Effect of a recombinant N-terminal fragment of bactericidal/permeability-increasing protein (rBPI23) on cerebrospinal fluid inflammation induced by endotoxin

Endotoxin triggers the subarachnoid inflammation of gram-negative meningitis. This study examined the ability of a recombinant N-terminal fragment of bactericidal/permeability-increasing protein (rBPI23) to block endotoxin-induced meningitis in rabbits. Intracisternal (ic) injection of 10-20 ng of meningococcal endotoxin induced high cerebrospinal fluid (CSF) concentrations of tumor necrosis factor (TNF) and CSF pleocytosis and increased CSF lactate concentrations. ic administration of rBPI23 significantly reduced meningococcal endotoxin-induced TNF release into CSF (P < .005), lactate concentrations (P < .001), and CSF white blood cell counts (P < .01). No such effect was observed in animals receiving intravenous rBPI23. Concentrations of rBPI23 in CSF were high after ic administration but low or undetectable after systemic administration. Thus, high concentrations of rBPI23 can effectively neutralize meningococcal endotoxin in CSF, but low CSF concentrations after systemic administration currently limit its potential usefulness as adjunctive drug treatment in gram-negative meningitis.

Immunocytochemical detection of tumor necrosis factor-alpha in infiltrating tumor cells in the cerebrospinal fluid from five patients with leptomeningeal carcinomatosis

We studied the immunoreactivity for tumor necrosis factor-alpha (TNF-alpha) in cerebrospinal fluid (CSF) cell smears from five patients with leptomeningeal carcinomatosis (LC). Immunostained TNF-alpha-positive tumor cells had brownish deposits in the cytoplasm, but no deposits were observed in the nucleus. The intensity of the TNF-alpha staining was greater in these tumor cells than in macrophages from patients with inflammatory diseases. Approximately 27-72% of the tumor cells were found to be TNF-alpha immunoreactive in all five samples from the patient with LC. These results suggest that the large amount of TNF-alpha produced by infiltrating tumor cells may play an important role in the development of the tumor.

Rapid induction of tumor necrosis factor alpha in the cerebrospinal fluid after intracerebroventricular injection of lipopolysaccharide revealed by a sensitive capture immuno-PCR assay

Tumor necrosis factor alpha (TNF-alpha) is an important mediator in many pathophysiologic processes, both in the central nervous system (CNS) and in the periphery. For this study, we have designed a very sensitive immuno-PCR detection system to investigate the time course of TNF-alpha induction in the rat cerebrospinal fluid after intracerebroventricular administration of bacterial lipopolysaccharide (LPS). Immuno-PCR combines antibody specificity with PCR signal amplification and provides a sensitivity in the picomolar range. The enhanced sensitivity of this assay allowed the detection of TNF-alpha in the cerebrospinal fluid as early as 15 min after intracerebroventricular administration of LPS. The present results suggest that the ventricular compartment of the CNS, although confined within the blood-brain barrier, is highly responsive to proinflammatory stimuli such as LPS administration. Insight into the molecular mechanisms underlying this compartmentalization could be key to the pathology and treatment of many CNS diseases, especially the meningitides.

Inflammatory response in bacterial meningitis: cytokine levels in the cerebrospinal fluid

Inflammatory response plays an important role in the pathogenesis of cerebral injury in bacterial meningitis. In this study, we evaluated the cytokine levels of interleukin 1-beta (IL1 beta), tumour necrosis factor alpha (TNF alpha) and interleukin 6 (IL6) in the cerebrospinal fluid (CSF), and determined their correlation with acute clinical complications and with changes in CSF biochemistry. Interleukin 6, TNF alpha and IL1 beta were present in 9/9, 3/9 and 4/9 patients, respectively. The CSFs with detectable TNF alpha or IL1 beta had higher levels of IL6 (p < 0.02), protein (NS) and lower glucose levels (p < 0.02), compared with those in which TNF alpha and IL1 beta were absent. Tumour necrosis factor alpha and IL1 beta levels also correlated with the presence of prolonged fever, fits, spasticity and death (logTNF alpha: r = 0.70, p < 0.05; logIL1 beta: r = 0.62, p = 0.08). The cytokine levels reflect the degree of inflammatory response and are positively correlated with the severity of acute clinical complications. Modulation of this inflammatory response in bacterial meningitis may improve its morbidity and mortality.

Cytokines and murine autoimmune encephalomyelitis: inhibition or enhancement of disease with antibodies to select cytokines, or by delivery of exogenous cytokines using a recombinant vaccinia virus system

To examine the complex role of cytokines in the pathogenesis of actively induced murine EAE we measured the levels of a number of cytokines (IL-6, IFN gamma and TNF) in the spinal cord and CSF of mice with active experimental autoimmune encephalomyelitis (EAE) and found them all to be elevated. We next treated mice with antibodies to these three cytokines, which were over expressed in the CNS, to determine if they would alter disease and found the following: anti-IL-6 had no significant effect on disease, anti-IFN gamma exacerbated disease, and anti-TNF either enhanced, had no effect or inhibited EAE depending on the antibody used. We then treated mice with exogenous cytokines, delivered using a recombinant vaccinia virus system, and found that the IL-6 and TNF virus constructs inhibited EAE whereas the IFN gamma construct had no effect on disease. Other cytokine recombinant viruses were also tested and it was found that the IL-1 beta, IL-2 and IL-10 viruses inhibited EAE while an IL-4 virus either had no effect or enhanced disease. We do not know the mechanism of action of the various cytokines in this system, but irrespective of the mechanism(s), this work clearly demonstrates that delivery of select cytokines using recombinant virus-cytokine constructs can provide a powerful means of down-regulating experimental organ-specific autoimmune disease.

Changes in interleukin-1 beta and soluble interleukin-2 receptor levels in CSF and serum of schizophrenic patients

Some evidence points towards a possible autoimmune role in the aetiology of schizophrenia. Experimental findings provide contradictory results regarding abnormalities in cytokine production in this disorder. In the present study we tested the production of cytokines in CSF and serum in 16 schizophrenic patients and 10 healthy controls (tumor necrosis factor alpha - TNF alpha; interleukins IL-1 beta, IL-2, IL-6, soluble IL-2 receptor). Cytokine levels were evaluated by radioactively-labeled antibodies (IL-1 beta, IL-2, IL-6), by enzyme-linked immunoassay (TNF) and by a sandwich enzyme immunoassay (soluble IL-2 receptor). No significant differences were found in either CSF fluid or serum levels of TNF and IL-2 or IL-6. Interleukin-1 beta was significantly decreased in patients' CSF and serum as compared to controls. Soluble interleukin-2 receptor levels were decreased in CSF of patients, but highly increased in their serum in comparison with controls. Changes in various cytokine levels in CSF fluid and serum of schizophrenic patients probably reflect interrelated process of growth, degeneration or neuroimmunological abnormalities, which may all play a role in the pathophysiology of schizophrenia. The present study supports evidence for change in immune activation, probably of peripheral origin, in schizophrenic patients.

Cerebrospinal fluid analysis in HIV-1-infected children: immunological and virological findings before and after AZT therapy

Immunological and viral studies were conducted on cerebrospinal fluid from 31 HIV-1-infected children, of whom 23 were neurologically asymptomatic and 8 had progressive encephalopathy. After AZT treatment, a second cerebrospinal fluid specimen was obtained from 15 children, 11 of whom were neurologically asymptomatic and 4 had progressive encephalopathy. Virus isolation and p24Ag detection were more frequent in children with progressive encephalopathy than in asymptomatic children (66% versus 12%) and were inversely correlated with intrathecal HIV-1-antibody detection (anti-gag AB: 25% versus 70%). High concentrations of interleukin-1 beta (IL-1 beta) and IL-6 were found in children with progressive encephalopathy (50% and 37%, respectively), but low levels were also detected in some asymptomatic children (13% and 9%, respectively). Tumour necrosis factor-alpha (TNF alpha) was not found. AZT treatment induced disappearance of p24Ag in cerebrospinal fluid, as well as a marked reduction in cytokine levels. Cytokine determination may be useful in monitoring AZT treatment in children with progressive encephalopathy.

The POEMS syndrome: report of six cases

We report six patients affected by POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, and Skin changes), a peculiar multiorgan disease frequently associated with osteosclerotic myeloma or other plasma cell disorders. Sensorimotor polyneuropathy was associated with multisystem involvement in all of the patients, with osteosclerotic myeloma in 2 cases, monoclonal gammopathy of undetermined significance in 2 cases and Castleman's disease in the final two. In all of the patients, sural nerve biopsy findings were consistent with a mixed, axonal and demyelinating neuropathy. Increased levels of Interleukin-6 were found in two cases, but the pathogenesis of the disease is far from established.

High cerebrospinal fluid and serum levels of tumor necrosis factor-alpha in asymptomatic HIV-1 seropositive individuals. Correlation with interleukin-2 and soluble IL-2 receptor

The relationship between tumour necrosis factor-alpha (TNF-alpha) and the interleukin-2 (ILL-2) system in HIV-1 infection is important in understanding the dynamics of early immune response before the development of acquired immunodeficiency syndrome. Levels of TNF-alpha, IL-2 and soluble IL-2 receptor (sIL-2R) in serum and cerebrospinal fluid (CSF) samples from 31 asymptomatic HIV-1 seropositive individuals were measured. High levels of TNF-alpha were detected in CSF of 17 (55%) and serum of 22 (71%) subjects, 15 (88%) of whom had elevated CSF IL-2 levels and 16 (94%) had high sIL-2R levels. Moreover, CSF levels of TNF-alpha significantly correlated with CSF levels of IL-2 and sIL-2R. TNF-alpha, IL-2 and sIL-2R seem to be released within the intrathecal compartment early in the course of HIV-1 infection. In view of the known cytotoxic effects of TNF-alpha, an early release may contribute to subsequent development of neurological complications.

Immunological fluctuations during intrathecal immunotherapy in three patients affected by CNS tumours disseminating via CSF

The immunological therapy of cancer has been proposed in a number of neoplasms (Borden, Sondel, 1989; Foon, 1989; Rosenberg, 1992) and has recently been adopted in the treatment of Central Nervous System (CNS) tumors in combination with conventional surgical and radiotherapeutical approach. In this context, loco-regional administration of immunomodulating agents (for instance in post-surgical cavity) allows to achieve much higher in situ concentrations than by systemic route. Since these treatments have potential adverse effects, careful assessment of clinical and immunological parameters in phase I trials is needed. CNS tumors disseminating via Cerebrospinal Fluid (CSF) pathways offer a stimulating opportunity for intrathecal immunotherapy. In this context, alpha-IFN and IL2 (alone or in combination with LAK cells) have been employed either loco-regionally or intrathecally (Merchant, Mc Vicar, Merchant & Young, 1992; Schiller, Hank, Storer, Borchert, Moore, Albertini, Bechhofer, Wesley, Brown, Bastin & Sondel, 1993). The rationale for the use of both these substances includes the known anti-tumor action of alpha-IFN (Mahaley, Urso, Whaley, Blue, Williams, Guaspari & Selker, 1985; Nagai, 1988) and the ability of r-IL2 to generate activated cells effective in lysing tumor cell targets (Hayes, Moore, Pierz, Chen, Da Rosso, Nirenberg & Allen, 1993). We treated 3 patients (2 affected by disseminating cerebellar medulloblastoma, 1 by disseminating thalamic glioblastoma) by intrathecal r-IL2 via recervoir. In the first 2 patients, this treatment was preceded by alpha-IFN (also intrathecally). Monitoring of immunological effects of the treatment schedule involved kinetics of CSF and serum TNF-alpha, IL2s and IL2R during the first day of r-IL2 treatment, as well as on day +2 and +4 of both r-IL2 cycles, and assessment of CSF cells, protein and CSF and PB NK cell activity and CD3-CD56+ cells during the course of all treatment cycles. We also assessed clinical and neuroradiological effects of immunotherapy.

Evaluation of central nervous system involvement in Lyme borreliosis patients with a solitary erythema migrans lesion

To determine whether early dissemination of Borrelia burgdorferi to the central nervous system occurs in stage I of Lyme borreliosis, neurological and cerebrospinal fluid examination was performed in 48 consecutive patients in whom the only sign of infection was a solitary erythema migrans lesion. Long-term follow-up after treatment with tetracycline was carried out by telephone interview. At presentation, neurological findings were normal in all 48 patients. Cerebrospinal fluid samples were obtained from 29 (60%) patients. Mild pleocytosis and mild impairment of the blood-brain barrier were present in four and one of these patients, respectively. No significant amount of tumor necrosis factor or interleukin 6 was found in the cerebrospinal fluid samples. Culture results of 13 cerebrospinal fluid samples were negative. Borrelia burgdorferi DNA was only detected by the polymerase chain reaction in one of two aliquots of the cerebrospinal fluid sample of one patient. None of 46 patients who were interviewed 12 to 51 (median 25) months after antibiotic treatment developed manifestations consistent with disseminated or chronic Lyme borreliosis. Thus, no compelling evidence was found for the presence of asymptomatic central nervous system involvement in patients with clinically localized Lyme borreliosis.

The use of cytokine and C-reactive protein measurements in cerebrospinal fluid during acute infective meningitis

Cerebrospinal fluid (CSF) concentrations of C-reactive protein (CRP), tumour necrosis factor alpha (TNF), interleukin-6 (IL-6), total protein (TP) and white cell count with differential (WCC) have been measured in 24 patients presenting with acute bacterial or viral meningitis and also in a non-infected, non-inflamed control group (n = 24). In acute viral meningitis, CRP levels were not raised when compared to controls and there was a discordance between high levels of the primary inflammatory mediators (IL-6 and TNF) and the low measured CRP levels. CRP levels were raised in cases of bacterial meningitis. A concentration of 100 ng/mL CRP had a sensitivity of 87% for bacterial meningitis. TNF concentrations in the CSF were significantly raised in cases of acute bacterial meningitis (P < 0.001). Smaller but variable elevations were seen in the patients with acute viral meningitis. One patient, who succumbed to bacterial infection, showed low CSF levels of CRP, TNF and WCC but an elevated IL-6 concentration. Another, presenting with low CSF WCC, had raised concentrations of CRP, TNF and IL-6 which pointed to the correct diagnosis of acute bacterial meningitis. The development of methods yielding rapid analysis for these cytokines together with a sensitive assay for CRP in CSF would be a useful adjunct to conventional investigation.

[The significance of elevated Mn SOD level in cerebrospinal fluid of patients with bacterial meningitis--its relation to cytokine]

We measured cerebrospinal fluid (CSF) levels of manganese superoxide dismutase (Mn SOD) using an enzyme immunoassay method in 19 patients with bacterial meningitis (BM), 33 with aseptic meningitis (AM) and 13 with encephalitis (EN), and examined the significance of their elevations, especially in BM. 1) In BM, the Mn SOD levels were obviously high, ranging from 10.4 to 1179.2 ng/ml. The mean level of Mn SOD was 234.6 +/- 306.7 (SD) ng/ml and 18 patients showed abnormal levels of Mn SOD (more than 13.1 ng/ml). On the other hand, in the remaining 2 diseases, the elevation of SOD levels was not remarkable: the mean levels of Mn SOD in AM and EN were 20.6 +/- 11.6 ng/ml and 41.9 +/- 23.6 ng/ml, respectively. 2) In AM and EN, Mn SOD levels well correlated with NSE or S-100b levels which are the markers of nervous tissue damages. But there was no correlation between the Mn SOD levels in BM and these markers. 3) In BM, there was a positive relationship between Mn SOD and total protein levels, but the disease days showing peak levels were different between them. In addition, Mn SOD levels showed no correlation with cell counts in CSF. 4) In BM, CSF levels of TNF-alpha and IL-1 alpha were remarkably high, whereas in AM and EN, the increases of these cytokines were not marked. And these cytokines in BM showed the peak values in the disease day before or when Mn SOD reached the peak levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrospinal fluid concentrations of interleukin-1 beta, tumour necrosis factor-alpha, and interferon gamma in bacterial meningitis

To investigate the role of the inflammatory cytokines, the cerebrospinal fluid concentrations of interleukin (IL)-1 beta, tumour necrosis factor-alpha (TNF-alpha), and interferon gamma (IFN-gamma) were measured in 11 children with bacterial meningitis and two with mycoplasmic meningoencephalitis and compared with those in 50 children with aseptic meningitis and 15 with non-pleocytotic cerebrospinal fluid. Concentrations of IL-1 beta and TNF-alpha were each significantly higher in the cerebrospinal fluid of patients with bacterial meningitis than in those with aseptic meningitis or those with non-pleocytotic cerebrospinal fluid. IFN-gamma was detected at low concentrations in the cerebrospinal fluid of only 2/11 of those with bacterial meningitis. On the other hand, the IFN-gamma concentration was the highest in the cerebrospinal fluid of patients with aseptic meningitis. These results suggest that the inflammatory cytokines are differently released in the intrathecal space infected with viruses or bacteria.

Tumor necrosis factor-alpha (TNF-alpha) increases both in the brain and in the cerebrospinal fluid from parkinsonian patients

Tumor necrosis factor-alpha (TNF-alpha), a glial-cell-related factor, was measured for the first time in the brain (striatum) and cerebrospinal fluid (CSF) from control and parkinsonian patients by a sensitive sandwich enzyme immunoassay. The concentrations of TNF-alpha in the brain and CSF were significantly higher in parkinsonian patients than those in controls. Since TNF-alpha is an important signal transducer of the immune system with cytotoxic and stimulator properties, these results suggest that an immune response may occur in the nigrostriatal dopaminergic regions in Parkinson's disease and that TNF-alpha may be related, at least in part, to the neuronal degeneration.

The presence of tumour necrosis factor in CSF and plasma after severe head injury

In a cohort of victims of traumatic brain injury, 18 out of 50 patients had a plasma tumour necrosis factor (TNF) concentration above 2 pg/ml within 24 h of injury (mean 12.19, SD 45.96 pg/ml). Twenty-six had CSF samples available of which 17 demonstrated TNF concentrations above 1 pg/ml (mean 3.98, SD 3.61 pg/ml). We conclude that traumatized brain parenchyma is a significant source of TNF activity and implicate the cytokine in cellular metabolic derangements following head injury.

Cerebrospinal fluid interleukin-1 beta/interleukin-1 receptor antagonist balance and tumor necrosis factor-alpha concentrations in tuberculous, viral and acute bacterial meningitis

The levels of interleukin-1 beta, IL-1 receptor antagonist and tumor necrosis factor-alpha (TNF-alpha) were analyzed in 19 cases of tuberculous, 14 cases of viral, and 22 cases of acute bacterial meningitis, and in 18 control subjects. 20 patients (91%) with acute bacterial and 8 (42%) with tuberculous meningitis had detectable amounts of TNF-alpha in the initial cerebrospinal fluid (CSF) sample (mean 1044 +/- 131 pg/ml, range 95-1950, and mean 61 +/- 23 pg/ml, range 25-300, respectively), whereas TNF-alpha was not detectable in any of the patients with viral meningitis, or in any of the control subjects. IL-1 beta levels were 767 +/- 110 pg/ml (185-2000) in acute bacterial, 345 +/- 63 pg/ml (50-670) in tuberculous, 257 +/- 70 pg/ml (20-700) in viral meningitis, and 37 +/- 4 pg/ml (10-68) in control subjects. Il-1 receptor antagonist concentrations were significantly elevated in all meningitis groups, without significant differences between the groups. Il-1 receptor antagonist levels were 2487 +/- 62 pg/ml (2250-2950) in acute bacterial, 2216 +/- 82 pg/ml (1350-2550) in tuberculous and 1985 +/- 92 pg/ml (650-2500) in viral meningitis, and 154 +/- 26 pg/ml (20-245) in control CSF samples. A positive correlation was found between TNF and IL-1 beta levels (p < 0.01), and TNF levels and conscious state (p < 0.05). The ratio of concentrations of IL-1 receptor antagonist to IL-1 beta was 3.2 in acute bacterial meningitis, 6.9 in tuberculous meningitis and 8.3 in viral meningitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of antifungal therapy on inflammation, sterilization, and histology in experimental Candida albicans meningitis

To assess the effects of antifungal therapy on the course of Candida albicans central nervous system infection and inflammation, we inoculated intracisternally 10(5) CFU of C. albicans into rabbits. Fluconazole (10 mg/kg of body weight) or amphotericin B (1 mg/kg) was infused intravenously daily for 14 days. Treatment was initiated 24 h or 5 days after infection. Cerebrospinal fluid (CSF) was repeatedly obtained to culture the organisms, assess the level of inflammation, and measure drug concentrations. Brain tissue was obtained at the end of therapy for culture, drug concentration determinations, and histopathology. The median number of days of treatment required to sterilize CSF cultures was 4 days for fluconazole therapy and 1 day for amphotericin B therapy (P = 0.037). There was a significant reduction in tumor necrosis factor alpha and leukocyte concentrations in the CSF of animals treated early versus those in untreated control animals (P < 0.05 and P < 0.001, respectively; analysis of variance). Compared with treated animals, a higher proportion of cultured CSF samples from untreated animals were positive for Candida (P < 0.001). A cultured brain sample from 1 of the 12 animals treated early with amphotericin B was positive for C. albicans (P < 0.01 versus controls); cultures of brain samples from 3 of 12 animals treated early with fluconazole were positive, whereas cultures of brain samples from 10 of 12 controls were positive (P < 0.05). The mean density of C. albicans was lower in the single culture-positive amphotericin B recipient (1 x 10(1) CFU/g of brain tissue) than in those treated with fluconazole (1 x 10(3) CFU/g) and in controls (8 x 10(4) CFU/g). In animals treated late, the density of C. albicans in the brain in relation to the number of days of therapy was significantly lower in amphotericin B recipients than in those treated with fluconazole (P < 0.01) and untreated controls (P < 0.01; analysis of covariance). By histopathology, a larger proportion of untreated animals compared with those treated early demonstrated features of severe infection such as perivasculitis, ventriculitis, and evidence of fungal organisms. Compared with amphotericin B-treated rabbits, those given fluconazole had a trend toward more severe pathologic lesions. Reduced susceptibility to both fluconazole and amphotericin B was observed in the C. albicans organisms isolated from the brain of one fluconazole-treated animal. These data suggest that amphotericin B is the preferred treatment for C. albicans infections of the central nervous system.

Alterations of anorectic cytokine levels from plasma and cerebrospinal fluid in idiopathic senile anorexia

Plasma and cerebrospinal fluid (CSF) concentrations of two well-known satiety cytokine peptides have been measured in elderly persons with idiopathic anorexia and normal weight healthy subjects in a similar age range. Plasma and CSF levels of tumor necrosis factor alfa (TNF alpha) and interleukin-1 beta (IL-1 beta) were assayed by commercially available kits. Elderly under-weight anorectic patients had significantly lower levels of TNF alpha but unchanged concentrations of IL-1 beta in both plasma and CSF when compared to controls. In addition to significantly lower levels of TNF alpha in CSF, we found a positive correlation between the body mass index and CSF TNF alpha concentrations (r = 0.61, P < 0.05) in the anorectic group. CSF IL-1 beta concentrations showed a significant negative correlation with plasma albumin levels in senile anorectics (r = -0.66, P < 0.05) but not in controls. On the basis of our findings, we conclude that a decrease in plasma and CSF TNF alpha concentrations could have beneficial effects for the primary anorexia of aging both at central level to offset anorexia and at peripheral sites decreasing tissue catabolism.

Murine tumor necrosis factor alpha is transported from blood to brain in the mouse

The cytokines are important components of the brain-immune axis. Recent work has shown that [125I]IL-1 alpha and [125I]IL-1 beta are transported from the blood into the brain by a saturable system. Here we show that murine tumor necrosis factor alpha (mTNF alpha) labeled with 125I (I-mTNF alpha) crosses the blood-brain barrier (BBB) after i.v. injection by a transport system different from that for the interleukins. Self inhibition with mTNF alpha showed that this transport system was saturable, and lack of inhibition by IL-1 alpha, IL-1 beta, IL-6, or MIP-1 alpha showed selectivity of the system. High performance liquid chromatography (HPLC) of the radioactivity recovered from brain and from cerebrospinal fluid after the i.v. injection of I-mTNF alpha showed that the cytokine crossed the BBB largely in intact form. Capillary depletion showed that the accumulation of I-mTNF alpha in the cerebral cortex was due to passage across the BBB rather than to sequestration by capillaries. Transport rate was not changed by acute treatment with the neurotoxin aluminium or by acute and chronic treatment with the cationic chelator deferoxamine, but it was more than three times faster in neonatal rats. Efflux of I-mTNF alpha from the brain was slower than would have been predicted based on reabsorption of cerebrospinal fluid, suggesting that TNF alpha is sequestered by the brain. The BBB was not disrupted by up to 50 micrograms kg-1 of mTNF alpha i.v. in either adult mice or neonatal rats as assessed by the BBB's impermeability to radioactively labeled albumin.(ABSTRACT TRUNCATED AT 250 WORDS)

Ependymal cells of the choroid plexus express tumour necrosis factor-alpha

Tumour necrosis factor-alpha (TNF alpha) is a major proinflammatory cytokine which appears in the cerebrospinal fluid very early after endotoxin challenge, and is likely to be produced locally. Following in vivo and in vitro challenge with endotoxin, we have demonstrated immunocytochemically and by in situ hybridization that pig and guinea-pig choroid plexus ependymal cells can produce TNF alpha. Immuno-electron microscopy shows that this protein is localized within ependymal cells to the cytoplasm and microvilli. We suggest that this TNF alpha may be important in the initiation of the inflammatory response in bacterial meningitis.

Increased release of tumor necrosis factor-alpha into the cerebrospinal fluid and peripheral circulation of aged rats

BACKGROUND AND PURPOSE

We earlier reported that risk factors for stroke prepare brain stem tissue for a modified Shwartzman reaction, including the development of ischemia and hemorrhage and the production of tumor necrosis factor-alpha, after a provocative dose of lipopolysaccharide. In the present study, we sought to determine whether blood and central nervous system cells of rats with the stroke risk factor of advanced age produce more proinflammatory and prothrombotic mediators than do those of young rats of the same strain.

METHODS

Levels of tumor necrosis factor-alpha and platelet activating factor in the cerebrospinal fluid and tumor necrosis factor-alpha in the serum of 2-year-old and 16-week-old Sprague-Dawley rats were monitored before and after challenge with lipopolysaccharide.

RESULTS

No consistent tumor necrosis factor-alpha activity was found in the cerebrospinal fluid or blood of control animals. Intravenous administration of lipopolysaccharide (1.8 mg/kg) increased serum tumor necrosis factor-alpha levels but had no effect on tumor necrosis factor-alpha in the cerebrospinal fluid. Serum tumor necrosis factor-alpha increased much more in aged rats than in young rats. When lipopolysaccharide was injected intracerebroventricularly, tumor necrosis factor-alpha activity in cerebrospinal fluid increased significantly more in old rats than in young rats. Baseline levels of platelet activating factor in cerebrospinal fluid were significantly higher in old rats than in young rats, and the levels increased to a greater degree in aged rats on stimulation.

CONCLUSIONS

Rats with the stroke risk factor of advanced age respond to lipopolysaccharide with a more exuberant production of tumor necrosis factor-alpha and platelet activating factor than young rats of the same strain. These findings are consistent with our working hypothesis that perivascular cells are capable of exaggerated signaling of endothelium through cytokines such as tumor necrosis factor-alpha in animals with stroke risk factors. The effect of such signaling might be to prepare the endothelium of the local vascular segment for thrombosis or hemorrhage in accord with the local Shwartzman reaction paradigm.

Granulocyte-macrophage colony-stimulating factor and interleukin-1 increase in cerebrospinal fluid, but not in serum, of HTLV-I-associated myelopathy

Based on our previous finding of elevated interferon-gamma levels in the cerebrospinal fluid (CSF), but not in serum, of HTLV-I-associated myelopathy (HAM), we assayed serum and CSF levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) in 20 HAM. GM-CSF and IL-1 also increased only in the CSF in 75% and 35%, respectively, of 20 HAM. TNF-alpha was not detected in any of the sera and CSFs. Multiple cytokines may be produced in the central nervous system and play an important role in HAM.

Interleukin-6 and tumor necrosis factor in cerebrospinal fluid: changes during pyrogen fever

Several peptides (cytokines), viz., interleukin-1 (IL-1), interferon-alpha (IFN-alpha), interleukin-6 (IL-6), tumor necrosis factor (TNF), are formed in response to conditions causing tissue inflammation or damage and are implicated in reactive changes of the host, including fever, while IL-1 has been considered an important mediator of fever, the other cytokines, specifically IL-6 and TNF, have recently acquired prominence. The present study extends earlier research on IL-1 and addresses the question of the role of IL-6 and TNF in the genesis of fever. Experiments were conducted in the conscious cat, and IL-6 and TNF were assayed concomitantly in cerebrospinal fluid (CSF) from the third ventricle using specific bioassays. In the absence of fever, IL-6 was usually below the threshold of the assay (4-32 pg/ml), while TNF appeared measurable (424 +/- 57 pg/ml) in most experiments. A single intravenous injection of endotoxin (bolus) or continuous infusion of IL-1 at doses eliciting a sustained fever increased CSF levels of IL-6, but had no effect on concentrations of TNF. Intracerebroventricular injection of a pyrogenic dose of endotoxin led to an elevation of TNF and IL-6 and, in either case, the effect was manifest during the latent period before the fever. In addition, by the same route, IL-1 caused a rise in IL-6. We conclude that brain is intrinsically capable of producing both IL-6 and TNF depending on the site of challenge. However, since IL-6 CSF levels are elevated regardless of the site of pyrogen injection, IL-6 lends itself better to a role in the pathogenesis of fever.

Cytokine expression of macrophages in HIV-1-associated vacuolar myelopathy

Macrophages are frequently present within the periaxonal and intramyelinic vacuoles that are located primarily in the posterior and lateral funiculi of the thoracic spinal cord in HIV-associated vacuolar myelopathy. But the role of these macrophages in the formation of the vacuoles is unclear. One hypothesis is that cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF)-alpha, are produced locally by macrophages and have toxic effects on myelin or oligodendrocytes. The resulting myelin damage eventually culminates in the removal of myelin by macrophages and vacuole formation. We studied thoracic spinal cord specimens taken at autopsy from HIV-positive (+) and HIV-negative individuals. The predominant mononuclear cells present in HIV+ spinal cords are macrophages. They are located primarily in the posterior and lateral funiculi regardless of the presence or absence of vacuolar myelopathy. Macrophages and microglia are more frequent in HIV+ than HIV-negative individuals and these cells frequently stain for class I and class II antigens, IL-1, and TNF-alpha. Activated macrophages positive for IL-1 and TNF-alpha are great increased in the posterior and lateral funiculi of HIV+ individuals with and without vacuolar myelopathy, suggesting they are present prior to the development of vacuoles. Cytokines, such as TNF-alpha, may be toxic for myelin or oligodendrocytes, leading to myelin damage and removal by macrophages and vacuole formation.

Tumor necrosis factor-alpha (TNF alpha) in cerebrospinal fluid from patients with meningitis of different etiologies: high levels of TNF alpha indicate bacterial meningitis

The levels of tumor necrosis factor (TNF)-alpha in cerebrospinal fluid (CSF) were analyzed in 139 patients with meningitis and in 20 control subjects. Elevated concentrations were observed in 42 (82%) of 51 patients with purulent bacterial meningitis (18/24 Haemophilus influenzae, 13/14 Streptococcus pneumoniae, 7/7 Neisseria meningitidis, and 4/6 with other purulent bacterial etiology). In contrast, elevated levels were found in only 5 of 78 individuals with nonbacterial meningitis (2/8 with herpes simplex type 2, 3/3 with varicella-zoster virus). Thus, the positive and negative predictive values were 0.89 for indicating a purulent bacterial meningitis. Raised CSF TNF alpha levels were observed in 7 of 8 patients with purulent bacterial meningitis in whom the routinely used parameters did not unequivocally indicate the diagnosis. Moderately increased levels were seen in 5 of 6 patients with Mycobacterium tuberculosis meningitis and in 1 of 4 cases of Borrelia burgdorferi. Thus, the present study indicates that concentrations of TNF alpha in CSF usually can discriminate between purulent bacterial and nonbacterial meningitis. These findings may contribute diagnostic guidance with routinely used CSF parameters.

Measurement of levels of tumor necrosis factor-alpha and interleukin-1 beta in the CSF of patients with meningitis of different etiologies: utility in the differential diagnosis

We assayed tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) concentrations in CSF from patients with meningitis of different etiologies and tested the usefulness of these assays for differentiating between pyogenic meningitis and aseptic meningitis of different etiologies. We used a monoclonal-antibody ELISA to test 125 CSF specimens from patients whose cases were classified as follows: pyogenic meningitis (n = 20), viral meningitis (n = 22), self-resolving aseptic meningitis for which no specific diagnosis was made (n = 25), meningitis due to other infectious agents (n = 11), and neoplastic meningitis (n = 5); we also tested normal CSF from healthy patients (n = 20) and those with neurological diseases (n = 22). Levels of TNF-alpha were above 200 pg/mL in 16 of 20 patients with pyogenic meningitis, but not in patients in the other groups. Levels of IL-1 beta were above 100 pg/mL in 15 of 20 patients with pyogenic meningitis and in one patient with a brain abscess. A positive correlation between levels of these cytokines and different inflammatory parameters was noted, whereas an inverse relationship with the duration of symptoms was observed. With regard to diagnosis, measurement of TNF-alpha and IL-1 beta levels showed sensitivities of 84.2% and 78.9%, respectively; specificities of 100% and 99%, respectively; a positive predictive value of 1 and 0.93, respectively; and a negative predictive value of 0.97 and 0.96, respectively.

Detection of tumor necrosis factor-alpha-positive cells in cerebrospinal fluid of patients with HTLV-I-associated myelopathy

Tumor necrosis factor (TNF)-alpha-positive cells constituted 1.6-18% and 8.2-23.5% of the total number of cerebrospinal fluid cells from six of 12 patients with HTLV-I-associated myelopathy and in all samples obtained from inflammatory cases, respectively. However, in non-inflammatory cases no TNF-alpha-positive cells were detected. These results suggest that some of the infiltrating CSF cells produce TNF-alpha, which plays a role in host immune defenses against causative agents including HTLV-I and in lesion formation within the central nervous system in inflammatory diseases.

Cellular and cytokine responses of the human central nervous system to intracranial administration of tumor necrosis factor alpha for the treatment of malignant gliomas

To elucidate the role of tumor necrosis factor alpha (TNF alpha) as a biological response modifier, we studied cellular and cytokine responses of the central nervous system to TNF alpha administered intracranially in a phase I clinical trial for patients with malignant gliomas. Six patients received injections of TNF alpha (1.25 x 10(3)-10 x 10(3) U/injection) into the tumor cavities, and regional fluids (RF) and lumbar cerebrospinal fluids (CF) were serially sampled before and after the injections. Recruitment of neutrophils occurred, mostly peaking 8 h after TNF alpha injection, and fewer numbers of CD4+ T cells and monocytes/macrophages migrated, subsequently peaking at 24 h. The CF leukocytosis persisted for 48 h and was associated with an increased level of neutrophil chemotactic activity in the CF. This neutrophil chemotactic activity was attributed to interleukin-8 (IL-8) by HPLC. The level of IL-6 activity in the CF and RF consistently increased; beginning 2 h after TNF alpha injection and reaching the maximum between 8 h and 12 h. It returned to the basal level within 48 h. IL-1 beta was detected in the CF of three patients, its level peaking at 8 h. Prostaglandin E2 also increased after injection of TNF alpha, peaking between 4 h and 12 h and then gradually decreasing. Transforming growth factor beta was found in all cases tested and one patient showed a significant change after TNF alpha injection. IL-2 activity, interferon alpha (INF alpha) activity, IFN beta, and granulocyte/macrophage-colony-stimulating factor were not detected in the CF or RF. In conclusion, TNF alpha is biologically effective in inducing migration of immune cells and generating multiple cytokine responses in the human central nervous system.

Markers of activated T lymphocytes and T cell receptor gamma/delta+ in patients with multiple sclerosis

We studied interferon-gamma (IFN-gamma), alpha-tumor necrosis factor (alpha-TNF) and granulocyte macrophage colony-stimulating factor (GM-CSF) in the cerebrospinal fluid and serum of 18 patients with multiple sclerosis (MS) and 10 subjects with other neurological diseases (OND). We also studied the cerebrospinal-fluid CD 69 expression, and T cells with T cell receptor (TcR) gamma/delta+. We found an increase of IFN-gamma (14.0 +/- 3.5 U/ml) and GM-CSF (8.0 +/- 3.4 pg/ml) levels in the cerebrospinal fluid of MS patients compared to the OND group (p < 0.005 and p < 0.01, respectively). The frequency of detectable cerebrospinal-fluid and serum alpha-TNF was similar in patients with MS and with OND. The cerebrospinal-fluid CD69 expression in lymphocytes was significantly higher in MS patients (15.0 +/- 9.9%) than in the control group (3.7 +/- 6.2%; p < 0.005). Comparable serum levels of IFN-gamma and GM-CSF were detected in patients with MS and in OND subjects. No significant difference in the incidence of TcR gamma/delta+ in the cerebrospinal fluid was found between the two groups. These results indicate an activation of T lymphocytes and macrophages in patients with MS. Our data do not suggest a role for an increased incidence of TcR gamma/delta+. However, we cannot rule out the possibility that these T cells could be present at the plaque site of MS patients.

Intrathecal administration of interleukin-2 for meningeal carcinomatosis due to malignant melanoma: sequential evaluation of intracranial pressure, cerebrospinal fluid cytology, and cytokine induction

A patient with interleukin (IL)-2 responsive metastatic melanoma developed meningeal carcinomatosis. Treatment was attempted with intrathecal (i.t.) IL-2 (5 weekly doses of 3-6 x 10(6) IU) without glucocorticosteroids. Marked increases in cerebrospinal fluid (CSF) pressure occurred 5-10 h following each IL-2 dose, resulting in reversible abnormalities of neurologic function. IL-2 clearance from the CSF ranged from 21 to 85 ml/h, with an apparent first order rate constant of 0.08-0.23 hr-1. These values were consistent with clearance by bulk flow mechanisms. Clearance also correlated directly with peak CSF pressure. Progressive increases in CSF tumor necrosis factor (TNF)-alpha and IL-6 levels, but not Il-1 alpha, were also noted over successive treatment cycles. Increasing neutrophilia (peaking at 12 h postdose) and a delayed lymphocytosis and monocytosis (at 20-30 h) were observed with each successive i.t. IL-2 dose. Activated lymphocytes were not observed in the CSF, however, suggesting that an exogenous source of activated lymphokine-activated killer (LAK) cells may be helpful in obtaining effective antitumor responses.

Evaluation of IL-2, sIL2R, IL-6, TNF-alpha, and IL-1 beta levels in serum and CSF of patients with optic neuritis

Optic neuritis (ON) is characterized by immune-mediated demyelination of the optic nerve. In this study we addressed the question of cytokine signalling as part of activation of the immune system. 20 patients with first episode of acute idiopathic unilateral ON, prolonged visual evoked potentials, but normal 1.5 tesla MRI of the brain, and normal somatosensory evoked potentials were included into the study. Paired cerebrospinal fluid (CSF) and serum samples of these patients were analyzed for the presence of interleukin (IL-)-2, soluble IL-2R (sIL2R), IL-6, tumor necrosis factor (TNF)-alpha, and IL-1 beta by an enzyme-linked immunosorbent assay (IL-2, sIL2R, TNF-alpha, IL-1 beta) or a bioassay (IL-6). IL-2 was significantly elevated in the CSF (P < 0.01), whereas sIL2R (P < 0.01) and IL-6 (P < 0.01) were significantly increased in serum. TNF-alpha could not be detected in CSF or serum, and IL-1 beta was negative in serum in all but one sample and positive in only low amount (mean 9 pg/ml) in the CSF of 6/20 patients. This cytokine pattern in ON indicates an activation of the immune system within and outside the central nervous system with a predominance of T-cell activation.

Tumor necrosis factor alpha production as a possible predictor of relapse in patients with multiple sclerosis

No biological parameter is currently available as a specific marker of multiple sclerosis (MS) activity. The aim of this study was to determine whether an evolution of the neurological disability is associated with a modified profile of cytokine production. Clinical disease activity was quantitated by the Kurtzke's expanded disability status scale (EDSS). Whole blood was stimulated with phytohemagglutinin (PHA) for 2 hours at 37 degrees C and the activated plasma was assayed for Tumor necrosis factor alpha (TNF-alpha) and Interleukin-1 beta (IL-1 beta). Relapsing-remitting MS patients enduring a relapse (RRMS, in relapse) (721 +/- 58 pg/ml, n = 27) and chronic progressive MS (CPMS) patients (516 +/- 33 pg/ml, n = 17) had an higher TNF-alpha production capacity as compared to healthy subjects (143 +/- 25 pg/ml, n = 17), RRMS, stable patients, (123 +/- 11 pg/ml, n = 26) or other neurological diseases (OND) without immunological or inflammatory disease in the peripheral immune compartment (131 +/- 24 pg/ml, n = 14) (t test: p < 0.0001). IL-1 beta production was also significantly higher but to a lesser extent in the same conditions. Concentration of TNF-alpha was also found to be significantly higher in the cerebrospinal fluid (CSF) of CPMS patients (199 +/- 7.8 pg/ml, n = 7, p < 0.0001) but also in RRMS, in relapse (149 +/- 5.7 pg/ml, n = 11, p < 0.05) as compared to RRMS, stable (130 +/- 4.4 pg/ml, n = 7) or OND without inflammatory or immunological disease of the central nervous system (CNS) (142 +/- 6.2 pg/ml, n = 8).(ABSTRACT TRUNCATED AT 250 WORDS)

Release of proinflammatory and prothrombotic mediators in the brain and peripheral circulation in spontaneously hypertensive and normotensive Wistar-Kyoto rats

BACKGROUND AND PURPOSE

We reported previously that stroke risk factors prepared the brain stem for the development of ischemia and hemorrhage and induced the production of tumor necrosis factor following an intrathecal injection of lipopolysaccharide, a prototypic monocyte-activating stimulus. This study evaluates whether blood or brain cells of hypertensive rats produce more proinflammatory and prothrombotic mediators than do blood or brain cells of normotensive rats.

METHODS

Levels of tumor necrosis factor, platelet-activating factor, 6-ketoprostaglandin F1 alpha, and thromboxane B2 in the cerebrospinal fluid and blood of spontaneously hypertensive and normotensive Wistar-Kyoto rats were monitored before and after a challenge with lipopolysaccharide.

RESULTS

Little or no activity from these mediators was found in the cerebrospinal fluid or blood of saline-injected control animals. Intravenous administration of lipopolysaccharide (0.001, 0.1, and 1.8 mg/kg) produced dose-dependent increases in blood levels of all mediators in hypertensive rats. In normotensive rats the levels were less than in hypertensive rats and were not clearly dose-related. When lipopolysaccharide was injected intracerebroventricularly, more tumor necrosis factor was measured in the cerebrospinal fluid than in the blood, suggesting local synthesis of this cytokine. Levels of tumor necrosis factor and platelet-activating factor in the cerebrospinal fluid were higher in hypertensive than in normotensive rats. The thromboxane A2/prostacyclin ratio was not altered significantly between the two rat strains.

CONCLUSIONS

It is suggested that the higher incidence of brain stem ischemia and hemorrhage after the intrathecal injection of lipopolysaccharide in hypertensive rats than in normotensive rats might be related to the higher levels of the two cytotoxic factors tumor necrosis factor and platelet-activating factor produced in response to such challenge.

Cerebrospinal fluid cytokines in AIDS dementia complex

We evaluated cerebrospinal fluid (CSF) and serum concentrations of interleukin-1-alpha (IL-1-alpha), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) in 30 patients with AIDS dementia complex (ADC), and in 20 HIV-seronegative subjects with other neurological diseases (OND). CSF TNF-alpha, IL-1-alpha and IL-6 were more frequently detectable in ADC patients than in OND subjects. These cytokines were also detectable in CSF of ADC patients with minimal symptoms. In contrast, the majority of both ADC and OND patients did not contain detectable serum levels of cytokines. Our data support the notion of intrathecal synthesis of cytokines in ADC patients and raise the possibility that activated macrophages may play a significant role in the pathogenesis of ADC.

Blood-brain barrier damage in patients with bacterial meningitis: association with tumor necrosis factor-alpha but not interleukin-1 beta

Brain damage after meningeal infection could result from impairment of cerebral endothelial cell functions and disruption of blood-brain barriers. Tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta (IL-1 beta) produce many of their effects by acting on endothelial cells. This study correlates levels of TNF alpha and IL-1 beta in paired cerebrospinal fluid (CSF) and serum samples with the degree of blood-brain barrier damage, as manifested by CSF to serum albumin quotient, in 48 patients with bacterial meningitis and 66 controls. CSF levels of TNF alpha and IL-1 beta in bacterial meningitis were significantly higher than in controls. Intrathecal levels of TNF alpha, but not IL-1 beta, correlated with albumin quotient (P less than .001), with degree of blood-brain barrier disruption (P less than .001), and with disease severity and indices of meningeal inflammation. Sequential CSF samples demonstrated that IL-1 beta and TNF alpha disappear from the CSF within 24 h of antibiotic treatment. Data presented here suggest that TNF alpha is related to blood-brain barrier damage in bacterial meningitis and that its effect could be dissociated from that of IL-1 beta.

Humoral CSF parameters in the differential diagnosis of hematologic CNS neoplasia

Cerebrospinal fluid (CSF) and serum samples of 20 patients with central nervous system manifestations of hematological malignancies including primary cerebral lymphoma (n = 5) and disseminated non-Hodgkin lymphoma (n = 7) were examined for albumin, IgG, IgM, fibronectin, beta 2-microglobulin, interleukin-6, soluble interleukin-2 receptor, tumor necrosis factor alpha, and oligoclonal immunoglobulin bands. Although a broad range of abnormalities were detected, no reliable CSF parameter for the diagnosis of leptomeningeal spread from hematological neoplasias could be identified. An analysis of 61 repeat lumbar punctures added little to the findings of the first CSF examinations. Currently, immunochemical studies of CSF cell surface markers and early biopsy have probably more clinical value than the determination of the humoral CSF parameters included in this study. However, analysis of cytokine synthesis by single CSF cells using molecular biology techniques may improve the differential diagnosis of hematological neoplasia of the brain and spinal cord in the future.

[In vitro and in vivo immunobiological responses of glioblastoma to human natural tumor necrosis factor-alpha]

Biological effects of human natural tumor necrosis factor-alpha (TNF) on glioblastoma cells in vitro and on glioma patients were investigated. TNF treatment on glioblastoma cells, even at a high dose (256 U/ml), exhibited no remarkable cytocidal activity in MTT assay, but at lower doses significantly inhibited colony forming and DNA synthesis. TNF at a low dose (10 U/ml) stimulated production of prostaglandin E2, Mn-superoxide dismutase, interleukin (IL)-6 and IL-8 by glioblastoma cells. These results indicated that the direct effect of TNF on human glioblastoma cells is rather antiproliferative than cytotoxic and is to modulate their metabolic pathways. In an early Phase I clinical trial, TNF was administered intracranially to six patients bearing glioblastoma. In this trial, the author studied in vivo immunological responses in the cerebrospinal fluid and regional fluid after the regional TNF injections. TNF in these body fluids were detected with a half life of several hours. There occurred a substantial number of leukocyte migration after the TNF administration. Neutrophils appeared first peaking at 8 to 12 hours, and then CD4+CD8-T cells and CD11b+CD13+CD14+ monocytes followed. IL-8 activity in the cerebrospinal fluid simultaneously corresponded to peak of the neutrophil migration. Increases in IL-6, IL-1 beta and prostaglandin E2 levels in the cerebrospinal fluid, regional fluid or both occurred peaking at 8 to 12 hours after TNA infection. Neither IL-2 nor interferons was detected. In conclusion, TNF may act as an antineoplastic agent by its direct cytostatic effects and indirectly through immune modulatory effects.

In vivo relationship of tumor necrosis factor-alpha to blood-brain barrier damage in patients with active multiple sclerosis

Tumor necrosis factor-alpha (TNF-alpha) has well recognized effects on cerebral endothelial cells and, therefore, may mediate disruption of blood-brain barrier in patients with multiple sclerosis (MS). To evaluate the in vivo relationship of TNF-alpha to blood-brain barrier impairment in MS, levels of this cytokine in cerebrospinal fluid (CSF) and serum samples from 38 patients with active MS and 48 controls were correlated with CSF to serum albumin ratios. TNF-alpha was detected in the serum of 74% and the CSF of 66% of patients with active MS. CSF levels of TNF-alpha were significantly higher in active MS compared to stable MS or other controls, and were significantly higher than corresponding serum levels. In patients with active MS, only those with detectable TNF-alpha showed signs of blood-brain barrier damage. Moreover, intrathecal levels of TNF-alpha in active MS correlated with albumin ratios and with the degree of barrier damage. Our findings are important in understanding some of the pathological changes in active multiple sclerosis.

Tumour necrosis factor (TNF-alpha) and neurological disorders in HIV infection

Tumour necrosis factor (TNF-alpha) concentrations were determined in the CSF from 42 HIV-infected patients, with or without CNS involvement. In addition, 14 subjects with various neurological disorders but without HIV antibodies were included as controls. Raised CSF concentrations of TNF-alpha (greater than 40 ng/l) were detected both in patients with AIDS dementia complex (ADC) (6/9) and with CNS opportunistic infections (10/19) and, less commonly, in HIV infected subjects without CNS diseases (2/14) and in anti-HIV negative controls (1/14). The highest CSF concentrations of TNF-alpha (greater than 100 ng/l), however, were found in seven out of eight patients with cryptococcal meningitis. Although a role for TNF-alpha in demyelinating lesions associated with ADC has been suggested, our results indicate that a clear elevation of TNF-alpha in the CSF from HIV positive patients mostly occurs in acute inflammatory disorders, such as cryptococcal meningitis.

Cytokine responses to intraventricular injection of interleukin 2 into patients with leptomeningeal carcinomatosis: rapid induction of tumor necrosis factor alpha, interleukin 1 beta, interleukin 6, gamma-interferon, and soluble interleukin 2 receptor (Mr 55,000 protein)

Interleukin 2 (IL-2) is a potent immunostimulant that causes the release of secondary cytokines and the production of lymphokine-activated killer cells. We investigated the cellular and cytokine responses to injection of recombinant human IL-2 into the human cerebrospinal fluid of 11 patients with metastatic tumors involving the spinal or cerebral leptomeninges. After initial intraventricular IL-2 administration (1.25 x 10(5) to 2 x 10(6) Cetus units/injection), cerebrospinal fluid samples were collected at intervals from 0 to 24 h. Enzyme-linked immunosorbent assay results indicated that IL-2 levels gradually decreased during the first 24 h, with an average t1/2 between 4 and 8 h. Induction of tumor necrosis factor alpha, interleukin 1 beta, interleukin 6, gamma-interferon, and interleukin 2 receptor (p55) was also assessed by enzyme-linked immunosorbent assay. Tumor necrosis factor alpha and interleukin 6 levels peaked at 2 to 4 h and 4 to 6 h, with concentrations between 71 to 1,714 pg/ml and 942 to 10,500 pg/ml, respectively. Interleukin 1 beta, gamma-interferon, and soluble IL-2 receptor peaked later, during 6 to 12 h; the levels achieved were 234 pg/ml, 25 NIH units/ml, and 207 units/ml, respectively. All cytokine concentrations returned to near baseline between 12 and 24 h; however, the soluble IL-2 receptor levels remained elevated. Additional observations included a rapid influx of neutrophilic leukocytes, followed by a prolonged presence of lymphocytes. These data indicate a broad and complex potential of the immune response in the central nervous system, as well as further define the cytokine cascade in response to IL-2 alone.

Ectopic parasellar pituitary adenoma with subarachnoid seeding

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Tumour necrosis factor-alpha in malignant melanomatous meningitis

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Tumor necrosis factor alpha levels in serum and cerebrospinal fluid of patients with AIDS

We used a sensitive enzyme-linked immunosorbent assay technique to measure tumor necrosis factor alpha (TNF alpha) levels in serum and cerebrospinal fluid (CSF) samples from 30 patients infected with human immunodeficiency virus type 1 and from 10 normal controls. We found detectable levels of TNF alpha in 19 of 30 CSF and in 17 of 30 serum samples. The values of TNF alpha ranged between 20-90 pg/ml. All the patients had overt AIDS. More elevated TNF alpha levels in CSF correlate with focal damage within the central nervous system (p less than 0.01). Our results suggest that an intrathecal production of TNF alpha may occur during active inflammation in course of AIDS.