U A, Papassotiriou I, Michalakakou K, Fessatou S, Fandridis E, Papachristou G, Terpos E: Higher levels of synovial fluid osteoprotegerin (OPG) and increased serum ratio of receptor activator of nuclear factorkappaB ligand (RANKL) to OPG correlate with disease severity in sufferers with key knee osteoarthritis. Clin Biochem 2008, 41:746-749. 18. Nelson AE, Fang F, Shi XA, Kraus VB, Stabler T, Renner JB: Failure of serum transforming development factor-beta (TGF-beta1) as a biomarker of radiographic osteoarthritis in the knee and hip: a cross-sectional Nav1.2 Formulation analysis within the Johnston County Osteoarthritis Project. Osteoarthritis Cartilage 2009, 17:772-776. 19. Niehrs C: Function and biological roles on the Dickkopf family of Wnt modulators. Oncogene 2006, 25:7469-7481. 20. Grotewold L, Theil T, R her U: Expression pattern of Dkk-1 in the course of mouse limb development. Mech Dev 1999, 89:151-153. 21. Grotewold L, R her U: Bmp, Fgf and Wnt signalling in programmed cell death and chondrogenesis for the duration of vertebrate limb improvement: the role of Dickkopf-1. Int J Dev Biol 2002, 46:943-947.Conclusions This study has revealed a important lower in plasma Dkk-1 of OA sufferers and illustrated a pronounced inverse correlation with the degree of radiographic severity in patients with major knee OA. The data of this study assistance the obtaining that Dkk-1 could be a beneficial prognostic parameter to reflect the disease severity of primary knee OA. Furthermore, Dkk-1 levels in plasma had been straight correlated with those in synovial fluid. This study has been the initial to investigate such a correlation and further research will probably be needed to define the mechanisms underlying this association. Added investigations are going to be essential to shed light on the feasible role of Dkk-1 involved in the pathogenesis of chronic degenerative joint disorder, using the aim of establishing helpful pharmacological agents to delay the progression to osteoarthritis.Abbreviations ANCOVA: evaluation of co-variance; ANOVA: evaluation of variance; BMI: body mass index; CI: self-assurance intervals; DKK-1: Dickkopf-1; ELISA: enzyme-linked immunosorbent assay; KL: Kellgren and Lawrence; LDL: low-density lipoprotein; LRP: low-density lipoprotein receptor-related proteins; OA: osteoarthritis; ROC: receiver-operating characteristic; SD: standard deviation; SPSS: statistical package for social sciences; WNT: Wingless. Acknowledgements This research was supported by the Ratchadapiseksompotch Fund, Faculty of Medicine, Chulalongkorn University, the Thailand Research Fund, the Commission on Higher Education, as well as the National Research Council of Thailand. The authors also would prefer to thank Prof. Yong Poovorawan and Ms. Petra Hirsch for reviewing the manuscript, Ms. Piyanuch Bumrungpanichthaworn for PRMT1 Purity & Documentation technical assistance, Mr.Wasan Punyasang for statistical guidance, and the Chulalongkorn Healthcare Study Center (ChulaMRC) for kindly providing facilities. Author specifics 1 Division of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand. 2Department of Orthopaedics, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand. Authors’ contributions SH was responsible for the conception and design of the study, the evaluation and interpretation from the information, and drafting of your manuscript. AT, PY, and SN performed operations, acquired patients, and contributed for the sample collection. NS and ST assisted sample collection and data evaluation. All authors have read and authorized the f.
