BETA-2-MICROGLOBULIN IN DISEASES WITH HIGH BONE REMODELING

beta(2)-microglobulin has been observed to behave as a biological mark er of bone remodeling. We measured beta(2)-microglobulin and tartrate- resistant acid phosphatase (TRAP), a specific biological marker of bon e remodeling, in 225 women: healthy premenopausal controls, healthy po stmenopausal controls, and patients with diseases characterized by enh anced bone turnover (postmenopausal osteoporosis, primary hyperparathy roidism, primary hyperthyroidism, polyostotic Paget's bone disease), a nd in other Paget's group before and after calcitonin treatment. beta( 2)-microglobulin levels differed significantly between the healthy pre menopausal women (n = 38) and the women with hyperparathyroidism (n = 20) compared with all the other groups. However, beta(2)-microglobulin levels did not differ significantly between healthy postmenopausal wo men (n = 38) and patients with Paget's bone disease (n = 40) (P = 0.50 95), or between women with postmenopausal osteoporosis (n = 30) and wo men with hyperthyroidism (n = 20) (P = 0.7890). TRAP concentrations di ffered significantly in all the groups paired except for women with Pa get's bone disease and women with either hyperparathyroidism or hypert hyroidism (P = 0.5179 and 0.6993, respectively); likewise, TRAP levels did not differ significantly between the women with hyperparathyroidi sm and those with hyperthyroidism (P = 0.7804). After calcitonin treat ment, there was a 22% increase in beta(2)-microglobulin, a 17% decreas e in TRAP, and a 39% decrease in alkaline phosphatase, all of which we re significant at P < 0.0001. Our findings indicate that serum beta(2) -microglobulin, like osteocalcin, behaves as a biological marker of re modeling in a number of diseases with enhanced bone remodeling but not in Paget's bone disease.