Intraoperative and postoperative PTH secretion mode in patients with hyperparathyroidism.

The development of a sensitive 2-site immunoradiometric assay which detects only intact human PTH (1-84) enabled us to study kinetics of PTH secretion intraoperatively. In a prospective study, we assessed the PTH (1-84) secretion mode intraoperatively in 54 patients with adenomas, in 14 patients with tertiary hyperparathyroidism (HPT), and in 2 patients with persistent HPT. After the removal of adenomatous or hyperplastic tissue, a significant drop of PTH (1-84) concentration was seen. A 50% decrease in the basal PTH concentration was reached significantly earlier for adenomas than for hyperplasias. In the 2 cases with unrevealing neck exploration, the PTH (1-84) concentrations showed hardly any change. The recovery of PTH secretion was studied in 23 patients, 20 of whom had a single adenoma; in 2 cases, a hyperplasia was present and 1 patient showed the clinical signs of a toxic HPT. We found an initial drop of PTH concentration 4 hours postoperatively below the limit of detection and a rapid recovery within 24 hours postoperatively. The PTH concentration values were well within the normal range after 48-72 hours.