ALTERED MINERAL METABOLISM AND BONE MASS IN CHILDREN DURING TREATMENTFOR ACUTE LYMPHOBLASTIC-LEUKEMIA

Children with acute lymphoblastic leukemia (ILL) often develop bone pa in, abnormal gait, and unusual fractures while in remission and receiv ing continuing chemotherapy. A prospective longitudinal cohort study w as undertaken of bone mass and biochemical mineral status in 40 consec utive children (27 male, 13 female, aged 0.3-17.0 years) receiving the rapy on the Dana-Farber Cancer Institute protocol 87-01, Radiography, lumbar spine dual-photon absorptiometry, and biochemical measurements of mineral status were performed at diagnosis and at 6-month intervals throughout 24 months of chemotherapy., Eleven patients were not compl etely evaluated (4 deaths and 7 off study). Radiographic evidence of o steopenia was observed in 10, 64, and 76% at diagnosis, 12 and 24 mont hs, respectively. Fractures occurred in 39% of children during treatme nt. Reduction in bone mineral content (BMC), as measured by Z scores, occurred in 64% of patients and was most severe in those greater than 11 years of age at diagnosis, Reduction in BMC during the first 6 mont hs of therapy had a positive predictive value of 64%, while an increas e in BMC had a negative predictive value of 82% for subsequent fractur e. By 6 months of therapy, 31/37 (83%) children were hypomagnesemic, o f whom 16 (52%) were hypermagnesuric. Plasma osteocalcin was subnormal at diagnosis in 29/40 (73%) but increased to normal by 6 months of tr eatment. Vitamin D status was normal throughout, but plasma 1,25-dihyd roxyvitamin D remained subnormal in greater than 70% of children, Urin ary cross-link N-telopeptide was normal at diagnosis and became elevat ed in 58% of children by the end of therapy, Suppressed bone mineraliz ation is evident at diagnosis in a minority of children with ALL, Skel etal morbidity and a reduction in bone mineral mass become more preval ent during treatment, with increased bone resorption, perhaps mainly a s a consequence of corticosteroid administration.