Serum osteoprotegerin levels in healthy controls and cancer patients.
OBJECTIVE
Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor receptor superfamily. In vitro, OPG blocks osteoclastogenesis in a dose-dependent manner. Serum OPG levels were assayed in cancer patients and healthy control subjects using an ELISA.


RESULTS
OPG levels in healthy controls were significantly higher in sera (0.17 ng/ml) than in plasma (0.14 ng/ml). OPG levels did not differ by age in either control group. Serum was available from patients with solid tumors (n = 145), hematological malignancies (n = 111), benign hematological disorders (n = 35), and rheumatologic diseases (n = 60). When adjusted for age and sex, there was no significant OPG elevation in the sera of patients with solid tumors compared with controls (0.2 versus 0.18 ng/ml). When analyzed by site of primary malignancy within the solid tumor patient group, serum OPG elevations were observed only in patients with colorectal cancer (0.29 ng/ml; P < 0.0001) and pancreatic cancer (0.35 ng/ml; P < 0.0001). When analyzed by site of metastasis within the solid tumor patient group, significant elevations in serum OPG were observed only in patients with liver metastases (0.29 ng/ml) and soft tissue metastases (0.21 ng/ml) but not in patients with bone or lung metastases. Within the hematological malignancy group, serum levels of OPG were significantly lower in patients with multiple myeloma (0.12 ng/ml) but were elevated in patients with Hodgkin's disease (0.29 ng/ml) and Non-Hodgkin's Lymphoma (0.24 ng/ml; P = 0.048).


CONCLUSIONS
Although some patients with malignancy have significant elevations of circulating OPG, these concentrations do not approach the level that would be expected to suppress osteoclast function.
Division of Hematology, Milton S. Hershey Medical Center, Hershey, PA 17033, USA. alipton@psu.edu
Allan
A
Lipton
Suhail M
SM
Ali
Kim
K
Leitzel
Vernon
V
Chinchilli
Lois
L
Witters
Linda
L
Engle
Donna
D
Holloway
Pirow
P
Bekker
Colin R
CR
Dunstan
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood* / Q000473:pathology; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear / Q000097:blood*; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood*; D012216:Rheumatic Diseases / Q000097:blood / Q000473:pathology
D006023:Glycoproteins; D053244:Osteoprotegerin; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C506030:TNFRSF11B protein, human