Inflammatory biomarkers do not distinguish between patients with sciatica and referred leg pain within a primary care population: results from a nested study within the ATLAS cohort

The association between inflammatory biomarkers and low back disorder: a systematic review and meta-analysis

INTRODUCTION

Low back disorder (LBD) is a major cause of disability worldwide. Inflammation results in proliferation of cytokines or consequent degradation products (collectively known as inflammatory biomarkers) that activate pain pathways which can result in non-specific LBD. This systematic review and meta-analysis aim to evaluate the relationship between inflammatory biomarkers and clinical outcomes in patients with LBD.

METHODS

The PRISMA guideline was followed for the systematic reivew. Three online databases were searched. Four RCTs and sixteen observational studies with 1142 LBD patients were analysed. The primary outcomes were back and leg pain scores, back-specific disability scores and expression of inflammatory biomarkers. Standardized mean difference (SMD) and their 95% confidence intervals (CI) were evaluated. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to summarize the strength of evidence.

RESULTS

Four RCTs and sixteen observational studies were included in the analysis of 1142 patients with LBD. There was a statistically significant reduction in back pain score and IL-1 beta and increase in the expression of CTX-1 and IL-10 levels post treatment. There was a significant relationship between increase in the expression of MCP- and reduction in the expression of hsCRP with increase in back pain. Significant relationship was also observed between increase in the expression of MCP-1 and reduction in the expression of IL-6 with increase in leg pain. Increase in the expression of IL-8 and reduction in the expression of hsCRP was also associated with increased disability score.

CONCLUSION

Inflammatory biomarkers play a significant role in the pathogenesis of LBD. CTX-1, IL-10 and IL-1 beta may be responsible for the decrease in back pain scores post treatment. There is a relationship between MCP-1, IL-6, IL-8 and hsCRP with clinical and functional assessments for LBD. Further studies will improve understanding of the pathogenesis of LBD and aid in targeted management strategies.

Markers of Tissue Deterioration and Pain on Earth and in Space

Purpose

Pain is an understudied physiological effect of spaceflight. Changes in inflammatory and tissue degradation markers are often associated with painful conditions. Our aim was to evaluate the changes in markers associated with tissue deterioration after a short-term spaceflight.

Patients and Methods

Plasma levels of markers for systemic inflammation and tissue degeneration markers were assessed in two astronauts before and within 24 h after the 17-day Axiom Space AX-1 mission.

Results

After the spaceflight, C-reactive protein (CRP) was reduced in both astronauts, while INFγ, GM-CSF, TNFα, BDNF, and all measured interleukins were consistently increased. Chemokines demonstrated variable changes, with consistent positive changes in CCL3, 4, 8, 22 and CXCL8, 9, 10, and consistent negative change in CCL8. Markers associated with tissue degradation and bone turnover demonstrated consistent increases in MMP1, MMP13, NTX and OPG, and consistent decreases in MMP3 and MMP9.

Conclusion

Spaceflight induced changes in the markers of systemic inflammation, tissue deterioration, and bone resorption in two astronauts after a short, 17-day, which were often consistent with those observed in painful conditions on Earth. However, some differences, such as a consistent decrease in CRP, were noted. All records for the effect of space travel on human health are critical for improving our understanding of the effect of this unique environment on humans.

A Review of the Clinical and Therapeutic Implications of Neuropathic Pain

Understanding neuropathic pain presents several challenges, given the various mechanisms underlying its pathophysiological classification and the lack of suitable tools to assess its diagnosis. Furthermore, the response of this pathology to available drugs is still often unpredictable, leaving the treatment of neuropathic pain still questionable. In addition, the rise of personalized treatments further extends the ramified classification of neuropathic pain. While a few authors have focused on neuropathic pain clustering, by analyzing, for example, the presence of specific TRP channels, others have evaluated the presence of alterations in microRNAs to find tailored therapies. Thus, this review aims to synthesize the available evidence on the topic from a clinical perspective and provide a list of current demonstrations on the treatment of this disease.

Piperine treating sciatica through regulating inflammation and MiR-520a/P65 pathway

Although the etiology of sciatica remains uncertain, there is increasing evidence that the disease process of sciatica is associated with the levels of inflammatory factors. Piperine, an alkaloid isolated from Piper nigrum, has previously been demonstrated to inhibit inflammation and analgesic effects. The purpose of this study is to verify the regulatory relationship between miR-520a and p65 and to explore how miR-520a/P65 affects the level of cytokines under the action of piperine, so as to play a therapeutic role in sciatica. Through ELISA experiment, we confirmed that four inflammatory factors (IL-1β, TNF-α, IL-10, TGF-β1) can be used as evaluation indexes of sciatica. The differentially expressed miRNA was screened as miR-520a, by microarray technology, and the downstream target of miR-520a was P65 by bioinformatics. Real-time fluorescence quantitative PCR confirmed that the expression of miR-520a was negatively correlated with pro-inflammatory cytokines, positively correlated with anti-inflammatory cytokines and negatively correlated with p65 expression at mRNA level. The expression of p65 was positively correlated with pro-inflammatory cytokines and negatively correlated with anti-inflammatory cytokines at the protein level verified by ELISA and Western blot. HE staining analysis showed that the nerve fibers were repaired by piprine, the vacuoles were significantly reduced, and the degree of nerve fiber damage was also improved. Immunohistochemical analysis showed that the expression of p65 decreased after administration of piperine. Dual-luciferase reporter gene assay confirmed that the luciferase signal decreased significantly after cotransfection of miR-520a mimics and p65 3'UTR recombinant plasmid. To sum up, in the rat model of non-compressed lumbar disc herniation, piperine plays a significant role in analgesia. MiR-520a can specifically and directly target P65, and piperine can promote the expression of miR-520a, then inhibit the expression of p65, down-regulate the pro-inflammatory factors IL-1β and TNF-α, and up-regulate the effects of anti-inflammatory factors IL-10 and TGF-β1, so as to treat sciatica.

Circulating Levels of Visceral Adipose Tissue-Derived Serine Protease Inhibitor (Vaspin) Appear as a Marker of Musculoskeletal Pain Disability

Musculoskeletal pain (MSP), specifically low back pain (LBP), is often associated with several adipose tissue-derived cytokines (adipokines) and body composition, but their correlations with the LBP-related disability/severity phenotypes remain poorly understood. In this cross-sectional study, two self-reported validated questionnaires were used to collect back pain and disability data in an ethnically homogeneous family-based population sample (N = 1078). Plasma levels of relatively new adipokines, vaspin and adipsin, were detected by ELISA. Body composition parameters, including fat, skeletal muscle mass, extracellular water (ECW), and others were assessed through bioelectrical impedance analysis (BIA) technology. Statistical analysis was conducted, accounting for the familial composition of the sample. The multiple regression analyses with four LBP-related phenotypes as dependent variables consistently showed, for the first time, the significant associations with vaspin levels, regardless of other covariates. The odds ratios (OR)/SD ranged between 1.24 (95%CI = 1.03-1.50) and 1.33 (95%CI = 1.07-1.64), depending on the LBP phenotype. Among the tested body composition covariates, only ECW levels displayed consistent and highly significant associations with all tested LBP phenotypes (OR from 1.43, 95%CI = 1.14-1.79 to 1.68, 95%CI = 1.26-2.24). The results clearly suggest that circulating concentrations of vaspin and ECW levels could serve as biomarkers of MSP/LBP severity and complications.