Both the phenotypic alterations of parathyroid (PT) cells, e.g. down-regulation of the calcium-sensing receptor, and the increase of the PT cell number in nodular hyperplasia are the main causes of refractory secondary hyperparathyroidism. It is of great importance to prevent PT growth in an early stage.
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Higashi-Ku, Fukuoka 812-8582, Japan. masatomo@kcu.med.kyushu-u.ac.jp