The clinical significance of hyperparathyroidism after renal transplantation.

Hypercalcemia after renal transplantation (post-TH) was detected in 32 (17%) of 188 long-term survivors. The mean time from renal transplantation (RT) till onset of post-TH was 60 (3-210) days. In 19 patients the hypercalcemia was mild and transient, resolving spontaneously within 1-65 (mean 18) months. In 6 patients s-calcium normalized simultaneously with a rejection episode treated with increased prednisone doses. The hypercalcemia was more pronounced (permanent) in 7 patients, and terminated by subtotal parathyroidectomy in 5 and still persists in 2. The hypercalcemia was asymptomatic and did not affect the function of the graft except in one patient who developed calculi in the graft and a fall in graft function, all of which disappeared after subtotal parathyroidectomy. The frequency of aseptic bone necrosis and spontaneous fractures was the same in recipients with and without post-TH. Serum parathyroid hormone (s-PTH) was significantly higher in patients with permanent than in those with transient post-TH, who had the same slight elevation of s-PTH as the normocalcemic recipients. A permanent course of post-TH can be expected when both s-calcium and s-PTH are persistingly elevated.