Parathyroid hormone assay in primary hyperparathyroidism: experiences with a radioimmunoassay based on commercially available reagents.

A radioimmunoassay is described for parathyroid hormone in human serum, in which commercially available reagents are used almost exclusively. This assay can be done by any laboratory with experience in radloimmunoassay. Thirty-two of thirty-three patients with surgically proven primary hyperparathyroidism had detectable concentrations of parathyroid hormone in their serum, and concentrations of the hormone exceeded the normal range in 24 of them. Significant positive correlations were found between pre-operative serum calcium, pre-operative serum parathyroid hormone, and the weight of parathyroid tissue removed at operation. These three parameters were also significantly correlated with severity of the skeletal changes as assessed by semiquantitative histological methods.