Parathyroid function in uremic children during periods of renal insufficiency, hemodialysis, and transplantation.

Function of the parathyroid gland was evaluated in children with renal insufficiency prior to and after imitation of hemodialysis, and again following renal transplantation. Serum levels of immunoreactive parathyroid hormone responded appropriately to increases or decreases of serum calcium concentrations in the three groups. Functional and histologic studies in the children with renal insufficiency demonstrated the cause of their elevated circulating levels of iPTH to be diffuse parathyroid hyperplasia. During hemodialysis, the serum concentration of calcium rose and that of iPTH decreased, when the calcium gradient between the dialysate and the blood favored movement of calcium into the body. During treatment with prednisolone (20 mg/kg intravenously) for reversal of renal transplant rejection, the serum concentration of calcium decreased and that of iPTH increased. These observations suggest that autonomy of the parathyroid gland rarely occurs in children with renal insufficiency, and that hemodialysis using a dialysate with a high concentration of calcium might assist in retarding the progression of renal osteodystrophy. Furthermore, if hyperparathyroidism contributes in part to growth failure in children with chronic renal disease, steroid-induced changes in cirulating iPTH following renal transplantation may inhibit growth.