[Diagnosis of primary hyperparathyroidism and differential diagnosis of hypercalcemia]

The leading symptom in patients with primary hyperparathyroidism (pHPT) is renal lithiasis and not osteopathy. The most abundant circulating forms of parathyroid hormone in pHPT represent COOH-terminal fragments with molecular weights ranging from 4000 to 7000. Radioimmunnoassays making use of antibodies directed to CCOH-terminal parts of human parathyroid hormone are therefore suitable in distinguishing patients with pHPT from control subjects and patients with hypercalcemia unrelated to hyperfunctioning parathyroid glands.