariable Logistic regression were used for analysis. Results: A total of 239 RA patients were enrolled, including 201 females and 38 males with a mean age of (54.5±14.3) years. Among them, 101 patients reached the therapeutic target [clinical remission or low disease activity assessed by 28-joint disease activity score (DAS28)-erythrocyte sedimentation rate (ESR)], accounting for 42.2% of the RA patients. Twenty-six patients met the European League Against Rheumatism (EULAR) definition of difficult-to-treat (D2T) RA, accounting for 10.9% of RA patients. The proportion of the RA patients who had ever used MTX was 84. 1%, and those who were currently on it accounted for only 39.7%. The MTX dose was generally low, with a starting dose of (9.5±3.0) mg/week, the maximum dose of 15.0 (10.0, 15.0) mg/week, and the current dose being (12.4±2.7) mg/week. The most common reasons for MTX dose reduction or discontinuation were adverse reactions, mainly including abnormalities of hepatic function, gastrointestinal discomfort, leucopenia, etc. Those who were currently on MTX had a higher rate of treatment to target (52.6% vs. 35.4%, P>0.05), lower disease activity score (DAS28-ESR, 3.6±1.8 vs. 4.2±1.8, P < 0.05), and fewer tender joint counts (4.8±8.3 vs. 8.6±10.4, P < 0.05) as compared with those who were not taking the drug, while swollen joint count, pain visual analog score and patient' s global score, C-reactive protein (CRP) level and ESR level were not significantly different between the two groups. Compared with those who did not reach the target of treatment, those who did had a higher rate of current MTX application (48.5% vs. 33.3%, P < 0.05), but the history of MTX did not differ between the two groups (84.2% vs. 84.1%, P>0.05). The maximum dose of MTX (median 15.0 mg/week vs. 13.7 mg/week, P>0.05) and the current dose [(12.9±2.5) mg/week vs. (11.8±2.8) mg/week, P>0.05] was higher in those who achieved the target, while the starting dose [(9.6±2.8) mg/week vs. (9.5±3.1) mg/week, P>0.05] and the rate of prior MTX (84.2% vs. 83.3%, P>0.05) was comparable between the two groups. The D2T RA patients had a higher rate of previous MTX use (96.2% vs. 82.6%, P < 0.05) and a higher starting dose [(11.6±4.3) mg/week vs. (9.8±2.7) mg/week, P>0.05], while the maximum dose (median 12.5 mg/week vs. 15.0 mg/week, P>0.05) and the current dose were both lower [(11.6±3.2) mg/week vs. (12.5±2.6) mg/week, P>0.05] than the non-D2T RA patients. Conclusion: The proportion of regular use of MTX among RA patients was low and the dose was generally small. The RA patients with regular use of MTX had a higher rate of achieving treatment target and lower disease activity. Those who achieved the target had a higher rate of current MTX use, higher maximum and current doses than those who did not. The D2T RA patients had lower maximum and current doses of MTX than the non-D2T RA patients. Therefore, increasing the usage and dosage of MTX in RA patients may help to improve the rate of achieving treatment targets.

Key words: Rheumatoid arthritis, Methotrexate, Dose-response relationship, drug, Treat-to-target