Assay of Parathyroid Hormone in Disturbances of Calcium Metabolism*

This is the authors' abstract. We don't add key points for this paper.

Summary: A radioimmunoassay using antiserum made to bovine parathyroid hormone (PTH) and purified bovine PTH labelled with I131has been applied to the measurement of PTH in human plasma. Evidence for the validity and precision of the assay is presented. PTH could not be detected in the plasma of normal subjects but was measured in most patients with primary hyperparathyroidism, and in some with hyper-calcaemia due to malignancy. In patients with secondary hyperparathyroidism, levels of PTH were higher than in primary hyperparathyroidism, and were elevated more frequently. The highest levels were found in patients with renal osteodystrophy. After renal transplantation PTH was not detectable with one exception. Infusions of calcium intravenously lowered the high levels of PTH in two patients with osteomalacia and in one with renal osteodystrophy; they had no effect on four patients with primary hyperparathyroidism. Serial studies over many months were carried out in two patients with renal disease. One showed some fall in PTH after dialysis commenced and no PTH could be measured after successful renal transplantation. The other showed a fall in PTH levels during treatment with vitamin D which caused radiological healing of osteodystrophy. Immunoreactive PTH could not be detected in urine.