Tumour necrosis factor-alpha is increased in the cerebrospinal fluid and serum of ischaemic stroke patients and correlates with the volume of evolving brain infarct

A growing body of evidence suggests the involvement of inflammatory mediators, including cytokines, in the development of ischaemic brain lesions. The aim of the present study was to investigate whether tumour necrosis factor-alpha (TNF-alpha), the proinflammatory cytokine, contributes to early pathophysiological mechanisms leading to brain damage as a consequence of acute stroke. We have studied TNF-alpha levels in cerebrospinal fluid (CSF) and serum in 23 stroke patients within the first 24 hours after ischaemic stroke, confirmed by computerized tomography of the brain (CT). The control group consisted of 15 patients with the diagnosis of tension headache and neurasthenia. In stroke patients the levels of TNF-alpha both in CSF and serum were significantly higher in comparison with the control group. The positive correlation between the levels of TNF-alpha in CSF and serum of the studied patients has been observed. Furthermore, a positive correlation between both TNF-alpha levels in CSF and serum and the volume of evolving brain infarct have been shown.

Effects of tacrolimus on hemispheric water content and cerebrospinal fluid levels of glutamate, hypoxanthine, interleukin-6, and tumor necrosis factor-α following controlled cortical impact injury in rats

Object. Disturbance of calcium homeostasis contributes to evolving tissue damage and energetic impairment following traumatic brain injury (TBI). Calcium-mediated activation of calcineurin results in production of tissue-damaging nitric oxide and free oxygen radicals. Inhibition of calcineurin induced by the immunosuppressant tacrolimus (FK506) has been shown to reduce structural and functional damage after ischemia. The aims of the present study were to investigate time- and dose-dependent short-term antiedematous effects of tacrolimus following TBI.

Methods. A left temporoparietal contusion (controlled cortical impact injury [CCII]) was induced in 51 male Sprague—Dawley rats. Tacrolimus (1 or 3 mg/kg body weight) was administered by a single intraperitoneal injection at 5 minutes, 30 minutes, or 4 hours after CCII occurred. Control rats received physiological saline. Water contents of traumatized and nontraumatized hemispheres, as well as cerebrospinal fluid (CSF) levels of mediators reflecting tissue damage (the proinflammatory cytokines interleukin [IL]-6 and tumor necrosis factor [TNF]—α, the excitotoxin glutamate, and the adenosine triphosphate—degradation product hypoxanthine), were determined 24 hours after trauma.

Although CSF levels of IL-6 and TNFα were completely suppressed by tacrolimus at all time points and at both concentrations, CSF levels of glutamate and hypoxanthine, as well as edema formation, were only marginally influenced. Significant reduction of cerebral water content was confined to nontraumatized hemispheres. In addition, the higher dose of tacrolimus failed to exert significant antiedematous effects on traumatized hemispheres.

Conclusions. Under the present study design, the potency of tacrolimus in reducing edema formation following CCII seems limited. However, its immunosuppressive effects could be of value in influencing the posttraumatic inflammatory response known to aggravate tissue damage.

In vivo neutralization of endogenous brain fractalkine increases hippocampal TNFalpha and 8-isoprostane production induced by intracerebroventricular injection of LPS

Fractalkine is a chemokine widely and constitutively expressed in the brain and, as suggested by in vitro studies, it is involved in brain inflammatory responses. In this study, we have investigated the in vivo anti-inflammatory potential of fractalkine in a model of neuroinflammation induced by intracerebroventricular injection of lipopolysaccharide (LPS) in rats. LPS induces a rapid and acute production of the pro-inflammatory cytokine, TNFalpha, in hippocampus and cerebrospinal fluid (CSF), and an increase of 8-isoprostane levels, a marker of oxidative stress, in hippocampus. Although intracerebroventricular injection of fractalkine has no effect on TNFalpha and 8-isoprostane production, neutralization of endogenous fractalkine within the brain with a specific anti-fractalkine antibody potentiates LPS effects. These data emphasize the involvement of constitutive brain fractalkine in the control of inflammatory reaction in CNS.

Inflammatory cytokines in subarachnoid haemorrhage: association with abnormal blood flow velocities in basal cerebral arteries

Subarachnoidal release of inflammatory cytokines (interleukin (IL)-1beta, IL-6, and tumour necrosis factor (TNF)-alpha) was characterised in 35 patients with subarachnoid haemorrhage (SAH) and control subjects and compared with development of complicating haemodynamic abnormalities in basal cerebral arteries and clinical outcome. Serial analysis allowed the observation of a subacute response profile of these key mediators of inflammation in the subarachnoidal space. This compartmentalised inflammatory host response was closely associated in time and extent with development of increased blood flow velocities in the basal cerebral vessels as recorded by transcranial Doppler sonography. Moreover, intrathecal secretion of inflammatory cytokines was significantly increased in patients with poor clinical outcome. Together, these findings suggest a role of excessive compartmentalised inflammatory host response in pathogenesis of cerebrovascular complications after SAH.

Determination of soluble ICAM-1 and TNFalphaR in the cerebrospinal fluid and serum levels in a population of Brazilian patients with relapsing-remitting multiple sclerosis

Cytokines and adhesion molecules have been implicated in the pathogenesis of multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system. In this study we analyzed intrathecal (CSF) and serum levels of soluble intercellular adhesion molecule (ICAM-1) and TNFalphaR (60kD) from 20 patients with clinically definite MS during acute relapse or stable disease. Comparing to control groups of healthy individuals and patients with intervertebral herniated disc, MS patients showed increased levels (p< 0.001) of sICAM-1 and TNFalphaR in both serum and CSF samples. Regardless stage of disease there was no significant difference in the levels of sICAM-1 during acute relapse (657+/-124.9 ng/ml) or remission (627+/-36.2 ng/ml). A steady increase of TNFalphaR (60kD) in both serum and CSF, indicate the existence of a continuous inflammatory process within the brain tissue of MS patients despite absence of clinical signs of disease activity.

Intrathecal cytokines in systemic lupus erythematosus with central nervous system involvement

Symptoms originating from central nervous system (CNS) are frequently occuring in patients with systemic lupus erythematosus (SLE). Reliable diagnostic markers for this condition are presently lacking. Importantly, CNS involvement in lupus patients is associated with increased morbidity and mortality. The aim of this retrospective evaluate was to study the diagnostic value of cerebrospinal fluid (CSF) cytokine levels in SLE patients with CNS involvement. 34 patients with SLE were hospitalized and investigated for the presence of CNS lupus. These patients were evaluated clinically and with magnetic resonance imaging (MRI) and CSF analyses, as well as with neuropsychiatric tests. 13 patients were found to have CNS lupus whereas another four of the patients fulfilled the criteria for CNS involvement but were excluded from this group due to other causes of CNS involvement. Lastly, in 17 SLE cases, the diagnosis of CNS lupus could not be confirmed. CSF levels of interleukin-6 (IL-6) and IL-8, as well as the CSF/serum IL-6 ratio, were elevated in the CNS lupus group, compared with the 17 SLE patients not fullfilling a diagnosis of cerebral lupus. Interestingly, follow-up of five patients being successfully treated for CNS lupus revealed profound decrease of intrathecal IL-6 levels. These results indicate that analysis of CSF cytokine levels, especially IL-6 and IL-8, may be useful in the diagnostics and possibly follow-up of SLE patients with cerebral lupus.

Interleukin levels in cerebrospinal fluid from children with neurocysticercosis

No information about the levels of pro-inflammatory interleukins has been described in children with neurocysticercosis (NCC). The levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-5, IL-6, and IL-12 in the cerebrospinal fluid from children with NCC were determined by enzyme-linked immunosorbent assay (ELISA). Twelve children with NCC, six with active and six with inactive disease, and six children without NCC were studied. TNF-alpha was undetectable in CSF from controls and five children with inactive NCC, whereas the levels were significantly higher (median 22.1 pg/ml; P = 0.008) in all children with active NCC. Levels of IL-6 were low in active and inactive NCC patients but two subjects with active subarachnoid disease had high levels. IL-5 and IL-12 were not detected. This study shows that high levels of TNF-alpha are present in CSF from children with active NCC. IL-6 levels are higher when infection occurs in the subarachnoid space.

Endothelin-1 in subarachnoid hemorrhage: An acute-phase reactant produced by cerebrospinal fluid leukocytes

BACKGROUND AND PURPOSE

The most potent vasoconstrictor known, endothelin-1, is currently considered to mediate cerebral vasospasm in subarachnoid hemorrhage (SAH), which can cause delayed cerebral ischemia. In our study, we performed clinical and in vitro experiments to investigate the origin and the mechanisms of the secretion of endothelin-1 in SAH.

METHODS

Endothelin-1 and markers of inflammatory host response (interleukin [IL]-1ss, IL-6, and tumor necrosis factor-alpha) were comparatively quantified in the cerebrospinal fluid (CSF) of SAH patients and control subjects, and concentrations were related to clinical characteristics. Furthermore, mononuclear leukocytes isolated from the CSF of SAH patients and control subjects were analyzed regarding their mRNA expression of endothelin-1 and inflammatory cytokines. Finally, complementary in vitro experiments were performed to investigate whether coincubation of blood and CSF can trigger leukocytic mRNA expression and release of these factors.

RESULTS

Activated mononuclear leukocytes in the CSF of SAH patients synthesize and release endothelin-1 in parallel with known acute-phase reactants (IL-1ss, IL-6, and tumor necrosis factor-alpha). Complementary in vitro experiments not only further confirmed this leukocytic origin of endothelin-1 but also showed that aging and subsequent hemolysis of blood is sufficient to induce such endothelin-1 production.

CONCLUSIONS

The demonstration that endothelin-1 is produced by activated CSF mononuclear leukocytes suggests that subarachnoid inflammation may represent a therapeutic target to prevent vasospasm and delayed cerebral ischemia after SAH.

Proinflammatory cytokines and early neurological worsening in ischemic stroke

BACKGROUND AND PURPOSE

The mechanisms for clinical deterioration in patients with ischemic stroke are not completely understood. Several proinflammatory cytokines are released early after the onset of brain ischemia, but it is unknown whether inflammation predisposes to neurological deterioration. We assessed the implication of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in early neurological worsening in ischemic stroke.

METHODS

Two hundred thirty-one patients consecutively admitted with first-ever ischemic cerebral infarction within the first 24 hours from onset were included. Neurological worsening was defined when the Canadian Stroke Scale (CSS) score fell at least 1 point during the first 48 hours after admission. IL-6 and TNF-alpha were determined in plasma and cerebrospinal fluid (CSF; n=81) obtained on admission.

RESULTS

Eighty-three patients (35.9%) deteriorated within the first 48 hours. IL-6 in plasma (>21.5 pg/mL; OR 37.7, CI 11.9 to 118.8) or in CSF (>6.3 pg/mL; OR 13.1, CI 2.2 to 77.3) were independent factors for early clinical worsening, with multiple logistic regression. The association was statistically significant in all ischemic stroke subtypes as well as in subjects with cortical or subcortical infarctions. IL-6 in plasma was highly correlated with body temperature, glucose, fibrinogen, and infarct volume. CSF and plasma concentrations of TNF-alpha were also higher in patients who deteriorated, but the differences observed did not remain significant on multivariate analysis.

CONCLUSIONS

In addition to participating in the acute-phase response that follows focal cerebral ischemia, IL-6 levels on admission are associated with early clinical deterioration. The association between IL-6 and early neurological worsening prevails without regard to the initial size, topography, or mechanism of the ischemic infarction.

Interleukin-6 and interleukin-1 receptor antagonist in cerebrospinal fluid from patients with recent tonic-clonic seizures

We have previously reported increased concentrations of interleukin (1L)-6 in CSF from patients with tonic-clonic seizures, where increased cytokine production most likely is a consequence of neuronal epileptic activity associated with seizures. The biological effects of IL-6 are mediated by other cytokines, which are studied here in addition to IL-6. The purpose of this study was to analyze levels of soluble cytokines from plasma and CSF from patients with newly developed tonic-clonic seizures. The concentrations of IL-6, IL-1 receptor antagonist (IL-1RA), IL-1beta, tumor necrosis factor (TNFalpha) and nerve growth factor (NGF) were measured from plasma and CSF from 22 patients with newly developed tonic-clonic seizures within 24 h from the seizure and 18 controls. The mean concentrations of IL-6 were significantly increased in CSF (P<0.001) and plasma (P<0.01) after tonic-clonic seizures, there was some indication of increased concentrations of IL-1RA and no significant change in NGF, IL-1beta or TNFalpha. Our study shows that cytokine network is activated in patients after recent tonic-clonic seizures. We provide evidence of intrathecal production of IL-6 associated with electrical seizure activity.

Inducible nitric oxide synthase expression elicited in the mouse brain by inflammatory mediators circulating in the cerebrospinal fluid

Expression of inducible nitric oxide synthase (iNOS) protein was studied in the brain after intracerebroventricular injections of interferon (IFN)-gamma, and IFN-gamma combined with lipopolysaccharide (LPS) or tumor necrosis factor (TNF)-alpha, compared to ovalbumin as control. Wild-type mice and mice with targeted deletion of the IFN-gamma receptor gene were used. Findings based on iNOS immunoreactivity were evaluated at 1, 2, 4 and 7 days post-injection, using also quantitative image analysis and double labeling with glial cell markers. IFN-gamma administration induced iNOS immmunostaining in activated microglia and macrophages in the parenchyma surrounding the ventricular system, several cortical fields and fiber tracts. IFN-gamma-elicited iNOS immunoreactivity was down-regulated after 1 day. The number of iNOS-immunopositive cells was significantly enhanced by co-administration of LPS or TNF-alpha; IFN-gamma+TNF-alpha injections also resulted in longer persistence of iNOS immunoreactivity. No immunopositive cells were seen in the brain of IFN-gamma receptor knockout mice after IFN-gamma administration; very few immunostained macrophages were detected in these cases, mostly around the injection needle track, after co-administration of LPS or TNF-alpha. Western blot analysis confirmed a marked iNOS induction in the brain of wild-type mice 24 h after IFN-gamma+LPS injections. The findings show that inflammatory mediators circulating in the cerebrospinal fluid induce in vivo iNOS in the brain with topographical selectivity and temporal regulation. The data also demonstrate that the signaling cascade activated by IFN-gamma binding to its receptor is critical for iNOS induction, and the synergistic action of LPS and TNF-alpha as iNOS inducers in brain cells is largely mediated by the receptor-regulated action of IFN-gamma.

Role of IS6110-targeted PCR, culture, biochemical, clinical, and immunological criteria for diagnosis of tuberculous meningitis

An open prospective clinical, microbiological, and molecular analysis of a national molecular diagnostic service for tuberculous meningitis (TBM) using an in-house IS6110-targeted PCR for molecular "Fastrack" diagnosis was carried out. Between April 1997 and June 1998. Consecutive cerebrospinal fluid (CSF) samples from 131 patients were assessed. Against a culture on the same sample, PCR had a sensitivity of 75% and a specificity of 94%. Of samples from patients classified as definite or probable TBM cases based on clinical criteria, 81% had raised CSF protein levels and 73% had a lymphocytosis, although 57% of all submitted samples showed a raised lymphocyte count. While only 46% had a CSF glucose level below the normal range, the CSF glucose level was significantly lower (P = 0. 0281) than in cases of meningitis of other etiologies. Levels of tumor necrosis factor alpha were also found to be significantly raised in definite or probable TBM cases (P = 0.028), while adenosine deaminase levels were not. The study showed IS6110-targeted PCR to be a rapid, sensitive, and specific test in routine use for the diagnosis of TBM.

Effects of multiple acute morphine exposures on feline immunodeficiency virus disease progression

Drug abuse is a common method of human immunodeficiency virus type 1 transmission, but the role of opiates on lentivirus disease progression is not well understood. The feline immunodeficiency virus (FIV)/cat system was used to model the weekend opiate abuser: the nondependent, nonaddicted, and nontolerant person. Sixteen cats were placed into 4 groups: FIV only, morphine only, morphine/FIV, and controls. Multiple acute morphine exposure did not increase the severity of early lentivirus infection. On the contrary, it delayed or moderated the FIV-induced disease progression. Although the animals were exposed to only 1 injection of morphine per day for 2 consecutive days per week, the morphine-treated FIV-infected animals had a delayed onset of the FIV-induced lymphadenopathy, did not develop or had a significant delay in the FIV-induced effects on brain stem auditory evoked potentials, and demonstrated a trend toward decreased virus load.

Interleukin-5 and interleukin-10 are major cytokines in cerebrospinal fluid from patients with active neurocysticercosis

Neurocysticercosis (NCC) is a common neurological disorder especially in developing countries, caused by infection of the brain with encysted larvae of the tapeworm Taenia solium. Seizures are a common finding associated with this disease. The objective of the present study was to evaluate the correlation between the levels of various cytokines present in the cerebrospinal fluid (CSF) of patients with NCC and the severity of the disease. The levels of the cytokines IL-1ss, TNF-alpha, IL-5, IL-10 and IFN-gamma were determined in the CSF of 22 patients with active NCC, 13 patients with inactive NCC and 15 control subjects. CSF from patients with active NCC presented significantly higher IL-5 levels compared to control subjects. IL-5 and IL-10 levels in CSF from NCC patients with inflammatory CSF were significantly higher than those detected in non-inflammatory CSF. These results show a predominant Th2 lymphocyte activation in human NCC and also indicate the possible use of cytokines in the CSF as a marker for the differential diagnosis between inactive disease and the active form of NCC.

AIDS myelopathy is not associated with elevated HIV viral load in cerebrospinal fluid

The pathogenesis of AIDS-associated myelopathy is unknown. Elevated HIV-1 viral load in CSF has been associated with cognitive impairment. The authors investigated if a similar association exists in patients with myelopathy. The authors evaluated levels of HIV-1 RNA in the CSF of 16 individuals with AIDS myelopathy and in 16 nonmyelopathic HIV-infected control subjects. There was no correlation between levels of HIV-1 RNA and the presence or severity of myelopathy.

Adjunctive thalidomide therapy of childhood tuberculous meningitis: possible anti-inflammatory role

The objective of this study was to determine the safety and tolerability of the immunomodulatory agent thalidomide as adjunct therapy in children with tuberculous meningitis. Children with stage 2 tuberculous meningitis received oral thalidomide for 28 days in a dose-escalating study, in addition to standard four-drug antituberculosis therapy, corticosteroids, and specific treatment of complications such as raised intracranial pressure. Clinical and laboratory evaluations were carried out. Fifteen patients (median age, 34 months) were enrolled. Thalidomide was administered via nasogastric tube in a dosage of 6 mg/kg/day, 12 mg/kg/day, or 24 mg/kg/day. The only adverse events possibly related to the study drug were transient skin rashes in two patients. Levels of tumor necrosis factor-alpha in the cerebrospinal fluid decreased markedly during thalidomide therapy. Clinical outcome and neurologic imaging showed greater improvement than that experienced with historical controls. Thalidomide appeared safe and well tolerated in children with stage 2 tuberculous meningitis and could have important anti-inflammatory effects. These promising results have led us to embark on a randomized, double-blind, placebo-controlled trial of the efficacy of thalidomide in tuberculous meningitis.

Blood-brain barrier function in cerebral malaria and CNS infections in Vietnam

BACKGROUND

The intraerythrocytic parasite Plasmodium falciparum induces the life-threatening neurologic syndrome of cerebral malaria (CM) from within cerebral blood vessels, without entering the brain parenchyma.

OBJECTIVES

1) To assess the use of CSF as an indicator of specific pathologic processes occurring in the brain during CM; 2) to compare this with other neurologic and infectious diseases to understand the distinct pathogenic features of CM; 3) to test the hypothesis that CM involves a specific functional breakdown of the blood-brain barrier (BBB).

METHODS

1) Radial immunodiffusion assays to detect albumin and IgG in matched plasma and CSF samples as indicators of BBB integrity and intrathecal IgG production; and 2) ELISA for soluble intracellular adhesion molecule-1 and sE-selectin, the cytokines tumor necrosis factor-alpha and transforming growth factor-beta1, and the matrix metalloproteinase MMP-9, to detect cellular activation and inflammatory responses within the brain.

RESULTS

Albumin and IgG indices implied only minimal degree of BBB breakdown in a few cases of CM, with most remaining within the normal range. In contrast, cryptococcal, tubercular, and acute bacterial meningitis produced detectable changes in the composition of the CSF and evidence of BBB breakdown.

CONCLUSIONS

CM appears to involve only subtle functional changes in BBB integrity with minimal intraparenchymal inflammatory responses compared with other neurologic infections. This focuses attention on local events within and around the cerebral microvasculature in CM, rather than indicating widespread parenchymal disease.

Temporal profile of cerebrospinal fluid glutamate, interleukin-6, and tumor necrosis factor-alpha in relation to brain edema and contusion following controlled cortical impact injury in rats

Traumatic brain injury is associated with release of the excitotoxin glutamate and production of pro-inflammatory cytokines IL-6 and tumor necrosis factor-alpha (TNF-alpha). Following controlled cortical impact injury, cerebrospinal fluid (CSF) glutamate, IL-6, and TNF-alpha concentrations were measured to investigate their relationship to evolving tissue damage. Compared to non-traumatized rats CSF glutamate, IL-6 and TNF-alpha levels were significantly increased by 8 h after trauma (P<0.005). Parallel to increasing brain swelling and contusion CSF glutamate was significantly elevated over time, reaching highest levels by 48 h (33+/-4 microM) while IL-6 and TNF-alpha showed maximum values at 24 h after trauma (42+/-7 and 4.7+/-1 pg/ml) (P<0.005). The observed different temporal profile of CSF glutamate, IL-6, and TNF-alpha following focal traumatic brain injury could be of therapeutic importance.

Cerebrospinal fluid concentrations of alpha-melanocyte-stimulating hormone in bacterial and aseptic meningitis

alpha-Melanocyte-stimulating hormone (alpha-MSH) has potent anti-inflammatory effects in several experimental models of inflammation. It inhibits both the actions and production of proinflammatory cytokines and neutrophil migration. We investigated whether alpha-MSH in cerebrospinal fluid (CSF) increases during the acute stage in patients with bacterial and aseptic meningitis by measuring alpha-MSH in CSF via radioimmunoassay. The alpha-MSH concentrations in CSF from the children with bacterial meningitis who survived (n = 8), those with aseptic meningitis (n = 16), and the control subjects (n = 23) were all below the detection limit. However, CSF alpha-MSH was elevated in four of the five children with bacterial meningitis who had neurological sequelae. We speculate that elevated alpha-MSH levels in CSF during acute bacterial meningitis reflect negative feedback in response to severe inflammation associated with neurological sequelae induced by proinflammatory cytokines.

CONCLUSION

CSF alpha-MSH is elevated in children with severe bacterial meningitis who had neurological sequelae.

TNF gene polymorphism and its relation to intracerebral production of TNFalpha and TNFbeta in AD

OBJECTIVE

To analyze the extent of tumor necrosis factor-alpha (TNFalpha) and TNFbeta gene polymorphism in patients with AD and to relate it to intrathecal levels of these cytokines.

METHODS

Analyses of TNFalpha and TNFbeta gene polymorphism were performed using PCR in 52 patients with AD and in 25 control subjects, and the levels of corresponding cytokines were analyzed using ELISA.

RESULTS

Patients with AD displayed significantly higher intrathecal levels of TNFalpha, but not TNFbeta, compared with the control subjects. The levels of these cytokines did not differ significantly in patients displaying different alleles of the TNF gene.

CONCLUSIONS

Results indicate that increased intrathecal production of TNFalpha in AD is preferentially controlled by environmental stimuli rather than genetic makeup.

CSF interleukin-1 beta, tumor necrosis factor-alpha and free radicals production in relation to clinical outcome in acute bacterial meningitis

OBJECTIVE

To study the relationship of CSF IL-1 beta and TNF-alpha with free radicals in acute bacterial meningitis (ABM) and to evaluate the clinical outcome in relation to the levels of these cytokines and free radicals in CSF.

DESIGN

Prospective with controls.

SETTING

Referral unit of a teaching hospital.

METHODS

32 children between 3m-12 yrs of age with proven acute bacterial meningitis comprised the study group. In the control group, 20 children with febrile seizures were included. CSF cytokines- Interleukin Ib and tumour necrosis factor a,free radicals O(2)-, H(2)O(2) and enzymes SOD and CPK were measured in all the children.

RESULTS

CSF IL-Ib and TNF-a concentration were markedly elevated in children with ABM (441.5 +/- 216.1 pg/ml, and 1009 +/- 529.1 pg/ml, respectively) as compared to controls (52.67 +/- 6.92 pg/ml, and 86.42 +/- 16.24 pg/ml) (p <0.0001). Free radicals viz., superoxide anion, hydrogen peroxide production and enzymes creatinine phosphokinase and superoxide dismutase were also significantly elevated in ABM as compared to controls. There was direct correlation of CSF cytokines with CSF cytology, protein and free radicals production in ABM. Patients who expired or had neurological sequelae had markedly elevated concentrations of cytokines and free radicals.

CONCLUSION

IL-I beta, TNF-alpha and free radicals are significantly elevated in CSF of patients with ABM. The concentration of these cytokines correlated well with free radical production, and with routinely measured CSF parameters and had a direct bearing on outcome of ABM

Inhibition of leukocyte entry into the brain by the selectin blocker fucoidin decreases interleukin-1 (IL-1) levels but increases IL-8 levels in cerebrospinal fluid during experimental pneumococcal meningitis in rabbits

The polysaccharide fucoidin is a selectin blocker that inhibits leukocyte recruitment into the cerebrospinal fluid (CSF) during experimental pneumococcal meningitis. In the present study, the effect of fucoidin treatment on the release of the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), and IL-8 into the CSF was investigated. Rabbits (n = 7) were treated intravenously with 10 mg of fucoidin/kg of body weight every second hour starting 4 h after intracisternal inoculation of approximately 10(6) CFU of Streptococcus pneumoniae type 3 (untreated control group, n = 7). CSF samples were obtained every second hour during a 16-h study period. Treatment with fucoidin caused a consistent and significant decrease in CSF IL-1 levels (in picograms per milliliter) between 12 and 16 h (0 versus 170, 0 versus 526, and 60 versus 1,467, respectively; P < 0.02). A less consistent decrease in CSF TNF-alpha levels was observed in the fucoidin-treated group, but with no significant difference between the two groups (P > 0.05). In contrast, there was no attenuation in CSF IL-8 levels. Indeed, there was a significant increase in CSF IL-8 levels (in picograms per milliliter) in the fucoidin-treated group at 10 and 12 h (921 versus 574 and 1,397 versus 569, respectively; P < 0.09). In conclusion, our results suggest that blood-derived leukocytes mainly are responsible for the release of IL-1 and to some degree TNF-alpha into the CSF during pneumococcal meningitis, whereas IL-8 may be produced by local cells within the brain.

Diagnostic value of cytokine assays in cerebrospinal fluid in culture-negative, polymerase chain reaction-positive bacterial meningitis

Analysis of bacterial DNA using a polymerase chain reaction performed with broad-range eubacterial 16S rDNA primers may yield a diagnosis of bacterial meningitis in cases where Gram staining of cerebrospinal fluid (CFS), antigen detection techniques or culture fail. Since this PCR technique occasionally gives false-positive results due to contamination of samples or laboratory reagents, a study was performed to establish the diagnostic value of assaying concentrations of tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) in 90 CSF samples. A high correlation was found between a positive PCR result and the concentrations of TNF-alpha and IL-10, indicating that cytokine assays may be used as a confirmatory test. The findings suggested that a combination of the PCR technique, amplicon sequencing and assay of TNF-alpha and IL-10 concentrations in CSF is a reliable and cost-effective procedure for diagnosis of culture-negative bacterial meningitis.

The efficacy of pentoxifylline as an anti-inflammatory agent in experimental Escherichia coli meningitis in the newborn piglet

This study was done to evaluate the anti-inflammatory effect and the ensuing neuroprotective effect of pentoxifylline in neonatal experimental bacterial meningitis. Newborn piglets were divided into three groups: 10 in the control group (CG), 13 in the meningitis group (MG), and 13 in the meningitis with pentoxifylline group (PG). Meningitis was induced by intracisternal injection of 10(8) colony-forming units of Escherichia coli in 100 microl of saline. In PG, 20 mg/kg of pentoxifylline was given as a bolus intravenous injection 30 min before induction of meningitis and 6 mg/kg/h was given continuously throughout the experiment. In PG, the increase of CSF TNF-alpha level observed in MG was abolished. Reduced brain glucose and ATP concentrations observed in MG were significantly increased in PG. However, other parameters of inflammatory responses such as increased intracranial pressure, reduced glucose and increased lactate concentrations in the CSF observed in MG were not significantly down-modulated. The extent of CSF leukocytosis was even higher in PG than in MG. Increased cerebral cortical cell membrane lipid peroxidation products and decreased Na(+),K(+)-ATPase activity observed in MG, indicative of meningitis-induced brain cell membrane dysfunction, tended to improve without statistical significance in PG. In summary, although some anti-inflammatory effects have been observed, the overall anti-inflammatory effects of pentoxifylline was very weak, and it failed to significantly reduce the brain damage in experimental neonatal bacterial meningitis.