Differential gene expression by oxyphil and chief cells of human parathyroid glands.

CONTEXT: Parathyroid oxyphil cells, whose function is unknown, are thought to be derived from chief cells. Oxyphil cells increase in number in parathyroid glands of patients with chronic kidney disease (CKD) and are even more abundant in patients receiving treatment for hyperparathyroidism with calcitriol and/or the calcimimetic cinacalcet. OBJECTIVE: We examined oxyphil and chief cells of parathyroid glands of CKD patients for differential expression of genes important to parathyroid function. DESIGN/SETTING/PARTICIPANTS: Parathyroid tissue from CKD patients with refractory hyperparathyroidism was immunostained for gene expression studies. MAIN OUTCOME MEASURE: Immunostaining for PTH, PTHrP, calcium-sensing receptor, glial cells missing 2, vitamin D receptor, 25-hydroxyvitamin D-1α-hydroxylase, and cytochrome c was quantified and expression reported for oxyphil and chief cells. RESULTS: Expression of all proteins analyzed, except for the vitamin D receptor, was higher in oxyphil cells than in chief cells. CONCLUSION: Human parathyroid oxyphil cells express parathyroid-relevant genes found in the chief cells and have the potential to produce additional autocrine/paracrine factors, such as PTHrP and calcitriol. Additional studies are warranted to define the secretory properties of these cells and clarify their role in parathyroid pathophysiology.