Lars Börnsen

Increased cerebrospinal fluid concentrations of the chemokine CXCL13 in active MS.

Background: Accumulating evidence supports a major role of B cells in multiple sclerosis (MS) pathogenesis. How B cells are recruited to the CNS is incompletely understood. Our objective was to study B-cell chemokine concentrations in MS, their relationship with disease activity, and how treatment with methylprednisolone and natalizumab affected the concentration in CSF. Methods: Using a cross-sectional design, CSF and blood samples were obtained from cohorts of patients with clinically isolated syndromes (CIS), relapsing-remitting MS (RRMS), primary progressive MS (PPMS), or secondary progressive MS (SPMS), and noninflammatory neurologic disease control subjects. Some patients with RRMS were studied before and after treatment with methylprednisolone or natalizumab. Results: In CSF, concentrations of CXCL13, but not CXCL12, were higher in patients with CIS, RRMS, SPMS, and PPMS than in controls. CSF concentrations of CXCL13 correlated with the CSF B-cell count, with markers of immune activation, and with disease activity in patients with CIS and RRMS. CSF concentrations of CXCL13 decreased after treatment with high-dose methylprednisolone and natalizumab. High CSF concentrations of CXCL13 correlated with low expression of messenger RNA encoding the immunoregulatory cytokines interleukin 10 and transforming growth factor β1, but not with the expression of T-helper type 1 (Th1) and Th17 factors. Conclusion: The chemokine CXCL13 may play a major role in recruitment of B cells and T-cell subsets expressing the chemokine receptor CXCR5 to the CNS in multiple sclerosis (MS), and may be a useful biomarker for treatment effects in MS. Furthermore, CXCL13 or its receptor CXCR5 should be considered as therapeutic targets in MS.

Systemic inflammation in progressive multiple sclerosis involves follicular T-helper, Th17- and activated B-cells and correlates with progression.

Pathology studies of progressive multiple sclerosis (MS) indicate a major role of inflammation including Th17-cells and meningeal inflammation with ectopic lymphoid follicles, B-cells and plasma cells, the latter indicating a possible role of the newly identified subset of follicular T-helper (TFH) cells. Although previous studies reported increased systemic inflammation in progressive MS it remains unclear whether systemic inflammation contributes to disease progression and intrathecal inflammation. This study aimed to investigate systemic inflammation in progressive MS and its relationship with disease progression, using flow cytometry and gene expression analysis of CD4+ and CD8+T-cells, B-cells, monocytes and dendritic cells. Furthermore, gene expression of cerebrospinal fluid cells was studied. Flow cytometry studies revealed increased frequencies of ICOS+TFH-cells in peripheral blood from relapsing-remitting (RRMS) and secondary progressive (SPMS) MS patients. All MS subtypes had decreased frequencies of Th1 TFH-cells, while primary progressive (PPMS) MS patients had increased frequency of Th17 TFH-cells. The Th17-subset, interleukin-23-receptor+CD4+T-cells, was significantly increased in PPMS and SPMS. In the analysis of B-cells, we found a significant increase of plasmablasts and DC-SIGN+ and CD83+B-cells in SPMS. ICOS+TFH-cells and DC-SIGN+B-cells correlated with disease progression in SPMS patients. Gene expression analysis of peripheral blood cell subsets substantiated the flow cytometry findings by demonstrating increased expression of IL21, IL21R and ICOS in CD4+T-cells in progressive MS. Cerebrospinal fluid cells from RRMS and progressive MS (pooled SPMS and PPMS patients) had increased expression of TFH-cell and plasmablast markers. In conclusion, this study is the first to demonstrate the potential involvement of activated TFH-cells in MS. The increased frequencies of Th17-cells, activated TFH- and B-cells parallel findings from pathology studies which, along with the correlation between activated TFH- and B-cells and disease progression, suggest a pathogenic role of systemic inflammation in progressive MS. These observations may have implications for the treatment of progressive MS.

The effects of natalizumab on inflammatory mediators in multiple sclerosis: prospects for treatment-sensitive biomarkers

Background:  Natalizumab affects systemic cytokine expressions and clinical course in relapsing–remitting multiple sclerosis (RRMS). We analyzed levels of inflammatory cytokines in cerebrospinal fluid (CSF) cells and peripheral blood mononuclear cells (PBMCs), levels of matrix metalloproteinase (MMP)‐9 and osteopontin (OPN) in CSF, and clinical outcome measures in 22 natalizumab‐treated RRMS patients.

Natalizumab in progressive MS: Results of an open-label, phase 2A, proof-of-concept trial

Objective: Natalizumab inhibits the migration of systemic immune cells to the CNS and may be beneficial in progressive multiple sclerosis (MS). The objective of the study was to examine the effects of natalizumab in progressive MS. Methods: In an open-label phase 2A study, 24 patients with progressive MS were included to receive natalizumab treatment for 60 weeks. Response to natalizumab was assessed in CSF and MRI studies. The primary endpoint was change in CSF osteopontin, a biomarker of intrathecal inflammation, from baseline to week 60. Results: Seventeen patients completed the study. No new safety issues were encountered. CSF osteopontin decreased by 65 ng/mL (95% confidence interval 34–96 ng/mL; p = 0.0004) from baseline to week 60 in conjunction with decreases in other CSF biomarkers of inflammation, axonal damage, and demyelination. Magnetization transfer ratio increased in both cortical gray and normal-appearing white matter and correlated with decreases in CSF neurofilament light chain. Conclusions: Natalizumab treatment of progressive MS reduces intrathecal inflammation and tissue damage, supporting a beneficial effect of natalizumab treatment in progressive MS and suggesting that systemic inflammation contributes to the pathogenesis. Moreover, the study establishes the feasibility of using CSF biomarkers in proof-of-concept trials, allowing a low number of participants and short study duration. Classification of evidence: This study provides Class IV evidence that in patients with progressive MS, natalizumab reduces biomarkers of intrathecal inflammation.

CSF inflammation and axonal damage are increased and correlate in progressive multiple sclerosis.

Background: The mechanism underlying disease progression in progressive multiple sclerosis (MS) is uncertain. Pathological studies found widespread inflammation in progressive MS brains correlating with disease progression and axonal damage. Objectives: To study cerebrospinal fluid (CSF) biomarkers and clarify whether inflammation and axonal damage are associated in progressive MS. Methods: Using enzyme-linked immunosorbent assay (ELISA), we analysed CSF from 40 secondary progressive (SPMS), 21 primary progressive (PPMS), and 36 relapsing–remitting (RRMS) and 20 non-inflammatory neurological disease (NIND) patients. Twenty-two of the SPMS patients participated in an MBP8298 peptide clinical trial and had CSF follow-up after one year. Results: Compared to NIND patients, inflammatory biomarkers osteopontin and matrix metalloproteinase-9 (MMP9) were increased in all MS patients while CXCL13 was increased in RRMS and SPMS patients. Biomarkers of axonal damage (NFL) and demyelination (MBP) were increased in all MS patients. In progressive MS patients CSF levels of osteopontin and CXCL13 correlated with NFL while osteopontin and MMP9 correlated with MBP. MBP8298 treatment did not affect the levels of the biomarkers after one year of treatment. All biomarkers were continuously increased after one year of follow-up except MBP, which decreased. Conclusion: CSF biomarkers of inflammation, axonal damage and demyelination are continuously increased in progressive MS patients and correlate. These findings parallel pathology studies, emphasise a relationship between inflammation, axonal damage and demyelination and support the use of CSF biomarkers in progressive MS clinical trials.

Cellular sources of dysregulated cytokines in relapsing-remitting multiple sclerosis

BackgroundNumerous cytokines are implicated in the immunopathogenesis of multiple sclerosis (MS), but studies are often limited to whole blood (WB) or peripheral blood mononuclear cells (PBMCs), thereby omitting important information about the cellular origin of the cytokines. Knowledge about the relation between blood and cerebrospinal fluid (CSF) cell expression of cytokines and the cellular source of CSF cytokines is even more scarce.MethodsWe studied gene expression of a broad panel of cytokines in WB from relapsing-remitting multiple sclerosis (RRMS) patients in remission and healthy controls (HCs). Subsequently we determined the gene expression of the dysregulated cytokines in isolated PBMC subsets (CD4+, CD8+T-cells, NK-cells, B-cells, monocytes and dendritic cells) from RRMS patients and HCs and in CSF-cells from RRMS patients in clinical relapse and non-inflammatory neurological controls (NIND).ResultsRRMS patients had increased expression of IFN-gamma (IFNG), interleukin (IL) 1-beta (IL1B), IL7, IL10, IL12A, IL15, IL23, IL27, lymphotoxin-alpha (LTA) and lymphotoxin-beta (LTB) in WB. In PBMC subsets the main sources of pro-inflammatory cytokines were T- and B-cells, whereas monocytes were the most prominent source of immunoregulatory cytokines. In CSF-cells, RRMS patients had increased expression of IFNG and CD19 and decreased expression of IL10 and CD14 compared to NINDs. CD19 expression correlated with expression of IFNG, IL7, IL12A, IL15 and LTA whereas CD14 expression correlated with IL10 expression.ConclusionsUsing a systematic approach, we show that expression of pro-inflammatory cytokines in peripheral blood primarily originates from T- and B-cells, with an important exception of IFNG which is most strongly expressed by NK-cells. In CSF-cell studies, B-cells appear to be enriched in RRMS and associated with expression of pro-inflammatory cytokines; contrarily, monocytes are relatively scarce in CSF from RRMS patients and are associated with IL10 expression. Thus, our findings suggest a pathogenetic role of B-cells and an immunoregulatory role of monocytes in RRMS.

Osteopontin concentrations are increased in cerebrospinal fluid during attacks of multiple sclerosis

Background:The cytokine osteopontin (OPN) is a potential key player in the immunopathogenesis of multiple sclerosis (MS) and a candidate biomarker for disease activity. Objective:The objective of this study was to examine concentrations of OPN in the cerebrospinal fluid (CSF) across the clinical spectrum of MS. Methods:Our research consisted of a cross-sectional study of patients from two randomized, placebo-controlled trials. Concentrations of OPN and other blood and CSF markers were determined using an enzyme-linked immunosorbent assay (ELISA). Samples were obtained from untreated patients with exacerbation of clinically isolated syndrome (CIS) (n = 25) and relapsing–remitting MS (RRMS) (n = 41) of whom 48 participated in clinical trials, randomly allocated to treatment with placebo or methylprednisolone (MP) and undergoing repeated sampling after 3 weeks. Furthermore, we obtained CSF and blood samples from patients with primary progressive MS (PPMS, n = 9), secondary progressive MS (SPMS, n = 28) and other neurological disorders (OND, n = 44), and blood samples from 24 healthy subjects. Results:OPN concentrations were significantly increased in the CSF of patients with CIS (p = 0.02) and RRMS (p < 0.001) in exacerbation compared to patients with OND, and increased levels of OPN were associated with high values of other biomarkers of inflammation. At 3-week follow-up CSF OPN concentrations had decreased significantly from baseline regardless treatment with placebo or MP. Patients with PPMS had increased OPN levels in the CSF (p = 0.004) and high CSF levels of OPN were associated with high degrees of disability. Conclusions:OPN concentration in the CSF is a dynamic indicator of disease activity in RRMS, presumably reflecting ongoing inflammation. Increased CSF OPN concentrations in PPMS may indicate ongoing inflammation even in these patients.

Effect of natalizumab on circulating CD4+ T-cells in multiple sclerosis.

In multiple sclerosis (MS), treatment with the monoclonal antibody natalizumab effectively reduces the formation of acute lesions in the central nervous system (CNS). Natalizumab binds the integrin very late antigen (VLA)-4, expressed on the surface of immune cells, and inhibits VLA-4 dependent transmigration of circulating immune-cells across the vascular endothelium into the CNS. Recent studies suggested that natalizumab treated MS patients have an increased T-cell pool in the blood compartment which may be selectively enriched in activated T-cells. Proposed causes are sequestration of activated T-cells due to reduced extravasation of activated and pro-inflammatory T-cells or due to induction of VLA-4 mediated co-stimulatory signals by natalizumab. In this study we examined how natalizumab treatment altered the distribution of effector and memory T-cell subsets in the blood compartment and if T-cells in general or myelin-reactive T-cells in particular showed signs of increased immune activation. Furthermore we examined the effects of natalizumab on CD4+ T-cell responses to myelin in vitro. Natalizumab-treated MS patients had significantly increased numbers of effector-memory T-cells in the blood. In T-cells from natalizumab-treated MS patients, the expression of TNF-α mRNA was increased whereas the expression of fourteen other effector cytokines or transcription factors was unchanged. Natalizumab-treated MS patients had significantly decreased expression of the co-stimulatory molecule CD134 on CD4+CD26HIGH T-cells, in blood, and natalizumab decreased the expression of CD134 on MBP-reactive CD26HIGHCD4+ T-cells in vitro. Otherwise CD4+ T-cells from natalizumab-treated and untreated MS patients showed similar responses to MBP. In conclusion natalizumab treatment selectively increased the effector memory T-cell pool but not the activation state of T-cells in the blood compartment. Myelin-reactive T-cells were not selectively increased in natalizumab treated MS.

High-dose erythropoietin in patients with progressive multiple sclerosis: A randomized, placebo-controlled, phase 2 trial

Background: Erythropoietin (EPO) is a part of an endogenous neuroprotective system in the brain and may address pathophysiological mechanisms in progressive multiple sclerosis (MS). Objective: To evaluate a treatment effect of EPO on progressive MS. Methods: This was a single-center, randomized, double-blind, placebo-controlled phase 2 trial, in which 52 patients with secondary or primary progressive MS were allocated to treatment with recombinant EPO (48,000 IU) or placebo, administered intravenously 17 times during 24 weeks. Patients had an Expanded Disability Status Score (EDSS) from 4 to 6.5 and clinical progression without relapses in the 2 preceding years. The primary outcome was the change in a composite measure of maximum gait distance, hand dexterity, and cognition from baseline to 24 weeks. Results: A total of 50 patients completed the study. Venesection was performed often but no thromboembolic events occurred. We found no difference in the primary outcome between the EPO and the placebo group using the intention-to-treat principle (p = 0.22). None of the secondary outcomes, neither clinical nor magnetic resonance imaging (MRI) measures showed any significant differences. Conclusion: This study provides class II evidence that treatment with high-dose EPO is not an effective treatment in patients with moderately advanced progressive MS.

Selected CSF biomarkers indicate no evidence of early neuroinflammation in Huntington disease

Objective: To investigate CSF biomarkers of neuroinflammation and neurodegeneration in Huntington disease (HD) gene-expansion carriers compared to controls and to investigate these biomarkers in association with clinical HD rating scales and disease burden score. Methods: We collected CSF from 32 premanifest and 48 manifest HD gene-expansion carriers and 24 gene-expansion negative at-risk controls. We examined biomarkers of neuroinflammation (matrix metalloproteinase 9, C-X-C motif chemokine 13, terminal complement complex, chitinase-3-like-protein 1 [CHI3L1], and osteopontin [OPN]) and neurodegeneration (microtubule-associated protein tau, neurofilament light polypeptide [NFL], and myelin basic protein [MBP]). The study was approved by the Ethics Committee of the Capital Region of Denmark (H2-2011-085) and written informed consent was obtained from each participant before enrollment. Results: NFL was the only biomarker that increased in premanifest stages and no evidence of early involvement of neuroinflammation in HD was found. However, we found that the biomarkers for neurodegeneration, MBP and tau, increased during the disease course in manifest HD gene-expansion carriers and were associated with an increase of the neuroinflammation biomarkers CHI3L1 and OPN. Tau was also increased in all gene-expansion carriers with psychiatric symptoms compared to gene-expansion carriers without psychiatric symptoms. Conclusions: Neuroinflammation, which seems not to be an early event in our cohort, may be secondary to neurodegeneration in late HD. NFL is a possible disease burden correlate in HD, reflecting neuronal loss even before motor symptom onset, and may be useful as a dynamic biomarker in intervention studies.