Changes in Cerebrospinal Fluid Balance of TNF and TNF Receptors in Naïve Multiple Sclerosis Patients: Early Involvement in Compartmentalised Intrathecal Inflammation.

An imbalance of TNF signalling in the inflammatory milieu generated by meningeal immune cell infiltrates in the subarachnoid space in multiple sclerosis (MS), and its animal model may lead to increased cortical pathology. In order to explore whether this feature may be present from the early stages of MS and may be associated with the clinical outcome, the protein levels of TNF, sTNF-R1 and sTNF-R2 were assayed in CSF collected from 122 treatment-naïve MS patients and 36 subjects with other neurological conditions at diagnosis. Potential correlations with other CSF cytokines/chemokines and with clinical and imaging parameters at diagnosis (T0) and after 2 years of follow-up (T24) were evaluated. Significantly increased levels of TNF (fold change: 7.739; p < 0.001), sTNF-R1 (fold change: 1.693; p < 0.001) and sTNF-R2 (fold change: 2.189; p < 0.001) were detected in CSF of MS patients compared to the control group at T0. Increased TNF levels in CSF were significantly (p < 0.01) associated with increased EDSS change (r = 0.43), relapses (r = 0.48) and the appearance of white matter lesions (r = 0.49). CSF levels of TNFR1 were associated with cortical lesion volume (r = 0.41) at T0, as well as with new cortical lesions (r = 0.56), whilst no correlation could be found between TNFR2 levels in CSF and clinical or MRI features. Combined correlation and pathway analysis (ingenuity) of the CSF protein pattern associated with TNF expression (encompassing elevated levels of BAFF, IFN-γ, IL-1ß, IL-10, IL-8, IL-16, CCL21, haptoglobin and fibrinogen) showed a particular relationship to the interaction between innate and adaptive immune response. The CSF sTNF-R1-associated pattern (encompassing high levels of CXCL13, TWEAK, LIGHT, IL-35, osteopontin, pentraxin-3, sCD163 and chitinase-3-L1) was mainly related to altered T cell and B cell signalling. Finally, the CSF TNFR2-associated pattern (encompassing high CSF levels of IFN-ß, IFN-λ2, sIL-6Rα) was linked to Th cell differentiation and regulatory cytokine signalling. In conclusion, dysregulation of TNF and TNF-R1/2 pathways associates with specific clinical/MRI profiles and can be identified at a very early stage in MS patients, at the time of diagnosis, contributing to the prediction of the disease outcome.

Biomarkers of central nervous system inflammation in infantile and juvenile gangliosidoses.

BACKGROUND: The gangliosidoses (Tay-Sachs disease, Sandhoff disease, and GM1-gangliosidosis) are progressive neurodegenerative diseases caused by lysosomal enzyme activity deficiencies and consequent accumulation of gangliosides in the central nervous system (CNS). The infantile forms are distinguished from the juvenile forms by age of onset, rate of disease progression, and age of death. There are no approved treatments for the gangliosidoses. In search of potential biomarkers of disease, we quantified 188 analytes in CSF and serum from living human patients with longitudinal (serial) measurements. Notably, several associated with inflammation were elevated in the CSF of infantile gangliosidosis patients, and less so in more slowly progressing forms of juvenile gangliosidosis, but not in MPS disease. Thirteen CSF and two serum biomarker candidates were identified. Five candidate biomarkers were distinguished by persistent elevation in the CSF of patients with the severe infantile phenotype: ENA-78, MCP-1, MIP-1α, MIP-1ß, and TNFR2. Correspondence of abnormal elevation with other variables of disease-i.e., severity of clinical phenotype, differentiation from changes in serum, and lack of abnormality in other neurodegenerative lysosomal diseases-identifies these analytes as biomarkers of neuropathology specific to the gangliosidosis diseases.

CSF concentrations of brain tryptophan and kynurenines during immune stimulation with IFN-alpha: relationship to CNS immune responses and depression.

Cytokine-induced activation of indoleamine 2,3-dioxygenase (IDO) catabolizes L-tryptophan (TRP) into L-kynurenine (KYN), which is metabolized to quinolinic acid (QUIN) and kynurenic acid (KA). QUIN and KA are neuroactive and may contribute to the behavioral changes experienced by some patients during exposure to inflammatory stimuli such as interferon (IFN)-alpha. A relationship between depressive symptoms and peripheral blood TRP, KYN and KA during treatment with IFN-alpha has been described. However, whether peripheral blood changes in these IDO catabolites are manifest in the brain and whether they are related to central nervous system cytokine responses and/or behavior is unknown. Accordingly, TRP, KYN, QUIN and KA were measured in cerebrospinal fluid (CSF) and blood along with CSF concentrations of relevant cytokines, chemokines and soluble cytokine receptors in 27 patients with hepatitis C after approximately 12 weeks of either treatment with IFN-alpha (n=16) or no treatment (n=11). Depressive symptoms were assessed using the Montgomery-Asberg Depression Rating Scale. IFN-alpha significantly increased peripheral blood KYN, which was accompanied by marked increases in CSF KYN. Increased CSF KYN was in turn associated with significant increases in CSF QUIN and KA. Despite significant decreases in peripheral blood TRP, IFN-alpha had no effect on CSF TRP concentrations. Increases in CSF KYN and QUIN were correlated with increased CSF IFN-alpha, soluble tumor necrosis factor-alpha receptor 2 and monocyte chemoattractant protein-1 as well as increased depressive symptoms. In conclusion, peripheral administration of IFN-alpha activated IDO in concert with central cytokine responses, resulting in increased brain KYN and QUIN, which correlated with depressive symptoms.

Soluble TNF receptors are associated with Aß metabolism and conversion to dementia in subjects with mild cognitive impairment.

OBJECTIVE: There is evidence supporting that tumor necrosis factor receptor (TNFR)-signaling can induce production of beta-amyloid (Aß) in the brain. Moreover, amyloid-induced toxicity has been shown to be dependent on TNFR-signaling. However, it is still unclear whether TNFRs are involved in the early stages of dementia. METHODS: We analyzed soluble TNFR1 and TNFR2 levels in plasma and cerebrospinal fluid (CSF) at baseline in 137 patients with mild cognitive impairment (MCI) and 30 age-matched controls. The MCI patients were followed for 4-6 years with an incidence of Alzheimer's disease (AD) or vascular dementia (VaD) of 15% per year. RESULTS: The patients with MCI who subsequently developed these forms of dementias had higher levels of sTNFR1 and sTNFR2 in both CSF and plasma already at baseline when compared to age-matched controls (p<0.05). In the CSF of MCI subjects and controls the levels of both sTNFR1 and sTNFR2 correlated strongly with ß-site APP-cleaving enzyme 1 (BACE1) activity (r(s)=0.53-0.68, p<0.01) and Aß 40 levels (r(s)=0.59-0.71, p<0.001). Similarly, both sTNFRs were associated with Aß 40 (r(s)=0.39-0.46, p<0.05) in plasma. Finally, the levels of both sTNFRs correlated with the axonal damage marker tau in the CSF of MCI subjects and controls (r(s)=0.57-0.83, p<0.001). CONCLUSION: TNFR-signaling might be involved in the early pathogenesis of AD and VaD, and could be associated with beta-amyloid metabolism.

Salvage therapy with abacavir and other reverse transcriptase inhibitors for human immunodeficiency-associated encephalopathy.

BACKGROUND: HIV-associated encephalopathy (HIV-AE) is a severe neurologic condition that affects HIV-infected children. The potential benefit of antiretroviral (ARV) agents with good cerebrospinal fluid (CSF) penetration remains to be defined. Abacavir (ABC) achieves good CSF concentrations and studies of high-dose ABC showed benefit in adults with HIV dementia. The present study evaluated the safety and virologic, immunologic and neuropsychological responses of an ARV regimen including high-dose ABC in children with HIV-AE. METHODS: Children between 3 months and 18 years old and abacavir-naive with HIV-AE and virologic failure were eligible. RESULTS: : Seventeen children (16 ARV-experienced) were enrolled and 14 children completed 48 weeks of therapy. The overall tolerability was good; 2 children had a possible hypersensitivity reaction. At week 48, 53% and 59% of the children achieved HIV RNA levels below the limit of quantitation in plasma and CSF, respectively. The median (25%-75% range) change of HIV RNA from baseline to week 48 was -2.29 (-0.81 to -2.47) log10 copies/mL in plasma and -0.94 (0 to -1.13) log10 copies/mL in CSF. The mean increases in CD4 (+/-standard error of mean) cell count and CD4% were 427 (+/-169) cells/mm and 8% (+/-2), respectively. Concentrations of soluble tumor necrosis factor receptor II were reduced in plasma and CSF. Children less than 6 years of age demonstrated significant neuropsychological improvement at week 48. CONCLUSIONS: In the present study with a limited number of children, highly active ARV therapy including high-dose ABC showed a safety profile similar to standard dose ABC and provided clinical, immunologic and virologic response in children with HIV-AE at week 48. Children less than 6 years of age also demonstrated significant neuropsychological improvement.