Common expression of parathyroid hormone-related protein and no correlation of calcium level in renal cell carcinomas.

Abstract

Parathyroid hormone-related protein (PTHrP) is the predominant cause of humoral hypercalcemia of malignancy (HHM). Using a PTHrP-specific monoclonal antibody (MoAb), 4B3, the authors investigated the immunohistochemical localization of PTHrP in formalin-fixed and paraffin-embedded sections of normal human kidney tissues and tissues from 42 human renal cell carcinomas obtained at operation or autopsy. In normal renal tissues, the distal tubules and collecting ducts showed positive immunostaining. PTHrP was detected in 40 of 42 renal cell carcinoma tissues (95%). Histopathologically, the granular cell subtypes of renal cell carcinomas tended to be more strongly positive than the clear cell subtypes. There was no significant correlation between the level of immunostaining and each patient's serum calcium level. PTHrP was commonly observed in renal cell carcinomas, and no significant correlation was seen between the intensity of PTHrP staining and the serum calcium level.