Elevated levels of TNF-? and TNFR1 in recurrent herniated lumbar discs correlate with chronicity of postoperative sciatic pain.
Spine J. 2015 Oct 30;
Authors: Andrade P, Hoogland G, Teernstra OP, van Aalst J, van Maren E, Daemen MA, Visser-Vandewalle V
BACKGROUND: Context: Sciatica is a condition characterized by radicular pain that can be secondary to a lumbar disc herniation (LDH). More than 10% of these patients report persistent pain after surgery. The underlying mechanisms of postoperative sciatica remain unclear. There is evidence demonstrating that inflammation plays a role in the pathophysiology of sciatica.
PURPOSE: To assess if the expression of TNF-? and TNFR were correlated with the severity of pre- and postoperative leg pain in LDH patients that underwent single or multiple decompressive discectomies.
SETTING: An experimental prospective human study of intraoperative intervertebral disc (IVD) samples and clinical scores evaluation.
METHODS: We analyzed mRNA and protein levels of TNF-?, TNFR1 and TNFR2 in IVD biopsies, and correlated them with visual analogue scale (VAS) scores from 1 day before surgery and 6 weeks and 6 months postoperatively.
RESULTS: We evaluated the correlation between the inflammation in the IVD with pre- and postoperative pain scores after discectomy in LDH patients operated for the first time (fLDH, n=12) and recurrent cases (rLDH, n=8). This analysis showed that TNF-? and TNFR1 mRNA levels were significantly greater in rLDH patients; 2-fold increase for TNF-? and 50% increase for TNFR1. Similarly, protein levels in IVD samples positively correlated with postoperative VAS scores, whereas TNFR2 protein levels negatively correlated with postoperative VAS scores.
CONCLUSIONS: These findings indicate that rLDH patients do not only present higher postoperative VAS scores, compared to fLHD patients, but also that these scores are correlated with increased inflammation and may contribute to pain chronicity.
PMID: 26523959 [PubMed – as supplied by publisher]