Clinical Usefulness of the (Chloride-90)/Phosphate Ratio for Distinguishing Primary Hyperparathyroidism from Hypercalcemia due to Other Causes

抄録

In order to obtain a good separation line between patients with primary hyperparathyroidism (1°HPT) and those with non-parathyroidal hypercalcemia (NPHC), serum chloride (Cl) and phosphate (P) concentrations were analyzed. Ninety-nine per cent of the patients with 1°HPT had a Cl/P ratio greater than or equal to 33, but 29% of patients with NPHC were also included in this range. When the (Cl-90)/P ratio was used to separate into two groups, 98% of the patients with 1°HPT had a ratio greater than or equal to 5.0, and 94% of the patients with NPHC had a ratio less than 5.0. From these results, while high sensitivity was achieved both with the Cl/P and (Cl-90)/P ratios, the (Cl-90)/P ratio provided higher specificity. Therefore we concluded that the (Cl-90)/P ratio was excellent in distinguishing 1°HPT from other types of hypercalcemia.