title: The expression of tumor necrosis factor-α and CD68 in high-intensity zone of lumbar intervertebral disc on magnetic resonance image in the patients with low back pain.
abstract: METHODS
  Several recent studies suggest a high-intensity zone (HIZ) within the posterior annulu of lumbar intervertebral disc seen on T2-weighted magnetic resonance (MR) images represents the inflammation in the annulus, an annular tear, and/or vascular granulation tissue. It has not be reported yet whether there is the expression of tumor necrosis factor (TNF-α) and inflammatory cells appear in HIZ of intervertebral disc on MR images.
  
  
  OBJECTIVE
  To study whether HIZ is a specific signal for the inflammatory reaction of painful intervertebral disc.
  
  
  BACKGROUND
  The presence of HIZ signal within the posterior annulus seen on sagittal T2-weighted spin-echo magnetic imaging sequences has already been used in the diagnosis of painful annular tears in the last decade. There have been studies suggesting that the presence of HIZ reflects inflammation in the annulus, an annular tear, and/or vascular granulation tissue.
  
  
  METHODS
  Twenty-six consecutive patients with low back pain underwent MR images and discography (age range = 26-65 years; mean age = 47.5 years; 16 men, 10 women). In all the patients, HIZ appeared in the involved intervertebral discs on T2-weighted MR images. Lumbar discography was usually performed on each patient for the discs L3-L4, L4-L5, and L5-S1. All patients received posterior lumbar interbody fusion procedures. The intervertebral disc specimens contained HIZ were excised en bloc during posterior interbody fusion. The distribution of TNF-α and CD68 in the intervertebral disc specimens within HIZ on MR images from 26 consecutive patients with low back pain and in the intervertebral disc specimens from five fresh cadavers were observed.
  
  
  RESULTS
  The histologic study of the consecutive sagittal slices of the HIZ showed a lot of proliferated small round cells and fibroblasts. There were a lot of TNF-α positive cells and some CD68 positive cells in HIZ and the number of TNF-α and CD68 positive cells in HIZ was significantly higher than that in the annulus fibrosus around HIZ and in the control (P < 0.05).
  
  
  CONCLUSIONS
  The results of this study indicate that HIZ may be a specific signal for the inflammatory reaction of painful intervertebral disc.
authors.affiliation: Department of Orthopaedics, Institute of Orthopaedics, First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China. stonedance1972@yahoo.com.cn
authors.forename: Ren
authors.initials: R
authors.lastname: Dongfeng
authors.forename: Shuxun
authors.initials: S
authors.lastname: Hou
authors.forename: Wenwen
authors.initials: W
authors.lastname: Wu
authors.forename: Huadong
authors.initials: H
authors.lastname: Wang
authors.forename: Weilin
authors.initials: W
authors.lastname: Shang
authors.forename: Jiaguang
authors.initials: J
authors.lastname: Tang
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Li
authors.forename: Guo
authors.initials: G
authors.lastname: Lei
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000096:biosynthesis*; D015214:Antigens, Differentiation, Myelomonocytic / Q000096:biosynthesis*; D049109:Cell Proliferation; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D006097:Granulation Tissue / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D007403:Intervertebral Disc / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D017116:Low Back Pain / Q000378:metabolism* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D014409:Tumor Necrosis Factor-alpha; C067980:CD68 antigen, human; D000097382:CD68 Molecule