Development and validation of an immunoradiometric assay of parathyrin-related protein in unextracted plasma.

摘要: This two-site immunoradiometric assay for human parathyrin-related protein 1-86 (PTHRP1-86) in plasma uses a mouse monoclonal antibody to PTHRP1-34 coupled cellulose particles immunoextraction of N-terminal immunoreactivity, and rabbit antiserum PTHRP37-67 that is indirectly labeled with 125I-labeled quantifying the bound analyte. The detection limit 0.23 pmol/L, corresponding 0.4 pg (0.04 fmol) per tube, sample volume 200 microL. Recovery PTHRP1-86 added serum essentially quantitative, within- between-batch precision 4.4% 11.1%, respectively. PTH1-84, PTHRP18-34, PTHRP9-34, PTHRP1-34, do not cross-react at concentrations up 2 nmol/L. Plasma were below or close normal subjects patients primary hyperparathyroidism, hypoparathyroidism, chronic renal failure, normocalcemic malignancy. In 37 hypercalcemic various malignancies, we found detectable 35 (95%, mean 7.4 range 0.46-24.7). data support proposed humoral role PTHRP cancer-associated hypercalcemia suggest has clinical utility differential diagnosis hypercalcemia.