Osteosclerosis in idiopathic myelofibrosis is related to the overproduction of osteoprotegerin (OPG).
OBJECTIVE
The aim of this study is to investigate the mechanism of osteosclerosis in IMF in relation to OPG derangement.


METHODS
Plasma OPG level was assayed by OPG ELISA in 19 patients with IMF, 15 patients with other myeloproliferative disorders (MPDs), and 12 normal volunteers as controls and correlated with the degree of osteosclerosis. Furthermore, the level of OPG mRNA, in the cultured bone marrow stromal (BMS) cells of patients with IMF and anemia patients used as controls, in the presence or absence of TGF-beta1, was studied by real-time RT-PCR.


RESULTS
The present study showed that blood OPG level was significantly elevated in patients with IMF as compared to patients with other MPDs (p < 0.01) or normal volunteer controls (p < 0.05), and there was no significant difference in the level between patients with MPDs and controls. In addition, there was a positive correlation (r=0.67, p=0.04) between plasma OPG levels and the degree of osteosclerosis. There was no difference in the OPG mRNA in patients with IMF as compared with controls even on TGF-beta1 stimulation.


CONCLUSIONS
These results suggest that osteosclerosis in IMF may be related to overproduction of OPG and enhanced level of OPG is not due to the effect of TGF-beta1 on the BMS cells. It could be due to the effect of TGF-beta1 or other growth factors on cells other than BMS cells such as the osteoblasts.
Wang
Jen C
JC
Division of Hematology/Oncology, Department of Medicine, Maimonide Medical Center, Brooklyn, NY 11219, USA. JCWant@aol.com
Hemavathy
Kirugaval
K
Charles
William
W
Zhang
Haowei
H
Dua
Punkaj K
PK
Novetsky
Allan D
AD
Chang
Tsonghui
T
Wong
Ching
C
Jabara
Marlena
M
D001854:Bone Marrow Cells / Q000378:metabolism; D016022:Case-Control Studies; D002478:Cells, Cultured; D006023:Glycoproteins / Q000097:blood / Q000235:genetics*; D006801:Humans; D009196:Myeloproliferative Disorders / Q000097:blood; D053244:Osteoprotegerin; D010026:Osteosclerosis / Q000097:blood / Q000209:etiology*; D055728:Primary Myelofibrosis / Q000097:blood / Q000150:complications* / Q000209:etiology; D012333:RNA, Messenger / Q000032:analysis; D018160:Receptors, Cytoplasmic and Nuclear / Q000097:blood / Q000235:genetics*; D018124:Receptors, Tumor Necrosis Factor; D017154:Stromal Cells / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1
D006023:Glycoproteins; D053244:Osteoprotegerin; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C508960:TGFB1 protein, human; C506030:TNFRSF11B protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1