Study Of Cytokines And Biomarkers Of Bone Remodeling In Ankylosing Spondylitis

Objective To investigate the DKK1and sclerostin expression and clinical significanein patients with ankylosing spondylitis in peripheral blood.Methods The study was performed in40patients with AS,34males and6females,age range17～45yrs, mean age28±8yrs which met the AS New York revisedclassification criteria in1984.20healthy controls, include17males3females,meanage27±2yrs. ex-and age-matched, served as a control group. All subjects receivedinformed consent in this study. AS patients was divided into untreated group(withoutregular treating more than three months,n=16) and treated group(non-steroidalanti-inflammatory and DMARDS more than three months,n=12) and biological agentsgroup(receiving at least one biological agent more than two months,n=12).Diseaseactivity was assessed with BASDAI,ESR,CRP,Ig,clinical data and sacroiliac jointimaging were collected.Imaging of the sacroiliac joint classification was defined as：Ilevel was suspicious;IIlevel may have limited erosion,sclerosis,but joint space wasnormal; IIIlevel has obvious abnormal change including erosion,sclerosis,joint spacenarrow even joint ankylosis.IVlevel have serious joint ankylosis.we difined sacroiliacjoint classification level<2as early period,>2as later period. All sample was collectedin room temperature then centrifugal at3000r/min for20min.Serum samples weretaken from each subject and stored at–70C until the assays were per-formed. thelevel of DKK1and sclerostin in sera were measured by enzyme-linked immunosorbentassay according to the introduction. Result①The level of DKK1in AS serum was significantly higher than that in thehealthy control group(P＜0.05)；②The level of DKK1in using anti-TNF-α group islower than that in the untreated group (P＜0.05)；③DKK1and BASDAI scorespositively correlated(,r=0.337, P＜0.05),there was no correlation between DKK1andscleroston with ESR，CRP,IgG,IgA,IgM.；④The levels of sclerostin in the serum of ASpatients was higher than that in normal control group (P＜0.01)；⑤The sclerostinlevels of early AS patients was higher than that of the later AS patients (P＜0.05)Conclusion DKK1may be involved in inflammatory process of AS patients,inhibition of TNF-α can affect the expression of DKK1, sclerostin levels werediferences in the early and later period AS patients. Objective To investigate the pathophysiology of AS-related osteoporosis byinvestigating the relation between bone mineral density(BMD) and bone turnovermarkers.Methods forty-seven AS patients were included in this study.including36males and11female.age range16～48yrs, mean age32±9yrs.disease duration rang1month to20years,mean81±69months which met the AS New York revised classificationcriteria in1984.25ex-and age-matched, served as a healthy controls,group. Allsubjects received informed consent in this study. AS patients was divided into untreatedgroup(without regular treating more than three months) and treated group(non-steroidalanti-inflammatory and DMARDS more than three months) and biological agentsgroup(receiving at least one biological agent more than two months).we difinedsacroiliac joint classification level<2as early period,>2as later period. BMD of lumbarspine(L1-L4), fermoral neck and radius were using dual-energy X-ray absorptionmethod.According to the World Health Organiziation(WHO) classification,osteopeniawas defined as a Z-score between-1and-2.5and osteoporo as a Z-score＜ -2.5.BASDAI,ESR,Ig was collected.bone formation markers including procollagen type1N-terminal peptide(PINP) and osteocalcin (OC),the formal was measured byradioimmunoassay and the later was measured by immunoradiometric assay and boneresorption marker β-CrossLaps was measured by electrochemiluminescenceimmunoassay.Results①47%of AS patients has bone loss(osteopenia was30%,osteoporosis was17%) while the percentage in the healthy control group is20%(osteopenia was20%,osteoporosis was0%). BMD of lumbar spine, fermoral neck and radius were lowerthan the control (p＜0.05）.②BMD of lumbar spine in later period group was was higerthan the early group,however,the BMD in femoral neck was not.③The PINP,OC andβ-CrossLaps has no significant difference in different periods.(p＞0.05).④BMD oflumbar spine was negatively correlated with the β-CrossLaps and ESR, The BMD infermoral neck was negatively correlated with β-CrossLaps and OC,but they were notcorrelaed with disease duration and BADSAI.⑤BMD of lumbar spine and fermoralneck were increased in receiving anti-TNF-α group than untreated group(p＜0.05）Conclusion Osteoporosis is gerenal in AS.,bone turnover including boneformation and bone resorption were increased in AS. β-CrossLaps is likely to precictbone loss in AS.anti-TNF-α therapy can increase BMD.