title: Expression of hypoxia-inducible factor-1α in synovial fluid and articular cartilage is associated with disease severity in knee osteoarthritis.
abstract: The aim of the present study was to examine hypoxia-inducible factor 1α (HIF-1α) levels in the synovial fluid and articular cartilage of patients with primary knee osteoarthritis (OA) and to investigate their association with the severity of disease. A total of 36 patients with knee OA and ten healthy controls were enrolled. Anteroposterior knee radiographs and/or Mankin scores were assessed to determine the disease severity of the affected knee. Radiographic grading of OA in the knee was performed according to Kellgren-Lawrence criteria. HIF-1α levels in synovial fluid were measured using enzyme-linked immunosorbent assay, whereas HIF-1α levels in articular cartilage were assessed with immunohistochemical methods. Compared with healthy controls, OA patients exhibited an increased HIF-1α concentration in synovial fluid (218.17±25.12 vs. 156.66±7.74 pg/ml; P<0.001) and articular cartilage (P<0.05). Furthermore, synovial fluid HIF-1α levels demonstrated a positive correlation with articular cartilage HIF-1α levels (Pearson's P=0.815; P<0.001). Subsequent analysis showed that synovial fluid HIF-1α levels were significantly correlated with the severity of disease (Spearman's ρ=0.933; P<0.001). Furthermore, articular cartilage levels of HIF-1α also correlated with disease severity (Spearman's ρ=-0.967; P<0.001). The findings of the present study suggested that HIF-1α in synovial fluid and articular cartilage is associated with progressive joint damage and is likely to be a useful biomarker for determining disease severity and progression in knee OA.
authors.affiliation: Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Liming
authors.initials: L
authors.lastname: Qing
authors.affiliation: Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Lei
authors.affiliation: Program of Biology and Biomedical Sciences, Division of Medical Sciences, Harvard Medical School, Harvard University, Boston, MA 02115, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Xie
authors.affiliation: Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Long
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wen
authors.affiliation: Department of Orthopedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China.
authors.forename: Yihe
authors.initials: Y
authors.lastname: Hu
keywords: articular cartilage; hypoxia-inducible factor 1α; osteoarthritis; synovial fluid