To the Editor.
—Johnson1 described three patients undergoing regular hemodialysis (RHD) who experienced unexplained hypercalcemia; serum calcium levels remained unchanged after parathyroidectomy. We observed two similar patients whose hypercalcemia was controlled with small doses of prednisolone.Regular hemodialysis treatment was given three times a week with 7.5 mg/dL of dialysate calcium. The following measurements were performed: radioimmunoassay (RIA) of aminoterminal immunoreactive parathyroid hormone2 (iPTH) (normal, up to 15 μLEq of parathyroid extract per milliliter), radiochemical assay of 25-hydroxyvitamin D3 (25-[OH]D3) (normal, 12 to 30 ng/mL), RIA of 1,25-dihydroxyvitamin D3 (1,25-[OH]2D3) (normal, 20 to 65 pg/mL), RIA of cortisol (normal, 10 to 22 μg/dL), and whole-body retention (WBR) of ingested 47Ca (normal, 25% to 40%).3 An iliac crest biopsy was done with a 3-mm diameter trephine.
Report of Cases.—Case 1.
—As seen in the Figure, a 25-year-old woman with