Protraction of neuropathic pain by morphine is mediated by spinal damage associated molecular patterns (DAMPs) in male rats.

We have recently reported that a short course of morphine, starting 10days after sciatic chronic constriction injury (CCI), prolonged the duration of mechanical allodynia for months after morphine ceased. Maintenance of this morphine-induced persistent sensitization was dependent on spinal NOD-like receptor protein 3 (NLRP3) inflammasomes-protein complexes that proteolytically activate interleukin-1ß (IL-1ß) via caspase-1. However, it is still unclear how NLRP3 inflammasome signaling is maintained long after morphine is cleared. Here, we demonstrate that spinal levels of the damage associated molecular patterns (DAMPs) high mobility group box 1 (HMGB1) and biglycan are elevated during morphine-induced persistent sensitization in male rats; that is, 5weeks after cessation of morphine dosing. We also show that HMGB1 and biglycan levels are at least partly dependent on the initial activation of caspase-1, as well as Toll like receptor 4 (TLR4) and the purinergic receptor P2X7R-receptors responsible for priming and activation of NLRP3 inflammasomes. Finally, pharmacological attenuation of the DAMPs HMGB1, biglycan, heat shock protein 90 and fibronectin persistently reversed morphine-prolonged allodynia. We conclude that after peripheral nerve injury, morphine treatment results in persistent DAMP release via TLR4, P2X7R and caspase-1, which are involved in formation/activation of NLRP3 inflammasomes. These DAMPs are responsible for maintaining persistent allodynia, which may be due to engagement of a positive feedback loop, in which NLRP3 inflammasomes are persistently activated by DAMPs signaling at TLR4 and P2X7R.

Human MMP28 expression is unresponsive to inflammatory stimuli and does not correlate to the grade of intervertebral disc degeneration.

BACKGROUND: MMP28 (epilysin) is a recently discovered member of the MMP (matrix metalloproteinase) family that is, amongst others, expressed in osteoarthritic cartilage and intervertebral disc (IVD) tissue. In this study the hypothesis that increased expression of MMP28 correlates with higher grades of degeneration and is stimulated by the presence of proinflammatory molecules was tested. Gene expression levels of MMP28 were investigated in traumatic and degenerative human IVD tissue and correlated to the type of disease and the degree of degeneration (Thompson grade). Quantification of MMP28 gene expression in human IVD tissue or in isolated cells after stimulation with the inflammatory mediators lipopolysaccharide (LPS), interleukin (IL)-1ß, tumor necrosis factor (TNF)-α or the histondeacetylase inhibitor trichostatin A was performed by real-time RT PCR. RESULTS: While MMP28 expression was increased in individual cases with trauma or disc degeneration, there was no significant correlation between the grade of disease and MMP28 expression. Stimulation with LPS, IL-1ß, TNF-α or trichostatin A did not alter MMP28 gene expression at any investigated time point or any concentration. CONCLUSIONS: Our results demonstrate that gene expression of MMP28 in the IVD is not regulated by inflammatory mechanisms, is donor-dependent and cannot be positively or negatively linked to the grade of degeneration and only weakly to the occurrence of trauma. New hypotheses and future studies are needed to find the role of MMP28 in the intervertebral disc.

Changes in Nerve Growth Factor Expression and Macrophage Phenotype Following Intervertebral Disc Injury in Mice.

Nerve growth factor (NGF) is increased in intervertebral discs (IVDs) after disc injury and anti-NGF therapy improves low back pain in humans. Furthermore, M1 and M2 macrophage subtypes play a role in degenerative IVD injury. We examined M1 and M2 macrophage markers and NGF and cytokine expression in IVD-derived cells from control and IVD-injured mice for 28 days following injury. Ngf messenger RNA (mRNA) expression was increased 1 day after injury in injured compared with control mice, and persisted for up to 28 days. Flow cytometric analysis demonstrated that the proportion of F4/80+ CD11b+ cells was significantly increased from 1 day after injury for up to 28 days in injured compared to control mice. mRNA expression of M1 macrophage markers Tnfa, Il1b, and Nos2 was significantly increased 1 day after injury in injured compared to control mice, before gradually decreasing. At 28 days, no significant difference was observed in M1 markers. The M2a marker, Ym1, was significantly increased 1 day after injury in injured compared with control mice, while M2a and M2c markers Tgfb and Cd206 were significantly increased 7, 14, and 28 days after injury. Tumor necrosis factor α (TNF-α) and transforming growth factor ß (TGF-ß) stimulated Ngf mRNA and NGF protein expression in IVD cells. Our results suggest that TNF-α and TGF-ß may stimulate NGF production under inflammatory and non-inflammatory conditions following IVD injury. As TNF-α and TGF-ß are produced by M1 and M2 macrophages, further investigations are needed to reveal the role of macrophages in NGF expression following IVD injury. Our results may aid in developing treatments for IVD-related LBP pathology. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1798-1804, 2019.

[Immunological monitoring in the surgical treatment of damages to the thoracic and lumbar parts of the vertebral column].

Adequacy of diagnostic actions, choice, on their basis, of a treatment for patients with vertebral fractures and spinal cord injury, improvement of the results of surgical treatment are anactual problem of modern traumatology and neurosurgery. The purpose of the study was to define the role of immunological monitoring in the evaluation of patients' condition in the presence of spinal damage. Blood was tested in 111 patients during two-stage surgical treatment for spinal damages: 1) osteosynthesis by an external fixation device and 2) anterior spinal fusion. The results of general clinical blood checks, lymphocytic phenotyping, determination of neutrophilic functional and metabolic activity, the levels of circulating immune complexes and immunoglobulins, the concentrations of cytokines (IL-1alpha, IL-1beta, IL-1ra, IL-8, tumor necrosis factor-alpha) and acute-phase proteins were estimated before surgery and in different periods up to 6 months inclusive. Statistical studies were conducted using the STATISTICA program. Examination of three groups of patients (two of which had postoperative complications, the other was a control group) has ascertained that immunological monitoring in the treatment of spinal injure may be used to predict postoperative complications, such as delayed consolidation and impaired formation of a bone block in the vertebral segment, be made in different management periods (before surgery and on follow-up days 2 or 10), and include prognostic tests, by taking into account the capacities of a laboratory service.

Toward developing a specific outcome instrument for spine trauma: an empirical cross-sectional multicenter ICF-based study by AOSpine Knowledge Forum Trauma.

STUDY DESIGN: Empirical cross-sectional multicenter study. OBJECTIVE: To identify the most commonly experienced problems by patients with traumatic spinal column injuries, excluding patients with complete paralysis. SUMMARY OF BACKGROUND DATA: There is no disease or condition-specific outcome instrument available that is designed or validated for patients with spine trauma, contributing to the present lack of consensus and ongoing controversies in the optimal treatment and evaluation of many types of spine injuries. Therefore, AOSpine Knowledge Forum Trauma started a project to develop such an instrument using the International Classification of Functioning, Disability and Health (ICF) as its basis. METHODS: Patients with traumatic spinal column injuries, within 13 months after discharge from hospital were recruited from 9 trauma centers in 7 countries, representing 4 AOSpine International world regions. Health professionals collected the data using the general ICF Checklist. The responses were analyzed using frequency analysis. Possible differences between the world regions and also between the subgroups of potential modifiers were analyzed using descriptive statistics and Fisher exact test. RESULTS: In total, 187 patients were enrolled. A total of 38 (29.7%) ICF categories were identified as relevant for at least 20% of the patients. Categories experienced as a difficulty/impairment were most frequently related to activities and participation (n = 15), followed by body functions (n = 6), and body structures (n = 5). Furthermore, 12 environmental factors were considered to be a facilitator in at least 20% of the patients. CONCLUSION: Of 128 ICF categories of the general ICF Checklist, 38 ICF categories were identified as relevant. Loss of functioning and limitations in daily living seem to be more relevant for patients with traumatic spinal column injuries rather than pain during this time frame. This study creates an evidence base to define a core set of ICF categories for outcome measurement in adult spine trauma patients. LEVEL OF EVIDENCE: 4.

Evaluation of prognostic significance of circulating interleukin-6 in patients with accident spine injuries.

Our study aimed to verify whether patients with spine accident injury present altered plasma levels of IL-6 and whether the levels of this cytokine are related with the production of acute phase proteins which are elevated after trauma and infection. 34 subjects admitted to an Intensive Care Unit for spine injuries were examined: 26 presented fever over 38.5 degrees C and in 13 of them blood or local cultures were positive for pathogenic bacteria. IL-6, C-reactive protein (CRP), haptoglobin (HPT), alpha 2-macroglobulin (alpha 2Mg), C3c and C4 Complement factors were determined on admission and in the course of their hospital stay. No changes in IL-6 systemic levels were present in the subjects examined and only CRP was constantly high. Although within the normal range IL-6 levels inversely correlated with fever. Our results show the difficulty to utilize the IL-6 circulating levels as prognosis parameter in patients subjected to spine accident injuries.

[Effect of spinal cord and spinal injuries on the phagocytic activity of neutrophils]. / Vliianie povrezhdenii spinnogo mozga i pozvonochnika na fagotsitarnuiu aktivnost' neitrofilov.

Study of neutrophil phagocytic activity in injuries to the spinal cord and spine and in damage to the spine without involvement of the spinal cord showed that injuries to the spinal cord have no specific effect on this activity. True, the phagocytic reaction is inhibited in the first 2-3 weeks after the trauma both in patients with injury to the spinal cord and spine and in those with injury only to the spine. In later periods after the trauma, however, with the neurological status remaining the same, the values of the phagocytic reaction do not differ from those in healthy persons. The level at which the spinal cord is injured hardly affects the activity of phagocytosis. The examination was conducted in 117 patients with spinal fractures 94 of whom had also sustained injury to the spinal cord.

[The possibility of immunocorrection in spinal-spinal cord trauma by using intravenous laser irradiation]. / Vozmozhnost' immunokorrektsii pri pozvonochno-spinnomozgovoi travme s pomoshch'iu vnutrivennogo lazernogo oblucheniia.

The natural defense factors of the body and the cell factors of immunity were studied in 60 patients with acute and early spinal trauma. Immunodeficiency develops in 100% of cases with acute and early spinal trauma. Blood intravenous laser radiation at wave lengths of 632 and 830 nm was shown to produce an immunostimulating effect.

Serum immunoglobulins after surgical operation.

We measured immunoglobulins in the sera of 33 patients on days 1, 3, 6, 10, and 17 and three to four weeks after surgical operations (mostly hysterectomy or appendectomy) or (six patients) after spinal injury. In the absence of infection or blood transfusion, IgG usually decreased slightly and transiently after hysterectomy or appendectomy, as did IgA or IgM after hysterectomy. IgD concentrations showed no consistent changes, but in one patient after hysterectomy and with minimal infection IgD concentration decreased sharply, which contrasted with significant and early increases in IgG, IgA, and IgM. IgD concentration was not correlated with type of operation, presence of infection, or changes in the other immunoglobulins. IgE concentrations either die not change or, in some patients, increased or decreased initially, after operation. We conclude that immunoglobulin concentrations in serum are subject to multiple, unpredictable influences after trauma.