Clinical impact of two different intraoperative parathyroid hormone assays in primary and renal hyperparathyroidism

Background: Intraoperative parathyroid hormone (PTH) monitoring predicts Successful surgery for primary hyperparathyroidism (pHPT). In renal intraoperative PTH assays can define whether parathyroid resection is adequate. Methods: Intraoperative PTH was measured with two different immunometric assays (Immulite Turbo DPC and ADVIA Centaur assay) in 91 patients undergoing parathyroidectomy for primary (n=57) and renal (n = 34) hyperparathyroidism. PTH was monitored preoperatively. 10, 20, and 30 min after parathyroicicctomy and 24 h postoperatively. Results: Ten minutes after parathyroidectomy, intraoperative PTH dropped into the normal range (< 7.6 pmol/1) in 84%, of patients with pHPT and tertiary HPT as measured with the ADVIA Centaur assay (PTH-A). compared with 100% of the samples measured with the Immulite Turbo DPC assay (PTH-I: P=0.0082). Twenty minutes after parathyroidectomy for secondary HPT, intraoperative PTH decreased to the normal range in 100%, measured with PTH-I compared with 50%, measured with PTH-A (P=0.009). Then, 24 h postoperatively. PTH-I and PTH-A levels were within the normal range in all of the successfully treated patients. Both assays correctly identified six patients with persistent disease and another patient with a double adenoma in pHPT. Conclusions: In patients undergoing parathyroidectomy For primary or renal HPT. PTH levels decreasing to the normal range indicated successful surgery in all of the patients as measured with the PTH-I assay. Comparing the two assays, PTH-I was able to quantify the intraoperative PTH decay more quickly than PTH-A.