Comparison of Two Third-Generation Parathyroid Hormone Assays

Abstract
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.