title: Circulating periostin levels in patients with AS: association with clinical and radiographic variables, inflammatory markers and molecules involved in bone formation.
abstract: OBJECTIVE
  The aim of this study was to evaluate serum periostin levels in patients with AS in comparison with healthy controls as well as their association with clinical, inflammatory and radiographic parameters and molecules involved in bone formation.
  
  
  METHODS
  Serum samples for periostin, total Dickkopf-1 (Dkk-1), sclerostin, VEGF and inflammatory markers were obtained from 65 TNF inhibitor-naive patients with AS. The BASDAI, BASFI, modified Stoke AS Spine Score and BASRI for the spine (BASRI-s) were assessed for each patient. Serum periostin levels were also measured in 36 sex-, age- and BMI-matched controls.
  
  
  RESULTS
  Serum periostin levels were significantly lower in AS patients compared with controls [234.4 pg/ml (s.e.m. 7.5) vs 291.4 (s.e.m. 8.3), respectively; P < 0.001]. Periostin levels were higher in AS patients with elevated CRP (P = 0.005), high BASDAI (P = 0.014) and low BASRI-s (P = 0.033) and were correlated with BMI (r = -0.304, P = 0.014), ESR (r = 0.395, P = 0.001), CRP (r = 0.413, P = 0.001), BASRI-s (r = -0.242, P = 0.047) and sclerostin (r = -0.280, P = 0.024). In multiple regression analysis, periostin levels were an independent variable of CRP (β = 0.160, P = 0.009) and sclerostin levels (β = -0.311, P = 0.012).
  
  
  CONCLUSIONS
  Our data suggest that periostin levels are low in patients with AS. Among AS patients, periostin levels are higher in those with higher disease activity, higher systemic inflammation and less extensive radiographic damage. Periostin is independently associated with CRP and sclerostin levels.
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece sakelgr@gmail.com.
authors.forename: Grigorios T
authors.initials: GT
authors.lastname: Sakellariou
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Athanasios D
authors.initials: AD
authors.lastname: Anastasilakis
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Ilias
authors.initials: I
authors.lastname: Bisbinas
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Oikonomou
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Spyridon
authors.initials: S
authors.lastname: Gerou
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Stergios A
authors.initials: SA
authors.lastname: Polyzos
authors.affiliation: Department of Rheumatology, Department of Endocrinology, 2 Department of Orthopaedics, Central Laboratory, 424 General Military Hospital, Laboratories 'Analysis', Second Medical Clinic, Department of Medicine, Ippokration General Hospital, 3 Department of Orthopaedics, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Fares E
authors.initials: FE
authors.lastname: Sayegh
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D015415:Biomarkers / Q000097:blood; D019485:Bone Morphogenetic Proteins / Q000097:blood / Q000502:physiology; D001842:Bone and Bones / Q000503:physiopathology; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000097:blood* / Q000502:physiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005819:Genetic Markers / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood / Q000502:physiology; D008297:Male; D010012:Osteogenesis / Q000502:physiology*; D011859:Radiography; D012044:Regression Analysis; D012720:Severity of Illness Index; D013167:Spondylitis, Ankylosing / Q000097:blood* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D042461:Vascular Endothelial Growth Factor A / Q000097:blood / Q000502:physiology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; D015815:Cell Adhesion Molecules; C501126:DKK1 protein, human; D005819:Genetic Markers; D036341:Intercellular Signaling Peptides and Proteins; C512835:POSTN protein, human; C422903:SOST protein, human; D042461:Vascular Endothelial Growth Factor A; D002097:C-Reactive Protein
keywords: Dkk-1; VEGF; ankylosing spondylitis; disease activity; inflammation; periostin; radiographic damage; sclerostin