RENAL BONE-DISEASE IN PEDIATRIC AND YOUNG-ADULT PATIENTS ON HEMODIALYSIS IN A CHILDRENS-HOSPITAL

Renal bone disease has been well defined in adult patients receiving c hronic dialysis and in children on peritoneal dialysis/continuous ambu latory peritoneal dialysis. However, little is known about the histolo gic features in patients undergoing chronic hemodialysis in a children 's hospital center. Twenty one patients, aged 17.5 +/- 1.5 yr, on hemo dialysis for 35 +/- 6 months underwent iliac crest bone biopsies and d eferoxamine infusion tests. Nineteen of 21 patients were receiving ora l calcitriol. The 21 patients were classified by histomorphometry as f ollows: osteitis fibrosa, 5; mild hyperparathyroidism, 3; normal histo logy, 3; aplastic, 6; and mixed lesions, 4. Four of 21 patients were s urface positive for aluminum, and seven other patients stained positiv e 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 pati ents with serum calcium levels >10. mg/dL and serum PTH levels <65 pg/ mL correctly identified three out of three patients with aluminum-rela ted bone disease. These findings suggest that measurements of serum in tact PTH levels by the immunoradiometric assay method may be valuable in distinguishing high-turnover lesions from normal or low-turnover sk eletal lesions in this population.