Bone mass change during methotrexate treatment in patients with juvenile rheumatoid arthritis

Thirty-two children affected by juvenile rheumatoid arthritis (JRA) were st udied with serial measurements of bone mass for an average of 18 months, to evaluate the effects of long-term methotrexate (MTX) treatment on bone. Bo ne mineral density (BMD) was measured on lumbar spine and total body. Durin g MTX therapy some increase in BMD was observed, though this was smaller th an in a control group of healthy children. Axial (spine and trunk) and appe ndicular (upper and lower Limbs) BMD showed similar increases. BMD, either as an absolute value or as a percent variation from baseline, did not corre late with either MTX dose or length of therapy. In children treated also wi th corticosteroids, these drugs negatively influenced bone mass increase. T he main determinant of absolute spine BMD value appeared to be weight, whil e height and lean mass seemed to be the determinants of total body BMD. Pub ertal stage and disease activity significantly influenced the yearly change in BMD. In conclusion, our data suggest that long-term, low-dose therapy w ith MTX does not induce osteopenia in children with JRA.