Altered Cerebrospinal Fluid (CSF) in Children with Ataxia Telangiectasia.

Ataxia telangiectasia (A-T) is a devastating multi-system disorder characterized by progressive cerebellar ataxia and immunodeficiency. The neurological decline may be caused by multiple factors of which ongoing inflammation and oxidative stress may play a dominant role. The objective of the present investigation was to determine cerebrospinal fluid (CSF) proteins and possible low-grade inflammation and its relation to age and neurological deterioration. In the present study, we investigated 15 patients with A-T from 2 to 16 years. Our investigation included blood and CSF tests, clinical neurological examination, A-T score, and MRI findings. The albumin ratio (AR) was analyzed to determine the blood-brain-barrier function. In addition, inflammatory cytokines (IL-1α, IL-6, IL-8, IL-12 p40, IL-17A, IFN-γ, TNF-α) were measured by the multiplex cytometric bead array. We compared the results with those from an age-matched control group. Three of the A-T patients were analyzed separately (one after resection of a cerebral meningioma, one after radiation and chemotherapy due to leukemia, one after stem cell transplantation). Patient had significantly more moderate and severe side effects due to CSF puncture (vomiting, headache, need for anti-emetic drugs) compared with healthy controls. Total protein, albumin, and the AR increased with age indicating a disturbed blood barrier function in older children. There were no differences for cytokines in serum and CSF with the exception of IL-2, which was significantly higher in controls in serum. The AR is significantly altered in A-T patients, but low-grade inflammation is not detectable in serum and CSF.

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.

Tau/α-synuclein ratio and inflammatory proteins in Parkinson's disease: An exploratory study.

BACKGROUND: No CSF or plasma biomarker has been validated for diagnosis or progression of PD. OBJECTIVES: To assess whether the CSF and plasma levels of proteins associated with PD neuropathological inclusions and with neuroinflammation might have value in the diagnosis of PD or in relation to disease severity. METHODS: CSF levels of α-synuclein, amyloid-ß1-42, total tau, and threonine-181 phosphorylated tau, as well as CSF and plasma levels of cytokines (interleukin-1ß, interleukin-2, interleukin, interferon-γ, and tumor necrosis factor α) were studied in 40 PD patients and 40 healthy controls. Plasma levels of cytokines were measured in 51 patients and 26 aditional controls. We also explored the Parkinson's Progression Markers Initiative data set as a replication cohort. RESULTS: CSF levels of α-synuclein, amyloid-ß1-42, and tumor necrosis factor α were lower in patients than in controls, and the total tau/α-synuclein, phosphorylated tau/α-synuclein, total tau/amyloid-ß1-42+α-synuclein, and phosphorylated tau/amyloid-ß1-42+α-synuclein ratios were higher in patients. The best area under the curve value was obtained for the phosphorylated tau/α-synuclein ratio alone (0.86) and also when this was combined with tumor necrosis factor α in CSF (0.91; sensitivity 92.9%, specificity 75% for a cut-off value of ≤ 0.71). Phosphorylated tau/α-synuclein and phosphorylated tau/amyloid-ß1-42+α-synuclein were higher in patients than in controls of the Parkinson's Progression Markers Initiative database. Plasma cytokines did not differ between groups, although interleukin-6 levels were positively correlated with UPDRS-I, -II, and -III scores. CONCLUSIONS: The CSF phosphorylated tau/α-synuclein ratio alone, and in combination with tumor necrosis factor α and plasma interleukin-6 levels, might serve as biomarkers to diagnose PD and monitor its severity. © 2017 International Parkinson and Movement Disorder Society.

Distinguishing the cerebrospinal fluid cytokine profile in neuropsychiatric systemic lupus erythematosus from other autoimmune neurological diseases.

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious complication in SLE. Although the mechanism of NPSLE remains unclear, cytokines and chemokines are considered to be involved in their pathogenesis. Here we used Bio-Plex Pro assays to examine 27 types of cytokines and chemokines in the cerebrospinal fluid (CSF) of 32 NPSLE patients. We used the CSF of 20 patients with multiple sclerosis (MS) and 22 patients with neuromyelitis optica (NMO) as a disease control group. Fourteen of 27 cytokines/chemokines were significantly higher in the NPSLE patients compared to the MS/NMO patients. We could identify six "minimum predictive markers" by using a weighted-voting algorithm that could distinguish NPSLE from MS and NMO: interleukin (IL)-17, IL-2, interferon (IFN)-γ, IL-5, basic fibroblast growth factor (FGF)-basic and IL-15. The determination of various types of CSF cytokine profiles may contribute to the diagnosis of NPSLE and may help elucidate the mechanisms underlying this disease.

Subpicogram per milliliter detection of interleukins using silicon photonic microring resonators and an enzymatic signal enhancement strategy.

The detection of biomolecules at ultralow (low to subpicogram per milliliter) concentrations and within complex, clinically relevant matrices is a formidable challenge that is complicated by limitations imposed by the Langmuir binding isotherm and mass transport, for surface-based affinity biosensors. Here we report the integration of an enzymatic signal enhancement scheme onto a multiplexable silicon photonic microring resonator detection platform. To demonstrate the analytical value of this combination, we simultaneously quantitated levels of the interleukins IL-2, IL-6, and IL-8 in undiluted cerebrospinal fluid in an assay format that is multiplexable, relatively rapid (90 min), and features a 3 order of magnitude dynamic range and a limit of detection ≤1 pg/mL. The modular nature of this assay and technology should lend itself broadly amenable to different analyte classes, making it a versatile tool for biomarker analysis in clinically relevant settings.

Doublecortin and Glypican-2 concentrations in the cerebrospinal fluid from infants are developmentally downregulated.

OBJECTIVE: Doublecortin (DCX) and glypican-2 (GPC2) are neurodevelopmental proteins involved in the differentiation of neural stem/progenitor cells (NSPCs) to neurons, and are developmentally downregulated in neurons after birth. In this study, we investigated whether the concentrations of DCX and GPC2 in the cerebrospinal fluid (CSF) from human pediatric patients reflect this developmental process or are associated with cerebral damage or inflammatory markers. METHODS: CSF was collected from pediatric patients requiring neurosurgical treatment. The concentrations of DCX, GPC2, neuron-specific enolase (NSE), S100 calcium-binding protein B (S100B), and cytokines (IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-13, IFN-γ, and TNF-⍺) were measured using immunoassays. RESULTS: From March 2013 until October 2018, 63 CSF samples were collected from 38 pediatric patients (20 females; 17 patients with repeated measurements); the median term born-adjusted age was 3.27 years [Q1: 0.31, Q3: 7.72]. The median concentration of DCX was 329 pg/ml [Q1: 192.5, Q3: 1179.6] and that of GPC2 was 26 pg/ml [Q1: 13.25, Q3: 149.25]. DCX and GPC2 concentrations independently significantly associated with age, and their concentration declined with advancing age, reaching undetectable levels at 0.3 years for DCX, and plateauing at 1.5 years for GPC2. Both DCX and GPC2 associated with hydrocephalus, NSE, IL-1ß, IL-2, IL-8, IL-13. No relationship was found between sex, acute infection, S100B, IL-4, IL-6, IL-10, IFN-γ, TNF-α and DCX or GPC2, respectively. CONCLUSIONS: Concentrations of DCX and GPC2 in the CSF from pediatric patients are developmentally downregulated, with the highest concentrations measured at the earliest adjusted age, and reflect a neurodevelopmental stage rather than a particular disease state.

A substantial number of Rasmussen syndrome patients have increased IgG, CD4+ T cells, TNFalpha, and Granzyme B in CSF.

PURPOSE: We studied the immunologic molecules in cerebrospinal fluid (CSF) and discussed their evolutional changes in pediatric patients with Rasmussen syndrome (RS). METHODS: CSF samples collected from 27 patients with RS (average onset age, 7.5 +/- 5.6 years) were studied. Cell count, protein, glucose, albumin, chloride, and immunoglobulin G (IgG) levels were measured by conventional methods. Surface markers of lymphocytes in CSF were examined by a cell sorter. Granzyme B, interferon gamma (IFNgamma), interleukin 4 (IL-4), tumor necrosis factor alpha (TNFalpha), and IL-12 in CSF were quantitated by enzyme-linked immunosorbent assay (ELISA). Autoantibodies against GluR epsilon2 (NR2B) were examined by immunoblot. RESULTS: The data of the first CSF examination showed that IgG levels (Mann-Whitney U test, p < 0.01), CD4(+) T cells (p = 0.02), TNFalpha levels (p < 0.01), and Granzyme B levels (p < 0.01) were elevated compared with disease controls. White blood cell count, IFNgamma level, IL-12 level, and Granzyme B level were elevated, especially in the early stage of disease. CD4(+) T cells, CD8(+) cells, CD3(+) T cells, IgG levels, and TNFalpha levels were elevated at all stages of disease evolution. Protein levels and albumin levels were elevated in the progressed stage. Autoantibodies against GluR epsilon2 (NR2B) (IgG) were found in 50% of patients in the early stage, and the positive rate was low at the progressed stage. DISCUSSION: The present findings suggest that complex pathophysiologic mechanisms involving CD4(+) T cells and CD8(+) T cells change evolutionally during the progression of RS. A crucial cytotoxic process occurs in the early stage, and declines in the progressed stage.

Cerebrospinal fluid levels of cytokines in non-herpetic acute limbic encephalitis: comparison with herpes simplex encephalitis.

BACKGROUND: Recently, non-herpetic acute limbic encephalitis (NHALE) was identified as a new subgroup of limbic encephalitis. The immunological pathophysiology of NHALE is still unclear. METHODS: We measured the concentrations of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, IL-10, and soluble TNF receptor 1 (sTNFR1) in the cerebrospinal fluid (CSF) of 15 patients with NHALE and 13 with herpes simplex encephalitis (HSE) by cytometric bead array or ELISA. RESULTS: The CSF concentrations of IL-6 in patients with NHALE and IFN-gamma, IL-6, IL-10, and sTNFR1 in HSE patients were significantly higher than those of controls (p<0.001, p=0.004, p<0.001, p=0.018, and p<0.001, respectively). There were significant correlations among CSF IL-6, IL-10, and sTNFR1 levels in HSE patients. The CSF concentrations of IFN-gamma and sTNFR1 levels of patients with HSE were significantly higher than those with NHALE (p=0.001 and p=0.002, respectively). CONCLUSIONS: CSF cytokine levels in NHALE were relatively low compared with those in HSE. These results may be related to the favorable prognosis of NHALE.

Neuroinflammation drives anxiety and depression in relapsing-remitting multiple sclerosis.

OBJECTIVE: To explore the inflammatory processes in the pathogenesis of psychiatric symptoms and the prognostic value of psychiatric comorbidities in multiple sclerosis (MS). METHODS: Four hundred five patients with relapsing-remitting (RR) MS underwent psychiatric evaluation by means of Beck Depression Inventory II (BDI-II) and State/Trait Anxiety Inventory (STAI-Y). The inflammatory activity level was assessed by MRI. In a subset of 111 treatment-naive patients, CSF levels of proinflammatory cytokines were determined. Correlation and regression analyses were performed to determine associations between variables. RESULTS: Relapsing patients demonstrated greater values of STAI-state and BDI-II compared with remitting patients but comparable trait-anxiety scores. There were no significant differences in psychometric parameters between relapsing and asymptomatic MRI-active patients, highlighting the effect of subclinical inflammation on mood disturbances. A significant reduction of STAI-state and BDI-II scores was recorded, along with the subsiding of neuroinflammation. Interleukin-2 CSF levels were found to correlate with STAI-state, while tumor necrosis factor-α and interleukin-1ß correlated with BDI-II. Because emotional disorders were associated with subclinical inflammation, variations of the psychometric profile were able to detect subclinical reactivation earlier. In line with this, high STAI-state values considerably predicted the possibility of disease reactivation. CONCLUSIONS: Mood alterations are induced by intrathecal inflammation, even though not clinically apparent, and are able to predict inflammatory reactivations in RRMS. Inflammation is therefore a biological event, not less important than the traditional psychosocial factors, involved in mood disorders.

Inflammatory markers in the patients of Japanese encephalitis.

OBJECTIVES: Japanese encephalitis (JE) is one of the commonest viral encephalitis especially prevalent in Southeast Asia. Estimated mortality rate of JE is approximately 30%, with survivors undergoing severe and irreversible neurological sequelae. Although central nervous system (CNS) inflammation is imminent upon JE infection, the pathways underlying the same have not yet been clearly elucidated. However, cytokines-tumor necrosis factor-alpha (TNF-alpha) and interlukin-2 (IL-2), are small secreted proteins, which mediate and regulate immunity. Therefore, we wanted to evaluate the role, if any, of these cytokines in the pathogenesis of JE. METHODS: We measured the levels of TNF-alpha and IL-2 in the serum and cerebrospinal fluid (CSF) of patients suffering JE, using enzyme-linked immunosorbent assay (ELISA). RESULTS: JE infection caused a remarkable increase (p<0.0001) in the levels of TNF-alpha in the serum and CSF, while IL-2 levels were unaffected. DISCUSSION: These results show that TNF-alpha pathway is involved in JE infection-triggered neuroinflammation.

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.

Cerebrospinal fluid (CSF) CD8+ T-cells that express interferon-gamma contribute to HIV associated neurocognitive disorders (HAND).

BACKGROUND: HIV associated neurocognitive disorders (HAND) continue to affect cognition and everyday functioning despite anti-retroviral treatment (ART). Previous studies focused on mechanisms related to monocyte/macrophage mediated inflammation. However, in the ART era, there is increasing evidence for the involvement of CD8+ T-cells in CNS pathogenesis. METHODS: To investigate the relationship between T-cell responses and neurocognitive impairment (NCI), cerebrospinal fluid (CSF) and peripheral blood CD4+ and CD8+ T-cell intracellular cytokine (IFNγ, IL-2, TNFα) and lytic marker (CD107a) expression were assessed in HIV infected subjects who underwent comprehensive neurocognitive (NC) evaluation and either initiated or changed ART. RESULTS: Data were collected from 31 participants at 70 visits. The frequency of cytokine expressing T-cells in CSF was significantly higher than in peripheral blood for CD4+T-cells: TNFα, IL-2, IFNγ and CD8+T-cells: IL-2 and IFNγ. Analysis of T-cell activity and NCI as a function of CSF HIV RNA levels suggested a general association between NCI, high CSF CD8+ (but not CD4+T-cell) cytokine expression and CSF HIV RNA <103 copies/ml (p<0.0001). Specifically, CSF CD8+ T-cell IFNγ expression correlated with severity of NCI (r = 0.57, p = 0.004). Multivariable analyses indicated that CSF CD8+T-cell IFNγ and myeloid activation (CD163) contributed equally and independently to cognitive status and a composite variable produced the strongest correlation with NCI (r = 0.83, p = 0.0001). In contrast, CD8+ cytolytic activity (CD107a expression) was negatively correlated with NCI (p = 0.05) but was dependent on CD4 levels >400/µl and low CSF HIV RNA levels (<103 copies/ml). In our longitudinal analysis of 16 subjects, higher CSF CD8+IFNγ expression at baseline predicted NC decline at follow-up (p = 0.02). Severity of NCI at follow-up correlated with level of residual HIV RNA in CSF. CONCLUSIONS: Presence of IFNγ expressing CD8+ T-cells, absence of cytolytic CD8+ T-cells, high myeloid activation, and failure of ART to suppress HIV replication in CSF contribute to increased risk of HAND.

Elevated CSF levels of interleukin-2 in neuroleptic-free schizophrenic patients.

Levels of CSF fluid interleukin-2, but not interleukin-1 alpha, were found to be higher in 10 neuroleptic-free schizophrenic patients than in 10 healthy subjects matched for sex and age. Because interleukin-2 increases dopaminergic neurotransmission and participates in autoimmunity and cell growth, the authors postulate that elevated levels of central interleukin-2 might contribute to the increased dopaminergic neurotransmission, autoimmune phenomena, and abnormal brain morphology described in some patients with schizophrenia.

Increases in CSF levels of interleukin-2 in schizophrenia: effects of recurrence of psychosis and medication status.

OBJECTIVE: Interleukin-2, traditionally viewed as solely involved in immunological events, has recently been shown to exert profound effects on the development and regulation of the central nervous system. This study examined the relationships between interleukin-2 in the CSF and plasma of schizophrenic patients and clinical measures, including relapse and medication status. Plasma and CSF interleukin-1 alpha levels were also measured to ascertain the specificity of changes in cytokine levels. METHODS: Seventy-nine physically healthy male patients with schizophrenia (DSM-III-R) received diagnostic evaluation and behavioral ratings. Haloperidol treatment was withdrawn for up to 6 weeks and patients were evaluated for symptom recurrence. CSF and plasma were obtained by established procedures before haloperidol withdrawal (N = 79) and after (N = 64). RESULTS: CSF levels of interleukin-1 alpha decreased significantly after haloperidol withdrawal but showed no relation to clinical status. In contrast, levels of CSF interleukin-2 were associated with recurrence of psychotic symptoms. Relapse-prone patients, examined both while medicated and after drug withdrawal, had significantly higher levels of CSF interleukin-2 than patients who did not relapse. CSF interleukin-2 level during haloperidol treatment was a significant predictor of worsening in psychosis. CONCLUSIONS: Levels of interleukin-2, a molecule that plays both neurodevelopmental and neuroregulatory roles, may have a role in relapse in schizophrenia. Levels of CSF interleukin-2 appear to be affected by relapse mechanisms, while peripheral blood levels are not. These changes are specific to interleukin-2, since levels of interleukin-1 alpha were affected by medication withdrawal but not by change in clinical state.

Serum and CSF levels of IL-2, sIL-2R, TNF-alpha, and IL-1 beta in chronic progressive multiple sclerosis: expected lack of clinical utility.

We measured interleukin-2 (IL-2), soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 beta (IL-1 beta) by ELISA in paired sera and CSF from 50 chronic progressive multiple sclerosis (CPMS) patients during worsening disability, 19 patients with other neurologic diseases (OND), and in sera from 40 healthy volunteers. In the CPMS patients, 28% (14/50), 10% (5/50), 16% (8/50), and 6% (3/50) had elevated serum levels of IL-2, sIL-2R, TNF-alpha and IL-1 beta, respectively, compared with healthy controls. The only analyte we detected in the CSF was IL-2 in 1 CPMS patient (1/50, 2%). We also saw elevated serum sIL-2R in 16% (3/19) of OND patients. We found no significant difference in mean levels of serum sIL-2R between the 3 groups. Our study, the largest to date of CPMS patients, shows that serum and CSF levels of IL-2, sIL-2R, TNF-alpha, or IL-1 beta are not sensitive for, and the serum sIL-2R level is not specific for, CPMS. Therefore, measurement of these analytes will not be clinically useful for therapeutic or prognostic purposes in the majority of CPMS patients.

Determination of interleukin-2 in cerebrospinal fluid by a sensitive enzyme-linked immunosorbent assay.

A sensitive technique was developed for the quantitative detection of intrathecal production of interleukin-2 (IL-2). Concentrations of IL-2 in paired cerebrospinal fluid (CSF) and serum samples were measured by an enzyme-linked immunosorbent assay using a monoclonal antibody and an affinity purified polyclonal antibody. The assay produced a linear response with respect to IL-2 concentration, and could readily detect levels of IL-2 as low as 1.5 international units/ml. Concentrations of IL-2 in CSF and serum samples were standardised by calculating their ratio to albumin concentration in order to correct for passive transudation of IL-2 across blood-CSF barriers. CSF IL-2/albumin ratios higher than concomitant serum ratios were considered indicative of intrathecal IL-2 production. The technique provides a sensitive, specific, and reproducible method for the determination of in vivo synthesis of IL-2 within the central nervous system.

The relationship of interleukin-2 and soluble interleukin-2 receptors to intrathecal immunoglobulin synthesis in patients with multiple sclerosis.

The in vivo relationship of interleukin-2 (IL-2) to the local humoral immune response within the central nervous system (CNS) in patients with multiple sclerosis (MS) is hitherto largely unknown. Intrathecal levels of IL-2 and soluble IL-2 receptors (sIL-2R) were correlated to the local CNS synthesis of immunoglobulin G, A, D, and M isotypes in 70 patients with clinically definite MS. Levels were also determined in 19 normal control subjects to establish normal reference limits. High cerebrospinal fluid levels of IL-2 and sIL-2R were detected mainly in patients with acute relapsing-remitting MS and were significantly higher than corresponding serum levels. Intrathecal levels of IL-2 significantly correlated with local CNS synthesis of IgD and IgM, while no correlation was found with either IgG or IgA. Similarly, intrathecal sIL-2R levels significantly correlated with local CNS production of IgD and IgM, but not IgG or IgA. These findings further extend previous reports and also suggest that IL-2 and sIL-2R are involved in the early intrathecal humoral immune response in MS.

Cytokine production by cells in cerebrospinal fluid during experimental allergic encephalomyelitis in SJL/J mice.

Cytokine production by T cells in the cerebrospinal fluid (CSF) and central nervous system (CNS) of SJL/J mice during myelin basic protein (MBP)-induced experimental allergic encephalomyelitis (EAE) was examined. Reverse transcriptase/polymerase chain reaction (RT/PCR) was used to measure interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) mRNA levels from perfused CNS tissue (brain and spinal cord) and from cells isolated from CSF. Animals were grouped according to EAE severity, ranging from asymptomatic (adjuvant only) to severe disease (paralysis or severe paresis). Cytokine signals, normalized to actin, were almost undetectable in control tissues, and only slightly elevated in whole CNS tissue from animals with mild EAE. Both cytokine messages were strongly upregulated in CNS tissues derived from severely affected animals, consistent with previous observations correlating disease progression with infiltration by memory/effector CD4+ T cells, the major source of these cytokines. This cytokine upregulation was specific to the CNS, since other organs from the same animals did not express significant levels of IL-2 and IFN-gamma. CSF was obtained from the cisterna magna of unperfused mice and verified as such by absence of red blood cells (RBCs) and by immunoglobulin concentration orders of magnitude lower than in serum. Cytokine message was measured in RNA isolated from cells in CSF. Levels of IL-2 and IFN-gamma mRNA in CSF cells were significantly elevated in mild EAE and strongly upregulated in severe disease, correlating with those in total CNS tissue. These results confirm the CSF as representative of the immune status of the CNS and indicate a role for IL-2 and IFN-gamma in inflammatory CNS disease.

Frequency of T cells specific for myelin basic protein and myelin proteolipid protein in blood and cerebrospinal fluid in multiple sclerosis.

T cell sensitization to two myelin components, myelin basic protein (MBP) and myelin proteolipid protein (PLP), may be important to the pathogenesis of multiple sclerosis (MS). Using the limiting dilution assay, we demonstrated that the blood of MS patients had an increased frequency of MBP-reactive T cells compared with normal subjects and patients with other neurological diseases (OND) and rheumatoid arthritis. There was no difference in T cell frequency to a synthetic peptide, PLP139-151, or Herpes simplex virus. Within cerebrospinal fluid (CSF), 37% of IL-2/IL-4-reactive T cell isolates from MS patients responded either to MBP or PLP139-151 while only 5% of similar isolates from OND patients responded to these myelin antigens. The mean relative frequency of MBP-reactive T cells within CSF from MS patients was significantly higher than that of OND patients (22 x 10(-5) cells versus 1 x 10(-5) cells) and was similar to that of MBP reactive T cells within the central nervous system of rats with experimental autoimmune encephalomyelitis. These results lend new support to the hypothesis that myelin-reactive T cells mediate disease in MS.

Interleukin-2 gene therapy of chronic neuropathic pain.

Previous research has revealed an antinociceptive (analgesic) effect of interleukin-2 (IL-2) in central and peripheral nervous systems. Unfortunately IL-2 is very short-lived in vivo, so it is impractical to apply IL-2 for analgesia in clinic. This study was performed to evaluate the effect of intrathecal delivery of human IL-2 gene on rat chronic neuropathic pain induced by chronic constriction injury of the sciatic nerve. Human IL-2 cDNA was cloned into pcDNA3 containing a cytomegalovirus promoter. The paw-withdrawal latency induced by radiant heat was used to measure the pain threshold. The results showed that recombinant human IL-2 had a dose-dependent antinociceptive effect, but that this only lasted for 10-25 min. The pcDNA3-IL-2 or pcDNA3-IL-2/lipofectamine complex in contrast also showed dose-dependent antinociceptive effects, but these reached a peak at day 2-3 and were maintained for up to 6 days. Liposome-mediated pcDNA3-IL-2 produced a more powerful antinociceptive effect than pcDNA3-IL-2 alone. The paw-withdrawal latencies were not affected by control treatments such as vehicle, lipofectamine, pcDNA3, or pcDNA3-lipofectamine. In the experimental groups, human IL-2 mRNA was detected by reverse transcription-polymerase chain reaction in the lumbar spinal pia mater, dorsal root ganglion, sciatic nerve, and spinal dorsal horn, but not in gastrocnemius muscle. The expressed IL-2 profile detected by western blot coincided with its mRNA profile except it was present in the spinal dorsal horn at a higher level. Furthermore, human IL-2 assayed by enzyme-linked immunosorbent assay in cerebrospinal fluid could still be detected at day 6, but lower than day 3. The antinociceptive effect of pcDNA3-IL-2 could be blocked by naloxone, showing some relationship of the antinociceptive effect produced by IL-2 gene to the opioid receptors. It is hoped that the new delivery approach of a single intrathecal injection of the IL-2 gene described here may be of some practical use as a part of a gene therapy for treating neuropathic pain.