|
|
||||||||
Clinical Chemistry, Vol 38, 2129-2135, Copyright © 1992 by American Association for Clinical Chemistry
R Lepage, S Whittom, S Bertrand, G Bahsali and P D'Amour
Andre-Viallet Clinical Research Center, Hopital Saint-Luc, Universite de Montreal, Canada.
We compared the clinical performance of assays of intact, C-terminal, and midmolecule parathyrin (PTH), when used with either a dynamic reference interval (based on the range of serum PTH concentrations observed in 35 healthy individuals during acute modifications of their blood calcium concentrations) or a gaussian (mean +/- 2 SD) interval derived from normocalcemic individuals. Dynamic intervals were substantially different from gaussian intervals, with half of the area delimited by the gaussian limits for calcium and intact PTH concentrations, and one-third for both C-terminal and mid-PTH assays, being outside the range of values observed during the dynamic tests. Use of the dynamic intervals increased the average clinical sensitivity of the three assays for detecting primary hyper- and hypoparathyroidism from 68% to 97% (and up to 100% for the intact and C-PTH assays). Even though only the intact PTH assay allowed complete separation between primary hyperparathyroid and nonparathyroidal hypercalcemic patients, the average proportion of patients correctly classified in this latter category was increased from 40% to 70% by the use of dynamic intervals. We conclude that gaussian reference intervals are largely responsible for the poor clinical sensitivity of many types of PTH immunoassays and that they should be replaced by dynamic reference intervals when evaluating calcemic disorders.
The following articles in journals at HighWire Press have cited this article:
![]() |
I. Titon, A. Cailleux-Bounacer, J. P. Basuyau, H. Lefebvre, A. Savoure, and J. M. Kuhn Evaluation of a standardized short-time calcium suppression test in healthy subjects: interest for the diagnosis of primary hyperparathyroidism Eur. J. Endocrinol., September 1, 2007; 157(3): 351 - 357. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. M. Henrich, A. D. Rogol, P. D'Amour, M. A. Levine, J. B. Hanks, and D. E. Bruns Persistent Hypercalcemia After Parathyroidectomy in an Adolescent and Effect of Treatment With Cinacalcet HCl Clin. Chem., December 1, 2006; 52(12): 2286 - 2293. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Lepage, G. Légaré, C. Racicot, J.-H. Brossard, R. Lapointe, M. Dagenais, and P. DAmour Hypocalcemia Induced during Major and Minor Abdominal Surgery in Humans J. Clin. Endocrinol. Metab., August 1, 1999; 84(8): 2654 - 2658. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |