Relationship between soluble markers of immune activation and bone turnover in post-menopausal women with rheumatoid arthritis.
OBJECTIVE
Regarding interactions between pro-inflammatory cytokines and bone metabolism in rheumatoid arthritis (RA), we investigated the relationship between the serum levels of interleukin (IL)-1beta, IL-6, soluble interleukin-2 receptor (sIL-2r), C-reactive protein (CRP), the vitamin D metabolites 25-hydroxyvitamin D3 (25OHD3) and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], intact parathyroid hormone (iPTH) as well as serum and urinary parameters of bone turnover in 74 post-menopausal women with RA.


RESULTS
SIL-2r correlated negatively with 1,25(OH)2D3 (P < 0.01), whereas IL-6 showed a positive correlation with urinary excretion of deoxypyridinoline collagen cross-links (P < 0.01). 1,25(OH)2D3 (P < 0.01) and iPTH (P < 0.01) were negatively related to CRP, whereas the urinary excretion of pyridinoline (P < 0.01) and deoxypyridinoline (P < 0.01)-collagen cross-links showed a positive correlation with CRP. 1,25(OH)2D3 (P < 0.01) and iPTH (P < 0.05) were positively related to bone alkaline phosphatase as a marker of osteoblast function.


CONCLUSIONS
Our data indicate that IL-6 is a critical determinant of increased bone resorption in post-menopausal RA women with high disease activity and that serum levels of 1,25(OH)2D3 are inversely related to T-cell activation.
Oelzner
P
P
Department of Internal Medicine IV, Friedrich-Schiller University of Jena, Germany.
Franke
S
S
Müller
A
A
Hein
G
G
Stein
G
G
D000368:Aged; D000375:Aging / Q000276:immunology / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism; D001862:Bone Resorption / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism; D002112:Calcifediol / Q000378:metabolism; D002117:Calcitriol / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000276:immunology* / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism
D007375:Interleukin-1; D015850:Interleukin-6; D010281:Parathyroid Hormone; D015375:Receptors, Interleukin-2; D012709:Serum Albumin; D002117:Calcitriol; D002112:Calcifediol; D002118:Calcium