Ozone as Modulator of Resorption and Inflammatory Response in Extruded Nucleus Pulposus Herniation. Revising Concepts

Ozone therapy has been used to treat disc herniation for more than four decades. There are several papers describing results and mechanism of action. However, it is very important to define the characteristics of extruded disc herniation. Although ozone therapy showed excellent results in the majority of spinal diseases, it is not yet fully accepted within the medical community. Perhaps it is partly due to the fact that, sometimes, indications are not appropriately made. The objective of our work is to explain the mechanisms of action of ozone therapy on the extruded disc herniation. Indeed, these mechanisms are quite different from those exerted by ozone on the protruded disc herniation and on the degenerative disc disease because the inflammatory response is very different between the various cases. Extruded disc herniation occurs when the nucleus squeezes through a weakness or tear in the annulus. Host immune system considers the nucleus material to be a foreign invader, which triggers an immune response and inflammation. We think ozone therapy modulates this immune response, activating macrophages, which produce phagocytosis of extruded nucleus pulposus. Ozone would also facilitate the passage from the M1 to M2 phase of macrophages, going from an inflammatory phase to a reparative phase. Further studies are needed to verify the switch of macrophages.

The inflammatory response in the regression of lumbar disc herniation

Lumbar disc herniation (LDH) is highly associated with inflammation in the context of low back pain. Currently, inflammation is associated with adverse symptoms related to the stimulation of nerve fibers that may lead to pain. However, inflammation has also been indicated as the main factor responsible for LDH regression. This apparent controversy places inflammation as a good prognostic indicator of spontaneous regression of LDH. This review addresses the molecular and cellular mechanisms involved in LDH regression, including matrix remodeling and neovascularization, in the scope of the clinical decision on conservative versus surgical intervention. Based on the evidence, a special focus on the inflammatory response in the LDH context is given, particularly in the monocyte/macrophage role. The phenomenon of spontaneous regression of LDH, extensively reported in the literature, is therefore analyzed here under the perspective of the modulatory role of inflammation.

The effect of percutaneous endoscopic lumbar discectomy under different anesthesia on pain and immunity of patients with prolapse of lumbar intervertebral disc

OBJECTIVE

To explore the effect of percutaneous transforaminal endoscopic discectomy under different anesthesia on pain and immunity of patients with lumbar disc herniation.

PATIENTS AND METHODS

92 cases of patients with lumbar disc herniation in the Affiliated Hospital of Qingdao University from February 2015 to January 2016 were collected. These patients were randomly divided into control group and observation group (n = 46). Patients in the control group underwent percutaneous transforaminal endoscopic discectomy with the use of local anesthesia, while patients in the observation group used continuous epidural anesthesia. Oswestry Disability Index (ODI) and Visual Analogue Scale of Pain (VAS) were used to compare the surgical effect and the degree of pain of patients in the two groups. Adverse reactions (nausea, vomiting, dizziness, drowsiness) of patients in two groups were compared. T lymphocytes subset level (CD4+, CD8+) and inflammatory cytokines (IL-2, TNF) in the immune system were compared on the 1st, 3rd, and 10th day post-operatively.

RESULTS

The pain degree of patients in the two groups had no significant difference before their operations (p > 0.05). The intraoperative pain rate of patients in the observation group was significantly lower than the control group (p < 0.05). Patients in both groups achieved a remarkable decrease of pain intensity on month 1 and month 3 post-operatively (p < 0.05). There is no significant difference between the two groups (p > 0.05). ODI scores of patients in the two groups had no significant difference pre-operatively (p > 0.05). Patients in both groups achieved a remarkable decrease of ODI scores after surgery (p < 0.05), and there is no significant difference between the two groups (p > 0.05). The occurrence of adverse reactions in the observation group was significantly lower than the control group (p < 0.05). On day 1 and 3 post-operatively, CD4+ and CD8+ levels of patients in both groups were lower than before operation, and data in the control group decreased more than the observation group (p < 0.05). IL-2 and TNF-α levels of patients in the two groups were significantly higher than pre-operatively, and data in the control group was higher than the observation group (p < 0.05). On day 10 post-operatively, all the indexes returned to the preoperative level.

CONCLUSIONS

Both continuous epidural anesthesia and local anesthesia can reduce or avoid perioperative pain, but continuous epidural anesthesia has more advantages than local anesthesia, and it can improve the immune function for patients undergoing PTED for LDH.

[Effects of sacral canal injection on nerve root local inflammatory factors in rat model with lumbar disc herniation]

OBJECTIVE

To explore the effects of sacral canal injection on nerve root local inflammatory factors in rat model with lumbar disc herniation, in order to identify its mechanism of treatment.

METHODS

Forty-eight male SD rats were randomly divided into sham operation group(group A), model group (group B), Chinese medicine group(group C) and western medicine group(group D). There were 12 rats in each group. The model of lumbar disc herniation was established using compression and inflammatory stimulation in group B, C, D. All rats were given epidural catheterization and group A and B with physiological saline (1 ml/kg), group C with mixed liquor of 2% lidocaine and compound Danshen injections and physiological saline (2:2: 16) and group D with mixed liquor of 2% lidocaine and triamcinolone acetonide injection and physiological saline (2:2:16), once a week for a total of three treatments. Four rats were killed every 1 week after injection for once, and the inflammatory factors of tumor necrosis factor (TNF-alpha), prostaglandin E2 (PGE2), interleukin-l (IL-1) and interleukin-6 (IL-6) were detected by ELISA method.

RESULTS

The levels of TNF-alpha, PGE2, IL-1 and IL-6 in compressed nerve tissues in group B were increased than those of group A (P < 0.01). The levels of PGE2, IL-1 and IL-6 in group C and D were decreased than those of group B, and group D was much less(P<0.05). There was no significant difference in level of TNF-alpha among group B, C, D (P > 0.05).

CONCLUSION

Compound compression with inflammatory stimulation can lead to massive release of inflammatory mediators, such as TNF-alpha, PGE2, IL-1 and IL-6. Both injection with compound Danshen injections and triamcinolone acetonide injections by sacral canal can reduce the levels of part inflammatory mediators (PGE2, IL-1 and IL-6), and the effect of Glucocorticoid is better than Danshen (P < 0.05).

Immune cascades in human intervertebral disc: the pros and cons

The unique structural hallmark of the intervertebral disc has made its central composition, the nucleus pulposus (NP), excluded from the immunologic tolerance. Consequently, the intervertebral disc is identified as an immune-privileged organ. Traditionally, local detrimental immune activities caused by NP at the lesion sites of the disc are noted as a significant factor contributing to disc degeneration. However, given the beneficial activities of immune cells in other immune-privileged sites on basis of current evidence, the degenerate disc might need the assistance of a subpopulation of immune cells to restore its structure and lessen inflammation. In addition, the beneficial impact of immune cells can be seen in the absorption of the herniated NP, which is an important factor causes the mechanical compression of nerve roots. Consequently, a modulated immune network in degenerate disc is essential for the restoration of this immune-privileged organ. Until now, the understandings of immune response in disc degeneration still rest on the harmful aspect. Further studies are needed to explore its beneficial influence. Accordingly, there are no absolutely the pros and cons in terms of immune reactions caused by NP.

[Effect of removing dampness and promoting diuresis method on IgG, IgM and IL-1beta, IL-8 in serum of rats with autoimmunity induced by nucleus pulposus]

OBJECTIVE

To explore the effects of removing dampness and promoting diuresis method on autoimmune and immuno-inflammatory response caused by nucleus pulposus of rats, in order to provide the basis for the treatment of lumbar disc herniation with Chinese medical immunotherapy.

METHODS

Forty male Wistar rats were divided into 4 groups randomly according to body weight layer:sham operation group (group A), model contrast group (group B), colchicine tablets group (group C), modified Qingyao decoction group (group D). There were 10 rats in each group. Nucleus pulposus of coccygeal vertebra was transplanted to the gluteal muscle by operation in groups B, C, D, which can lead to autoimmune and immuno-inflammatory response of rats; the rats of group A were only treated with sham operation. At the 3rd day after operation, the rats were fed through intragastric administration, the group A and B with distilled water (10 ml/kg), the group C and D respectively with suspension of colchicine tablets (10 ml/kg, 0.01 mg/ml) and water-decocted liquid of modified Qingyao decoction (10 ml/kg,1.035 g/ml), once a day and continuous medication for 18 days. All rats were killed at the 21th day after operation. The immunoglobulin G (IgG), immunoglobulin M (IgM) and interleukin-1beta (IL-1beta), interleukin-8 (IL-8) level in serum of different groups were detected by ELISA method. At the same time, surrounding tissues of the transplanted nucleus pulposus were observed by pathological section.

RESULTS

The level of IgG, IgM, IL-1beta, IL-8 in serum of group B was significantly higher than that of group A (P < 0.01), while the level of IgG, IgM, IL-1beta, IL-8 in serum of group C, D was significantly lower than that of group B (P < 0.05 or P < 0.01). Moreover, pathological section indicated that immuno-inflammatory response was hardly found in surgical site of group A, while local immuno-inflammatory response of surrounding tissues of the transplanted nucleus pulposus of group C and D was much lighter than that of group B.

CONCLUSION

Removing dampness and promoting diuresis method could inhibit autoimmune and immuno-inflammatory response caused by nucleus pulposus of rats.

Proinflammatory cytokine expression profile in degenerated and herniated human intervertebral disc tissues

OBJECTIVE

Prior reports document macrophage and lymphocyte infiltration with proinflammatory cytokine expression in pathologic intervertebral disc (IVD) tissues. Nevertheless, the role of the Th17 lymphocyte lineage in mediating disc disease remains uninvestigated. We undertook this study to evaluate the immunophenotype of pathologic IVD specimens, including interleukin-17 (IL-17) expression, from surgically obtained IVD tissue and from nondegenerated autopsy control tissue.

METHODS

Surgical IVD tissues were procured from patients with degenerative disc disease (n = 25) or herniated IVDs (n = 12); nondegenerated autopsy control tissue was also obtained (n = 8) from the anulus fibrosus and nucleus pulposus regions. Immunohistochemistry was performed for cell surface antigens (CD68 for macrophages, CD4 for lymphocytes) and various cytokines, with differences in cellularity and target immunoreactivity scores analyzed between surgical tissue groups and between autopsy control tissue regions.

RESULTS

Immunoreactivity for IL-4, IL-6, IL-12, and interferon-gamma (IFNgamma) was modest in surgical IVD tissue, although expression was higher in herniated IVD samples and virtually nonexistent in control samples. The Th17 lymphocyte product IL-17 was present in >70% of surgical tissue fields, and among control samples was detected rarely in anulus fibrosus regions and modestly in nucleus pulposus regions. Macrophages were prevalent in surgical tissues, particularly herniated IVD samples, and lymphocytes were expectedly scarce. Control tissue revealed lesser infiltration by macrophages and a near absence of lymphocytes.

CONCLUSION

Greater IFNgamma positivity, macrophage presence, and cellularity in herniated IVDs suggests a pattern of Th1 lymphocyte activation in this pathology. Remarkable pathologic IVD tissue expression of IL-17 is a novel finding that contrasts markedly with low levels of IL-17 in autopsy control tissue. These findings suggest involvement of Th17 lymphocytes in the pathomechanism of disc degeneration.

[A study of a rat lumbar disc herniation model and the mechanism spontaneous of resorption]

OBJECTIVE

To establish a new animal model of resorption of lumbar disc herniation.

METHODS

Twenty 3-month-old Sprague Dawley (SD) male rats were randomly divided into experimental group and control group. The caudal discs of the experimental rats were surgically removed and were implanted in the epidural. The animals were killed at 30 days, and the implanted nucleus pulposus were took out for HE staining,flow cytometry and immunohistochemistry. In the control group, coils were implanted in the back muscles, and the animals were killed at 30 days after the operation for the above test.

RESULTS

In the experimental group, immunohistochemical staining of TNF-alpha, VEGF were positive at 30 days. The Th cells and B cells in the experimental group were more than that in the control group with statistically significant differences.

CONCLUSION

The model can well reveal the re-absorption process the of the ruptured disc, and provide a new re-absorption disc animal model for the further study.

[Effect of the mixed liquor of danshen and magnesium sulfate injection on IgG and IgM in serum of rabbits with lumbar intervertebral disc herniation]

OBJECTIVE

To explore the effect of the mixed liquor of danshen and magnesium sulfate injection on inflammatory reaction caused by autoimmune response of rabbits with lumbar intervertebral disc herniation.

METHODS

Sixty rabbits were divided into blank group (10 rabbits), sham operation group (10 rabbits), model group (40 rabbits) according to method of random digits table. Then model group was divided into made group (group A, 10 rabbits), normal saline group (group B, 10 rabbits), aescin natrium group (group C, 10 rabbits) and danshen and magnesium sulfate injection group (group D,10 rabbits). After model success of lumbar intervertebral disc herniation, different drugs were given to rabbits with lumbar intervertebral disc herniation by ear margin vein. The rabbits of the group C,B,D were respectively given aescin natriu (0.5 mg/kg), normal saline (5 ml/kg), danshen and magnesium sulfate injection (2.0 mg/kg). The rabbits of blank group, sham operation group and group A were not given any disposal. The IgG and IgM level in serum of different groups were determined with ELISA method in fourteen day after model success and drugs given.

RESULTS

The level of IgG and IgM in the group A was higher than that of blank group and sham operation group (P < 0.05). The level of IgG and IgM in the group D was lower than that of group B,C (P < 0.05).

CONCLUSION

The mixed liquor of danshen () and magnesium sulfate injection could inhibit inflammatory reaction caused by autoimmune response of lumbar intervertebral disc herniation,which provides a new alternative for lumbar intervertebral disc herniation.

[Immunologic theory investigation and discussion of pain caused by lumbar intervertebral disc herniation (LDH)]

To explore the main clinical manifestation (lower back pain and ischialgia) of LDH with immunologic method and study the relationship and clinical significance of the cardinal symptom (pain) and immune comple (IC), macrophage (MP),interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF), prostaglandin E2 (PGE2), phosphatidase A2 (PLA2), nitrogen monoxidum (NO) expressing, finding a new way in order to prevention and cure of LDH. We will review immunologic theory of LDH pain.

[An experimental study on the influence of radix astragali on the ressorption of ruptured disc herniation]

OBJECTIVE

To investigate the possible mechanism of immune response in the resorption of the ruptured intervertebral disc herniation, and the possible mechanism of radix astragali on the resorption of the ruptured disc herniation.

METHODS

Twenty-eight male SD (Sprague-dawley) rats were chosen. The rats were randomly divided into 4 groups: the control group, model group, the group treated with radix astragali injection and the group treated whit thymic peptide. The rats were killed and discs were harvested 10 days after treatment. Flow cytometry and HE staining were used for analysis of cells and tissue.

RESULTS

Compared with the control group, the proportion of activated T cells (CD4+ and CD8+) and B cells were significantly higher in the two drug-treatment groups.

CONCLUSION

Herniated nucleus pulposus attracts activated T and B cells and triggered an immune response. Radix astragali could strengthen the autoimmune response.

[Intervertebral disc pathologies from an immunological perspective]

INTRODUCTION

The back pain associated to intervertebral prolapsed disc is a frequent pathology, that produces in many cases severe work-disability. The mechanisms of pain generation are controversial, the mechanical theories of nerve compression have been weak for explaining severe pain in patients with low protrusion grades.

DEVELOPMENT

In the last years several studies have been accomplished in order to determinate the contribution of inflammatory phenomena into the intervertebral disc disease's evolution. Abnormal values of cytokines like TNF-alpha, IL-1 beta, IL-6, and other molecules related with the immune system have been found, although the available studies are inconsistent. The analysis of immune cells in the intervertebral disc is in the same way contradictory, but the presence of macrophages appears constantly. The variability might be originated by the self-heterogeneity of the immune system in a disease with repeated episodes of injury-reparation that could conduce to deregulation and progressive tissular damage.

CONCLUSION

Until now it seems clear the association of macrophages in the pathologic degeneration of the intervertebral disc, but the interaction of these in this microenvironment not totally. The understand of the cellular and molecular networks is fundamental for explaining the poor correlation between clinical and radiological findings, in addition to the potential impact on the actual management applied.

The association of the activation-inducible tumor necrosis factor receptor and ligand with lumbar disc herniation

PURPOSE

Herniated nucleus pulposus fragments are recognized by the immune system as a foreign-body, which results in an autoimmune reaction. Human activation-inducible tumor necrosis factor receptor (AITR) and its ligand, AITRL, are important costimulatory molecules in the pathogenesis of autoimmune diseases. Despite the importance of these costimulatory molecules in autoimmune disease, their role in the autoimmune reaction to herniated disc fragments has yet to be explored. The purpose of the present study is to investigate whether the overexpression of AITR and AITRL might be associated with lumbar disc herniation.

MATERIALS AND METHODS

The study population consisted of 20 symptomatic lumbar disc herniation patients. Ten macroscopically normal control discs were obtained from patients with spinal fractures managed with anterior procedures that involved a discectomy. Peripheral blood samples from both the study patients and controls were collected. The expression levels of AITR and AITRL were investigated by flow cytometric analysis, confocal laser scanning microscopy, immunohistochemistry and by reverse transcriptase-polymerase chain reaction (RT-PCR). The soluble AITR and AITRL serum levels were measured by an enzyme-linked immunosorbent assay.

RESULTS

Flow cytometric analysis revealed significantly higher levels of both AITR and AITRL in the lumbar disc herniation patients than in the controls. The AITRL expression levels were also increased in patients with lumbar disc herniation, shown by using confocal laser scanning microscopy, immunohisto-chemistry, and RT-PCR. Finally, soluble AITR and AITRL were elevated in the patients with lumbar disc herniations.

CONCLUSION

The AITR and AITRL are increased in both the herniated disc tissue and the peripheral blood of patients with lumbar disc herniation.

Intervertebral disc degeneration in relation to the COL9A3 and the IL-1ss gene polymorphisms

Disc degeneration is a complex condition in which environmental factors and multiple genes are expected to act together to determine the degenerative phenotype. Recently associations of COL9A2 (Trp2 allele) and COL9A3 (Trp3 allele) polymorphisms with lumbar disc disease characterized by sciatica have been reported. However, it is not known whether the Trp2 or Trp3 alleles contribute to disc degeneration (DD). In this study, the association between the collagen genes polymorphisms and lumbar DD was investigated. Furthermore, the influence of the IL-1beta(C(3954)-T) polymorphism on the association of collagen genes polymorphisms with DD was examined. Lumbar intervertebral discs of 135 middle-aged occupationally active men were evaluated with magnetic resonance imaging, using decreased signal intensity of the nucleus pulposus, disc bulges, and decreased disc height as signs of degeneration. Blood samples were analysed for the presence of COL9A3 and COL9A2 tryptophan alleles (Trp3 and Trp2 alleles). The COL11A2, COL2A1 and IL-1beta(C(3954)-T) polymorphisms were also analysed. Multivariate logistic regression analysis allowing for occupation and body mass index showed that the carriage of the Trp3 allele in the absence of the IL-1betaT(3954) allele increased the risk of dark nucleus pulposus (OR 7.0, 95% CI 1.3-38.8) and joint occurrence of degenerative changes (OR 8.0, 95% CI 1.4-44.7). There was no effect of the Trp3 allele on DD in the presence of the IL-1betaT(3954) allele. The carriers of the COL11A2 minor allele had an increased risk of disc bulges (OR 2.1, 95% CI 1.0-4.2) as compared with non-carriers. The results suggest that the effect of the COL9A3 gene polymorphism on DD might be modified by the IL-1beta gene polymorphism.

Positive feedback loop of interleukin-1beta upregulating production of inflammatory mediators in human intervertebral disc cells in vitro

OBJECT

Interleukin-1beta (IL-1beta) induces neurological symptoms in intervertebral disc herniation (IDH). Recently, the existence of a positive feedback loop of IL-1beta, which encourages an inflammatory reaction or degeneration in the cells of tendon, has been reported. The authors hypothesized that there is a positive feedback loop of IL-1beta in the cells of IDH.

METHODS

Eight human intervertebral disc specimens were harvested during spinal surgery for lumbar disc herniation. The cells were stimulated in serum-free medium with or without exogenous IL-1beta. The messenger RNA (mRNA) was extracted for reverse-transcription polymerase chain reaction (PCR) and real-time PCR to quantify the mRNA of endogenous IL-1beta, IL-6, cyclooxygenase-2 (COX-2), and matrix metalloproteinases (MMPs). The cells were then stimulated in serum-free medium with or without exogenous IL-1beta, and then exogenous IL-1beta was removed. After 2, 4, and 6 days, the medium was collected, and enzyme-linked immunosorbent assay was used to measure the protein concentration of endogenous IL-1beta. The mRNA expressions of endogenous IL-1beta, IL-6, COX-2, and MMPs were increased significantly depending on the concentration of exogenous IL-1beta. The protein concentration of endogenous IL-1beta was increased over time.

CONCLUSIONS

There was a positive feedback loop of IL-1beta in the cells of IDH. Furthermore, the productions of IL-6, COX-2, MMP-1, and MMP-3 were upregulated as a result of the increasing concentration of IL-1beta in a positive feedback loop of IL-1beta. The authors concluded that this positive feedback loop of IL-1beta upregulated the production of mediators and thus can cause cessation of symptoms in IDH.

Hepatitis C virus infection in psoriatic arthritis

OBJECTIVE

To evaluate the prevalence of hepatitis C virus (HCV) infection in patients with psoriatic arthritis (PsA), compared with patients affected by non HCV-related rheumatic degenerative disorders.

METHODS

One-hundred consecutive subjects with PsA, and a statistically comparable group of 100 consecutive patients with peripheral osteoarthritis (OA) or sciatica due to L4-L5 or L5-S1 herniated disc were tested for HCV infection with a third-generation microparticle enzyme immunoassay (MEIA). Positive cases were submitted to a third-generation recombinant immunoblot assay (RIBA) confirmatory test. Comparison between the HCV prevalence obtained in the 2 enrolled groups was performed using Fisher's exact test.

RESULTS

Anti-HCV antibodies were found with the MEIA method, in 1 patient with PsA, and in 4 patients with OA or sciatica. The RIBA method confirmed MEIA results in all positive patients. The difference in HCV prevalence detected in the PsA group and in the control group was not statistically significant (P = 0.68). Furthermore, HCV prevalence in PsA patients was lower than the ones reported in different geographic areas of Italy.

CONCLUSION

Our present report does not confirm previous data that indicated an increased prevalence of HCV in PsA patients, and as a consequence, does not sustain a possible trigger role of HCV in cases of PsA. The absence of clinical or instrumental resources that consent a definite differential diagnosis between PsA and HCV-related arthritis was outlined and analyzed.

Intervertebral disc cells produce tumor necrosis factor alpha, interleukin-1beta, and monocyte chemoattractant protein-1 immediately after herniation: an experimental study using a new hernia model

STUDY DESIGN

A new hernia model that simulates human disc herniations was developed in rabbits. The herniated discs were examined by gross appearance and histology and production of tumor necrosis factor alpha, interleukin-1beta, and monocyte chemoattractant protein-1 was investigated.

OBJECTIVES

To clarify the early mechanism of spontaneous herniated disc resorption.

SUMMARY OF BACKGROUND DATA

Macrophage infiltration in herniated discs is essential for disc resorption. However, surgically removed human herniated disc tissues and existing animal hernia models are not suitable for analyzing the mechanism of macrophage infiltration. Recently, we have demonstrated that intervertebral disc cells are capable of producing monocyte chemoattractant protein-1, a potent macrophage chemoattractant, after stimulation with tumor necrosis factor alpha and interleukin-1beta.

METHODS

Intervertebral disc herniations were surgically developed in rabbits using a new technique. The herniated discs were excised at appropriate time intervals after the surgery, and the size and histologic findings were examined. Expressions of tumor necrosis factor alpha, interleukin-1beta, and monocyte chemoattractant protein-1 in herniated discs were investigated immunohistochemically.

RESULTS

A new rabbit model of disc herniation was established. The herniated discs spontaneously reduced in size by 12 weeks postsurgery. Infiltrating cells, mainly composed of macrophages, were observed from day 3. Immunohistochemically, intervertebral disc cells in the herniated discs produced tumor necrosis factor alpha and interleukin-1beta on day 1, followed by monocyte chemoattractant protein-1 on day 3.

CONCLUSIONS

The new hernia model appears to be very useful for studying herniated disc resorption. Intervertebral disc cells may produce inflammatory cytokines/chemokine immediately after the onset of disc herniation, possibly triggering subsequent macrophage infiltration that leads to disc resorption.

Angiogenesis and inflammatory cell infiltration in lumbar disc herniation

STUDY DESIGN

Immunohistochemical study of the angiogenesis and inflammatory cell invasion in lumbar disc herniation. OBJECTIVES To observe the blood vessel formation within the extracellular matrix in lumbar disc herniation, and to elucidate the role of angiogenesis in the natural shrinking of hernias.

SUMMARY OF BACKGROUND DATA

There have been few reports of detailed observation of blood vessel formation within the extracellular matrix, and the role that angiogenesis plays in the natural shrinking of hernias has not been elucidated.

METHODS

Twenty tissue samples surgically removed from 17 patients with herniated discs were studied (9 men, 8 women, 23-58 years old, 11 extrusion type, 9 sequestration type). In the immunohistochemical study, an anti-CD34 antibody for vascular endothelial cells, an anti-CD68 for macrophages, and an anti-vascular endothelial growth factor antibody was used for vascular endothelial growth factor.

RESULTS

Many spindle-shaped cells expressing vascular endothelial growth factor were seen inside granulation tissue infiltrating the cartilage matrix, and the number of vascular endothelial growth factor-positive cells and the number of CD34+ cells were positively correlated (R = 0.73, P < 0.001). In the area surrounding CD34+ cells that had formed a lumen, many CD68+ cells were observed, and the number of CD34+ cells and the number of CD68+ cells were positively correlated (R = 0.66, P < 0.001).

CONCLUSIONS

The results suggest that the vascular endothelial growth factor produced by the spindle-shaped cells acts to promote angiogenesis inside granulation tissue infiltrating the cartilage matrix, and that new blood vessels play an important role as a passage for macrophages into the degenerated matrix.

Pain resolution after lumbar disc surgery is influenced by macrophage tissue infiltration. A prospective consecutive study on 177 patients

The aim of this study was to assess the influence of inflammatory reactions in herniated lumbar disc specimens on pain resolution after lumbar disc surgery. Disc specimens of 200 patients who underwent surgery for lumbar disc herniation were studied immunohistologically. Preoperatively each patient received a verbal rating scale (VRS) for classification of the pain level and general clinical data were recorded prospectively. Varying amounts of macrophages could be demonstrated. Eighty-nine percent of patients could be followed up for a mean period of 7 months. A statistically significant correlation between the histologically observed macrophage infiltration and postoperative pain grading according to the VRS was found. Patients with evidence of inflammatory reactions rated their postoperative complaints lower than patients with no evidence of inflammatory reactions on the VRS (P = 0.04). In our study, a statistically significant correlation between inflammatory changes in the herniated lumbar disc specimen and outcome after lumbar disc surgery could be demonstrated.

Quantifying the stress induced by distress in patients with lumbar disc herniation in terms of natural killer cell activity measurements: chromium release assay versus multiparameter flow cytometric assay

STUDY DESIGN

A comparative study was conducted.

OBJECTIVES

To attempt quantification of the stress in patients with lumbar disc herniation by measuring natural killer cell activity, and to evaluate the assay methodology.

SUMMARY OF BACKGROUND DATA

Stressful events may have adverse effects on health. Distress in the patient with lumbar disc herniation also may be a stressful event. Previous findings have shown the activity of natural killer cells to be impaired in medical student volunteers and after bereavement or other stressful life events. However, the stress in patients with spinal disorders has not been evaluated. The standard assay for natural killer cell activity has been the chromium release assay. However, this assay requires the use of radioactive chromium. Flow cytometric assay is a nonradioactive method that analyzes the activated natural killer lymphocyte subsets: CD45+, CD56+, CD69+.

METHODS

Peripheral blood lymphocytes were obtained from 20 patients with lumbar disc herniation (mean age, 30.8 years) and 20 healthy individuals (mean age, 38.9 years). Both chromium release assay and flow cytometric assay were performed for each patient.

RESULTS

The mean natural killer cell activity in the patients (8.0% +/- 4.3%) was significantly lower than in the 20 healthy adult volunteers (12.6% +/- 4.5%). The mean natural killer cell activity in the healthy volunteers was 12.6% +/- 4.5% for the chromium release assay and 11.0% +/- 4.1% for the flow cytometric assay. The correlation (r = 0.77) of natural killer cell activity between the two methods was high.

CONCLUSIONS

Natural killer cell activity in the patients with lumbar disc herniation was significantly lower than in healthy individuals, and the stress induced by pain and other distress may be present in patients with lumbar disc herniation. For measuring natural killer cell activity, flow cytometric assay is a reproducible assay, and it may be a viable alternative to the standard chromium release assay.

Glycosphingolipid antibodies in serum in patients with sciatica

STUDY DESIGN

Serum antibody titers against 10 different glycosphingolipids were investigated by enzyme-linked immunosorbent assay in three groups of patients: patients with acute sciatica (Group IA, radicular pain for 32 +/- 36 days, n = 68), a subgroup of these patients 4 years later (Group IB, n = 23), and patients undergoing lumbar discectomy because of disc herniation (Group II, n = 37).

OBJECTIVES

To investigate the immunologic response in sciatica patients by analyzing circulating autoantibodies against glycosphingolipids, molecules highly expressed in cells from the nervous system, and the possible correlation of such antibodies to clinical and imaging findings as well as to subjective symptoms.

SUMMARY OF BACKGROUND DATA

The titers of glycosphingolipid antibodies are elevated in neurologic diseases with autoimmune stimulation such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy.

METHODS

Antiglycosphingolipid antibodies were assayed by a microtiter enzyme-linked immunosorbent assay method. Antibody titers were related to a healthy population by a method that judges all positive results (positive result = patient sera/pooled blood donor serum >2, at titer 1/400) as indicating a pathologic condition.

RESULTS

Increased levels of circulating antibodies against one or more glycosphingolipids were detected in 71% of patients with acute sciatica, in 61% of sciatica patients at a 4-year follow-up visit (eight antigens analyzed) and in 54% in patients undergoing discectomy. These frequencies were somewhat higher than, and in the last group similar to, those reported for generalized nervous system disorders with autoimmune involvement. In the acute sciatica patients, positive neurologic findings were associated with increased levels of two of the examined antibodies: 3'LM1 (immunoglobulin M and/or immunoglobulin G), P = 0.023, and GD1a (immunoglobulin M), P = 0.017.

CONCLUSION

The presence of glycosphingolipid antibodies in patients with sciatica and disc herniation suggests an activation of the immune system and thus a process possibly involved in the pathophysiology of sciatica. The autoimmune response was not limited to antibodies against one specific glycosphingolipid target; rather, an overall increase in autoantibodies against nervous system-associated glycosphingolipids was observed. These results encourage further studies of the pathophysiologic and clinical relevance of autoimmune responses in patients with sciatica and disc herniation.

Proinflammatory cytokines in cerebrospinal fluid and serum in patients with disc herniation and sciatica

Proinflammatory cytokines have been identified in herniated intervertebral discs in humans, and such cytokines have experimentally been demonstrated to be important in the pathophysiological mechanisms of disc herniation. Cerebrospinal fluid (CSF) and serum concentrations of interleukin (IL)-1beta IL-6, IL-8, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha were investigated using the enzyme-linked immunosorbent assay (ELISA) technique in 39 patients with lumbar disc herniation and sciatica. Pain duration and pain intensity (visual analogue scale, VAS) were recorded at inclusion, and a clinical examination was performed evaluating neurological findings. The extent of disc herniation (protrusion or extrusion/sequestration) was evaluated perioperatively. Normal concentrations of IL-1beta, IL-6, IFN-gamma and TNF-alpha were present in CSF and serum in almost all patients with lumbar disc herniation. The concentrations of IL-8 in CSF were increased in 12 out of 39 patients, and these increased levels of IL-8 correlated to a short duration of pain and to more pronounced herniation (extrusion or sequestration). No relationship between IL-8 concentrations in CSF and pain intensity, positive neurological findings or a positive straight leg-raising (SLR) test was found. The observation of increased concentrations of IL-8 in CSF in patients with a short duration of symptoms supports the concept of the initial involvement of inflammatory mechanisms after a disc herniation. The finding that most of the patients with increased concentrations of IL-8 in CSF had an extrusion or a sequestration may suggest that the increase in IL-8 is related to mechanical nerve root compression, but may also indicate a biochemical effect exerted by the herniated disc on the surrounding tissue. Further studies on the potential role of IL-8 as a biomarker for disc herniation are warranted.

Immunophenotypic analysis of the inflammatory infiltrates in herniated intervertebral discs

STUDY DESIGN

The herniated portion of the lumbar disc was analyzed immunohistochemically for inflammatory infiltrates to determine their immunophenotype.

OBJECTIVE

To investigate the pathomechanism behind spontaneous regression of herniated discs.

SUMMARY OF BACKGROUND DATA

Spontaneous regression of herniated intervertebral discs has been increasingly reported. The inflammatory response of the host has been suggested as a factor in this phenomenon. However, whether the inflammation is induced from direct chemical irritation of the nucleus pulposus material or whether it is secondary to an autoimmune response to the nucleus pulposus remains controversial.

METHODS

The herniated portion of the disc was collected from 38 patients who underwent surgery for lumbar disc herniation. Thin cryostat sections were made, and the extent to which inflammatory cells had infiltrated the disc specimen was defined. Then the immunophenotype of cellular infiltrates in the herniated disc specimens was assessed by immunostaining using a series of antibodies for lymphocyte, monocyte, macrophage, and dendritic cell markers.

RESULTS

The inflammatory infiltrates in 14 of the 38 herniated discs were subjected to immunohistochemical analysis. None of them expressed the immunophenotypic markers of the lymphocyte (CD20, CD45RO, CD4, CD8, TCRgammadelta), mature monocyte (CD33), or dendritic cell (CD1a, CD80, CD86, S100). Abundant infiltration of CD68-positive cells that lacked CD33 but had a variable amount of CD11b, CD11c, and CD40 likely represents a process of differentiation from monocytes to macrophages.

CONCLUSIONS

These findings are consistent with an immunophenotype of inflammatory responses to tissue injury or chemical irritation rather than antigen-specific immune responses. Therefore, understanding the mechanism of tissue repair is fundamentally important in the management of patients with disc herniations.

[Release of pro- and anti-inflammatory cytokines during different anesthesia procedures]

The modulation of immune functions, induced by trauma, surgical interventions and anaesthesia, is thought to play a crucial role in the development of post-traumatical or postoperative disorders. The balance of pro- and anti-inflammatory cytokines was shown to affect the outcome of the patients. This work studied the effects of different anaesthesiological procedures--total intravenous anaesthesia using Propofol/Sufentanil (TIVA) versus balanced inhalational anaesthesia using Trapanal/Sevoflurane (BIA) in patients with elective lumbal discectomia--on the secretion of various cytokines and their correlation to endocrine stress response. The concentrations of the pro-inflammatory cytokines IL-2, IL-6, IL-12 and IFN-gamma and their soluble receptor molecules as well as the concentrations of the anti-inflammatory cytokines IL-10, IL-1RA and TGF-beta were determined in plasma samples obtained pre-, intra- and postoperatively. Additionally, the plasma concentrations of the stress-related hormones cortisol, epinephrine and norepinephrine were measured. Changes in the cytokine profile were observed immediately after induction of anaesthesia. Significant differences were found particularly in IL-6 production as well as in the release of the soluble IL-2R alpha and the IL-1 receptor antagonist (IL-1RA). Whereas under BIA, the concentrations of IL-6 were found to be significantly elevated during the course of the study, the release of the soluble IL-2R alpha and the production of IL-1RA were reduced in this patient group in comparison to the TIVA group. The increase of the postoperative concentrations of cortisol, epinephrine and norepinephrine under BIA indicated enhanced activation of the hypothalamo-pituitary-adrenal axis and the sympathetic system. Thus, with respect to limitation of surgery-associated stress, total intravenous anaesthesia seems to have a favourable effect. Moreover, induction of the release of anti-inflammatory mediators under TIVA might contribute to the prevention of excessive postoperative inflammation. Taken together, these data suggest that the anaesthesiological management may have considerable influence on the postoperative inflammatory process. This might be of particular relevance for surgical interventions in patients after injuries, infections or malignant diseases which are known to be associated with immune dysfunction.

Inflammatory cells, motor weakness, and straight leg raising in transligamentous disc herniations

STUDY DESIGN

Possible statistically significant relationships between inflammatory cells and either motor weakness or straight leg raising were determined.

OBJECTIVES

To look for any clinically relevant links between inflammatory cells in disc herniations and signs of radiculopathy.

SUMMARY OF BACKGROUND DATA

Many studies have during recent years shown a presence of various types of inflammatory cells in disc herniations, but their clinical relevance has been questioned. To be clinically relevant, a presence of inflammatory cells should show a clear relationship to clinical evidence of nerve root involvement. Macrophages repeatedly demonstrated in a high proportion of disc herniations studied are of particular interest. Their major role may be in disc herniations tissue resorption and not in sciatica.

METHODS

A total of 96 disc herniations, all transligamentous, were analyzed by immunohistochemistry for presence of macrophages, T or B lymphocytes, and activated T lymphocytes separately. From recorded patient data, motor weakness and straight leg raising data were compared with a presence or absence of abundant (+ = at least 20 cells in a group) inflammatory cells. When not abundant, inflammatory cells were classified as "only few cells" (+) and grouped together with "no cells" (-). Patients with or without motor weakness were compared. Straight leg raising was compared for a positive (at <70 degrees ) or a negative test, and separately using the median as cut-off value. Groups were compared by chi-square analysis with the level of statistical significance set at P<0.05.

RESULTS

None of the four inflammatory cell types showed any significant association with motor weakness. Nor was any association observed when comparing positive and negative straight leg raising. With the median (straight leg raising = 47.5 degrees ) as cut-off, only activated T cells showed a weak (chi2 = 4.40, P<0.05) relationship with tighter straight leg raising, but none of the other cell types did. Even when straight leg raising was < 47.5 degrees, three times more disc herniations lacked (n = 34) inflammatory cells than showed (n = 13) inflammation. In a subgroup of only sequestrated discs, the findings were similar. However, in the patients with a bilaterally positive straight leg raising (n = 25), the prevalence of at least one inflammatory cell type was much higher in sequestrated discs (80%) than in extrusions (33%). This may suggest more subtle interrelationships between type of disc herniation, straight leg raising, and inflammatory cells.

CONCLUSIONS

The results of this study do not support a clinically relevant role for disc herniation inflammatory cells in sciatica. For the cells to be clinically relevant, a strong relationship between a presence of inflammatory cells and either or both of motor weakness and a tight straight leg raising should have been observed. The authors conclude that macrophages, which have been demonstrated in a high proportion of disc herniations in previous studies, are probably more important for disc tissue resorption processes than for producing sciatica. Other types of inflammatory cells are more rarely observed and may have no clinical meaning at all. However, more subtle interrelationships, considering the various types of disc herniations, should be further explored.

Immunohistological study of intervertebral disc herniation of lumbar spine

In order to observe histological changes in the extruded and sequestrated intervertebral disc, we conducted pathological and immunological examinations of herniated disc materials taken at the time of discectomy. There were 49 disc materials (from 38 men and 10 women [aged 19 to 78 years; average, 36.6 years]). The herniation was classified into four types, based on the intraoperative observations: protrusion (P), subligamentous extrusion (SE), transligamentous extrusion (TE), and sequestration (S). There were 19 P type discs, 3 SE type, 10 TE type, and 17 S type. The surgical specimens were stained with hematoxylin-eosin, as well as immunohistological staining with the labelled streptavidin biotin method, using human T-cell, human B-cell, and human macrophage antibodies. Inflammatory-cell infiltration was observed at the border of the disc. These findings were present in 19 discs (70%) of the 27 discs of TE and S types (10 TE and 17 S types), but were not seen in the 22 discs of P and SE types (19 P and 3 SE types). Immunohistological staining of the area with inflammatory-cell infiltration revealed the presence of T cells and macrophages, which suggested that this cell infiltration originated from T cells and macrophages, and that the spontaneous resorption of the disc may have resulted from the phagocytic activities of these cells.

Monitoring of blood parameters following anterior cervical fusion

OBJECT

Both C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) were measured prospectively in 51 cases in which uncomplicated cervical anterior fusion was performed. The object of the authors was to quantify the differences in the responses of these parameters recorded in the immediate postoperative period and to determine factors influencing their course.

METHODS

Nineteen one-level, 23 two-level, and nine three-level procedures for disc herniation and degenerative disease of the cervical spine were performed in 22 female and 29 male patients (mean age 49.2 years). Blood samples were obtained 1 day before as well as on 10 consecutive days and 3 months following anterior cervical fusion. Serum CRP level was measured using a fluorescence polarization immunoassay and ESR was determined from the same samples. Operative time, the number of blood transfusions, and drugs administered in the postoperative period were recorded. In addition, hemoglobin, hematocrit, red blood cell count, platelet count, white cell count, and axillary body temperature were checked daily.

CONCLUSIONS

Monitoring of CRP level is superior to that of ESR for early detection of infections after cervical spine surgery. Although CRP was not related to any of the factors that have been proposed to explain its peak value variance in previous studies, individual acute-phase protein metabolism response to tissue affection appears to be a more decisive element in this respect.

Influence of macrophage infiltration of herniated lumbar disc tissue on outcome after lumbar disc surgery

STUDY DESIGN

An immunohistochemical examination of the presence of inflammatory cells in routinely processed resection specimens of the lumbar disc, and a comparison of the histologic results with clinical data collected prospectively before and after surgery.

OBJECTIVES

To assess the influence of inflammatory reactions in herniated lumbar disc specimens on the outcome after lumbar disc surgery.

SUMMARY OF BACKGROUND DATA

Histologic and biochemical studies on herniated lumbar disc tissue led to the notion of inflammation-induced sciatic pain. At this writing, no investigations have sought to discover how outcome after lumbar disc surgery is influenced by histologically described inflammation.

METHODS

Disc specimens from 79 patients who underwent surgery for lumbar disc herniation were studied immunohistologically with regard to the presence of inflammatory reactions. Of these, 92% were followed up approximately 7 months after surgery. The histologic results were compared with the outcome at follow-up evaluation.

RESULTS

A statistically significant correlation was found between the histologically proven inflammation and the outcome, as shown by the pain grading scale.

CONCLUSIONS

The results from this study seem to support the theory of a foreign body reaction to the herniated material. This reaction may result in inflammation-induced sciatic pain.

Serum immunoglobulins in brain tumours and lumbar disc diseases

Changes of serum immunoglobulin (Ig) concentrations may occur in both brain tumours and lumbar disc diseases (LDD). The purpose of this study was to investigate the changes of pre- and post-operative serum Ig levels in brain tumours and LDDs. Serum IgG, IgA and IgM levels were measured in 127 patients with brain tumour, 100 patients with LDD and 20 healthy subjects without neurological disease. Increases in one or more of the pre-operative serum Ig levels were observed in the patients with both brain tumours and LDDs compared with controls. However pre-operative serum IgG level was highly increased in all brain tumour types and LDDs (p<0.001). Serum IgA levels and IgM levels in the post-operative stage were significantly decreased in patients with acoustic neurinoma (p<0.01, p<0.001, respectively). Post-operative serum IgG, IgA and IgM levels were significantly decreased (p<0.001) in patients with meningioma. Post-operative serum IgG and IgM levels were significantly decreased (p<0.001) in patients with glioma. Patients with LDD showed a significantly decline in post-operative serum IgA and IgM levels (p<0.001). We think that decline in post-operative serum Ig levels may be of prognostic value in the patients with brain tumours and LDDs.

Presence and distribution of antigen-antibody complexes in the herniated nucleus pulposus

STUDY DESIGN

Herniated tissue was studied by immunohistochemistry in eight patients with lumbar disc herniation. The results were compared with those of control subjects.

OBJECTIVE

To assess the presence and distribution of possible antigen-antibody complexes in herniated disc tissue.

SUMMARY OF BACKGROUND DATA

It has been suggested that the nucleus pulposus may be recognized as a foreign-body by the immune system and that this will lead to secondary nerve root disturbance. Such immunologic events should be initiated by binding of antibodies to a specific antigen in the disc tissue. However, the presence of antigen-antibody complexes in the herniated disc tissue has not been assessed.

METHODS

Amplification of the peroxidase reaction produced in avidin-biotin-peroxidase complex immunostaining by diaminobenzidine was used to visualize antigen-antibody complexes in the herniated tissue. The authors used herniated tissue from eight patients with lumbar disc herniation and nucleus pulposus from five control subjects with nonlumbar disc herniation. Thin paraffin sections, prefixed in 4% paraformaldehyde, were incubated with anti-human IgG antibody to allow visualization of antigen-antibody complexes in the specimens.

RESULTS

A brown deposit, indicating antigen-antibody complexes, could be observed in the pericellular capsule in herniated disc tissue but not in control discs or in the residual discs of the herniation patients.

CONCLUSION

Antigen-antibody complexes seem to be commonly present in herniated disc tissue, but not in healthy discs. However, the pathophysiologic and clinical significance of this observation has to be elucidated further.

A comparative immunohistochemical study of inflammatory cells in acute-stage and chronic-stage disc herniations

STUDY DESIGN

Herniated lumbar disc specimens were obtained from patients undergoing surgical discectomy for persistent radicular pain (radiculopathy) and stained for inflammatory cells to determine their occurrence in relation to the duration of radicular pain and to analyze the role of the time factor in the inflammatory response.

OBJECTIVES

To analyze the presence of inflammatory cells and their involvement in the pathophysiology of radicular pain and to determine whether there is a clear difference in the occurrence of inflammatory cells between the earlier phase of radicular pain (after herniation) and the later chronic stage.

SUMMARY OF BACKGROUND DATA

Previously, inflammatory cells were reported in herniated disc tissues, and macrophages were most prevalent. Biologically active inflammatory mediators have also been repeatedly observed. However, there have been no observations regarding possible differences in the occurrence of inflammatory cells in radicular pain of different durations.

METHODS

Forty-four herniated lumbar discs were obtained from 44 patients undergoing disc surgery. Two groups of 22 age- and gender-matched patients with comparable affected disc levels were studied. In the first group (acute group) pain duration ranged from 3 days to 21 days. In the second group (chronic group) pain duration was 6 months or longer. All disc herniation specimens were subjected to indirect immunocytochemistry to study and compare the presence of inflammatory cells.

RESULTS

Inflammatory cells, predominantly macrophages, were observed in both groups. Macrophages were abundantly present in eight (36%) disc samples in the acute group; in three (14%) samples only few scattered macrophages were observed. In the chronic group, in nine (41%) disc samples, abundant macrophages were observed; in six (27%) there were a few scattered macrophages. In the acute group, in three (14%) disc samples abundant activated T lymphocytes were observed; in two (9%) there were only a few activated T lymphocytes, whereas in the chronic group abundant activated T lymphocytes were not seen; only a few scattered activated T lymphocytes were observed in five (23%) disc tissue samples. In two (9%) samples in the acute group, B cells were abundantly present, and in two (9%) only a few B cells were observed. In the chronic group, abundant B cells were seen in no samples, and only a few B cells were noted in one (5%) sample. Only in the acute group and only in lateral disc herniations were abundant lymphocytes observed. In disc samples from intraspinal herniations, acute and chronic, there were only abundant macrophages, not lymphocytes.

CONCLUSIONS

Because of the small size of the study groups and the low prevalence particularly of lymphocytes in both groups, no major group differences were noted. The prevalence of macrophages was highest, similar in both groups, and was similar to the results in prior studies. The results indicate no major differences in the occurrence of inflammatory cells in acute and chronic disc herniations. They also indicate that only macrophages may have a clinical relevance in disc tissue inflammation.

Inflammatory cells in full-thickness anulus injury in pigs. An experimental disc herniation animal model

STUDY DESIGN

Inflammatory cells were studied by indirect immunocytochemistry in experimental full-thickness anulus fibrosus lesions in pigs.

OBJECTIVES

First, to determine the occurrence, by immunocytochemistry, of T lymphocytes and macrophages in experimentally produced, anterolateral full-thickness disc lesions in pigs, and second, to compare the presence of inflammatory cells in 1) the injury area, 2) the adjacent noninjured part of the disc, and 3) control discs.

SUMMARY OF BACKGROUND DATA

Previous studies on disc herniation material obtained from human disc surgeries have demonstrated inflammatory cells in a subgroup of herniations. Macrophages were most prevalent, being more numerous than lymphocytes. Macrophages have furthermore been suggested to be important in the resorption process of extruded disc tissue. No similar studies on an animal model of disc herniation, however, have so far been presented.

METHODS

A full thickness anular incision, 10 mm long, was made with a scalpel in the L3-L4 or L4-L5 intervertebral discs of 12 adult pigs. The incision was made in the anterolateral part of the disc. Nucleus material was observed outside the injury site when tissue samples were taken, suggesting a disc herniation. Tissue then was analyzed from the area of injury, from the area adjacent to the injury, and from separate control discs from three additional pigs of the same age. Thin frozen sections were studied by indirect immunocytochemistry (alkaline phosphatase anti-alkaline phosphatase method) using monoclonal anti-human antibodies applicable to porcine tissues, T lymphocytes (CD3), and macrophages (CD68). Cells were graded as: -, absent; (+), only a few scattered cells; and +, abundant cells. Disc tissue samples were taken 1 month (three discs), 2 months (four discs), and 3 months (five discs) after the operation.

RESULTS

Macrophages were present more commonly than T cells, and were abundant in seven of 12 discs (58%), with T cells abundant in four of 12 discs (33%). Only a few macrophages were present in the injured tissue from one additional disc, and scattered T cells were seen in four additional discs. Abundant macrophages were also observed in one of two discs in the adjacent noninjured area, whereas only a few T lymphocytes at the most were present in such noninjured disc tissue. In four (33%) and three (25%) injured discs, respectively, no macrophages or T lymphocytes could be found. No inflammatory cells were observed in three of 12 discs (25%). The three control discs showed no inflammatory cells.

CONCLUSIONS

Inflammatory cells, predominantly macrophages, were present in a subsample of experimental discs with full-thickness anulus defects, as has previously been observed for human disc herniations. In this animal model, macrophages may have spread to adjacent noninjured parts of the disc. The induced herniation in this animal model is, however, anterolateral and may not fully correspond to clinical disc herniations, most of which are posterolateral. However, the results from this model support a role for inflammation in disc herniation.

The inflammatory properties of contained and noncontained lumbar disc herniation

STUDY DESIGN

The inflammatory properties of nucleus pulposus were assessed in biopsy samples from patients who underwent surgery for lumbar disc herniation.

OBJECTIVES

To investigate the inflammatory properties of the different types of disc herniation.

BACKGROUND DATA

High levels of phospholipase A2 previously have been demonstrated in a small number of patients undergoing lumbar disc surgery. Phospholipase A2 is the enzyme responsible for the liberation of arachidonic acid from cell membranes at the site of inflammation and is considered to be the limiting agent in the production of prostaglandins and leukotrienes, which are powerful mediators of inflammation. Cytokines are among the many agonists inducing phospholipase A2 activation. Several reports previously have demonstrated the difference in clinical appearance of different types of lumbar disc herniation.

METHODS

Thirty-seven patients undergoing surgery for lumbar disc herniation were investigated. During surgery the disc pathology of each patient was classified into one of three groups: bulging disc, contained herniation, and noncontained disc herniation. Also during surgery, biopsy samples were taken from the nucleus, immediately frozen in liquid nitrogen, and subsequently stored at -70 C until analyzed.

RESULTS

No traces of interleukin-6 or tumor necrosis factor alpha were found in the biopsy samples. There was a significant difference in the levels of leukotriene B4 and thromboxane B2 in contained versus noncontained disc herniation, and the highest concentration was found in the noncontained disc herniation group.

CONCLUSION

The results support the theory that inflammatory mechanisms are involved in sciatica because of lumbar disc herniation and indicate that the different types of disc herniation have different inflammatory properties.

C-reactive protein levels determine the severity of soft-tissue injuries

Increased serum levels of C-reactive protein (CRP), a nonspecific indicator of tissue injury, may be valuable in determining the extent of soft-tissue injury. Patients with three types of musculoskeletal injury were included in this study: anterior cruciate ligament tear (n = 11), Achilles tendon tear (n = 7), and intervertebral disc rupture (n = 18). Patients in these three groups and three control groups (n = 37) had serum CRP levels measured immediately after injury and at 48 hours, 1 week, and 2 weeks postinjury. The status of the injury in both patient groups was confirmed through clinical findings, imaging studies, or surgical findings. Mean CRP levels in all three injury groups were highest at 48 hours (anterior cruciate ligament tears [9.2 +/- 2.1 mg/dL], Achilles tendon tears [10.1 +/- 2.2 mg/dL], and acute disc rupture [4.1 +/- 1.0 mg/dL]). In all three groups, CRP levels dropped significantly (P < 0.001) after 1 week and returned to nearly normal levels by 2 weeks. All control patients had normal levels of CRP (< 1.0 mg/dL). In the absence of other causes, an elevation in CRP concentration will aid in determining the severity of acute tissue injury.

Immunocytochemical localization of immunoglobulins in disc herniations

STUDY DESIGN

Disc herniation and control discs were studied for the presence of immunoglobulins immunocytochemically.

OBJECTIVES

To study a possible presence of immunoglobulin complexes in herniated disc tissue and to locate them at the tissue level by immunocytochemistry; to compare immunohistologic findings with those obtained in control disc tissue; and to compare the prevalences of immunoglobulin M and immunoglobulin G.

SUMMARY OF BACKGROUND DATA

In herniated disc tissue, high activity of inflammatory phospholipase A2 was previously demonstrated, and inflammatory cells were noted immunohistochemically. Immunoglobulins G and M were observed biochemically but have not been located at the tissue level.

METHODS

Fifty-two disc herniations and three macroscopically normal fresh cadaver discs were managed by an identical immunocytochemical protocol, using monoclonal antihuman antibodies to immunoglobulins M and G.

RESULTS

In 29 of 52 disc herniations (56%), immunoglobulin M deposits were observed, and in 18 of 52 disc herniations (35%) immunoglobulin G could be demonstrated. Almost all the disc herniations where immunoglobulin G was present also contained immunoglobulin M deposits (except for two). In the control discs studied, neither immunoglobulin could be observed immunohistochemically. The immunoglobulin deposits were noted in areas where blood vessels were also present. Morphologically, immunoglobulin immunoreactivity resembling immune complexes was observed.

CONCLUSIONS

The results lend support to previous suggestions of inflammation and immune reaction in disc herniations, including previous biochemical studies suggesting immunoglobulin deposition. The exact role of the demonstrated immunoglobulins in disc tissue pathophysiology will have to be clarified further.

[A system of individual psycho- and immunotherapy in neuroanesthesiological practice]

Effects of the newly developed system of individual immunotherapy on the immune reactions of patients with disc hernias were examined in order to validate the use of immunotherapy in neuroanesthesiology. Preoperative treatment in the form of standard immunotherapy with an immunomodulating agent leakadin has been shown to lead mainly to activation of the humoral immunity. A system of individually selected immunotherapy activates both humoral and cellular immunity and, judging from the helper-suppressor coefficient, the processes regulating the immune reactions as well.

Immunohistologic study of the ruptured intervertebral disc of the lumbar spine

STUDY DESIGN

This study analyzed immunohistological features of the extruded or sequestrated intervertebral disc of the lumbar spine. To clarify the pathogenesis of neovascularization, cells isolated from herniated disc were cultured and examined biologically.

OBJECTIVES

The objectives of this study were to characterize the histologic features of extruded or sequestrated discs and inflammatory cells that infiltrate along the margins of the disc tissue and to clarify the pathogenesis of neovascularization observed at the edge of the disc tissue.

SUMMARY OF BACKGROUND DATA

When some of the contents of the disc extrudes into the epidural space and is considered "foreign," an autoimmune response develops, which can lead to a chronic inflammatory response. However, the pathogenesis of inflammatory cell infiltrations and neovascularization are not clearly defined.

METHODS

The herniated discs were obtained during surgery and were stained with anti-interleukin-1, intercellular adhesion molecule-1, lymphocyte function-associated antigen, and basic fibroblast growth factor antibodies by using an indirect immunoperoxidase method. Cells isolated from herniated disc were cocultured with human endothelial cells and basic fibroblast growth factor contained by cultured disc cells were measured by radioimmunoassay.

RESULTS

The ingrowth of granulation tissue with vascularization, occurring at the edge of fibrocartilage fragment, was present at 11 of 16 of extruded and 3 of 5 of sequestrated discs. Anti-interleukin-1, intracellular adhesion molecule-1, lymphocyte function-associated antigen, and basic fibroblast growth factor were expressed on most of mononuclear cells infiltrating into the extruded or sequestrated disc. Cells from the extruded or sequestrated disc demonstrated significantly greater levels of basic fibroblast growth factor than those from the protruded disc, and they enhanced the proliferation of endothelial cells.

CONCLUSIONS

This study showed that mononuclear cells infiltrating along the margins of extruded discs expressed inflammatory mediators and might induce neovascularization and persistence of inflammation.

Herniated cervical intervertebral discs spontaneously produce matrix metalloproteinases, nitric oxide, interleukin-6, and prostaglandin E2

STUDY DESIGN

Herniated cervical disc specimens were obtained from patients undergoing surgical discectomy for persistent radiculopathy and cultured in vitro to determine whether various biochemical agents were being produced.

OBJECTIVES

Our hypothesis is that biochemical mediators of inflammation and tissue degradation play a role in cervical intervertebral disc degeneration and in the pathophysiology of cervical radiculopathy.

SUMMARY OF BACKGROUND DATA

Neck pain with or without radiculopathy is a common clinical problem, but the etiology of neck pain and the exact pathophysiology of radiculopathy remain uncertain. We have previously reported the production of various biochemical agents by herniated lumbar disc specimens in vitro. Because of a lack of such studies in the literature with respect to the cervical spine, the purpose of this study was to determine whether similar biochemical agents of inflammation and tissue degradation were being produced by herniated cervical disc specimens.

METHODS

Eighteen herniated cervical discs were obtained from 15 patients undergoing anterior disc surgery. The specimens were cultured and incubated for 72 hours, and the media were subsequently collected for biochemical analysis. Biochemical assays for matrix metalloproteinases, nitric oxide, prostaglandin E2, and a variety of cytokines were performed. As a control group, six cervical discs specimens were obtained from three patients undergoing anterior surgery for traumatic burst fractures, and similar biochemical analyses were performed.

RESULTS

The culture media from the herniated cervical disc specimens showed increased levels of matrix metalloproteinase activity compared with the control discs. Similarly, the levels of nitric oxide, prostaglandin E2, and interleukin-6 were significantly higher in the herniated disc specimens compared with the control discs. Interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor-alpha, interleukin-1 receptor antagonist protein, and substance P were not detected in the culture media of the herniated or control discs.

CONCLUSIONS

Herniated cervical disc specimens were making spontaneously increased amounts of matrix metalloproteinases, nitric oxide, prostaglandin E2, and interleukin-6. These results were similar to those obtained in herniated lumbar disc specimens that we have previously reported. These products may be intimately involved in the biochemistry of disc degeneration and the pathophysiology of radiculopathy.

IgG and IgM concentration in the prolapsed human intervertebral disc and sciatica etiology

STUDY DESIGN

A prospective study was conducted in patients who underwent surgeries for sciatica. The results were compared to those of control subjects.

OBJECTIVES

This study expanded knowledge about the pathogenesis of back pain and sciatica in disc herniation.

METHODS

Nucleus pulposus, retrieved from 10 patients who underwent surgeries for sciatica caused by disc herniation and from 8 patients used as control subjects, was homogenized and together with serum and cerebrospinal fluid was examined for local production of IgG and IgM by rate nephelometry.

SUMMARY OF THE BACKGROUND DATA

Experimental data have shown an inflammatory reaction in the nucleus pulposus of animal models.

RESULTS AND CONCLUSIONS

An increased ratio IgGNP/IgGs x 10(3) and IgMNP/IgMs x 10(3) was found in all patient samples, whereas only the IgMNP/IgMs x 10(3) ratio was significantly higher (P < 0.005) when compared with those of the control values. These findings may be secondary to an inflammatory reaction close to the nerve root and prolapsed nucleus pulposus. Therefore, they may contribute in some way to the inflammatory origin of sciatica.

The short-term effect of an immunosuppressive treatment on CSF myelin basic protein in chronic progressive multiple sclerosis

CSF levels of myelin basic protein (MBP) and intrathecally produced CSF IgG (de novo IgG) were measured in 11 chronic progressive multiple sclerosis patients with a deteriorating course of the disease for at least 6 months preceding observation and a reference group of 17 neurological patients suffering from disc herniation. In the multiple sclerosis patients, CSF levels were determined just before and once in the period 3 to 10 weeks after the start of an immunosuppressive treatment with cyclophosphamide and prednisone. For multiple sclerosis patients the CSF MBP levels before treatment were significantly higher than for controls. The CSF MBP levels after the treatment were nearly all within the control range. The abnormal high concentration of intrathecally produced CSF IgG (de novo IgG) in multiple sclerosis patients was reduced after treatment. A correlation between CSF MBP and CSF de novo IgG in multiple sclerosis patients could not be demonstrated. If CSF MBP is an indicator of the (activity of) myelin breakdown in the brain, it can be concluded that an intensive immunosuppressive treatment in combination with prednisone has, at least, a short-term, beneficial effect on the amount of demyelinisation and possibly on the disease activity.

Biochemical and immunological study of lumbar disc degeneration

Proteoglycans of 18 lumbar discs obtained at surgery for lumbar disc lesion were studied biochemically and immunologically (using monoclonal antibody that recognizes core protein of annulus fibrosus proteoglycans) and compared with the results of similar studies on discs obtained at autopsy and Zielke's operation for scoliosis. Disc proteoglycans showed a decrease in extraction and hexuronic acid/protein weight ratio with age in both surgical and post-mortem specimens. Although the molecular weight of proteoglycan monomer seemed to show a slight decrease, that of chondroitin sulfate chain showed no change with age in surgical discs. The proportion of proteoglycan aggregate showed a decrease with age until 40 years old, it went up thereafter because of the loss of proteoglycan monomers. This biochemical degeneration paralleled discogramic degeneration and monoclonal antibody that recognized core protein showed a strong affinity with severely degenerated discs. Besides aging, lumbar instability seemed to exert a profound influence on the progression of degeneration.

Reactivity of IgE and IgG serum levels to chymopapain after chemonucleolysis

Patients suffering from herniated lumbar intervertebral disks can currently be treated by chemonucleolysis. This procedure involves reducing the nucleus pulposus by injecting chymopapain into the affected intervertebral disk. A small percentage of the patients who undergo this treatment experience an immediate hypersensitivity reaction. In this study the IgE and IgG specific for sensitivity to chymopapain of 21 patients receiving chymopapain (Discase for injection) was monitored over a 6-month period after injection. This study demonstrates that serum levels of IgE and IgG to chymopapain increase after chemonucleolysis.

The Limulus test of the cerebrospinal fluid in the diagnosis of disc hernia and its possible correlation with the auto-immune pathogenesis of root pain

The writers examined by means of the Limulus test 130 samples of cerebrospinal fluid and eighteen samples of serum obtained from subjects affected by extremely varied neurological conditions as well as by lumbar and sciatic pain of disc origin. They demonstrated that the Limulus test was positive in cases of lumbar and sciatic pain in which clinical, myelographic and surgical findings gave positive results. It is therefore probable that there is correlation between positivity of the test and an auto-immune pathogenesis of root pain in disc hernia.