Renal bone disease in pediatric and young adult patients on hemodialysis in a children's hospital.

Renal bone disease has been well defined in adult patients receiving chronic dialysis and in children on peritoneal dialysis/continuous ambulatory peritoneal dialysis. However, little is known about the histologic features in patients undergoing chronic hemodialysis in a children's hospital center. Twenty one patients, aged 17.5 +/- 1.5 yr, on hemodialysis for 35 +/- 6 months underwent iliac crest bone biopsies and deferoxamine infusion tests. Nineteen of 21 patients were receiving oral calcitriol. The 21 patients were classified by histomorphometry as follows: osteitis fibrosa, 5; mild hyperparathyroidism, 3; normal histology, 3; aplastic, 6; and mixed lesions, 4. Four of 21 patients were surface positive for aluminum, and seven other patients stained positive for iron in bone. Serum parathyroid hormone (PTH) levels correlated directly with the bone formation rate (r = 0.84) and with eroded bone perimeter (r = 0.67). Eight of the nine patients with serum PTH levels above 125 pg/mL had marrow fibrosis. All patients with serum calcium levels < 10.0 mg/dL and serum PTH levels > 125 pg/mL had either osteitis fibrosa or mixed bone lesions--a group of patients that might benefit from aggressive vitamin D therapy. In contrast, an examination of patients with serum calcium levels > 10.0 mg/dL and serum PTH levels < 65 pg/mL correctly identified three out of three patients with aluminum-related bone disease. These findings suggest that measurements of serum intact PTH levels by the immunoradiometric assay method may be valuable in distinguishing high-turnover lesions from normal or low-turnover skeletal lesions in this population.