PERSISTENT HYPERCALCEMIA AFTER SUCCESSFUL RENAL-TRANSPLANTATION

Persistent hypercalcemia and significant secondary hyperparathyroidism occurred in 26.6% (16/60) of renal transplant recipients followed for 1-7 yr. Renal function remained stable in 14 of the 16 patients, indicating that mild hypercalcemia does not constitute a threat to the function of the renal graft. However, renal function should be followed carefully and frequently in renal transplant recipients who develop hypercalcemia. If renal function deteriorates in the absence of evidence for rejection, subtotal parathyroidectomy should be considered. The state of persistent hyperparathyroidism in renal transplant recipients may also be responsible for the increased incidence of aseptic necrosis of the femoral head observed in the hypercalcemic patients. An argument against such a postulate is the rarity of aseptic necrosis of the femoral head in patients with primary hyperparathyroidism. None of the patients with aseptic necrosis underwent subtotal parathyroidectomy; it is not possible to predict the effect of this procedure on this bone abnormality. In renal transplant recipients with evidence of persistent secondary hyperparathyroidism, subtotal parathyroidectomy should be considered. Although the patients showed no deterioration of renal function, subtotal parathyroidectomy may prevent deleterious effects of long-term hypercalcemia on graft function.