title: The value to the surgeon of parathyroid hormone assays in primary hyperparathyroidism.
abstract: The role of various parathyroid hormone (PTH) radio-immunoassays in the diagnosis of primary hyperparathyroidism (PHP) is controversial. A series of 204 patients with surgically proven PHP was studied. Serum total calcium, serum ionized calcium, amino (N)-terminal PTH and carboxyl(C)-terminal PTH were assessed in relation to the volume and weight of adenomatous or hyperplastic parathyroid tissue excised at operation. N-terminal PTH was elevated above the normal laboratory range in only 24% of patients and correlated relatively poorly with the volume of abnormal parathyroid tissue (r = 0.20, P = 0.05). C-terminal PTH was elevated above the normal range in 91% of patients and had a strong correlation with the volume of abnormal parathyroid tissue (r = 0.63, P less than 0.001). The correlation coefficients between C-terminal PTH and serum total calcium and serum ionized calcium were both 0.63 (P less than 0.001). In contrast, there was no correlation between N-terminal PTH and serum total calcium (r = -0.02), serum ionized calcium (r = -0.04) or C-terminal PTH (r = 0.09). A combination of hypercalcaemia and elevated C-terminal PTH can be regarded as strong diagnostic evidence of PHP. Furthermore, the level of C-terminal PTH can assist the surgeon by approximately predicting the amount of adenomatous or hyperplastic parathyroid tissue that may be expected at surgical exploration.
authors.affiliation: Department of Surgery, University of Queensland, Brisbane, Australia.
authors.forename: I R
authors.initials: IR
authors.lastname: Gough
authors.forename: N W
authors.initials: NW
authors.lastname: Thompson
authors.forename: F E
authors.initials: FE
authors.lastname: Eckhauser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D002648:Child; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*
chemical_list: D010281:Parathyroid Hormone; D002118:Calcium