Usefulness of a rapid immunometric assay for intraoperative parathyroid hormone measurements

Abstract

Intraoperative parathyroid hormone (IO-PTH) measurements have been proposed to improve operative success rates in primary, secondary and tertiary hyperparathyroidism (PHP, SHP and THP). Thirty-one patients requiring parathyroidectomy were evaluated retrospectively from June 2000 to January 2002. Sixteen had PHP, 7 SHP and 8 THP. Serum samples were taken at times 0 (before resection), 10, 20 and 30 min after resection of each abnormal parathyroid gland. Samples from 28 patients were frozen at -70ºC for subsequent tests, whereas samples from three patients were tested while surgery was being performed. IO-PTH was measured using the Elecsys immunochemiluminometric assay (Roche, Mannheim, Germany). The time necessary to perform the assay was 9 min. All samples had a second measurement taken by a conventional immunofluorimetric method. We considered as cured patients who presented normocalcemia in PHP and THP, and normal levels of PTH in SHP one month after surgery and who remained in this condition throughout the follow-up of 1 to 20 months. When rapid PTH assay was compared with a routine immunofluorimetric assay, excellent correlation was observed (r = 0.959, P < 0.0001). IO-PTH measurement showed a rapid average decline of 78.8% in PTH 10 min after adenoma resection in PHP and all patients were cured. SHP patients had an average IO-PTH decrease of 89% 30 min after total parathyroidectomy and cure was observed in 85.7%. THP showed an average IO-PTH decrease of 91.9%, and cure was obtained in 87.5% of patients. IO-PTH can be a useful tool that might improve the rate of successful treatment of PHP, SHP and THP.

Total Parathyroidectomy with Presternal Intramuscular Autotransplantation in Renal Patients: A Prospective Study of 66 Patients

“…The time required to carry out the assay is 9 minutes, and reference values are 10–70 pg/mL. Peripheral venous blood sample (4.0 mL) was obtained immediately after induction of anesthesia and 20 minutes after removal of all parathyroid glands [6, 7]. …”

A 10-Year Experience in Intraoperative Parathyroid Hormone Measurements for Primary Hyperparathyroidism: A Prospective Study of 91 Previous Unexplored Patients

“…Total time to perform the assay is 9 minutes; reference values are 10–65 pg/mL. To validate the rapid PTH assay, 170 samples from the study were also measured using a standard immunofluorimetric assay (IFMA) [8]. …”

From mild to severe primary hyperparathyroidism: the Brazilian experience

“…Of those patients with severe bone disease, 70% already showed an increased uptake in the initial images (10-15 minutes), compared with asymptomatic patients, in whom the increase in uptake was seen only in the later images, as expected (figure 4). When minimally invasive parathyroidectomy is the preferred operation, intraoperative PTH testing (IOPTH) is also available (21) to guide the surgeon regarding the removal of an abnormal parathyroid gland (50% fall from preoperative values, ten minutes after surgical excision of the parathyroid tumor). Both sestamibi scanning and IOPTH are less accurate in patients with multiple gland disease (35-50%).…”