Evaluation of response to methotrexate by a functional index in juvenile chronic arthritis

In juvenile chronic arthritis (JCA) the indices of disease activity, such as joint swelling, pain, tenderness, and limitation of motion, may poorly correlate with the degree of functional impairment. Since the improvement of functional capacity is one of the main objectives of treatment, we evaluated the effect of methotrexate (MTX) in 29 children with JCA by assessing both the articular indices and a functional status measure. After 6 months of therapy, 15 of the 29 patients had a significant (≥50%) reduction in the number of joints with active arthritis and/or the articular severity score and were then judged as responders, while 14 did not respond to MTX. In the responder group, the median functional index score decreased from 17 (range: 13-27) at baseline to 13 (range: 13-15) at 6 months (p<0.001); the median score of the non-responder group was 20 both at baseline and at 6 months (ranges: 14-27, and 13-36, respectively). These results show an improvement of functional impairment in those patients who respond to MTX according to the conventional indices of articular inflammation.