Comparison of Two Third-Generation Parathyroid Hormone Assays

[摘要] Parathyroid hormone (PTH) is an 84-amino acid peptide secreted by the parathyroid glands that is important in regulating the extracellular calcium concentration in the body. Because this hormone is rapidly metabolized into fragments, its measurement has always been problematic (1).During the last few years, it has been shown that the current intact PTH, or second-generation, assays will cross-react with a large C-terminal fragment, PTH (7–84), which lacks the six N-terminal amino acids (2)(3). Because of the lack of specificity in these second-generation systems, falsely increased PTH values have been observed (3). New third-generation PTH tests do not detect PTH (7–84) and therefore provide a more accurate measurement of bioactive PTH.The specificity of third-generation parathyroid assays is important, particularly when evaluating patients with end stage renal disease. In these patients, the clearance of C-terminal PTH fragments is dramatically impaired, leading to increased concentrations of …

[学科分类] 过敏症与临床免疫学