Evidence of healing of secondary hyperparathyroidism in chronically hemodialyzed uremic patients treated with long-term intravenous calcitriol

摘要

Evidence of healing of secondary hyperparathyroidism in chronically hemodialyzed uremic patients treated with long-term intravenous calcitriol. The aim of this study was to assess the effect of a long-term course of high-dose i.v. pulses of calcitriol (CLT) on hyperparathyroid bone disease (HBD) and functional mass of parathyroid glands of chronically hemodialyzed uremic (CHU) patients. We prospectively studied nine CHU patients treated with CLT, 30 ng/kg/body wt, i.v., thrice weekly over a period of eight months. Plasma concentrations of intact parathyroid hormone (iPTH), bone GLA protein (bGLA) and bone isoenzyme of alkaline phosphatase (biALP) were sampled throughout. Transiliac bone biopsies were made before and after the start of CLT therapy. Double scanning scintigraphy of the neck with 201Tl-99Tc was made before, during and eight months after the start of the treatment. All patients but one, who later responded to higher than planned CLT doses, had significant decreases of plasma iPTH (F = 76; P 201Tl uptake before therapy scored 7.8 (range 4 to 9.2) arbitrary visual units and decreased significantly (P < 0.001; Wilcoxon test) to 0.4 (0 to 8.25) after eight months of CLT treatment, suggesting significant decreases of the mass of the parathyroid glands. Thus, this study demonstrates that long-term therapy with high-dose i.v. pulses of CLT in CHU with proven HBD is able to consistently decrease their circulating iPTH to levels comparable with those of subjects with mild or no HBD and also to decrease the functional mass of their parathyroid glands. Further studies will ascertain what dose of CLT is required to maintain this state of euparathyroidism once the hyperparathyroidism has been reversed.