Tumor necrosis factor-α blockade in recurrent and disabling chronic sciatica associated with post-operative peridural lumbar fibrosis: results of a double-blind, placebo randomized controlled study

Development of Anti-fibrotic Therapy in Stricturing Crohn's Disease: Lessons from Randomized Trials in Other Fibrotic Diseases

Intestinal fibrosis is considered an inevitable complication of Crohn's disease (CD) that results in symptoms of obstruction and stricture formation. Endoscopic or surgical treatment is required to treat the majority of patients. Progress in the management of stricturing CD is hampered by the lack of effective anti-fibrotic therapy; however, this situation is likely to change because of recent advances in other fibrotic diseases of the lung, liver and skin. In this review, we summarized data from randomized controlled trials (RCT) of anti-fibrotic therapies in these conditions. Multiple compounds have been tested for the anti-fibrotic effects in other organs. According to their mechanisms, they were categorized into growth factor modulators, inflammation modulators, 5-hydroxy-3-methylgultaryl-coenzyme A (HMG-CoA) reductase inhibitors, intracellular enzymes and kinases, renin-angiotensin system (RAS) modulators and others. From our review of the results from the clinical trials and discussion of their implications in the gastrointestinal tract, we have identified several molecular candidates that could serve as potential therapies for intestinal fibrosis in CD.

Platelet-rich plasma and cytokines in neuropathic pain: A narrative review and a clinical perspective

BACKGROUND AND OBJECTIVE

Neuropathic pain arises as a direct consequence of a lesion or disease affecting the somatosensory system. A number of preclinical studies have provided evidence for the involvement of cytokines, predominantly secreted by a variety of immune cells and by glial cells from the nervous system, in neuropathic pain conditions. Clinical trials and the use of anti-cytokine drugs in different neuropathic aetiologies support the relevance of cytokines as treatment targets. However, the use of such drugs, in particularly biotherapies, can provoke notable adverse effects. Moreover, it is challenging to select one given cytokine as a target, among the various neuropathic pain conditions. It could thus be of interest to target other proteins, such as growth factors, in order to act more widely on the neuroinflammation network. Thus, platelet-rich plasma (PRP), an autologous blood concentrate, is known to contain a natural concentration of growth factors and immune system messengers and is widely used in the clinical setting for tissue regeneration and repair.

DATABASE AND DATA TREATMENT

In the present review, we critically assess the current knowledge on cytokines in neuropathic pain by taking into consideration both human studies and animal models.

RESULTS

This analysis of the literature highlights the pathophysiological importance of cytokines. We particularly highlight the concept of time- and tissue-dependent cytokine activation during neuropathic pain conditions.

RESULTS

Conclusion: Thus, direct or indirect cytokines modulation with biotherapies or growth factors appears relevant. In addition, we discuss the therapeutic potential of localized injection of PRP as neuropathic pain treatment by pointing out the possible link between cytokines and the action of PRP.

SIGNIFICANCE

Preclinical and clinical studies highlight the idea of a cytokine imbalance in the development and maintenance of neuropathic pain. Clinical trials with anticytokine drugs are encouraging but are limited by a 'cytokine candidate approach' and adverse effect of biotherapies. PRP, containing various growth factors, is a new therapeutic used in regenerative medicine. Growth factors can be also considered as modulators of cytokine balance. Here, we emphasize a potential therapeutic effect of PRP on cytokine imbalance in neuropathic pain. We also underline the clinical interest of the use of PRP, not only for its therapeutic effect but also for its safety of use.

LRP1 deficiency in microglia blocks neuro-inflammation in the spinal dorsal horn and neuropathic pain processing

Following injury to the peripheral nervous system (PNS), microglia in the spinal dorsal horn (SDH) become activated and contribute to the development of local neuro-inflammation, which may regulate neuropathic pain processing. The molecular mechanisms that control microglial activation and its effects on neuropathic pain remain incompletely understood. We deleted the gene encoding the plasma membrane receptor, LDL Receptor-related Protein-1 (LRP1), conditionally in microglia using two distinct promoter-Cre recombinase systems in mice. LRP1 deletion in microglia blocked development of tactile allodynia, a neuropathic pain-related behavior, after partial sciatic nerve ligation (PNL). LRP1 deletion also substantially attenuated microglial activation and pro-inflammatory cytokine expression in the SDH following PNL. Because LRP1 shedding from microglial plasma membranes generates a highly pro-inflammatory soluble product, we demonstrated that factors which activate spinal cord microglia, including lipopolysaccharide (LPS) and colony-stimulating factor-1, promote LRP1 shedding. Proteinases known to mediate LRP1 shedding, including ADAM10 and ADAM17, were expressed at increased levels in the SDH after PNL. Furthermore, LRP1-deficient microglia in cell culture expressed significantly decreased levels of interleukin-1β and interleukin-6 when treated with LPS. We conclude that in the SDH, microglial LRP1 plays an important role in establishing and/or amplifying local neuro-inflammation and neuropathic pain following PNS injury. The responsible mechanism most likely involves proteolytic release of LRP1 from the plasma membrane to generate a soluble product that functions similarly to pro-inflammatory cytokines in mediating crosstalk between cells in the SDH and in regulating neuropathic pain.

A Comparison of the Efficacy and Tolerability of the Treatments for Sciatica: A Network Meta-Analysis

Background: There remains a lack of a systematic summary of the efficacy and safety of various medicines for sciatica, and discrepancies among these exist. Objective: The aim of this study is to comprehensively assess the efficacy of and tolerance to several medical options for the treatment of sciatica. Methods: We performed a network meta-analysis and illustrated the results by the mean difference or odds ratio. The surface under the cumulative ranking curve (SUCRA) was used for indicating the preferable treatments. All data analyses and graphs were achieved via R 3.3.2 and Stata 13.0. Results: The subcutaneous anti–tumor necrosis factor–α (anti-TNF-α) was superior to the epidural steroid + anesthetic in reducing lumbar pain in both acute + chronic sciatica patients and acute sciatica patients. The epidural steroid demonstrated a better ability regarding the Oswestry disability score (ODI) compared to the subcutaneous anti-TNF-α. In addition, for total pain relief, the use of nonsteroidal antiinflammatory drugs was inferior to the epidural steroid + anesthetic. The epidural anesthetic and epidural steroid + anesthetic both demonstrated superiority over the epidural steroid and intramuscular steroid. The intravenous anti-TNF-α ranked first in leg pain relief, while the subcutaneous anti-TNF-α ranked first in lumbar pain relief, and the epidural steroid ranked first in the ODI on the basis of SUCRA. In addition, their safety outcome (withdrawal) rankings were all medium to high. Conclusions: Intravenous and subcutaneous anti-TNF-α were identified as the optimal treatments for both acute + chronic sciatica patients and acute sciatica patients. In addition, the epidural steroid was also recommended as a good intervention due to its superiority in reducing ODI.

A Randomized Clinical Trial Comparing the Effectiveness of Electroacupuncture versus Medium-Frequency Electrotherapy for Discogenic Sciatica

Objective. To investigate the short- and long-term effects of electroacupuncture (EA) compared with medium-frequency electrotherapy (MFE) on chronic discogenic sciatica. Methods. One hundred participants were randomized into two groups to receive EA (n = 50) or MFE (n = 50) for 4 weeks. A 28-week follow-up of the two groups was performed. The primary outcome measure was the average leg pain intensity. The secondary outcome measures were the low back pain intensity, Oswestry Disability Index (ODI), patient global impression (PGI), drug use frequency, and EA acceptance. Results. The mean changes in the average leg pain numerical rating scale (NRS) scores were 2.30 (1.86-2.57) and 1.06 (0.62-1.51) in the EA and MFE groups at week 4, respectively. The difference was significant (P < 0.001). The long-term follow-up resulted in significant differences. The average leg pain NRS scores decreased by 2.12 (1.70-2.53) and 0.36 (-0.05-0.78) from baseline in the EA and MFE groups, respectively, at week 28. However, low back pain intensity and PGI did not differ significantly at week 4. No serious adverse events occurred. Conclusions. EA showed greater short-term and long-term benefits for chronic discogenic sciatica than MFE, and the effect of EA was superior to that of MFE. The study findings warrant verification. This trial was registered under identifier ChiCTR-IPR-15006370.