Evaluation of the intact hormone assay in the study of parathyroid autograft function.

Parathyroid autograft function was studied using radioimmunoassay measuring intact parathormone (iPTH) and C-terminal PTH (C-PTH). Blood samples were taken from graft and non-graft arms pre- and post-dialysis. The intact assay showed an appreciably greater differential gradient pre- and post-dialysis than the C-terminal assay. We conclude that particularly in patients with chronic renal failure the intact assay is of greater value in monitoring graft function than the commonly used C-terminal assay. It may also be of value in distinguishing between graft overactivity and ectopic cervical parathyroid tissue in cases of recurrent hyperparathyroidism following apparently total parathyroidectomy and autotransplantation.