Intrathecal release of pro- and anti-inflammatory cytokines during stroke

A growing body of evidence points out the potential role of inflammatory mechanisms in the pathophysiology of ischaemic brain damage. We have recently demonstrated that stroke patients display an intrathecal production of proinflammatory cytokines, such as IL-1beta and IL-6 already within the first 24 h after the beginning of symptoms (Tarkowski et al., 1995). The aim of the present study was to investigate patterns of local inflammatory responses as a consequence of acute stroke. Thirty stroke patients were studied prospectively on days 0-3, 7-9, 21-26 and after day 90 with clinical evaluations, radiological assessments and analysis of cerebrospinal fluid (CSF) cytokine levels. In addition, 15 healthy control CSF samples were used. Significantly increased CSF levels of IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-10 were observed early during the stroke with a peak on day 2 for the proinflammatory cytokines IL-8 and GM-CSF, and on day 3 for the immunoregulatory cytokine IL-10. Patients with a brain infarct predominantly located in the white matter showed significantly higher levels of IL-8 in CSF than patients with an infarct mainly located in the grey matter. Also, high levels of intrathecal tumour necrosis factor-alpha (TNF-alpha) were associated with the presence of white matter disease. Our study demonstrates an intrathecal production of proinflammatory and immunoregulatory cytokines in patients with stroke, supporting the notion of localized immune response to the acute brain lesion. A better understanding of the inflammatory response in stroke may lead to new treatment strategies.

Central nervous system TNFalpha-mRNA expression during rabbit experimental pneumococcal meningitis

In pneumococcal meningitis inflammatory mediators such as tumor necrosis factor alpha (TNFalpha) are produced in large quantities and play a major role in pathogenesis. It is not known exactly which cells produce these mediators during infection. We investigated the localisation of TNFalpha-mRNA in the central nervous system (CNS) by in situ hybridisation during experimental Streptococcus pneumoniae meningitis. TNF-positive cells were detected only in inflammatory infiltrates within the meninges. Cells within the brain parenchyma and the choroid plexus were completely negative. After monocyte depletion, no TNFalpha-mRNA positive cells were detected in the CNS. These findings suggest that TNFalpha in pneumococcal meningitis is produced in the CNS mainly by blood-derived, infiltrating monocytes.

[The assessment of tumor necrosis factor (TNF) alpha and interleukin (IL)-1 beta levels in cerebrospinal fluid (CSF) and serum in patients with purulent meningitis]

The purpose of this work was to detect the concentration of cytokines--tumor necrosis factor (TNF)-alpha and Interleukin (IL)-1 beta in cerebrospinal fluid (CSF) and serum, their diagnostic and prognostic usefulness among patients with purulent meningitis. 25 patients of Centre of Parasitic Diseases and Neuroinfections hospitalized with diagnosis or suspicion of purulent meningitis were studied. The patients were divided into two groups: I-12 persons with diagnosis of purulent meningitis and group II-13 controls where suspicion of meningitis was excluded during clinical procedure. The cytokines were detected by immunometric assay. This examination was performed twice--before and after treatment. In group I-patients with purulent meningitis, TNF-alpha and IL-1 beta CSF concentrations were significantly higher in comparison with group II. After treatment the concentrations of cytokines did not show significant differences between group I and II. In acute phase of meningitis correlations between CSF concentration of TNF-alpha and IL-1 beta and other indexes of inflammation in CSF: pleocytosis, concentration of protein and glucose were found. The serum concentrations of the cytokines were many times lower than in CSF. The detection of TNF-alpha and IL-1 beta CSF concentration can be used to estimate the efficacy of therapy and regression of inflammation in the central nervous system.

[Proinflammatory cytokine levels in cerebrospinal fluid from children with acute encephalitis]

We investigated interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and soluble TNF receptor 1 (sTNF-R 1) during the acute stage in the cerebrospinal fluid (CSF) from children with acute encephalitis by means of a sandwich enzyme immunoassay. We divided the 24 children with acute encephalitis into two groups: those who survived without neurological sequelae (Group 1, n = 15), and those who died or were left with sequelae (Group 2, n = 9). The IL-1 beta, IL-6, TNF-alpha and sTNF-R 1 levels in CSF in the two groups were significantly higher than those in control subjects (n = 23). The CSF sTNF-R 1 levels in Group 2 were significantly higher than those in Group 1. Our findings suggest that the IL-1 beta, IL-6 and TNF-alpha in CSF are related to the pathogenesis of acute encephalitis, and that the CSF level of sTNF-R1 during the acute stage of encephalitis is an important index for predicting the neurological outcome.

Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 concentrations in cerebrospinal fluid predict ventriculoperitoneal shunt infection

OBJECTIVE

To determine the diagnostic value of cerebrospinal fluid tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, and IL-6 released into the cerebrospinal fluid of patients with ventriculoperitoneal shunt infection.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital.

PATIENTS

Sixty-four patients requiring cerebrospinal fluid aspiration for suspected ventriculoperitoneal shunt malfunction.

INTERVENTIONS

Cerebrospinal fluid samples were obtained by shunt aspiration at the time of patient presentation.

MEASUREMENTS AND MAIN RESULTS

TNF-alpha and IL-1 beta concentrations were measured by enzyme-linked immunosorbent assay, and IL-6 activity by bioassay. The sensitivity, specificity, predictive values, and overall efficiency for each cytokine were determined based on the cerebrospinal fluid culture results. Ten patients had positive cerebrospinal fluid cultures, eight of which yielded Staphylococcus species, and one each Acinetobacter and Pseudomonas. Cerebrospinal fluid TNF-alpha, IL-1 beta, IL-6, protein, and leukocyte concentrations were significantly increased in patients with shunt infection. Cerebrospinal fluid IL-6 activity had the highest diagnostic accuracy of the cytokines evaluated, with sensitivity of 80% and specificity of 98%.

CONCLUSIONS

The presence of cerebrospinal fluid inflammatory cytokines strongly suggests ventriculoperitoneal shunt infection. Detection of these cytokines in the cerebrospinal fluid could be used for earlier diagnosis of bacterial infection.

Clinical significance of cytokine measurement for detection of meningitis

Levels of interleukin-6 and tumor necrosis factor alpha were measured in cerebrospinal fluids from patients with meningitis. Interleukin-6 was increased in aseptic and bacterial meningitis, whereas tumor necrosis factor alpha was increased only in bacterial meningitis. We concluded that measurement of cytokines in cerebrospinal fluid may be useful for the rapid diagnosis of meningitis.

Cerebrospinal fluid cytokines in patients with tuberculous meningitis

The level of tumor necrosis factor (TNF)-alpha, soluble TNF receptors p75 (sTNFR-75) and sTNFR-55, interferon (IFN)-gamma, and interleukin (IL)-10 and IL-12 were measured in 59 cerebrospinal fluid (CSF) samples from 15 patients with tuberculous meningitis (TBM). TBM was associated with elevated concentrations of TNF-alpha, sTNFR-75, sTNFR-55, IFN-gamma, and IL-10, while CSF IL-12 was undetectable in all TBM patients. A significant correlation between cytokines and CSF adenosine deaminase activity was also found. The levels of TNF-alpha did not decrease over time, being still detectable in the CSF 16 months after starting antibiotic therapy, whereas IFN-gamma along with anti-inflammatory mediators sTNFR-75, sTNFR-55, and IL-10 remained elevated in the CSF for 4-8 months. The chronic release of cytokines in the CSF compartment was related neither to the TBM stage nor to the clinical outcome of the disease, thus suggesting the presence of a continuous activity of the inflammatory process at the site of infection.

Cerebrospinal fluid interleukin-1 receptor antagonist and tumor necrosis factor-alpha following subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) causes an inflammatory reaction and may lead to ischemic brain damage. Experimental ischemia has been shown to be connected with the alarm-reaction cytokines interleukin-1 receptor antagonist (IL-1Ra) and tumor necrosis factor-alpha (TNF alpha). Increased levels of these cytokines, however, have not been detected thus far in patients following an SAH event. For this reason daily cerebrospinal fluid (CSF) samples were collected from 22 consecutively enrolled patients with SAH and from 10 non-SAH patients (controls). The CSF samples were studied using immunoassays for IL-1Ra and TNF alpha to investigate whether an SAH caused increased cytokine levels. The mean IL-1Ra levels were significantly higher in patients with SAH who were in poor clinical condition on admission than in those who were in good condition (318 pg/ml vs. 82 pg/ml, p < 0.02). The IL-1Ra levels increased during delayed ischemic episodes and after surgery in patients who were in poor clinical condition. Significant increases in IL-1Ra and TNF alpha were detected during Days 4 through 10 in patients suffering from SAH who eventually had a poor outcome (p < 0.05). Patients with good outcomes and control patients had low levels of these cytokines. The levels of IL-1Ra increased after surgery in patients with Hunt and Hess Grades III through V, but not in those with Grade I or II. This finding indicates that patients in poor clinical condition have a labile biochemical state in the brain that is reflected in increased cytokine levels following the surgical trauma. Both IL-1Ra and TNF alpha are known to induce fever, malaise, leukocytosis, and nitric oxide synthesis and to mediate ischemic and traumatic brain injuries. The present study shows that levels of these cytokines increase after SAH occurs and that high cytokine levels correlate with brain damage. It is therefore likely that fever, leukocytosis, and nitric oxide synthesis are also mediated by IL-1 in patients suffering from SAH and it is probable that the inflammatory mediators contribute to brain damage.

[Evaluation of tumor necrosis factor and C-reactive protein level determination in cerebrospinal fluid of meningitis and encephalitis]

The evaluation of TNF-alpha and CRP in cerebrospinal fluid (CSF) concentrations determining in the differential diagnosis of infectious meningitis was shown. The highest concentrations of these parameters were detected in the group of patients with bacterial meningitis. The findings correlated with the severity of clinical course of bacterial meningitis and with the routine determined laboratory data of CSF. Usefulness of examination CSF for TNF-alpha and CRP in differential diagnosis of meningitis was underlined, especially in cases, where routine parameters of CSF are not conclusive.

Trovafloxacin delays the antibiotic-induced inflammatory response in experimental pneumococcal meningitis

This study evaluates the ability of the new fluoroquinolone trovafloxacin to attenuate the inflammatory burst known to occur after initiation of antibiotic treatment in pneumococcal meningitis. After exposure to trovafloxacin or ceftriaxone for 3 h in vitro, Streptococcus pneumoniae was injected intracisternally (i.c.) into rabbits every 3 h over 9 h (n = 6 for each antibiotic). Ceftriaxone-treated S. pneumoniae induced consistently higher CSF leucocyte counts (median 2568/microL versus 543/microL at 6 h; P = 0.03; 4560/microL versus 2207/microL at 18 h; P = 0.03) than trovafloxacin-treated bacteria. Meningitis induced in rabbits by i.c. injection of live S. pneumoniae was treated with equal doses of trovafloxacin or ceftriaxone i.v. (ten per group). The bactericidal rates of both antibacterial agents in CSF were almost identical. In comparison with ceftriaxone, trovafloxacin resulted in lower tumour necrosis factor (TNF) and interleukin 1beta (IL-1beta) CSF levels 2 h after the initiation of treatment (TNF levels, median 26 U/mL versus 141 U/mL; P = 0.02; IL-1beta levels 455 pg/mL versus 1399 pg/mL; P = 0.02). Twelve hours after initiation of therapy, however, TNF and IL-1beta were higher in trovafloxacin-treated animals (TNF, 61 U/mL versus 7 U/mL; P = 0.001; IL-1beta, 4320 pg/mL versus 427 pg/mL; P = 0.006). The increase in CSF lactate was less during trovafloxacin therapy than with ceftriaxone (median: 2.0 mmol/L versus 4.0 mmol/L; P = 0.03). In conclusion, S. pneumoniae treated in vitro with trovafloxacin induced less CSF leucocytosis than ceftriaxone-treated S. pneumoniae. After i.c. inoculation of live S. pneumoniae, trovafloxacin therapy delayed, but did not inhibit, the release of the proinflammatory cytokines TNF and IL-1beta, probably by slowing the liberation of bacterial cell wall components into the subarachnoid space.

TNF alpha in cerebrospinal fluid of meningitis patients reduces astrocytes membrane potential

During inflammatory CNS diseases cytokines are released into the cerebrospinal fluid (CSF). Astrocytes which are target cells for cytokines also contribute importantly to undisturbed neuronal function e.g. by maintaining local ion homeostasis. The effects of CSF from patients with septic (CSF-SM) and aseptic (CSF-ASM) meningitis on electrophysiological membrane properties of cultured rat cortical astrocytes were investigated. Astrocytes significantly depolarized from a membrane potential of -75.6 +/- 2.3 to -47.4 +/- 6.2 mV in CSF-SM (n = 8). 12 of 18 CSF-ASM also induced a depolarization. The depolarization of astrocytes was inhibited by a neutralizing anti-TNF alpha antibody, indicating that the cytokine TNF alpha initiates the depolarization.

Association of interleukin-6 in the cerebrospinal fluid during crisis of calf with ammoniated feed syndrome

Ammoniated feed syndrome (AFS) in cattle is a neurotoxic syndrome caused by feeding specific ammoniated forage. To clarify the pathophysiology of AFS, we examined the association of interleukin-6 (IL-6) in the brain. By feeding milk either from cows fed such ammoniated forage or milk added with 4-methyl-imidazole, newborn calves showed a neurotoxic crisis of hyperexcitability, ataxia, muscle tremor, circling, roaring, epileptoid seizure, sweating and marked fever response. Although these calves had no pathological lesions in the brain, we detected a rise in IL-6 in the cerebrospinal fluid (CSF). Tumor necrosis factor-alpha (TNF-alpha) was not detected in the CSF. In the sera, IL-6 and TNF-alpha hardly changed during the experiment. Administration of recombinant human IL-6 into the lateral ventricle resulted in fever. Thus, we believe IL-6 in the CSF is related to the fever response in newborn calves with AFS.

Blood-brain barrier permeability during the development of experimental bacterial meningitis in the rat

In an attempt to examine whether routes of bacterial entry into the central nervous system have any bearing on subsequent changes in blood-brain barrier permeability, we examined cerebrospinal fluid (CSF) penetration of circulating 125I-albumin in two different models of experimental meningitis due to K1 Escherichia coli, type III group B streptococcus, or Haemophilus influenzae type b in infant rats: hematogenous meningitis subsequent to subcutaneous inoculation of bacteria vs meningitis induced by direct inoculation of bacteria into the CSF via the cisterna magna. In the model of hematogenous meningitis, the mean CSF penetration was significantly greater in animals with H. influenzae type b meningitis than in those with meningitis due to K1 E. coli or type III group B streptococcus. In contrast, the mean CSF penetration was significantly enhanced in all animals with meningitis induced by intracisternal inoculation regardless of infecting pathogens. Tumor necrosis factor activity in CSF appeared to correlate with the functional penetration of circulating albumin across the blood-brain barrier in both models of experimental meningitis. These findings suggest that the alterations of blood-brain barrier permeability during development of experimental meningitis may vary for different models of inducing meningitis and that the mechanisms responsible for these different permeability changes may be multifactorial.

Interleukin-12 and tumor necrosis factor-alpha levels in cerebrospinal fluid of multiple sclerosis patients

Concentrations of interleukin (IL)-12 and tumor necrosis factor-alpha (TNF-alpha) in cerebrospinal fluid (CSF) were measured in patients with multiple sclerosis (MS) and control patients with non-inflammatory neurological diseases (NIND) by an enzyme-linked immunosorbent assay. TNF-alpha was detectable in the CSF of 60% of the patients with active MS, none of those with inactive MS and 29% of patients with NIND. CSF concentrations of TNF-alpha correlated with the degree of disability in MS patients (P < 0.05). Detectable levels of IL-12 were found in 10% of the MS CSF samples and 18% of NIND CSF samples. There was a significant relationship between CSF concentrations of IL-12 and those of TNF-alpha in MS patients (P < 0.05); no relationship was observed between the presence of IL-12 and disease activity or severity. These findings further stress the involvement of T helper 1 type-response within the central nervous system in MS.

HTLV-I induced myeloneuropathy in WKAH rats: apoptosis and local activation of the HTLV-I pX and TNF-alpha genes implicated in the pathogenesis

To investigate the pathogenesis of HTLV-I associated diseases, we established a rat model for HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in WKAH rats. In the spinal cords of WKAH rats carrying HTLV-I, chronological histopathology revealed the occurrence of apoptotic cell death starting at 9 months after the infection, followed by demyelination, macrophage infiltration, and the activation of astrocytes starting at 12, 15 and 20 months, respectively. Apoptosis of the Schwann cells was also observed in the peripheral nerves of these rats. By RT-PCR, pX mRNA of HTLV-I was selectively expressed in the diseased spinal cords and peripheral nerves, but not in the unaffected cerebra, cerebella, even though provirus DNAs were consistently identified in these tissues. Among several cytokines examined, mRNA expression and production of TNF-alpha were frequently detected in the spinal cord and the cerebrospinal fluid. The collective evidence suggests that the selective activation of HTLV-I, in particular Tax expression, and/or the production of TNF-alpha in target spinal cord and peripheral nerves are causally related to apoptotic death of the oligodendrocytes and Schwann cells, a major pathogenetic pathway of HTLV-I induced myeloneuropathy in the WKAH rat.

Tumor necrosis factor-alpha and interleukin-1 beta levels in children with bacterial, tuberculous and aseptic meningitis

Cerebrospinal fluid levels of tumor necrosis factor-alpha and interleukin-1 beta in 78 children with nonbacterial, bacterial and tuberculous meningitis, and in 34 control subjects were analyzed in order to evaluate the involvement of these cytokines in the pathogenesis of acute bacterial meningitis and their discriminative value between different etiologies of meningitis. Tumor necrosis factor-alpha and interleukin-1 beta levels were significantly higher in bacterial and tuberculous meningitis than in aseptic meningitis and in control subjects (p < 0.0001). There was no difference in the levels of tumor necrosis factor-alpha and interleukin-1 beta between nonbacterial meningitis and control groups. The finding that both tumor necrosis factor-alpha and interleukin-1 beta are increased in the cerebrospinal fluid of patients with bacterial and tuberculous meningitis whereas normal levels of these two cytokines have been found in patients with nonbacterial meningitis signifies that these cytokines may be used to differentiate between bacterial and nonbacterial meningitis.

Increased levels of interleukin-1beta and soluble intercellular adhesion molecule-1 in cerebrospinal fluid of patients with subacute sclerosing panencephalitis

Proinflammatory cytokines (interleukin [IL]-1beta, tumor necrosis factor [TNF]-alpha, and IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) were measured in paired cerebrospinal fluid (CSF) and serum samples from patients with subacute sclerosing panencephalitis (SSPE), multiple sclerosis (MS), or other neurologic diseases (OND) by ELISA. IL-1beta was significantly increased in CSF of the SSPE group compared with levels in the MS or OND group. IL-1beta CSF/serum ratios were higher in the SSPE than in the MS or OND group. TNF-alpha and IL-6 levels were similar in the 3 groups. CSF sICAM-1 was higher in the SSPE group than in the MS or OND group. sICAM-1 CSF/serum ratios were higher in the SSPE than the OND group. The increased CSF/serum ratios of IL-1beta and sICAM-1 in SSPE indicate synthesis of IL-1beta and sICAM-1 in the central nervous system and may be important in the pathogenesis of disease.

Intrathecal production of interleukin-12 and gamma interferon in patients with bacterial meningitis

To assess the role of interleukin-12 (IL-12) and gamma interferon (IFN-gamma) in children with bacterial meningitis, bioactive IL-12 (p70) and the inactive subunit p40 and IFN-gamma were measured in serum and cerebrospinal fluid (CSF) from 35 children with bacterial meningitis and 10 control subjects. The production of IFN-gamma is induced by IL-12 with tumor necrosis factor alpha (TNF-alpha) as a costimulator and inhibited by IL-10. CSF concentrations of IL-12 p40 as well as those of IFN-gamma were markedly elevated, whereas IL-12 p70 was hardly detectable. Detectable CSF levels of IFN-gamma correlated positively with IL-12 p40 (r = 0.40, P = 0.02) and TNF-alpha (r = 0.46, P = 0.04) but not with IL-6, IL-8, or IL-10. In contrast to CSF levels of TNF-alpha, IL-12, and IL-10, those of IFN-gamma were significantly higher in patients with pneumococcal meningitis than in children with meningitis caused by Haemophilus influenzae and Neisseria meningitidis, presumably because of a high CSF TNF-alpha/IL-10 ratio in the former. We suggest that IL-12- and TNF-alpha-induced IFN-gamma production may contribute to the natural immunity against microorganisms in the CSF compartment during the acute phase of bacterial meningitis.

Correlation of tumor necrosis factor levels in the serum and cerebrospinal fluid with clinical outcome in Japanese encephalitis patients

To investigate the prognostic role of tumour necrosis factor (TNF) in Japanese encephalitis virus (JEV) infection, we measured the immunoreactive forms of TNF concentrations in the serum and cerebrospinal fluid (CSF) of 47 laboratory-confirmed cases of JE. It was observed that TNF levels were elevated (> 15 pgm/ml) in all the 47 serum samples (range 19.4-923.8 pg/ml), while in 46/47 CSF samples TNF was elevated (range 10.8-376 pg/ml). The mean (SD) TNF levels in the serum of fatal cases was 234.34 pg/ml (304.40) as compared to the mean of 85.31 pg/ml (SD 153.92) in nonfatal cases. Similar observations were also made with respect to the TNF levels in the CSF; the mean of fatal cases was 69.39 pg/ ml (SD 39.00) in contrast to the mean of 62.41 pg/ml (SD 75.25) of nonfatal cases. The increase in TNF levels did not show any correlation to the duration of illness. It was further observed that the mortality rate increased with increasing concentrations of TNF in the serum and CSF. Correlation of laboratory parameters to final outcome revealed that TNF concentrations above 50 pg/ ml in serum correlated significantly (P = .05) with a fatal outcome, whilst high levels of JEV-IgM antibodies (> 500 units) in the CSF correlated with a nonfatal outcome (P = .03). These results suggest that TNF can be used as a possible prognosticator of a fatal outcome in JEV infection.

Cerebrospinal fluid soluble interleukin-2 receptor in cerebral lupus

Cerebrospinal fluid (CSF) and serum samples of 20 young adults (mean age 41 +/- 3.4 yr) with a first episode of stroke were tested for interleukin-2 (IL-2), soluble interleukin-2 receptor (SIL-2R), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1 beta) levels. The results were compared to 20 patients who had neurological symptoms without evidence of a neurological disease. Three subgroups were formed according to the aetiological source of the stroke, determined by the neurological examination and evaluation. In 13 patients, the presence of atheromatous carotid plaque or cardiac disease was found. In five of the patients, stroke was the presenting symptom of systemic lupus erythematosus (SLE), which developed during the follow-up period. In two patients, no obvious aetiology could be demonstrated. The SIL-2R level was significantly higher in the CSF of patients who later developed definite SLE (P = 0.001). Other CSF interleukins and all serum interleukin levels were not significantly different in any of the groups. No correlation between albumin quotient and CSF SIL-2R was found. The SIL-2R level in the CSF may be used as a diagnostic tool to differentiate immunologically mediated vascular processes in the CNS from stroke of other origin.

Expression of tumor necrosis factor-alpha and transforming growth factor-beta 1 in cerebrospinal fluid cells in meningitis

Meningitis is an acute inflammatory disease of the pia and arachnoid and the fluid in the subarachnoid space, in which a participation of cytokines can be expected. While tumor necrosis factor-alpha (TNF alpha) promotes inflammatory reactions, transforming growth factor-beta 1 (TGF beta 1) has antagonistic effects and suppresses the inflammation in the subarachnoid space. We investigated the protein concentration and mRNA expression of TNF alpha and TGF beta 1 in cerebrospinal fluid (CSF) by ELISA and intracellularly by non-radioactive in situ hybridization in 23 patients with bacterial or viral meningitis. A higher amount of both cytokines on protein and mRNA level, especially of TNF alpha, could be detected in bacterial infection. While an imbalance of both cytokines with a preponderance of TNF alpha- compared to TGF beta 1-mRNA was visible in CSF cells of patients with bacterial meningitis, a balance of TNF alpha- and TGF beta 1-mRNA or a higher expression of TGF beta 1-mRNA could be detected in viral meningitis. In the acute phase of the disease neutrophil granulocytes expressed more TNF alpha- and TGF beta 1-mRNA than lymphocytes and monocytes/macrophages, while these cell types were dominating the cytokine synthesis during the healing phase. These data indicate that immunomodulatory mechanisms take place in the CSF compartment itself, regulated by CSF cells in different but specific ways. In addition, TGF beta 1 seems to be involved in the down-regulation of the inflammatory activity and to be one factor in the cytokine network, which could contribute to a lower rate of complications and positive outcomes. Moreover this study favors the possibility to monitor the immunomodulatory mechanisms by non-radioactive in situ hybridization.

Production of tumor necrosis factor in spinal cord following traumatic injury in rats

Production of tumor necrosis factor (TNF) in the spinal cord following traumatic injury has been studied. In these experiments, the level of TNF was examined in the homogenate of the spinal cord, cerebrospinal fluid (CSF) and serum (n = 56). TNF could be detected in the injured spinal cord but not in the normal spinal cord. The TNF level increased in the spinal cord after the injury. At the lesion site, a maximal TNF concentration was observed 1 h after the injury, and the TNF concentration remained at this level until 8 h after the injury. Thereafter, it decreased gradually. However, TNF still could be detected 72 h after the injury. No TNF could be detected in the CSF and serum, collected from rats both with and without spinal cord injury (SCI). This study thus suggests that TNF is produced locally in the spinal cord following traumatic injury, and this TNF production is caused by the injury. The present results also demonstrate that TNF production is an acute and rapid reaction in the spinal cord following traumatic injury.

Human T lymphocyte virus type I-induced myeloneuropathy in rats: implication of local activation of the pX and tumor necrosis factor-alpha genes in pathogenesis

The pathogenetic roles of human T lymphocyte virus type I (HTLV-I) and cytokines were investigated in HTLV-I-induced myeloneuropathy in Wistar-King-Aptekman-Hokudai rats. In the nervous system, pX messenger RNAs of HTLV-I were selectively expressed in the diseased spinal cord and peripheral nerves but not in the unaffected cerebrum and cerebellum, even though proviral DNAs were consistently identified in these tissues. Among several cytokines examined, mRNA expression and production of tumor necrosis factor (TNF)-alpha in the spinal cord and cerebrospinal fluid correlated positively with the development of spinal cord lesions. The collective evidence strongly suggests that selective activation of HTLV-I, in particular Tax expression and production of TNF-alpha induced by HTLV-I infection in target spinal cord and peripheral nerves, is causally related to apoptotic death of oligodendrocytes and Schwann cells, a major pathogenetic pathway of the HTLV-I-induced myeloneuropathy.

Immunological features of HTLV-I myelopathy in Rio de Janeiro, Brazil, and in vitro effects of cyclosporin A

Brazilian patients with HTLV-1 myelopathy present a significant spontaneous lymphocyte proliferation (SLP), and an increased response to IL-2 exogenous stimulation, in both peripheral blood lymphocytes and in whole blood proliferative assays, when compared to the control group. High antibody titers against HTLV-I antigens were also observed in comparison to healthy seropositive individuals. IL-6 was detected in cerebrospinal fluid (CSF) of 50% of the patients (10 out of 20) and TNF-alpha in four out of nineteen individuals. No correlation was found between the presence of levels of cytokines IL-6 and TNF-alpha and duration or severity of disease. The addition of cyclosporin A (CsA) significantly inhibited SLP suggesting that this therapeutic agent should be studied in HTLV-1 myelopathy. Brazilian patients with HTLV-I myelopathy present the same immunological abnormalities described in other endemic regions. The whole blood assay reflects the same results of separated blood cells and, due to its rapid execution may be used as an assay to follow clinical trials.

Interleukin (IL)-1 beta, IL-2, IL-4, IL-6 and transforming growth factor-alpha levels are elevated in ventricular cerebrospinal fluid in juvenile parkinsonism and Parkinson's disease

Interleukin (IL)-1 beta , IL-2, IL-4, IL-6, epidermal growth factor (EGF), and transforming growth factor (TGF)-alpha were measured for the first time in ventricular cerebrospinal fluid (VCSF) from control non-parkinsonian patients, patients with juvenile parkinsonism (JP) and patients with Parkinson's disease (PD) by highly sensitive sandwich enzyme immunoassays. All cytokines were detectable in VCSF from control and parkinsonian patients, and the concentrations were much higher than those in lumbar CFS. The concentrations of IL-1 beta, IL-2, IL-4 and TGF-alpha in VCSF were higher in JP than those in controls (P < 0.05). In contrast, the concentrations of IL-2 and IL-6 in VCSF from patients with PD were higher than those from control patients (P < 0.05). These results agree with our previous reports, in which the cytokine levels were elevated in the striatal dopaminergic region of the brain from patients with PD. Since VCSF is produced in the ventricles, the alteration of cytokines in VCSF may reflect the changes of cytokines in the brain. Because cytokines play an important role as mitogens and neurotrophic factors in the brain, the increases in cytokines as a compensatory response may occur in the brain of patients of JP or PD during the progress of neurodegeneration. Increase in cytokines may contribute not only as a compensatory response but as a primary initiating trigger for the neurodegeneration.

Interleukin-10 and soluble tumor necrosis factor receptors in cerebrospinal fluid of children with bacterial meningitis

The antiinflammatory mediators interleukin (IL)-10 and soluble tumor necrosis factor (TNF) receptors p55 (sTNFR-55) and sTNFR-75 in cerebrospinal fluid (CSF) from 37 children with bacterial meningitis were studied. CSF concentrations of IL-10, sTNFR-55, and sTNFR-75 and of the proinflammatory cytokines TNF-alpha, IL-6, and IL-8 were markedly elevated and were, with the exception of the sTNFRs, significantly higher in CSF than in serum. CSF concentrations of sTNFR- 55 and sTNFR-75 were only associated positively with IL-10 levels. CSF glucose levels correlated highly with levels of IL-10, sTNFR-55, and sTNFR-75 and weakly with TNF-alpha and IL-6. Cytokine levels in CSF decreased rapidly, while sTNFR levels remained elevated for at least 24 h.

AIDS-associated vacuolar myelopathy and tumor necrosis factor-alpha (TNF alpha)

The spinal cords from 15 patients with AIDS-associated vacuolar myelopathy (VM), 4 AIDS patients without VM, and 5 HIV-seronegative controls, were studied with immunocytochemistry for TNF alpha. CSF and blood from HIV-seropositive patients with VM (n = 16), non-vacuolar myelopathies (n = 8), CNS infection but no clinical myelopathy (n = 31), no clinical or radiological evidence of CNS disease (n = 9), and from 7 HIV-seronegative controls with motor neurone disease were assayed for TNF alpha using an ELISA technique. TNF alpha was present on immunostaining in all the 15 cords with VM studied. The stained cells were macrophages, microglia and endothelial cells. The amount of immunostaining was higher in cords with VM compared with cords from HIV-seropositive patients without VM (p = 0.001). The distribution of staining corresponded to the areas of pathology but did not correlate with the severity of the VM. Immunostaining was also higher in the HIV-seropositive group compared to the HIV-seronegative controls (p = 0.001). There was no significant difference in the levels of TNF alpha in the CSF of patients with VM compared to any of the other groups studied. Blood levels of TNF alpha were lower in the HIV-seropositive controls without CNS disease and in the HIV-seronegative MND controls, than in patients with VM, non-vacuolar myelopathies, and CNS disease. CSF TNF alpha levels did not appear to be a reliable indicator of intramedullary levels. The findings support the hypothesis that TNF alpha may be relevant in the pathogenesis of vacuolar change in VM.

Multiple sclerosis: prospective analysis of TNF-alpha and 55 kDa TNF receptor in CSF and serum in correlation with clinical and MRI activity

The possibility of antagonizing tumor necrosis factor-alpha (TNF-alpha) in vivo with antibodies or soluble TNF receptor has focused much interest on the role of this cytokine in the natural course of MS. We studied nine patients prospectively and serially for one year (14 time points, 131 observations). TNF-alpha and the 55 kDa soluble TNF receptor were measured every 4 weeks in the serum and at defined time points in the CSF. Each value was correlated to clinical symptoms and to MRI measurements obtained on the same day. All patients with relapsing-remitting disease showed periodic increases of TNF concentrations. Overall, the association between serum TNF-alpha levels and bursts of Gd-DTPA enhancement on cranial MRI was not sufficiently tight to reach statistical significance. However, serum TNF levels > 50 pg/ml and measurable CSF levels were always associated with Gd-DTPA enhancing MRI lesions. Isolated high serum TNF peaks were noted during episodes of infection, hay fever or psychic stress. After treatment with glucocorticoids, TNF levels were suppressed for several months, whereas new Gd-DTPA enhancing lesions continued to appear. The concentrations of the soluble 55 kDa TNF receptor did not show marked fluctuations. These results are consistent with an active role of TNF-alpha in MS during periods of disease activity and provide further support for the clinical evaluation of anti-TNF therapies.

Determination of shelf life and activation energy for tumor necrosis factor-alpha in cerebrospinal fluid samples

The cytokine rumor necrosis factor-alpha (TNF-alpha) plays a prominent role in the inflammatory response and has been quantified in several kinds of body fluids. A safe method for keeping samples under the best storage conditions for later studies is clearly needed. We estimated TNF-alpha shelf life by using an accelerated stability testing protocol based on the Arrhenius equation. We investigated two kinds of samples: cerebrospinal fluid (CSF) normal pool (from patients without meningitis) and CSF pathological pool (from patients with pyogenic meningitis). Results of the stress protocol indicated that storing both normal and pathological CSF samples at -70 degrees C would maintain sample stability-i.e., retain at least 90% of the original TNF-alpha content-for approximately 5 years. At -20 degrees C and 4 degrees C, the projected stability time at which the same recovery would be obtained was 190 and 90 days, respectively.

Multiple sclerosis: the proinflammatory cytokines lymphotoxin-alpha and tumour necrosis factor-alpha are upregulated in cerebrospinal fluid mononuclear cells

Lymphotoxin-alpha (LT-alpha) and tumour necrosis factor-alpha (TNF-alpha) promote inflammation in autoimmune diseases and have been detected in the multiple sclerosis (MS) brain lesions and blood, suggesting these cytokines are also present in the cerebrospinal fluid (CSF). To study this, mononuclear cells (MNC) were examined for transcripts of LT-alpha and TNF-alpha, using in situ hybridization (ISH) with synthetic oligonucleotide probes. Most patients with MS had LT-alpha and TNF-alpha mRNA-expressing MNC in their CSF at mean frequencies of about 1/2800 cells for both cytokines. Numbers were dramatically higher than in the paired blood specimens. Control patients with other inflammatory neurological diseases (OIND) also had LT-alpha and TNF-alpha mRNA-expressing cells in CSF but at mean frequencies of only 1/36,000 and 1/18,000 cells, respectively. In blood, levels were similar in OIND and MS. To elucidate the influence of myelin antigen stimulation on LT-alpha and TNF-alpha expression, MNC were cultivated with or without myelin basic protein. Strongly elevated levels of MBP-reactive TNF-alpha mRNA-expressing cells were detected in the MS patients' CSF, in particular when examined during clinical exacerbations, as well as MBP-reactive LT-alpha mRNA-expressing MNC. No such patterns were observed in the OIND controls. The strong accumulation of LT-alpha- and TNF-alpha-producing cells and of MBP-reactive LT-alpha and TNF-alpha mRNA-positive cells in the immediate vicinity of the demyelinating process in MS patients implicates a role of these cytokines in the development of MS.

A pilot study investigating the effects of orally administered pentoxifylline on selected immune variables in patients with multiple sclerosis

Multiple sclerosis is probably mainly mediated by T-helper 1 (TH1)-lymphocytes. TH1-function can be down-regulated in vitro and in animal experiments by pentoxifylline. Therefore, we included 20 multiple sclerosis patients in an open label pilot trial of pentoxifylline. Outcome parameter was the effect of treatment on levels of various cytokines and adhesion molecules in cerebrospinal fluid and serum, on production of TH1- and TH2-cytokines using cell stimulation assays, as well as on measures of T-cell activation and proliferation. Kurtzke's EDSS was a secondary efficacy parameter. A convincing and consistent effect of pentoxifylline could not be demonstrated.

The expression of tumour necrosis factor in the hypothalamus after treatment with lipopolysaccharide

To investigate the effects of tumour necrosis factor (TNF) in the hypothalamus, Wistar rats received an intravenous administration of lipopolysaccharide (LPS) at a dose of 3.0 mg/100 g. Concentrations of TNF-alpha in the cerebral liquor and blood sera rapidly increased at 30 minutes after administration of LPS, rose to the maximum level at 1 hour, and then gradually decreased. Using horse-radish peroxidase as a tracer, a transient increase in paracellular permeability throughout the tight junctions of the ependymal cell layer covering the third ventricle was observed by electron microscopy at 30 minutes and in that of the capillary endothelium at 1 hour after administration, respectively. Following LPS administration, TNF was preferentially localized by immunoelectron microscopy in the tight junctional area of the ependymal cell layer and the capillary. These data indicate that TNF, synthesized in the ependymal cell layer, induces a deterioration in the cerebrospinal fluid-brain barrier and subsequently in the blood-brain barrier. The present study suggests that oedematous changes in the hypothalamic areas determined by ultrastructural and magnetic resonance analyses were mainly due to TNF conveyed from the ependymal cell layer to the hypothalamus after administration of LPS.

Interleukin-8 in cerebrospinal fluid from patients with septic and aseptic meningitis

Using a monoclonal antibody enzyme immunoassay, the concentration of interleukin-8 (IL-8) in cerebrospinal fluid (CSF) from 52 patients suspected of having meningitis was studied. The CSF IL-8 concentration was significantly higher in septic meningitis of known and unknown etiology than in aseptic meningitis and significantly higher in aseptic meningitis than in patients without meningitis. The CSF levels of IL-8 correlated with the levels of tumor necrosis factor-alpha, leukocyte count, neutrophil count, protein level, CSF/blood glucose ratio, and the number of days patients were hospitalized. The IL-8 values used to distinguish septic from aseptic meningitis, at a cut-off point of 3.00 micrograms/l, showed a sensitivity of 81%, a specificity of 92%, and a positive predictive value of 96%. The results suggest that determining IL-8 levels may be useful in the differential diagnosis of meningitis.

Cerebrospinal fluid interleukin-6, interleukin-8, and tumor necrosis factor-alpha in children with central nervous system infections

Concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) in cerebrospinal (CSF) samples were determined from 11 control and 42 children with central nervous system infections including 11 patients with bacterial meningitis, 20 patients with aseptic meningitis, 11 patients with encephalitis. The CSF IL-6, IL-8 and TNF-alpha concentrations in patients with bacterial meningitis were significantly higher than those with aseptic meningitis, encephalitis and the control groups. CSF IL-6, IL-8 and TNF-alpha levels in patients with aseptic meningitis were also significantly higher than those in the control group. There was no significant increase of CSF IL-6, IL-8 and TNF-alpha concentrations in patients with encephalitis compared to the control group. CSF IL-6 and TNF-alpha concentrations were decreased in patients with bacterial meningitis after treatment. CSF IL-8 levels were significantly decreased in both bacterial and aseptic meningitis groups at recovery period. There were no correlation between CSF IL-6, IL-8 and TNF-alpha levels and other parameters including CSF leukocytes, protein, sugar, IgG levels and IgG indexes in patients with bacterial meningitis. These results suggest that IL-6, IL-8 and TNF-alpha are important mediators in the meningeal inflammatory process in patients with meningitis. The levels of these mediators are good indicators for the extent of the meningeal inflammation.

Correlation of high serum levels of tumor necrosis factor-alpha with disease severity in human African trypanosomiasis

The levels of tumor necrosis factor-alpha (TNF-alpha) in sera from Trypanosoma brucei gambiense-infected patients from the endemic region of Boko Songho (Bouenza focus in Congo) were measured. An increase was observed in sera from patients (geometric mean = 53.75 pg/ml, n = 69) compared with control subjects from the same endemic area (6.72 pg/ml, n = 31). The patients were classified as being in the early (blood lymphatic) stage and late (meningo-encephalitic) stage of disease according to the presence of parasites and cells in cerebrospinal fluid (CSF). An increase in TNF-alpha was noted in late stage patients (68.42 pg/ml, n = 28) compared with early stage patients (43.68 pg/ml, n = 41). Those patients with fever, asthenia, and edema and those with neurologic signs had higher levels of TNF-alpha (89.36 pg/ml, n = 26) than others (38.07 pg/ml, n = 43). No differences in TNF-alpha levels were seen when trypanosomes were detected in one location (blood, lymph nodes, or CSF) or two or three locations. These data show that the levels of TNF-alpha in serum of T. b. gambiense-infected patients were correlated with disease severity (presence of signs of inflammation or presence of major neurologic signs) and indicate that TNF-alpha could be involved in some aspects of human African trypanosomiasis physiopathology.

Effect of thalidomide on the inflammatory response in cerebrospinal fluid in experimental bacterial meningitis

In experimental bacterial meningitis in rabbits, the inflammatory process is largely mediated by cytokines such as IL-1 and TNF-alpha. Since thalidomide has been shown to inhibit TNF-alpha production, experiments were carried out to determine whether the drug can modulate the inflammatory response to either lysates of H. influenzae (gram negative) or heat killed S. pneumoniae (gram positive) in rabbits. The introduction of a lysate of H. influenzae into the CSF of rabbits causes a very acute inflammatory response, as indicated by a rapid increase in TNF-alpha levels in the CSF and a concomitantly rapid leukocytosis. In contrast, the introduction of heat killed S. pneumoniae, induces a more indolent inflammatory response which also wanes more slowly. Thalidomide treatment reduces TNF-alpha production in both experimental systems, but has a greater effect on the more indolent gram positive inflammatory response in which peak TNF-alpha levels in the CSF are reduced by > 50%. Also, a sustained inhibition of leukocytosis is observed in the inflammatory response to heat-killed gram positive bacteria. In meningeal inflammation induced by the Gram negative lysate, treatment with thalidomide results in only a 29% inhibition of TNF-alpha release into the CSF. In contrast to the drug effect on TNF-alpha, thalidomide treatment does not significantly affect IL-1 levels in these models of rabbit bacterial meningitis.

Concentrations of interferon gamma, tumor necrosis factor alpha, and interleukin-1 beta in the cerebrospinal fluid of children treated for tuberculous meningitis

Concentrations of interferon gamma (IFN-gamma) in the lumbar cerebrospinal fluid (CSF) of 30 children (mean age, 27 months) being treated for stage III (16 children) and stage II (14 children) tuberculosis meningitis (TBM) were determined by ELISA. Nine children with stage III TBM and six with stage II TBM received prednisone (4 mg/kg). Concentrations of IFN-gamma in 73 CSF specimens (18 from the first week of therapy, 20 from the second, 19 from the third, and 16 from the fourth) were determined. The mean concentrations were 780 pg/mL in the first week of therapy and 554 pg/mL, 529 pg/mL, and 269 pg/mL in the second, third, and fourth weeks, respectively. Tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) concentrations in 56 specimens from 23 of these same children were determined by ELISA. The mean CSF TNF-alpha concentration in 12 specimens obtained during the first week of therapy was 17 pg/mL, and the mean was 11 pg/mL during each of the subsequent weeks (14 specimens were evaluated in the second week and 15 specimens in the third and fourth weeks of therapy). Mean IL-1beta concentrations in these same groups of specimens were 52 pg/mL, 43 pg/mL, 42 pg/mL, and 18 pg/mL. No correlation could be shown between cytokine concentration and stage of disease, and no differences existed between those who did and those who did not receive prednisone. A significant decline in IL-1beta concentrations was shown during the 4-week period, but none in TNF-alpha or IFN-gamma concentrations was noted. Persistently high CSF INF-gamma concentrations in cases of TBM (as in cases of aseptic meningitis but not bacterial meningitis) at the time of diagnosis suggest an immune response fundamentally different from that in bacterial meningitis.

Tumor necrosis factor-alpha and total parenteral nutrition-induced anorexia

BACKGROUND

We hypothesize that total parenteral nutrition (TPN) induces anorexia by an increase in anorexigenic cytokines (factors with central action via the hypothalamus) and tested this hypothesis by measuring changes in food intake and cytokines in response to TPN.

METHODS

Fischer rats with an internal jugular catheter and ad libitum food received saline solution for 10 days. On day 11, rats were randomized to TPN (G:F:AA = 50:30:20) for 4 days (days 11 through 14); control rats received on saline solution for 5 days. On day 14, one half of the TPN group was switched back to saline solution for 1 day. Daily food intake was measured. On day 14 in one half of all rats and on day 15 in the remaining, tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 alpha were measured in plasma and cerebrospinal fluid (CSF). Spontaneous in vitro TNF-alpha and IL-1 alpha were also measured in peripheral blood mononuclear cells.

RESULTS

With TPN, an 80% decrease (p < 0.01) in food intake occurred; plasma TNF-alpha increased (78 +/- 9 pg/ml vs undetectable; p < 0.001), and IL-1 alpha was undetectable. Spontaneous in vitro TNF-alpha and IL-1 alpha production were unchanged. Stoppage of TPN led to return toward normal of food intake and plasma TNF-alpha. TNF-alpha and IL-1 alpha in CSF were undetectable in both groups during and after TPN.

CONCLUSION

Increase in plasma TNF-alpha with no increase in CSF-TNF-alpha during TPN, when food intake decreased, suggests an association between TPN and TNF-alpha but not necessarily cause and effect.

The limited role of pneumolysin in the pathogenesis of pneumococcal meningitis

The aim of this study was to determine the role of pneumolysin, an intracellular toxin of Streptococcus pneumoniae, in the pathogenesis of pneumococcal meningitis. Recombinant pneumolysin (1 microgram), when injected intracisternally into rabbits, resulted in a brisk inflammatory response. However, a pneumolysin-deficient strain of S. pneumoniae caused meningeal inflammation in rabbits indistinguishable from that induced by the parent pneumolysin-producing strain. Furthermore, similar enhancement of meningeal inflammation occurred after ampicillin therapy in animals infected with either the parent strain or the pneumolysin-deficient mutant. These results suggest that although pneumolysin can stimulate the inflammatory cascade in the central nervous system, it is not necessary for the pathogenesis of meningeal inflammation nor does it play a role in postantibiotic enhancement of meningeal inflammation.

Production of systemic and hypothalamic cytokines during the early phase of endotoxin fever

Changes in concentrations of cytokines in plasma and in hypothalamic push-pull perfusates of guinea pigs were measured within the 1st hour after intramuscular injections of bacterial lipopolysaccharide (LPS; Escherichia coli, 20 micrograms/kg) or solvent (0.9% saline). In control animals injected with solvent, interleukin (IL)-1 and tumor necrosis factor alpha (TNF-alpha) were not detectable in plasma. Only IL-6 was present in picogram quantities. Within 45 min after injection of LPS, the concentrations of IL-1, TNF-alpha, and IL-6 increased in the plasma: by several orders of magnitude for TNF-alpha and about tenfold for IL-G. Picogram amounts of biologically active IL-1 were detected in plasma after injection of LPS. No steady state levels of systemic cytokines were reached during the experimental period. In hypothalamic perfusates of animals injected with the solvent, no IL-1 was detectable. TNF-alpha could be detected at higher concentrations than IL-6. IL-6 was detectable at tenfold lower concentrations than in the plasma. In animals injected with LPS, the hypothalamic concentration of IL-6 started to increase during the period 15-30 min and the concentrations of TNF-alpha during the period 30-45 min after LPS injection. The concentrations of IL-6 increased by 300-400% and did not exceed picogram values. No progressive increase of hypothalamic levels of these cytokines was observed during the time course of the experiment. The method used did not detect any changes in the amount of biologically active IL-1 in hypothalamic perfusates of LPS-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)

High levels of interleukin 10 and tumor necrosis factor alpha in cerebrospinal fluid during the onset of bacterial meningitis

Since interleukin-10 (IL-10) controls the production of tumor necrosis factor alpha (TNF-alpha) and this latter cytokine has a deleterious effect on neuronal cells, we determined the levels of both cytokines in cerebrospinal fluid (CSF) from children with bacterial meningitis. High levels of IL-10 (1,164 pg/mL) and TNF-alpha (3,158 pg/mL) were detected in CSF from 10 children with meningitis, but these cytokines were not detectable in CSF from 12 controls. In vitro neutralization of IL-10 demonstrated that endogenously formed IL-10 is important for limiting the production of TNF-alpha by leukocytes. We assume that IL-10 in CSF will decrease the inflammatory reaction associated with meningitis and will result in the development of fewer sequelae because of its inhibitory effect on the production of TNF-alpha.

Assessment of a possible imbalance between tumor necrosis factor (TNF) and soluble TNF receptor forms in tuberculous infection of the central nervous system

Distributions of tumor necrosis factor (TNF) and its soluble receptor forms, R55-BP and R75-BP, were analyzed in the cerebrospinal fluid of patients with severe acute or chronic central nervous system infections. Tuberculous infections were associated with high ratios of R55-BP and R75-BP to TNF, 27.2 and 28.0, respectively, suggesting a small biologically active fraction of TNF. The opposite was found in subjects with acute bacterial meningitis. They had large fractions of biologically active TNF and thus low ratios of R55-BP and R75-BP to TNF, 3.7 and 4.0, respectively. It is hypothesized that chronic infectious diseases, such as tuberculous infections, may be associated with inadequate production of TNF and a concomitant relative increase of soluble TNF receptors, which may prolong the disease.

Elevated cerebrospinal fluid levels of manganese superoxide dismutase in bacterial meningitis

We examined the mechanism of increase of manganese superoxide dismutase (Mn SOD) in the cerebrospinal fluid (CSF) in bacterial meningitis (BM). The elevated levels of Mn SOD in the CSF in BM, measured with an enzyme immunoassay method, were more prominent than those in aseptic meningitis (AM) and encephalitis (EN). In AM and EN Mn SOD levels well correlated with levels of neuron-specific enolase and S-100b protein, which are markers of damages to nervous tissues, but did not with any of them in BM. CSF concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 alpha (IL-1 alpha) were higher in BM than in AM and EN. From the serial measurements in BM, the peak values of these cytokines chronologically preceded or corresponded to those of Mn SOD. Immunohistochemically, a large number of the glial cells were stained for Mn SOD in the cerebral cortex from a patient with BM. By contrast, in the normal cerebral cortex, the glial cells were negative for Mn SOD staining. These results suggest that the marked increase of Mn SOD in the CSF in BM may be related to the increase of such cytokines as TNF-alpha and IL-1 alpha and that these cytokines may play a role in the induction of Mn SOD in nervous tissues.

Tumor necrosis factor-alpha and interleukin-1 beta in cerebrospinal fluid of patients with coccidioidal meningitis during therapy with fluconazole. National Institute of Allergy and Infectious Diseases Mycoses Study Group

The levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1 beta in the cerebrospinal fluid (CSF) of 66 patients with coccidioidal meningitis during therapy with fluconazole were measured by ELISA. The median concentration of TNF-alpha was 15.2 pg/mL for 322 samples; for IL-1 beta, it was 4.7 pg/mL for 316 samples. There were no significant changes in the level of either cytokine over 24 months of follow-up nor was there an association between the initial CSF concentrations of TNF-alpha and IL-1 beta and subsequent fluconazole treatment failure. Over time, concentrations of IL-1 beta were significantly associated with both clinical symptoms and white blood cell counts in CSF. These results indicate that CSF levels of TNF-alpha and IL-1 beta are relatively low compared with those associated with acute bacterial meningitis.

[Alpha tumor necrosis factor in central nervous system disease associated with HIV infection]

The aim of the present study is to evaluate the relationship between the alpha tumor necrosis factor (TNF-alpha), interleukin 1 beta (IL-1 beta) and the neurological disease associated to the HIV-1 infection and different neurological manifestations (15 infections of the CNS and 11 AIDS-dementia complexes) and 14 from a control group. The mean value of TNF-alpha in CSF of patients with HIV-1 infection and AIDS-dementia complex was 19.8 +/- 30.6 pg/ml, superior to that of the control group (p < 0.05). The group of patients with HIV-1 and opportunistic CNS infection has a TNF-alpha value of 28.5 +/- 37.8 pg/ml, that is superior to that of the patients with the AIDS-dementia complex (TNF-alpha = 7.9 +/- 9.4 pg ml; p < 0.05). Within the group of patients with a CNS infection, the value of TNF-alpha was greater in those in the acute phase (44.2 +/- 42.4 pg/ml) than in those in the chronic phase (6.8 +/- 7.6 pg/ml; p < 0.05). The TNF-alpha in the CSF is a good marker of infection of the CNS in the HIV-1 infection.

Cytokine elevations in infants with bacterial and aseptic meningitis

We sought to determine whether the detection of cytokines, produced during the inflammatory response, would aid in the diagnosis of meningitis in young infants. We measured cerebrospinal fluid (CSF) and plasma levels of interleukin-6 (IL-6) and tumor necrosis factor (TNF) in 62 infants less than 6 months of age whose condition was evaluated for meningitis. Twenty infants had culture-proved meningitis, 22 had aseptic meningitis, and 20 control infants had no evidence of meningitis. The CSF IL-6 levels were elevated in all 20 infants with bacterial meningitis and in 9 of 22 infants with aseptic meningitis but were undetectable in all control subjects. Furthermore, CSF IL-6 levels were 10 times greater in infants with bacterial versus aseptic meningitis (p < 0.001). Levels of TNF in CSF were detected in 12 of 20 infants with bacterial meningitis and were undetectable in infants with aseptic meningitis and in control infants (p < 0.02). Plasma IL-6 and TNF levels were unreliable for the detection of meningitis in this patient population. We conclude that the presence of IL-6 in the CSF reliably identifies infants with meningitis and that the presence of CSF TNF is a highly specific indicator of bacterial meningeal inflammation.