Nerve growth factor expression and innervation of the painful intervertebral disc

• Published in: The Journal of pathology 2002-07, Vol.197 (3), p.286-292
• Main Authors: Freemont, A. J., Watkins, A., Le Maitre, C., Baird, P., Jeziorska, M., Knight, M. T. N., Ross, E. R. S., O'Brien, J. P., Hoyland, J. A.
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing; Adult; angiogenesis; Biological and medical sciences; Biomarkers - analysis; Chondrocytes - chemistry; Diseases of the osteoarticular system; Diseases of the spine; Female; GAP-43 Protein - analysis; Humans; Immunohistochemistry - methods; In Situ Hybridization; intervertebral disc; Intervertebral Disc - blood supply; Intervertebral Disc - metabolism; Intervertebral Disc - pathology; Low Back Pain - metabolism; Lumbosacral Region; Male; Medical sciences; Middle Aged; Nerve Growth Factor - genetics; Nerve Growth Factor - metabolism; Nerve Regeneration; NGF; Platelet Endothelial Cell Adhesion Molecule-1 - analysis; Receptor, trkA - analysis; RNA, Messenger - analysis; S100 Proteins - analysis; Thiolester Hydrolases - analysis; Trans-Activators - analysis; Transcription Factors; Ubiquitin Thiolesterase
• ISSN: 0022-3417; 1096-9896
• DOI: 10.1002/path.1108

Following a previous description of nociceptive nerve fibre growth into usually aneural inner parts of painful intervertebral disc (IVD), this study has investigated whether nociceptive nerve ingrowth into painful IVD is stimulated by local production of neurotrophins. Immunohistochemistry and in situ hybridization have been used to investigate expression of the candidate neurotrophin, nerve growth factor (NGF), and its high‐ and low‐affinity receptors trk‐A and p75, respectively, in painful IVD excised for the management of low back pain. IVD from patients with back pain were of two types: those that when examined by discography reproduced the patient symptoms (pain level IVD) and those that did not (non‐pain level IVD). Microvascular blood vessels accompanied nerve fibres growing into pain level IVD and these expressed NGF. The adjacent nerves expressed the high‐affinity NGF receptor trk‐A. These vessels entered the normally avascular IVD through the discal end plates. NGF expression was not identified in non‐pain level or control IVD. Some non‐pain level IVD had vessels within them, which entered through the annulus fibrosus. These did not express NGF nor did nerves accompany them. These findings show that nociceptive nerve ingrowth into painful IVD is causally linked with NGF production by blood vessels growing into the IVD, from adjacent vertebral bodies. Copyright © 2002 John Wiley & Sons, Ltd.