Objective: To determine incidence of increased levels of alanine transferase (ALT) >2× upper limit of normal (ULN) in patients receiving methotrexate (MTX), treated according to a dynamic strategy, and to identify predictors of ALT of >2× ULN.
Methods: Data of 508 recent-onset rheumatoid arthritis (RA) patients from the BeSt study, randomized to initial monotherapy or combination therapy, were used. Treatment was dynamic, aiming at a disease activity score = ≤ 2.4. ALT was measured every three months. With logistic regression analyses, baseline variables predictive of first ALT of >2× ULN were identified and the association between use of concomitant antirheumatic drugs, the actual and cumulative dose of MTX and ALT of >2× ULN was determined.
Results: In total, 498 patients ever initiated MTX, with a total duration on MTX of 1,416 patient-years. In 89 patients, a first incidence of ALT of >2× ULN occurred. Incidence rate was 6.3 per 100 patient-years and cumulative incidence 18 %. ACPA positivity and baseline ALT of >1× ULN were independent predictors of later ALT of >2× ULN (OR 1.8 (95 % CI, 1.1-3.1) and OR 3.1 (95 % CI, 1.6-6.2), respectively). Smoking showed a trend (OR 1.6 (95 % CI, 0.98-2.7)). Mean MTX dosage over time was higher in patients with an ALT of >2× ULN. Patients who did not have an ALT of >2× ULN used more concomitant disease-modifying antirheumatic drugs and longer.
Conclusions: In RA patients treated with MTX according to a dynamic strategy resembling daily clinical practice, incidence of increased ALT of >2× ULN was lower than previously reported, and also without treatment adjustments, persistence was rare. The recommendations for ALT monitoring may be reevaluated.