Horwitz M J, Bilezikian J P
Columbia University, New York, New York.
Curr Opin Rheumatol. 1994 May;6(3):321-8. doi: 10.1097/00002281-199405000-00014.
Hypercalcemia is most commonly associated with primary hyperparathyroidism and malignancy due to parathyroid hormone-related protein (PTHrP). Primary hyperparathyroidism is characterized by excessive secretion of parathyroid hormone in association with hypercalcemia. The modern presentation of primary hyperparathyroidism is as an asymptomatic disorder. Diagnostic tools such as bone mineral densitometry, bone histomorphometry, and the measurement of markers of bone turnover, as well as other clinical assessments, have all led to the development of guidelines to help direct decisions for parathyroid surgery or for medical management. Hypercalcemia of malignancy is often distinguishable from primary hyperparathyroidism by the presence of an obvious tumor. Primary hyperparathyroidism is excluded by the immunoradiometric assay for parathyroid hormone, which is suppressed. A number of clinical characteristics of hypercalcemia of malignancy can be explained on the basis of the tumor product, PTHrP, which directly causes hypercalcemia in many cases. Assays for PTHrP show elevated levels in patients in whom hypercalcemia is associated with the classic syndrome. Recent recognition that PTHrP is found ubiquitously in virtually all normal tissues and that it is possibly involved in a number of normal physiologic processes, apart from its pathologic role, provides an exciting basis for future research.
高钙血症最常与原发性甲状旁腺功能亢进症以及由甲状旁腺激素相关蛋白（PTHrP）引起的恶性肿瘤相关。原发性甲状旁腺功能亢进症的特征是甲状旁腺激素分泌过多并伴有高钙血症。原发性甲状旁腺功能亢进症的现代表现为一种无症状性疾病。诸如骨密度测定、骨组织形态计量学以及骨转换标志物的测量等诊断工具，以及其他临床评估，都促使了相关指南的制定，以帮助指导甲状旁腺手术或药物治疗的决策。恶性肿瘤引起的高钙血症通常可通过明显肿瘤的存在与原发性甲状旁腺功能亢进症相区分。通过免疫放射测定法检测甲状旁腺激素，若其被抑制，则可排除原发性甲状旁腺功能亢进症。恶性肿瘤引起的高钙血症的许多临床特征可以基于肿瘤产物PTHrP来解释，在许多情况下，PTHrP直接导致高钙血症。对PTHrP的检测显示，在高钙血症与典型综合征相关的患者中其水平升高。最近认识到PTHrP几乎在所有正常组织中普遍存在，并且除了其病理作用外，它可能还参与许多正常生理过程，这为未来的研究提供了令人兴奋的基础。
