BONE CHANGES, MINERAL HOMEOSTASIS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA

Summary . In childhood acute lymphobastic leukemia [ALL] skeletal changes are frequently found at the time of diagnosis and treatment, including: metafyseal lines, periostal reaction, lysis, sclerosis, osteoporosis and occasionally spontaneous fracture. Different factors, including the disease itself, may be responsible for a defective bone homeostasis in these patients. Solubil products of malignant cells like the osteoclast activated factor (OAF), lymphotoxin, IL-1, tumor necrosis factor (TNF) and other cytokines may cause bone demineralization. Citotoxic drugs, like methotrexate corticosteroids and radiotherapy, have been incriminated as elements of the treatment that may cause bone changes. Prospective analysis of the bone and mineral status in 108 children with ALL was performed. Markers of bone turnover (Ca, P, Mg homeostasis in urine and serum, osteocalcin and PTH) were measured before the initiation of the therapy, on the 28 th day of therapy and six months after it. The bone mass was determined on the x-ray and densitometry was measured. At the time of diagnosis musculoskeletal pain was present in 37.5% of patients. It was common in children with better prognosis (CD 10 immunophenotype, low leucocytes count, L1-morphology). We found hypocalcemia, hypomagnesaemia and calciuria. PTH and osteocalcin decreased at the time of diagnosis 80% children with ALL had decrease bone mineral density.