[Immunohistochemical study of parathyroid hormone related protein (PTHrP) in renal cell carcinoma]

Parathyroid hormone related protein (PTHrP) is the main factor of humoral hypercalcemia of malignancy (HHM). Using anti-PTHrP monoclonal antibody 4B3, we investigated the immunohistochemical localization of PTHrP in human normal renal tissues and renal cell carcinomas. Among normal renal tissues, distal tubules and collecting ducts showed positive immunostaining. Among 36 cases of renal cell carcinoma, PTHrP was detected in 30 cases (83%), and there was no significant correlation between the degree of the immunostaining and the serum calcium levels of the patients. As for the histopathological types of the renal cell carcinomas, granular cell subtypes tended to be more strongly positive than clear cell ones. In conclusion, it was not uncommon that PTHrP was commonly presented by renal cell carcinoma, and HHM occurred when the PTHrP transgressed the homeostatic mechanisms.