Parathyroid hormone and parathyroid hormone related protein assays in the investigation of hypercalcemic patients in hospital in a Chinese population

Abstract

There are many pathological causes and potential mechanisms for hypercalcemia. We measured intact parathyroid hormone (PTH) and parathyroid hormone related protein (PTHrP) in the hypercalcemic in-patients and attempted to evaluate the roles of PTH and PTHrP in hypercalcemia due to malignancy. We performed a prospective study of 178 patients with corrected serum calcium concentrations greater than 2.74 mmol/l in a hospital over a 3-year period. We measured calcium and albumin using a Hitachi 747 autoanalyzer, and we measured PTH and PTHrP by two-site immunoradiometric assays (IRMA). Hypercalcemia was attributed to malignancy alone in 93 patients (52.3%), primary hyperparathyroidism (HPT) alone in 28 patients (15.7%), uremia with hemodialysis in 23 patients (12.9%), unknown in 16 patients (9%), primary HPT coexisting with malignancy in 7 patients (3.9%) and other rare causes (6.2%). Plasma PTHrP levels were elevated in 71/93 (76.3%) patients with hypercalcemia due to malignancy, but the elevated PTHrP percentage differed for each kind of tumor. PTHrP levels were elevated in 100% of patients with squamous carcinomas (CA) in the lung, esophagus, skin, cholangiocarcinoma of liver, and breast CA. The positive bony metastatic rate was 44.1% (41/93). There was no correlation between high PTHrP and bony metastasis. There was a good correlation between the corrected serum calcium and PTHrP levels (r = 0.476, p < 0.001), but no correlation between survival time and serum calcium level or PTHrP level. There was no significant difference in life expectancy after cancer diagnosis between the high PTHrP group and normal PTHrP group, and there was no significant difference in life expectancy after the first occurrence of hypercalcemia between the two groups. Measurement of both PTH and PTHrP levels led to a change in the initial diagnosis in 7 patients. In routine practice, measurement of serum PTH alone is not enough. This study suggests that the appropriate combination of PTH and PTHrP assays results in a more accurate diagnosis of the hypercalcemic causes. In addition, especially high PTHrP levels should be screened for malignancy. However, the prognosis in cancer patients after hypercalcemia with high PTHrP group, as compared to those with the normal PTHrP group is not significantly different.

The Causes of Hypercalcemia in Okinawan Patients: AnInternational Comparison

“…With an unusually high association of hypercalcemia, about 40% of patients with ATL are known to eventually develop hypercalcemia (15,16). On the other hand, breast carcinoma was relatively uncommon in our series as well as in other Asian studies (9,10), in contrast to Western series with this carcinoma typically accounting for more than 20% (3,6,(17)(18)(19). The low prevalence of hypercalcemia due to breast carcinoma may reflect the low incidence of this tumor in Asia (9), while the high prevalence of hypercalcemia due to ATL may be due to the high incidence of this hematologic malignancy in Okinawa and southern areas of Japan (20)(21)(22)(23).…”

“…Two reports from Taiwan also noted this point (10,30 We detected no cases of granulomatous diseases. Sarcoidosis was relatively rare but its incidence has recently increased in the northern part of Japan (31).…”

“…We reviewed adult patients (16 years (10). (11)(12)(13)(14) and to determine specific and effective anti-tumor therapy (6).…”

Association of primary hyperparathyroidism and humoral hypercalcemia of malignancy in a patient with clear cell renal carcinoma

“…Besides the Chinese study mentioned before (10), in the present research there were only 3 references of this association: a 65 year-old woman with a clear cells endometrial cancer (11); a 47 year-old man with carcinoma in the external manubrium (12); and a patient with multiple endocrine neoplasia type 1 and a neuroendocrine pancreas tumor (13).…”

“…Interestingly a Chinese study evaluated, PTH and PTHrP in 178 patients hospitalized with hypercalcemia, 93 patients had hypercalcemia of malignancy and in seven an association with primary hyperparathyroidism was present, suggesting that. PTH and PTHrP should be measured routinely (10).…”