title: Expression and role of connective tissue growth factor in painful disc fibrosis and degeneration.
abstract: METHODS
  We collected the specimens of lumbar intervertebral discs from patients with discogenic low back pain, to study the histopathological features and connective tissue growth factor (CTGF) expressions.
  
  
  OBJECTIVE
  To study the expression and role of CTGF in fibrosis and degeneration of painful disc tissue.
  
  
  BACKGROUND
  Previous studies have demonstrated that degenerative disc commonly showed fibrosis in histology. CTGF, a downstream effector mediated by transforming growth factor-beta1 (TGF-beta1), is commonly related to tissue fibrosis. We do not know whether CTGF is expressed in painful disc, and related to painful disc degeneration and fibrosis.
  
  
  METHODS
  This study included 43 lumbar intervertebral disc specimens from 28 patients with discogenic low back pain obtained during posterior lumbar interbody fusion and 16 asymptomatic degenerative discs from patients without low back pain. Further, 8 normal discs were included as controls. Their histopathological features were studied, and the expression of CTGF was assessed using immunohistochemistry.
  
  
  RESULTS
  Histologic examination revealed that the painful discs showed chronic inflammatory reaction with blood vessel infiltration in varying degrees. The anulus fibrosus had lost its normal lamellar architecture, and instead, disorganization, disruption, and crossed fusion were observed. Normal fibroblasts were replaced by chondrocytes in the anulus fibrosus. The nucleus pulposus showed marked fibrosis, blood vessel infiltration, and inflammatory granulation tissue formation. Immunohistochemical staining demonstrated strong CTGF expression in the painful discs, weak expression in the asymptomatic degenerative disc, and no expression in the control discs.
  
  
  CONCLUSIONS
  The painful degenerative disc is significantly different from the asymptomatic degenerative disc with regard to histopathological findings. The strong CTGF expression in the painful disc may be related to disc fibrosis and degeneration.
authors.affiliation: Department of Spinal Surgery, General Hospital of Armed Police Force, Beijing, People's Republic of China. pengbaogan@163.com
authors.forename: Baogan
authors.initials: B
authors.lastname: Peng
authors.forename: Jindong
authors.initials: J
authors.lastname: Chen
authors.forename: Zhengda
authors.initials: Z
authors.lastname: Kuang
authors.forename: Duanming
authors.initials: D
authors.lastname: Li
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Pang
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001706:Biopsy; D002356:Cartilage / Q000378:metabolism / Q000473:pathology; D002908:Chronic Disease; D055513:Connective Tissue Growth Factor / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D005355:Fibrosis; D006801:Humans; D007150:Immunohistochemistry; D007403:Intervertebral Disc / Q000378:metabolism* / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D017116:Low Back Pain / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D055513:Connective Tissue Growth Factor