Tumor necrosis factor-immunoreactive cells and PGP 9.5-immunoreactive nerve fibers in vertebral endplates of patients with discogenic low back Pain and Modic Type 1 or Type 2 changes on MRI.
METHODS
Immunohistochemistry for tumor necrosis factor (TNF) and protein gene product (PGP) 9.5 in vertebral endplates of patients with discogenic low back pain and Modic Type 1 or Type 2 endplate changes on MRI.


OBJECTIVE
To examine whether inflammatory cytokines and nerve in-growth into the vertebral endplate are associated with discogenic low back pain.


BACKGROUND
Degenerated discs and endplate abnormalities can be a cause of discogenic low back pain. However, the presence of TNF-immunoreactive cells and PGP 9.5-immunoreactive nerve fibers has not been studied in patients with discogenic low back pain and endplate changes on MRI.


METHODS
Eighteen endplates showing either normal intensity signals on MRI (endplate change -), Modic Type 1 signals (low intensity on T1-weighted spin-echo images), or Modic Type 2 signals (high intensity) from patients with discogenic low back pain (n = 14) or controls requiring surgery for other back problems (n = 4; scoliosis and traumatic injury of vertebra) were harvested during surgery. Endplates were immunostained using antibodies to TNF and PGP 9.5 and immunostained cells and nerve fibers in the endplates were counted.


RESULTS
Vertebral endplates from patients with Modic Type 1 or Type 2 endplate changes on MRI had significantly more PGP 9.5-immunoreactive nerve fibers and TNF-immunoreactive cells in comparison with patients with normal endplates on MRI (P < 0.01). The number of TNF-immunoreactive cells in endplates exhibiting Modic Type 1 changes was significantly higher than in endplates exhibiting Modic Type 2 changes (P < 0.05).


CONCLUSIONS
The results suggest that endplate abnormalities are related to inflammation and axon growth induced by TNF. TNF expression and PGP 9.5-positive nerve in-growth in abnormal endplates may be a cause of low back pain.
Ohtori
Seiji
S
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. sohtori@faculty.chiba-u.jp
Inoue
Gen
G
Ito
Toshinori
T
Koshi
Takana
T
Ozawa
Tomoyuki
T
Doya
Hideo
H
Saito
Tomoko
T
Moriya
Hideshige
H
Takahashi
Kazuhisa
K
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000294:innervation / Q000378:metabolism* / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D017116:Low Back Pain / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D043222:Ubiquitin Thiolesterase / Q000378:metabolism*
D014409:Tumor Necrosis Factor-alpha; C482860:UCHL1 protein, human; D043222:Ubiquitin Thiolesterase