Serum osteoprotegerin levels are reduced in patients with multiple myelomawith lytic bone disease

Osteoprotegerin (OPG), the neutralizing decoy receptor for the osteoclast a ctivator RANK ligand, was measured in serum taken from patients with multip le myeloma at the time of diagnosis. Median OPG was lower in the patients w ith myeloma (7.4 ng/mL; range, 2.6-80; n = 225) than in healthy age- and se x-matched controls (9.0 ng/mL; range 5.1-130; n = 40; P = .02). Importantly , OPG levels were associated with degree of radiographically assessed skele tal destruction (P = .01). The median OPG level in patients lacking osteoly tic lesions was 9.1 ng/mL, as compared with 7.6 ng/mL and 7.0 ng/mL, respec tively, in patients with minor or advanced osteolytic disease. Furthermore, OPG levels were associated with World Health Organization performance stat us (P = .003) and correlated to serum levels of carboxy-terminal propeptide of type I procollagen (PICP; P < .001) but not with clinical stage or surv ival. These findings suggest impaired OPG function in myeloma and give a ra tionale for OPG as a therapeutic agent against myeloma bone disease. (C) 20 01 by The American Society of Hematology.