Do Intracerebral Cytokine Responses Explain the Harmful Effects of Dexamethasone in Human Immunodeficiency Virus-associated Cryptococcal Meningitis?

BACKGROUND: The CryptoDex trial showed that dexamethasone caused poorer clinical outcomes and slowed fungal clearance in human immunodeficiency virus-associated cryptococcal meningitis. We analyzed cerebrospinal fluid (CSF) cytokine concentrations from participants over the first week of treatment to investigate mechanisms of harm and test 2 hypotheses: (1) dexamethasone reduced proinflammatory cytokine concentrations, leading to poorer outcomes and (2) leukotriene A4 hydrolase (LTA4H) genotype influenced the clinical impact of dexamethasone, as observed in tuberculous meningitis. METHODS: We included participants from Vietnam, Thailand, and Uganda. Using the Luminex system, we measured CSF concentrations of the following: interferon γ, tumor necrosis factor (TNF) α, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant 1, macrophage inflammatory protein 1α, and interleukin 6, 12p70, 8, 4, 10, and 17. We determined the LTA4H genotype based on the promoter region single-nucleotide polymorphism rs17525495. We assessed the impact of dexamethasone on cytokine concentration dynamics and the association between cytokine concentration dynamics and fungal clearance with mixed effect models. We measured the influence of LTA4H genotype on outcomes with Cox regression models. RESULTS: Dexamethasone increased the rate TNF-α concentration's decline in (-0.13 log2pg/mL/d (95% confidence interval, -.22 to -.06 log2pg/mL/d; P = .03), which was associated with slower fungal clearance (correlation, -0.62; 95% confidence interval, -.83 to -.26). LTA4H genotype had no statistically significant impact on outcome or response to dexamethasone therapy. Better clinical outcomes were associated with higher baseline concentrations of interferon γ. CONCLUSIONS: Dexamethasone may slow fungal clearance and worsen outcomes by increasing TNF-α concentration's rate of decline.

Cerebrospinal fluid biomarkers and HIV-associated neurocognitive disorders in HIV-infected individuals in Rakai, Uganda.

In the USA, increased cerebrospinal fluid (CSF) inflammatory cytokines have been observed in antiretroviral therapy (ART)-naive, HIV-seropositive individuals with HIV-associated neurocognitive disorder (HAND). We characterized the relationship between HAND and CSF biomarker expression in ART-naive, HIV-seropositive individuals in Rakai, Uganda. We analyzed CSF of 78 HIV-seropositive, ART-naive Ugandan adults for 17 cytokines and 20 neurodegenerative biomarkers via Luminex multiplex assay. These adults underwent neurocognitive assessment to determine their degree of HAND. We compared biomarker concentrations between high and low CD4 groups and across HAND classifications, adjusting for multiple comparisons. Individuals with CD4 <200 cells/µL (N = 38) had elevated levels of CSF Interleukin (IL)-2, IL-12, granulocyte-macrophage colony-stimulating factor (GM-CSF), TNF-α, matrix metalloproteinase (MMP)-1, MMP-7, and S100 calcium-binding protein B (S100B) and lower levels of amyloid ß42. Individuals with CD4 351-500 cells/µL (N = 40) had significantly higher CSF levels of interleukin (IL)-1ß, amyloid ß42, and soluble receptor for advanced glycation end products (sRAGE). Increasing levels of S100B, platelet-derived growth factor-AA (PDGF-AA), brain-derived neurotrophic factor (BDNF), and sRAGE were associated with decreased odds of mild neurocognitive disorder (n = 22) or HIV-associated dementia (n = 15) compared with normal function (n = 30) or asymptomatic neurocognitive impairment (n = 11). Increased levels of interferon (IFN)-γ were associated with increased odds of mild neurocognitive impairment or HIV-associated dementia relative to normal or asymptomatic neurocognitive impairment. Proinflammatory CSF cytokines, chemokines, and neurodegenerative biomarkers were present in increasing concentrations with advanced immunosuppression and may play a role in the development of HAND. The presence of select CNS biomarkers may also play a protective role in the development of HAND.

Coronavirus Infections in the Central Nervous System and Respiratory Tract Show Distinct Features in Hospitalized Children.

BACKGROUND/AIMS: Coronavirus (CoV) infections induce respiratory tract illnesses and central nervous system (CNS) diseases. We aimed to explore the cytokine expression profiles in hospitalized children with CoV-CNS and CoV-respiratory tract infections. METHODS: A total of 183 and 236 hospitalized children with acute encephalitis-like syndrome and respiratory tract infection, respectively, were screened for anti-CoV IgM antibodies. The expression profiles of multiple cytokines were determined in CoV-positive patients. RESULTS: Anti-CoV IgM antibodies were detected in 22/183 (12.02%) and 26/236 (11.02%) patients with acute encephalitis-like syndrome and respiratory tract infection, respectively. Cytokine analysis revealed that the level of serum granulocyte colony-stimulating factor (G-CSF) was significantly higher in both CoV-CNS and CoV-respiratory tract infection compared with healthy controls. Additionally, the serum level of granulocyte macrophage colony-stimulating factor (GM-CSF) was significantly higher in CoV-CNS infection than in CoV-respiratory tract infection. In patients with CoV-CNS infection, the levels of IL-6, IL-8, MCP-1, and GM-CSF were significantly higher in their cerebrospinal fluid samples than in matched serum samples. CONCLUSION: To the best of our knowledge, this is the first report showing a high incidence of CoV infection in hospitalized children, especially with CNS illness. The characteristic cytokine expression profiles in CoV infection indicate the importance of host immune response in disease progression.

Growth factors and synaptic plasticity in relapsing-remitting multiple sclerosis.

During multiple sclerosis (MS) inflammatory attacks, and in subsequent clinical recovery phases, immune cells contribute to neuronal and oligodendroglial cell survival and tissue repair by secreting growth factors. Animal studies showed that growth factors also play a substantial role in regulating synaptic plasticity, and namely in long-term potentiation (LTP). LTP could drive clinical recovery in relapsing patients by restoring the excitability of denervated neurons. We recently reported that maintenance of synaptic plasticity reserve is crucial to contrast clinical deterioration in MS and that the platelet-derived growth factor (PDGF) may play a key role in its regulation. We also reported that a Hebbian form of LTP-like cortical plasticity, explored by paired associative stimulation (PAS), correlates with clinical recovery from a relapse in MS. Here, we explored the role of PDGF in clinical recovery and in adaptive neuroplasticity in relapsing-remitting MS (RR-MS) patients. We found a correlation between the cerebrospinal fluid (CSF) PDGF concentrations and the extent of clinical recovery after a relapse, as full recovery was more likely observed in patients with high PDGF concentrations and poor recovery in subjects with low PDGF levels. Consistently with the idea that PDGF-driven synaptic plasticity contributes to attenuate the clinical consequences of tissue damage in RR-MS, we also found a striking correlation between CSF levels of PDGF and the amplitude of LTP-like cortical plasticity explored by PAS. CSF levels of fibroblast growth factor, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor did not correlate with clinical recovery nor with measures of synaptic transmission and plasticity.

Characteristic cerebrospinal fluid cytokine/chemokine profiles in neuromyelitis optica, relapsing remitting or primary progressive multiple sclerosis.

BACKGROUND: Differences in cytokine/chemokine profiles among patients with neuromyelitis optica (NMO), relapsing remitting multiple sclerosis (RRMS), and primary progressive MS (PPMS), and the relationships of these profiles with clinical and neuroimaging features are unclear. A greater understanding of these profiles may help in differential diagnosis. METHODS/PRINCIPAL FINDINGS: We measured 27 cytokines/chemokines and growth factors in CSF collected from 20 patients with NMO, 26 with RRMS, nine with PPMS, and 18 with other non-inflammatory neurological diseases (OND) by multiplexed fluorescent bead-based immunoassay. Interleukin (IL)-17A, IL-6, CXCL8 and CXCL10 levels were significantly higher in NMO patients than in OND and RRMS patients at relapse, while granulocyte-colony stimulating factor (G-CSF) and CCL4 levels were significantly higher in NMO patients than in OND patients. In NMO patients, IL-6 and CXCL8 levels were positively correlated with disability and CSF protein concentration while IL-6, CXCL8, G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IFN-γ were positively correlated with CSF neutrophil counts at the time of sample collection. In RRMS patients, IL-6 levels were significantly higher than in OND patients at the relapse phase while CSF cell counts were negatively correlated with the levels of CCL2. Correlation coefficients of cytokines/chemokines in the relapse phase were significantly different in three combinations, IL-6 and GM-CSF, G-CSF and GM-CSF, and GM-CSF and IFN-γ, between RRMS and NMO/NMOSD patients. In PPMS patients, CCL4 and CXCL10 levels were significantly higher than in OND patients. CONCLUSIONS: Our findings suggest distinct cytokine/chemokine alterations in CSF exist among NMO, RRMS and PPMS. In NMO, over-expression of a cluster of Th17- and Th1-related proinflammatory cytokines/chemokines is characteristic, while in PPMS, increased CCL4 and CXCL10 levels may reflect on-going low grade T cell and macrophage/microglia inflammation in the central nervous system. In RRMS, only a mild elevation of proinflammatory cytokines/chemokines was detectable at relapse.

Anti-GM-CSF autoantibodies in patients with cryptococcal meningitis.

Cryptococcal meningitis has been described in immunocompromised patients, as well as in those for whom no immune defect has been identified. GM-CSF regulates the function of phagocytes and pulmonary alveolar macrophages, critical elements in cryptococcal control. We performed clinical histories, immunological evaluation, and anticytokine autoantibody screening in four current patients with cryptococcal meningitis and identified and tested 103 archived plasma/cerebrospinal fluid samples from patients with cryptococcal meningitis. We assessed the ability of anti-GM-CSF autoantibody-containing plasmas to inhibit GM-CSF signaling. We recognized anti-GM-CSF autoantibodies in an otherwise healthy female with cryptococcal meningitis who later developed pulmonary alveolar proteinosis (PAP). Her diagnosis prompted screening of patients with cryptococcal meningitis for anticytokine autoantibodies. We identified seven HIV-negative patients with cryptococcal meningitis who tested positive for high-titer anti-GM-CSF autoantibodies. Two of the seven later developed evidence of PAP. Plasma from all patients prevented GM-CSF-induced STAT5 phosphorylation and MIP-1α production in normal PBMCs. This effect was limited to their IgG fraction. Anti-GM-CSF autoantibodies are associated with some cases of cryptococcal meningitis in otherwise immunocompetent patients. These cases need not have associated PAP.

Stage-specific changes in the levels of granulocyte-macrophage colony-stimulating factor and its receptor in the biological fluid and organ of mouse fetuses.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine that has neurotrophic and neuroprotective functions. However, its function in the mid- to late-gestational fetus remains unclear. We used enzyme-linked immunosorbent assay to analyze GM-CSF levels in cerebrospinal fluid (CSF), serum, and amniotic fluid of mouse fetuses. We also examined GM-CSF and receptor α (GM-CSFRα) levels in the fetal brain, liver, and placenta. GM-CSF peaked between embryonic day (E) 14 and E15 in the CSF. GM-CSF level was higher in the fetal serum than in the dam serum on E13 and decreased thereafter. GM-CSF and GM-CSFRα levels peaked between E13 and E15 in the brain. These results suggest that GM-CSF plays stage- and organ-specific roles in fetal development.

IL-8 in cerebrospinal fluid from children with acute encephalopathy is higher than in that from children with febrile seizure.

We identify possible differences in the cytokine/chemokine profiles in cerebrospinal fluid (CSF) from children with encephalopathy and febrile seizure. Interleukin (IL)-1beta, 2, 4, 5, 6, 7, 8, 10, 12, 13, 17, interferon-gamma, tumour necrosis factor-alpha, granulocyte colony-stimulating factor, granulocyte monocyte colony-stimulating factor, monocyte chemoattractant protein-1 and macrophage inflammatory protein-1beta were measured simultaneously in CSF supernatants from children with encephalopathy (n = 8), febrile seizure (n = 16) and fever without neurological complications (n = 8). IL-8 in CSF from children with encephalopathy was significantly elevated compared to that in CSF from children with febrile seizure and fever without neurological complications. IL-8 in CSF was also higher than serum IL-8, suggesting that increased IL-8 was generated from glia cells or astrocytes, not by leakage from serum. Increased IL-8 in CSF in encephalopathy may protect against severe brain damage.

Intrathecal upregulation of granulocyte colony stimulating factor and its neuroprotective actions on motor neurons in amyotrophic lateral sclerosis.

To investigate cytokine/chemokine changes in amyotrophic lateral sclerosis (ALS), we simultaneously measured 16 cytokine/chemokines (interleukin [IL]-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 [p70], IL-13, IL-17, interferon-gamma, tumor necrosis factor-alpha, granulocyte colony stimulating factor [G-CSF], macrophage chemoattractant protein-1 [MCP-1], and macrophage inflammatory protein-1beta) in cerebrospinal fluid (CSF) and sera from 37 patients with sporadic ALS and 33 controls using a multiplexed fluorescent bead-based immunoassay. We also conducted immunohistochemical analyses from 8 autopsied ALS cases and 6 nonneurologic disease controls as well as cell culture analyses of relevant cytokines and their receptors. We found that concentrations of G-CSF and MCP-1 were significantly increased in ALS CSF compared with controls. In spinal cords, G-CSF was expressed in reactive astrocytes in ALS cases but not controls, whereas G-CSF receptor expression was significantly decreased in motor neurons of spinal cords from ALS cases. Biologically, G-CSF had a protective effect on the NSC34 cell line under conditions of both oxidative and nutritional stress. We suggested that G-CSF has potentially neuroprotective effects on motor neurons in ALS and that downregulation of its receptor might contribute to ALS pathogenesis. On the other hand, MCP-1 correlated with disease severity, which may aggravate motor neuron damage.

Intrathecal inflammation precedes development of Alzheimer's disease.

OBJECTIVES: To analyse the cerebrospinal fluid (CSF) values of the proinflammatory cytokines, interleukin 1beta (IL1beta), tumour necrosis factor alpha (TNFalpha), GM-CSF, of the anti-inflammatory cytokine TGFbeta, of tau protein, a marker for neurodegeneration, and of beta amyloid (Abeta), a protein involved in the formation of senile plaques, in prospectively followed up patients with mild cognitive impairment (MCI). METHODS: Analyses of CSF levels of TNFalpha, IL1beta, GM-CSF, TGFbeta, betaa, and tau protein were performed using ELISA in 56 patients with MCI who were followed up prospectively and in 25 age matched, healthy controls. RESULTS: Patients with MCI displayed significantly higher levels of TNFalpha and tau protein and significantly lower levels of TGFbeta and Abeta compared with the healthy controls. After nine months of follow up, 25 patients still displayed MCI while the remaining 31 patients had progressed to Alzheimer's disease (AD). Only MCI patients who progressed to AD at follow up, showed significantly higher CSF levels of TNFalpha than controls. In addition, reduced CSF-Abeta42 levels were only found in MCI patients that progressed to AD, further supporting the notion that disturbed metabolism of Abeta is an early finding in AD. CONCLUSIONS: These results demonstrate increased production of the proinflammatory cytokine, TNFalpha and decreased production of the anti-inflammatory cytokine TGFbeta in patients with MCI at risk to develop AD, suggesting a propensity towards inflammation in this patient group and indicating that CNS inflammation is a early hallmark in the pathogenesis of AD.

Local and systemic GM-CSF increase in Alzheimer's disease and vascular dementia.

A growing body of evidence points out the potential role of inflammatory mechanisms in the pathophysiology of brain damage in dementia. The aim of the present study was to investigate patterns of local and systemic cytokine release in patients with Alzheimer's disease (AD) and vascular dementia (VAD). The intrathecal levels of cytokines were related to neuronal damage and cerebral apoptosis. Twenty patients with early AD and 26 patients with VAD were analyzed with respect to cerebrospinal fluid (CSF) and serum levels of pro- and anti-inflammatory cytokines. In addition, CSF levels of Fas/APO-1 and bcl-2, a measure for apoptosis, and Tau protein, a marker for neuronal degradation, were studied. Significantly increased CSF levels of GM-CSF but not of other cytokines were observed in both dementia groups. These patients displayed a significant correlation between the GM-CSF levels and the levels of Fas/APO-1 and Tau protein in CSF. Our study demonstrates an intrathecal production of GM-CSF, a cytokine stimulating microglial cell growth and exerting inflammatogenic properties. It is suggested that GM-CSF once secreted induces programmed cell death in the brain tissue of patients with dementia.

Granulocyte-macrophage colony-stimulating factor activity in cerebrospinal fluid.

OBJECTIVES: The purpose of this study was to analyse the presence of the granulocyte-macrophage colony-stimulating factor (GM-CSF) in human cerebrospinal fluid (SF) of patients affected by multiple sclerosis (MS) in comparison with non-inflammatory neurological diseases. MATERIAL AND METHODS: All SFs were collected from 59 patients for diagnostic purpose. The presence of GM-CSF was revealed by measuring its activity and by immunoassay. The data obtained were statistically evaluated. RESULTS: We found that GM-CSF is constitutively present in human SF; this presence was confirmed by its stimulating activity of colony-forming-unit granulocyte-macrophage (CFU-GM) production. No significant changes of the GM-CSF concentration in the SFs were observed among different neurological disorders (degenerative or vascular) and MS. CONCLUSION: Our data suggest that GM-CSF is a constitutive component of human SF, relatively uninfluenced by the different morbid conditions of the nervous system.

Cytokine-activated endothelial cells delay neutrophil apoptosis in vitro and in vivo. A role for granulocyte/macrophage colony-stimulating factor.

The activation of endothelium is important in recruiting neutrophils to sites of inflammation and in modulating their function. We demonstrate that conditioned medium from cultured, activated endothelial cells acts to significantly delay the constitutive apoptosis of neutrophils, resulting in their enhanced survival and increased phagocytic function. The antiapoptotic activity is, in part, attributable to granulocyte/macrophage colony-stimulating factor (GM-CSF) secreted by activated endothelial cells. The in vivo relevance of these findings was investigated in a cytokine-induced model of acute meningitis in mice. Peripheral blood neutrophils (PBNs) from mice with meningitis exhibited a delay in apoptosis compared with untreated mice. Furthermore, neutrophils recovered from the inflamed cerebrospinal fluid (CSF) exhibited enhanced survival compared with neutrophils isolated from the peripheral blood of the same animals. In unchallenged GM-CSF-deficient mice, the apoptosis of circulating PBNs was similar to wild-type animals; however, after cytokine-induced meningitis, the delay in neutrophil apoptosis typically observed in wild-type mice was attenuated. In contrast, the apoptosis of neutrophils recovered from the CSF of mice of both genotypes was comparable. Taken together, these studies suggest that neutrophil apoptosis is regulated during an inflammatory response, in both intravascular and extravascular compartments. GM-CSF released by activated endothelium can act to increase neutrophil survival and function in the peripheral blood, whereas other factor(s) appear to perform this function in the extravascular space.

Cytokine response in cerebrospinal fluid after birth asphyxia.

Experimental studies suggest that cytokine-mediated inflammatory reactions are important in the cascade leading to hypoxic-ischemic brain injury. The purpose was to study the content of pro- and antiinflammatory cytokines in cerebrospinal fluid (CSF) of asphyxiated and control infants. Samples of CSF were obtained from 20 infants who fulfilled the criteria of birth asphyxia and from seven newborn control subjects. The concentrations of IL-1beta, IL-8, IL-10, tumor necrosis factor (TNF)-alpha, and granulocyte/monocyte colony-stimulating factor (GM-CSF) were determined with ELISA and of IL-6 using a bioassay. The concentration of IL-6 (pg/mL) was higher in asphyxiated (250, 35-543; median, interquartile range) than in control (0, 0-18) infants (p = 0.001). There was also a significant relationship between IL-6 and the degree of HIE, and between IL-6 and outcome. In addition, the content of IL-8 (pg/mL) was higher (p = 0.009) in the asphyxia group (170, 70-1440), than in the the control group (10, 0-30) and there was an association between IL-8 and degree of HIE. The levels of IL-10, TNF-alpha, GM-CSF, and IL-1beta did not differ between groups. In conclusion, the proinflammatory cytokines IL-6 and IL-8 were markedly elevated in CSF of asphyxiated infants, and the intrathecal levels of these cytokines corresponded to the degree of HIE.

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.

Cerebral ventricular fluid distribution of subcutaneous granulocyte-macrophage colony stimulating factor.

After treating a child suffering from disseminated primitive neuroectodermal tumor and hydrocephalus with bilateral ventriculostomies, we administered intravenous high dose thiotepa followed by a single subcutaneous dose of GM-CSF 24 hours later. The appearance and clearance of GM-CSF were measured from both ventricles, one of which was surrounded by tumor. Peak levels of GM-CSF were recorded simultaneously in both ventricles 11 hours after injection. Complete clearance from injection required 15 hours and 31 hours for the tumor-free right ventricle and the tumor-involved left ventricular wall, respectively. Tumor response was ephemeral and limited to ventricular fluid WBC, protein and LDH decreases. Microglia were detected; however, there was no evidence of anti-tumor activity in biopsied tumor tissue. Tumored regions of the brain may have perturbation of GM-CSF distribution and clearance which may contribute to the lack of microglial activity.

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.

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.

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.