Finn Sellebjerg

Expression of specific chemokines and chemokine receptors in the central nervous system of multiple sclerosis patients

Chemokines direct tissue invasion by specific leukocyte populations. Thus, chemokines may play a role in multiple sclerosis (MS), an idiopathic disorder in which the central nervous system (CNS) inflammatory reaction is largely restricted to mononuclear phagocytes and T cells. We asked whether specific chemokines were expressed in the CNS during acute demyelinating events by analyzing cerebrospinal fluid (CSF), whose composition reflects the CNS extracellular space. During MS attacks, we found elevated CSF levels of three chemokines that act toward T cells and mononuclear phagocytes: interferon-gamma-inducible protein of 10 kDa (IP-10); monokine induced by interferon-gamma (Mig); and regulated on activation, normal T-cell expressed and secreted (RANTES). We then investigated whether specific chemokine receptors were expressed by infiltrating cells in demyelinating MS brain lesions and in CSF. CXCR3, an IP-10/Mig receptor, was expressed on lymphocytic cells in virtually every perivascular inflammatory infiltrate in active MS lesions. CCR5, a RANTES receptor, was detected on lymphocytic cells, macrophages, and microglia in actively demyelinating MS brain lesions. Compared with circulating T cells, CSF T cells were significantly enriched for cells expressing CXCR3 or CCR5. Our results imply pathogenic roles for specific chemokine-chemokine receptor interactions in MS and suggest new molecular targets for therapeutic intervention.

CCR1+/CCR5+ Mononuclear Phagocytes Accumulate in the Central Nervous System of Patients with Multiple Sclerosis

Mononuclear phagocytes (monocytes, macrophages, and microglia) are considered central to multiple sclerosis (MS) pathogenesis. Molecular cues that mediate mononuclear phagocyte accumulation and activation in the central nervous system (CNS) of MS patients may include chemokines RANTES/CCL5 and macrophage inflammatory protein-1alpha/CCL3. We analyzed expression of CCR1 and CCR5, the monocyte receptors for these chemokines, on circulating and cerebrospinal fluid CD14+ cells, and in MS brain lesions. Approximately 70% of cerebrospinal fluid monocytes were CCR1+/CCR5+, regardless of the presence of CNS pathology, compared to less than 20% of circulating monocytes. In active MS lesions CCR1+/CCR5+ monocytes were found in perivascular cell cuffs and at the demyelinating edges of evolving lesions. Mononuclear phagocytes in early demyelinating stages comprised CCR1+/CCR5+ hematogenous monocytes and CCR1-/CCR5- resident microglial cells. In later stages, phagocytic macrophages were uniformly CCR1-/CCR5+. Cultured in vitro, adherent monocytes/macrophages up-regulated CCR5 and down-regulated CCR1 expression, compared to freshly-isolated monocytes. Taken together, these findings suggest that monocytes competent to enter the CNS compartment derive from a minority CCR1+/CCR5+ population in the circulating pool. In the presence of ligand, these cells will be retained in the CNS. During further activation in lesions, infiltrating monocytes down-regulate CCR1 but not CCR5, whereas microglia up-regulate CCR5.

Multiple sclerosis: a study of CXCL10 and CXCR3 co-localization in the inflamed central nervous system

T-cell accumulation in the central nervous system (CNS) is considered crucial to the pathogenesis of multiple sclerosis (MS). We found that the majority of T cells within the cerebrospinal fluid (CSF) compartment expressed the CXC chemokine receptor 3 (CXCR), independent of CNS inflammation. Quantitative immunohistochemistry revealed continuous accumulation of CXCR3+ T cells during MS lesion formation. The expression of one CXCR3 ligand, interferon (IFN)-gamma-inducible protein of 10 kDa (IP-10)/CXC chemokine ligand (CXCL) 10 was elevated in MS CSF, spatially associated with demyelination in CNS tissue sections and correlated tightly with CXCR3 expression. These data suggest a critical role for CXCL10 and CXCR3 in the accumulation of T cells in the CNS of MS patients.

CCR5 Δ32, matrix metalloproteinase-9 and disease activity in multiple sclerosis

Abstract Chemokines and matrix metalloproteinases (MMPs) appear to be crucial in leukocyte recruitment to the central nervous system in multiple sclerosis (MS). CCR5 Δ32, a truncated allele of the CC chemokine receptor CCR5 gene encoding a non-functional receptor, did not confer protection from MS. CCR5 Δ32 was, however, associated with a lower risk of recurrent clinical disease activity. High CSF levels of MMP-9 activity were also associated with recurrent disease activity. These results directly link intrathecal inflammation to disease activity in patients with MS, suggesting that treatments targeting CCR5 or treatment with MMP inhibitors may attenuate disease activity in MS.

Clinical Relevance of Brain Volume Measures in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease with an inflammatory and neurodegenerative pathology. Axonal loss and neurodegeneration occurs early in the disease course and may lead to irreversible neurological impairment. Changes in brain volume, observed from the earliest stage of MS and proceeding throughout the disease course, may be an accurate measure of neurodegeneration and tissue damage. There are a number of magnetic resonance imaging-based methods for determining global or regional brain volume, including cross-sectional (e.g. brain parenchymal fraction) and longitudinal techniques (e.g. SIENA [Structural Image Evaluation using Normalization of Atrophy]). Although these methods are sensitive and reproducible, caution must be exercised when interpreting brain volume data, as numerous factors (e.g. pseudoatrophy) may have a confounding effect on measurements, especially in a disease with complex pathological substrates such as MS. Brain volume loss has been correlated with disability progression and cognitive impairment in MS, with the loss of grey matter volume more closely correlated with clinical measures than loss of white matter volume. Preventing brain volume loss may therefore have important clinical implications affecting treatment decisions, with several clinical trials now demonstrating an effect of disease-modifying treatments (DMTs) on reducing brain volume loss. In clinical practice, it may therefore be important to consider the potential impact of a therapy on reducing the rate of brain volume loss. This article reviews the measurement of brain volume in clinical trials and practice, the effect of DMTs on brain volume change across trials and the clinical relevance of brain volume loss in MS.

Guidelines on routine cerebrospinal fluid analysis. Report from an EFNS task force

A great variety of neurological diseases require investigation of cerebrospinal fluid (CSF) to prove the diagnosis or to rule out relevant differential diagnoses. The objectives were to evaluate the theoretical background and provide guidelines for clinical use in routine CSF analysis including total protein, albumin, immunoglobulins, glucose, lactate, cell count, cytological staining, and investigation of infectious CSF. The methods included a Systematic Medline search for the above‐mentioned variables and review of appropriate publications by one or more of the task force members. Grading of evidence and recommendations was based on consensus by all task force members. It is recommended that CSF should be analysed immediately after collection. If storage is needed 12 ml of CSF should be partitioned into three to four sterile tubes. Albumin CSF/serum ratio (Qalb) should be preferred to total protein measurement and normal upper limits should be related to patients’ age. Elevated Qalb is a non‐specific finding but occurs mainly in bacterial, cryptococcal, and tuberculous meningitis, leptomingeal metastases as well as acute and chronic demyelinating polyneuropathies. Pathological decrease of the CSF/serum glucose ratio or increased lactate concentration indicates bacterial or fungal meningitis or leptomeningeal metastases. Intrathecal immunoglobulin G synthesis is best demonstrated by isoelectric focusing followed by specific staining. Cellular morphology (cytological staining) should be evaluated whenever pleocytosis is found or leptomeningeal metastases or pathological bleeding is suspected. Computed tomography‐negative intrathecal bleeding should be investigated by bilirubin detection.

T helper cell type 1 (Th1), Th2 and Th17 responses to myelin basic protein and disease activity in multiple sclerosis.

Autoreactive T cells are thought to play an essential role in the pathogenesis of multiple sclerosis (MS). We examined the stimulatory effect of human myelin basic protein (MBP) on mononuclear cell (MNC) cultures from 22 patients with MS and 22 sex‐matched and age‐matched healthy individuals, and related the patient responses to disease activity, as indicated by magnetic resonance imaging. The MBP induced a dose‐dependent release of interferon‐γ (IFN‐γ), tumour necrosis factor‐α (TNF‐α) and interleukin‐10 (IL‐10) by patient‐derived MNCs. The patients’ cells produced higher amounts of IFN‐γ and TNF‐α, and lower amounts of IL‐10, than cells from healthy controls (P < 0·03 to P < 0·04). Five patients with MS and no controls, displayed MBP‐induced CD4+ T‐cell proliferation. These high‐responders exhibited enhanced production of IL‐17, IFN‐γ, IL‐5 and IL‐4 upon challenge with MBP, as compared with the remaining patients and the healthy controls (P < 0·002 to P < 0·01). A strong correlation was found between the MBP‐induced CD4+ T‐cell proliferation and production of IL‐17, IFN‐γ, IL‐5 and IL‐4 (P < 0·0001 to P < 0·01) within the patient group, and the production of IL‐17 and IL‐5 correlated with the number of active plaques on magnetic resonance images (P = 0·04 and P = 0·007). These data suggest that autoantigen‐driven CD4+ T‐cell proliferation and release of IL‐17 and IL‐5 may be associated with disease activity. Larger studies are needed to confirm this.

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.

Double-blind, randomized, placebo-controlled study of oral, high-dose methylprednisolone in attacks of MS.

Objective: There is only limited evidence from adequately controlled clinical trials to support high-dose methylprednisolone therapy for attacks of multiple sclerosis (MS) and none supporting oral administration. We assessed the effect of oral high-dose methylprednisolone therapy in attacks of MS. Methods: Twenty-five patients with an attack of MS lasting less than 4 weeks were randomized to placebo treatment. Twenty-six patients received oral methylprednisolone (500 mg once a day for 5 days with a 10-day tapering period). The patients received scores on the Scripps Neurological Rating Scale (NRS) and Kurtzke Expanded Disability Status Scale. The symptoms were scored on a visual analog scale (VAS) before treatment and after 1, 3, and 8 weeks of treatment. Primary efficacy measures were NRS and VAS scores in the first 3 weeks and changes in NRS score and answers to an efficacy questionnaire administered after 8 weeks of treatment. Results: Changes in NRS scores among methylprednisolone- and placebo-treated patients differed significantly in the first 3 weeks and after 8 weeks(p = 0.005 and p = 0.0007). VAS scores the first 3 weeks and treatment efficacy after 8 weeks also favored a beneficial effect of methylprednisolone treatment (p = 0.02 and p = 0.05). After 1, 3, and 8 weeks, 4%, 24%, and 32% in the placebo group and 31%, 54%, and 65% in the methylprednisolone group had improved one point on the Expanded Disability Status Scale score (all p < 0.05). No serious adverse events were seen. Conclusion: Oral high-dose methylprednisolone is recommended for managing attacks of MS.

A randomized, controlled trial of oral high-dose methylprednisolone in acute optic neuritis

Objective: To assess the efficacy of oral high-dose methylprednisolone in acute optic neuritis (ON). Background: It has been determined that oral high-dose methylprednisolone is efficacious in attacks of MS. Methods: A total of 60 patients with symptoms and signs of ON with a duration of less than 4 weeks and a visual acuity of 0.7 or less were randomized to treatment with placebo (n = 30) or oral methylprednisolone (n = 30; 500 mg daily for 5 days, with a 10-day tapering period). Visual function was measured and symptoms were scored on a visual analog scale (VAS) before treatment and after 1, 3, and 8 weeks. Primary efficacy measures were spatial vision and VAS scores the first 3 weeks (analysis of variance with baseline values as the covariate), and changes in spatial vision and VAS scores after 8 weeks. A significance level of p < 0.0125 was employed. Results: The VAS score (p = 0.008) but not the spatial visual function (p = 0.03) differed in methylprednisolone- and placebo-treated patients during the first 3 weeks. After 8 weeks the improvement in VAS scores (p = 0.8) and spatial visual function (p = 0.5) was comparable with methylprednisolone- and placebo-treated patients. A post hoc subgroup analysis suggested that patients with more severe baseline visual deficit and patients treated early after onset of symptoms had a more pronounced response to treatment. The risk of a new demyelinating attack within 1 year was unaffected by treatment. No serious adverse events were seen. Conclusion: Oral high-dose methylprednisolone treatment improves recovery from ON at 1 and 3 weeks, but no effect could be demonstrated at 8 weeks or on subsequent attack frequency.