Resolution of hyperparathyroidism associated with immunosuppressive therapy.

A patient maintained on continuous ambulatory peritoneal dialysis with severe hyperparathyroidism received a cadaver renal transplant. In the weeks following the transplant there was dramatic biochemical resolution of parathyroid hyperfunction associated with intensive immunosuppressive therapy, but without sustained return of function of the transplant kidney. Tertiary hyperparathyroidism often resolves slowly with successful renal transplantation. There are no previous reports of spontaneous resolution of hyperparathyroidism as demonstrated by this patient. Possible mechanisms, including the role of cytolytic antirejection therapy, are discussed.