EFFICACY AND TOLERABILITY OF METHOTREXATE IN ANTIMALARIAL RESISTANT LUPUS ARTHRITIS

Objective. To determine the efficacy and tolerability of low dose inte rmittent methotrexate (MTX) in antimalarial resistant lupus arthritis. Methods, Retrospective cohort study from the University of Toronto Lu pus Clinic. Seventeen patients receiving MTX for persistently active a rthritis, despite a previous therapeutic trial of antimalarial therapy , were identified. Seventeen control patients were selected who had ac tive arthritis despite 6 months of treatment with an antimalarial agen t. The primary outcome measure was a reduction in actively inflamed jo int count of at least 60% over 6 months. Secondary outcome measures we re the reduction in steroid dose and Systemic Lupus Erythematosus Dise ase Activity Index (SLEDAI), and tolerability of MTX. Results, Baselin e characteristics including sex, race, age at diagnosis, and concomita nt use of other medications were similar. Patients in the MTX group ha d 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 con trol 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 SLEDA I reduction of 0.76 was obtained in the MTX group, compared to an incr ease of 2.05 in the control group (p = 0.03). Over a mean followup per iod of 3.5 years, toxicity leading to termination was infrequent, as o nly 2 patients discontinued MTX due to a side effect. Conclusion, Meth otrexate appears to be effective in the treatment of antimalarial resi stant lupus arthritis and is well tolerated.