Multisite immunochemiluminometric assay for simultaneously measuring whole-molecule and amino-terminal fragments of human parathyrin.
The immunochemiluminometric assay described uses immobilized anti-human parathyrin (parathyroid hormone, hPTH)(1-44) and anti-hPTH(44-68) antisera and acridinium ester-labeled anti-hPTH(1-34) to simultaneously measure both intact hPTH and its amino-terminal fragments. Results by the assay correlate well with those by a cAMP-based bioassay and the Nichols Allegro immunoradiometric assay. The minimal detection limit is 0.08 pmol/L. The normal range is 1.0-5.0 pmol/L, and values are higher in older women. About 90% of study patients with surgically proven parathyroid adenomas had above-normal preoperative PTH concentrations, whereas patients with hypercalcemia of malignancy had normal or suppressed values. This assay was designed to detect both intact PTH and amino-terminal PTH fragments; however, chromatographic fractionation of pools of primary and secondary hyperparathyroid plasma showed virtually no amino-terminal fragment activity. Nonetheless, the design is important because the absence of carboxyl-terminal binding sites prevents interference by carboxyl-terminal fragments and because bioactive amino-terminal fragments will react in the assay if they are present in the patients' sera or if they are produced by in vitro proteolysis of intact PTH.
Klee
G G
GG
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905.
Preissner
C M
CM
Schryver
P G
PG
Taylor
R L
RL
Kao
P C
PC
D002845:Chromatography; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood; D007118:Immunoassay / Q000379:methods* / Q000706:statistics & numerical data; D007676:Kidney Failure, Chronic / Q000097:blood; D008163:Luminescent Measurements; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012016:Reference Values
D010281:Parathyroid Hormone; D010446:Peptide Fragments