[Primary hyperparathyroidism: value of "intact parathormone" assay (PTH 1-84)]

In a prospective study of 20 patients with primary hyperparathyroidism the diagnostic value of the intact parathormone assay was compared with that of intermediate fragment measurement and that of nephrogenic cyclic AMP determination. In the basal state, measuring the intact parathormone is the best way of separating hyperparathyroid patients form normal subjects. During calcium infusion tests, there is good concordance between changes in intact parathormone and in nephrogenic cyclic AMP. In addition, the intact parathormone assay enables a thorough study of the relationship between ionized calcaemia and parathyroid secretion to be performed and confirms the existence, in hyperparathyroid patients, of two types of secretory response to a rise in calcaemia. Being more reliable than the measurement of a C-terminal or intermediate fragment and easier to perform than nephrogenic cyclic AMP determination, the intact parathormone assay seems to be particularly suitable for the study of primary hyperparathyroidism.