TY - JOUR
T1 - Bioassay of parathyrin
T2 - Analytical characteristics and clinical performance in patients with hypercalcemia
AU - Klee, G. G.
AU - Preissner, C. M.
AU - Schloegel, I. W.
AU - Kao, P. C.
PY - 1988
Y1 - 1988
N2 - This new bioassay for parathyrin (PTH) in plasma (bio-PTH) combines immunoextraction on affinity columns [goat anti-hPTH (1-44) conjugated to Sepharose 4B] and a receptor assay involving an osteosarcoma cell line. The mean extraction efficacy ranges from 87% (as determined with immunopurified 125I-labeled PTH) to 62% for hPTH bioactivity. The assay is standardized with synthetic hPTH (1-84) and can detect as little as 0.9 pmol/L of PTH in 2 mL of plasma. In 100 healthy adults, the 95% reference interval for bio-PTH was <0.9 to 6.1 pmol/L (median, 2.0 pmol/L) In 185 patients with surgically confirmed hyperparathyroidism, bio-PTH concentrations ranged from 1.0 to >120 pmol/L (median 12.9 pmol/L); 80% of values were >6.1 pmol/L. In 50 patients with both preoperative and postoperative determinations, the mean (± SD) concentrations of calcium in serum were 113 ± 10 and 89 ±6 mg/L, respectively; the median bio-PTH concentrations were 13.6 and 2.0 pmol/L, respectively. In 22 patients with nonparathyroid-mediated hypercalcemia, the concentration of bio-PTH ranged from <0.9 to 5.3 pmol/L (median, 1.8 pmol/L). This bio-PTH assay is slightly less sensitive than our GP235 immunoreactive PTH (iPTH) immunoassay for detecting hyperparathyroidism (Clin Chem 1982;28:69-74); however, the bioassay is more specific and detected some cases missed by the iPTH assay. Overall, 95% of the hyperparathyroid patients had an increased test result for either the bio-PTH or the iPTH assay.
AB - This new bioassay for parathyrin (PTH) in plasma (bio-PTH) combines immunoextraction on affinity columns [goat anti-hPTH (1-44) conjugated to Sepharose 4B] and a receptor assay involving an osteosarcoma cell line. The mean extraction efficacy ranges from 87% (as determined with immunopurified 125I-labeled PTH) to 62% for hPTH bioactivity. The assay is standardized with synthetic hPTH (1-84) and can detect as little as 0.9 pmol/L of PTH in 2 mL of plasma. In 100 healthy adults, the 95% reference interval for bio-PTH was <0.9 to 6.1 pmol/L (median, 2.0 pmol/L) In 185 patients with surgically confirmed hyperparathyroidism, bio-PTH concentrations ranged from 1.0 to >120 pmol/L (median 12.9 pmol/L); 80% of values were >6.1 pmol/L. In 50 patients with both preoperative and postoperative determinations, the mean (± SD) concentrations of calcium in serum were 113 ± 10 and 89 ±6 mg/L, respectively; the median bio-PTH concentrations were 13.6 and 2.0 pmol/L, respectively. In 22 patients with nonparathyroid-mediated hypercalcemia, the concentration of bio-PTH ranged from <0.9 to 5.3 pmol/L (median, 1.8 pmol/L). This bio-PTH assay is slightly less sensitive than our GP235 immunoreactive PTH (iPTH) immunoassay for detecting hyperparathyroidism (Clin Chem 1982;28:69-74); however, the bioassay is more specific and detected some cases missed by the iPTH assay. Overall, 95% of the hyperparathyroid patients had an increased test result for either the bio-PTH or the iPTH assay.
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U2 - 10.1093/clinchem/34.3.482
DO - 10.1093/clinchem/34.3.482
M3 - Article
C2 - 2832099
AN - SCOPUS:0023948194
SN - 0009-9147
VL - 34
SP - 482
EP - 488
JO - Clinical chemistry
JF - Clinical chemistry
IS - 3
ER -