Remission induction therapy with methotrexate and prednisone in patients with early rheumatoid and undifferentiated arthritis (the IMPROVED study).

Aim: Classifying more patients as rheumatoid arthritis (RA) (2010 American College of Rheumatology/European League Against Rheumatism criteria for RA) may improve treatment outcomes but may cause overtreatment in daily practice. The authors determined the efficacy of initial methotrexate (MTX) plus prednisone treatment in patients with 1987 or 2010 classified RA and undifferentiated arthritis (UA).

Method: 610 recent onset RA or UA patients started with MTX 25 mg/week and prednisone 60 mg/day tapered to 7.5 mg/day in 7 weeks. Percentage remissions after 4 months were compared between RA (1987 or 2010 criteria) and UA. Predictors for remission were identified.

Results: With the 2010 criteria, 19% more patients were classified as RA than with the 1987 criteria, but similar remission rates were achieved: 291/479 (61%) 2010 classified RA and 211/264 (58%) 1987 classified RA patients (p=0.52), and 79/122 (65%) UA patients (p=0.46). Anticitrullinated protein antibodies (ACPA) positive RA patients achieved more remission (66%) than ACPA negative RA patients (51%, p=0.001), but also had a lower mean baseline Disease Activity Score (DAS) (3.2 vs 3.6, p<0.001). Independent predictors for remission were male sex, low joint counts, DAS and Health Assessment Questionnaire, low body mass index and ACPA positivity.

Conclusion: Initial treatment with MTX and a tapered high dose of prednisone results in similarly high remission percentages after 4 months (about 60%) in RA patients, regardless of fulfilling the 1987 or 2010 criteria, and in UA patients. Independent predictors indicate that initiating treatment while disease activity is relatively low results in more remission.