Study On The Role Of Osteopotin In Ankylosing Spondylitis

Objective: To clarify the role of osteopontin (OPN) in the Ankylosing spondylitis (AS) pathogenic mechansim, we detected the expression of osteopontin (OPN), osteocalcin (OCN), C-terminal telopeptides of type I collagen (CTX-1) and tumor necrosis factor–α(TNF-α) at protein level in the peripheral blood and OPN at mRNA expression in peripheral blood mononuclear cells (PMBCs) of AS.Methods: Accroding to the 1984 modified New York criteria, 39 patients with AS and 30 healthy volenteers were randomly collected from inpatients and outpatients in our hospital from May 2009 to April 2010 . The serum levels of OPN, OCN, CTX-1 and TNF-αin AS patients and normal controls were detected by enzyme linked immunosorbent assay (ELISA). Expressions of OPNmRNA in PMBCs were determined by Reverse transcription polymerse chain reaction (RT-PCR). The changes of OPN, OCN, CTX-1 and TNF-αlevel were observed before and after treatment with TNF-αblock.Results: (1) The serum levels of OPN, OCN, CTX-1 and TNF-αin AS patients were higher than control group (p<0.01). (2) The serum level of TNF-αwas correlated with ESR and BASDAI (p<0.01),the levels of OPN, OCN and CTX-1 were no correlated with ESR and BASDAI ( p> 0.05). (3) Level of OPN was correlated with the levels of OCN and CTX-1 (p<0.01), Level of OPN was no correlated with TNF-α(p =0.213). (4) Compared with control group, the serum levels of OPN, OCN, CTX-1 and TNF-αwere increased in active and inactive groups of AS (p<0.01). Compared with inactive group, the levels of OPN, OCN and CTX-1 had no difference in active group (p >0.05). However, the level of TNF-αin active group was higher than inactive group (p<0.01). (5) Compared with control group, the up-regulation of OPN mRNA expression in PMBC was observed in active and inactive groups of AS (p<0.01). Compared with inactive group, the mRNA expression of OPN in PMBC had no difference in active group (p>0.05). (6) The serum levels of OPN, OCN and CTX-1 in patients with AS were no Statistical difference between phase I and Phase II,phase II and phaseⅢ,phaseⅢand phase IV (different stages of X-ray) (p>0.05). The serum levels of OPN, OCN were difference between phase I and phaseⅢ,phase I and Phase IV ,phase II and phase IV (p<0.01). The serum level of CTX-1 were difference between phase I and phaseⅢ(p<0.01).The level of OPN was correlated with the levels of OCN and CTX-1 in different stages (p<0.01). (7) The levels of OPN, OCN and CTX-1 in patients with AS had not been influenced after treatment with TNF-αblock (p>0.05), while the level of TNF-αsignificantly decreased (p<0.01).Conclusions: The level of OPN has no correalte with activy of AS, but it has correalte with indexs of bone metabolism. OPN may have effect on bone metabolism of AS, which participate in the development of AS.