MHC CLASS-I AND CLASS-II ANTIGEN EXPRESSION ON PARATHYROID CELLS AND PROSPECTS FOR THEIR ALLOGENIC TRANSPLANTATION

Homologous parathyroid transplantation has been utilized with rare success in patients suffering from parathyroid hypofunction. Major factors determining the possibility for such transplantation comprise the hitherto essentially unexplored expression and inducibility of MHC class I and II antigens on parathyroid cells. Cryosectioned and dispersed normal human parathyroid tissue displayed no or very low immunohistochemical reactivity for both class I and II antigens on the parenchymal cells, whereas the adenomatous and hyperplastic parenchyma of pathological glands encompassed a higher expression of these antigens. Monolayer culture of parathyroid cells in the presence of IFN-alpha or IFN-gamma induced class I and II antigens on the abnormal but not on the normal parathyroid cells, and no detectable induction of these molecules was obtained by varying the extracellular calcium concentration. The results indicate that normal parathyroid cells may constitute candidates for allogenic transplantation, and that further studies on the modulation of MHC-coded molecules in these cells should facilitate the utility of this potential therapy.