Abstract
BackgroundThere is increasing interest in the role of pro-inflammatory cytokines in the pathogenesis of sciatica and whether these could be potential targets for treatment. We sought to investigate serum biomarker levels in patients with low back-related leg pain, including sciatica.MethodsPrimary care consulters aged > 18 with low back-related leg pain were recruited to a cohort study (ATLAS). Participants underwent a standardised clinical assessment, lumbar spine MRI and a subsample (n = 119) had samples taken for biomarker analysis. Participants were classified having: a) clinically confirmed sciatica or referred leg pain, and then subdivided into those with (or without) MRI confirmed nerve root compression due to disc prolapse. Seventeen key cytokines, chemokines and matrix metalloproteinases (MMPs) implicated in sciatica pathogenesis including TNFα and IL-6, were assayed in duplicate using commercial multiplex detection kits and measured using a Luminex suspension array system. Median biomarker levels were compared between the groups using a Mann Whitney U test. Multivariate logistic regression analysis was used to investigate the association between clinical measures and biomarker levels adjusted for possible confounders such as age, sex, and symptom duration.ResultsNo difference was found in the serum level of any of the 17 biomarkers tested in patients with (n = 93) or without (n = 26) clinically confirmed sciatica, nor between those with (n = 44) or without (n = 49) sciatica and MRI confirmed nerve root compression.ConclusionIn this cohort, no significant differences in serum levels of TNFα, IL-6 or any other biomarkers were seen between patients with sciatica and those with back pain with referred leg pain. These results suggest that in patients with low back-related leg pain, serum markers associated with inflammation do not discriminate between patients with or without clinically confirmed sciatica or between those with or without evidence of nerve root compression on MRI.
Highlights
There is increasing interest in the role of pro-inflammatory cytokines in the pathogenesis of sciatica and whether these could be potential targets for treatment
The aim of this study was to examine serum levels of key biomarkers in patients presenting in primary care with symptoms of low back-related leg pain including sciatica, and to see whether levels were different in patients with clinically diagnosed sciatica with or without or evidence of nerve root compression on magnetic resonance imaging (MRI)
Previous studies have confirmed the presence of key cytokines such as TNFα and interleukins 6 (IL-6) in surgical disc samples, and recent data have suggested that serum levels of these cytokines may be elevated in patients with sciatica symptoms [8–10], other studies have shown no association [14]
Summary
There is increasing interest in the role of pro-inflammatory cytokines in the pathogenesis of sciatica and whether these could be potential targets for treatment. Interest on possible inflammatory aetiologies for sciatica initially focused on the cytokine TNFα, including randomised trials of anti-TNF inhibitors infliximab [3] and adalumimab [4], showing some improvement in leg pain and reduction in numbers of patients needing spinal surgery [4], with meta-analyses suggesting further trials are warranted [5,6,7] These therapies may represent a novel way to treat sciatica but are expensive, and given that sciatica is common, data is required to effectively target these drugs at patients more likely to derive benefit. Such an approach would help further elucidate whether these biomarkers are elevated early in the symptom course or could be used in predicting outcome or guide treatment for sciatic pain
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
