DEFLAZACORT IN JUVENILE CHRONIC ARTHRITIS

Vertebral crush fracture associated with glucocorticoid therapy causes major morbidity in juvenile chronic arthritis (JCA). Deflazacort (DFZ ) may have an advantage over prednisone (PRED) because of its alleged bone sparing properties. Of 34 children with JCA receiving more than 5 mg PRED/day, 31 completed a 1-year, double blind, randomized, compara tive trial of DFZ and PRED. Patient characteristics at trial entry wer e well matched. DFZ and PRED were prescribed in equivalent amounts. DF Z achieved similar disease control to PRED, and was not associated wit h untoward effects. Joint counts, hematological indices and biochemica l values did not differ between treatment groups initially or during t he trial. Bone density trends (velocities) in the lumbar spine were me asured using dual photon absorptiometry at 3-monthly intervals and tre nds in bone and soft tissue growth calculated. Lumbar spine bone growt h correlated with indices of somatic growth, with wide ranges in each group. Co-variance analysis showed a significant advantage (p < 0.007) of DFZ over PRED when spinal bone density was compared to body surfac e area and weight. Children taking DFZ showed less weight gain but sim ilar height gain to children taking PRED. Children with poor or no som atic growth showed significant lumbar bone loss only in the PRED group . Of the children originally treated with PRED; 11 were switched to DF Z after completing the double blind study. Data for 26 children treate d with DFZ for 1 year were thus available and confirmed a significantl y greater rate of spinal bone growth relative to somatic growth, p < 0 .002. Of the children treated with DFZ for a 2nd year, 14 showed simil ar spinal bone mineral growth rates to those in the 1st year, but ther e was a resumption in somatic growth so the relative rates were simila r. DFZ therapy in JCA appears to permit appropriate spinal growth in r elation to the rest of the body against a background of variable growt h impairment due to the disease itself and its treatment.