Evolution of secondary hyperparathyroidism during oral calcitriol therapy in pediatric renal osteodystrophy

The course of renal bone disease in children undergoing regular peritoneal dialysis has not been fully evaluated. In particular, only limited data are available regarding the therapeutic efficacy of oral calcitriol in this group of patients. Thus, bone biopsies were done before and after 12 months of treatment with daily doses of oral calcitriol in 33 pediatric patients undergoing CAPD or CCPD. In 10/13 patients with initial biopsy findings of osteitis fibrosa, skeletal lesions either failed to improve or worsened after 12 months of treatment; in contrast, 4/6 patients with mild lesions of secondary hyperparathyroidism demonstrated histologic improvement. Serum PTH levels, determined using a mid-region assay, were higher in patients who failed to improve during oral calcitriol therapy, and values increased progressively in this group. Serum PTH levels were unchanged in those who improved. These data indicate that secondary hyperparathyroidism remains a substantial clinical problem in pediatric patients receiving regular peritoneal dialysis; treatment with daily doses of oral calcitriol is only partially effective for the control of this disorder. Further assessment of alternatives to daily oral calcitriol administration such as pulse oral or intermittent intraperitoneal calcitriol therapy is warranted in order to provide more effective approaches to the management of secondary hyperparathyroidism in pediatric dialysis patients.