Efficacy and tolerability of methotrexate in antimalarial resistant lupus arthritis.

Abstract

To determine the efficacy and tolerability of low dose intermittent methotrexate (MTX) in antimalarial resistant lupus arthritis. Retrospective cohort study from the University of Toronto Lupus Clinic. Seventeen patients receiving MTX for persistently active arthritis, despite a previous therapeutic trial of antimalarial therapy, were identified. Seventeen control patients were selected who had active arthritis despite 6 months of treatment with an antimalarial agent. The primary outcome measure was a reduction in actively inflamed joint count of at least 60% over 6 months. Secondary outcome measures were the reduction in steroid dose and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and tolerability of MTX. Baseline characteristics including sex, race, age at diagnosis, and concomitant use of other medications were similar. Patients in the MTX group had a higher mean joint count than the control group at baseline (p = 0.003). After 6 months, 15/17 patients in the MTX group showed at least a 60% improvement in the joint count compared to only 2/17 for the control group (p < 0.001). The mean daily prednisone dose fell by 35 and 27% in the MTX and control groups, respectively (p = NS). A mean SLEDAI reduction of 0.76 was obtained in the MTX group, compared to an increase of 2.05 in the control group (p = 0.03). Over a mean followup period of 3.5 years, toxicity leading to termination was infrequent, as only 2 patients discontinued MTX due to a side effect. Methotrexate appears to be effective in the treatment of antimalarial resistant lupus arthritis and is well tolerated.