[Evaluation of new markers of bone metabolism in renal osteodystrophy in children].

Serum intact parathormone (PTH 1.84) and osteocalcin levels were evaluated as early markers for secondary hyperparathyroidism in a group of pediatric patient treated with chronic hemodialysis. PTH 1.84 levels which were more closely related with alkaline phosphatase levels than PTH 53.84 levels, allowed to identify a group of children without biologic or roentgenographic evidence of hyperparathyroidism and with a normal residual hormone level. PTH 1.84 levels seem to be a reliable indicator of parathormone secretion than conventional assays and may be used as a routine test for monitoring children under chronic hemodialysis. Conversely, the plasma osteocalcin level measured by radioimmunoassay was increased in all studied patients regardless of parathyroid status and seemed to be of little value for monitoring renal osteodystrophia. Lumbar vertebral plate bone density studies disclosed abnormalities of bone mineralization in half the children with renal failure. Dialyzed or non dialyzed. Patients with decreased bone mineralization presented, in most of cases, a history of previous steroid treatment. A group of children with very severe renal failure had increased bone mineralization. The interpretation of this abnormality remains to be determined.