Immunological profile of patients with primary progressive multiple sclerosis. Expression of adhesion molecules

The IL-27/IL-27R axis is altered in CD4+ and CD8+ T lymphocytes from multiple sclerosis patients

Objectives

Pro‐ and anti‐inflammatory properties have been attributed to interleukin‐27 (IL‐27). Nevertheless, the impact of this cytokine on chronic inflammatory diseases such as multiple sclerosis (MS) remains ill‐defined. We investigated the biology of IL‐27 and its specific receptor IL‐27Rα in MS patients.

Methods

Levels of IL‐27 and its natural antagonist (IL‐27‐Rα) were measured by ELISA in biological fluids. CD4⁺ and CD8⁺ T lymphocytes were isolated from untreated relapsing–remitting MS patients and healthy donors. Transcriptome‐wide analysis compared T‐cell subsets stimulated or not with IL‐27. Expression of the IL‐27Rα, key immune factors, STAT phosphorylation and cytokine production was assessed by flow cytometry.

Results

We observed elevated levels of IL‐27 in the serum and cerebrospinal fluid of MS patients compared with controls. Moreover, we show that specific IL‐27‐mediated effects on T lymphocytes are reduced in MS patients including the induction of PD‐L1. IL‐27‐triggered STAT3 signalling pathway is enhanced in CD4⁺ and CD8⁺ T lymphocytes from MS patients. Elevated IL‐27Rα levels in serum from MS patients are sufficient to impair the capacity of IL‐27 to act on immune cells. We demonstrate that shedding of IL‐27Rα by activated CD4⁺ T lymphocytes from MS patients contributes to the increased IL‐27Rα peripheral levels and consequently can dampen the IL‐27 responsiveness.

Conclusion

Our work identifies several mechanisms that are altered in the IL‐27/IL‐27R axis in MS patients, especially in T lymphocytes. Our results underline the importance of characterising the biology of cytokines in human patients prior to design new therapeutics.

Baseline and overtime variations of soluble adhesion molecule plasma concentrations are associated with mobility recovery after rehabilitation in multiple sclerosis patients

Rehabilitative exercise outcomes and plasma concentrations of soluble adhesion molecules (sEndoglin, sE-Selectin, sL-Selectin, sICAM-1, sNCAM, sNCAM-1, sVCAM-1, sPECAM-1, sVAP-1) were evaluated in 60 severely disabled progressive multiple sclerosis (MS) patients at 4-time points. Changes of sE-Selectin, sL-Selectin, and sPECAM-1 concentrations were observed over time, and their variations were significantly correlated with rehabilitative outcome variations. Baseline sVAP-1 concentrations were able to predict functional mobility recovery. Our data suggest that the evaluation of adhesion molecules in plasma provides useful information to interpret rehabilitative exercise processes and to identify potential predictors of the rehabilitation-induced changes in mobility outcomes in MS patients.

A novel fumarate, isosorbide di-(methyl fumarate) (IDMF), replicates astrocyte transcriptome responses to dimethyl fumarate (DMF) but specifically down-regulates genes linked to a reactive phenotype

Dimethyl fumarate (DMF) has emerged as a first-line treatment for the relapsing-remitting multiple sclerosis (RRMS) subtype. It is hypothesized that DMF has anti-inflammatory and antioxidant effects although mechanisms are not fully understood. This study used RNA-seq to profile gene expression responses to DMF in cultured astrocytes. Responses were compared with those of isosorbide di-(methyl fumarate) (IDMF), a newly designed fumarate that may partially replicate DMF activity with fewer adverse effects. Both compounds altered the expression of MS-associated genes, including those near MS susceptibility loci and genes dysregulated in MS patient astrocytes. The shared DMF/IDMF transcriptome response involved altered expression of antioxidant genes (e.g., HMOX1) and genes linked to extracellular matrix integrity (TIMP3, MMP9) and migration of pro-inflammatory cells into CNS (CCL2). IDMF-specific transcriptome responses included down-regulation of mitotic genes associated with a proliferative reactive astrocyte phenotype (ICAM1) and repression of genes encoding NF-kappaB subunits (NFKB2, RELA, RELB) and NF-kappaB targets (NCAPG, CXCL1, OAS3). Overall, these results identify astrocyte-centered mechanisms that may contribute to the established efficacy of DMF as an RRMS treatment. Furthermore, our findings support a rationale for further studies of IDMF as a novel fumarate, which may have unique suppressive effects on astrocyte reactivity and glial scar formation. [200 words].

Chemokine and Adhesion Molecule Profiles in Aqueous Humor of Clinically Quiescent Uveitic Cataracts

PURPOSE

To investigate the chemokine and adhesion molecule profiles in aqueous humor (AH) of eyes with inactive uveitis and their correlations with inflammation relapse after cataract surgery.

METHODS

Patients with inactive uveitis who underwent cataract surgery between July 2014 and January 2016 at our center were included. Undiluted AH samples (100-120 µl) were obtained through lateral corneal incisions during surgery, and concentrations of monocyte chemoattractant protein 1 (MCP-1/CCL2), macrophage inflammatory protein 1 (MIP-1), interleukin 8 (IL-8), regulated on activation, normal T cell expressed and secreted (RANTES/CCL5), soluble vascular cell adhesion molecule (sVCAM) and soluble intercellular adhesion molecule (sICAM) were measured by cytometric bead array (BD Bioscience, San Jose, CA). AH levels of these inflammatory factors were compared between different uveitis entities and non-inflammatory control. Risk factors for postoperative inflammation relapse were also analysed in uveitic eyes.

RESULTS

As compared with the control group, the panuveitis group had significantly higher aqueous concentrations of MCP-1, IL-8, sVCAM, sICAM; the anterior uveitis group had significantly higher concentrations of MCP-1, MIP-1, sVCAM. Uveitic cataracts with postoperative inflammation relapse had significantly higher levels of MCP-1 and IL-8 in AH than those without. And multivariate cox regression analysis revealed that high AH levels of MCP-1 was an independent predictor for postoperative inflammation relapse.

CONCLUSIONS

Clinically quiescent uveitic eyes have elevated levels of chemokines and soluble adhesion molecules in AH, of which MCP-1 is associate with inflammation relapses after cataract surgery.

The role of integrin antagonists in the treatment of inflammatory bowel disease

INTRODUCTION

Ulcerative colitis (UC) and Crohn's disease are chronic inflammatory diseases of the bowel associated with complex inflammatory cascades within the mucosal lining of the gut.

AREAS COVERED

INTEGRINS and their use as therapies in UC and Crohn's.

EXPERT OPINION

The anti-adhesion molecules are a welcome addition to the armamentarium of medical therapies for inflammatory bowel disease.

Selectins and their ligands as potential immunotherapeutic targets in neurological diseases

Selectins are a family of adhesion receptors that bind to highly glycosylated molecules expressed on the surface of leukocytes and endothelial cells. The interactions between selectins and their ligands control tethering and rolling of leukocytes on the vascular wall during the process of leukocyte migration into the tissues under physiological and pathological conditions. In recent years, it has been shown that leukocyte recruitment in the CNS plays a pivotal role in diseases such as multiple sclerosis, ischemic stroke, epilepsy and traumatic brain injury. In this review, we discuss the role of selectins in leukocyte–endothelial interactions in the pathogenesis of neurological diseases, highlighting new findings suggesting that selectins and their ligands may represent novel potential therapeutic targets for the treatment of CNS diseases.

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 (T_FH) 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⁺T_FH-cells in peripheral blood from relapsing-remitting (RRMS) and secondary progressive (SPMS) MS patients. All MS subtypes had decreased frequencies of Th1 T_FH-cells, while primary progressive (PPMS) MS patients had increased frequency of Th17 T_FH-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⁺T_FH-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 T_FH-cell and plasmablast markers. In conclusion, this study is the first to demonstrate the potential involvement of activated T_FH-cells in MS. The increased frequencies of Th17-cells, activated T_FH- and B-cells parallel findings from pathology studies which, along with the correlation between activated T_FH- 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 role of osteopontin: a shared pathway in the pathogenesis of multiple sclerosis and osteoporosis?

Osteopontin (OPN) was suggested to have a role in the pathophysiology of MS and in bone metabolism. However, we formerly reported increased presence of osteoporosis in MS patients independent of corticosteroid treatment, there is only limited information about the mechanism of bone loss. In this study, we investigated the role of OPN on bone mineral density in MS patients. Thirty-three relapsing-remitting (RR), 12 secondary progressive (SP), and 5 primary progressive (PP) MS patients and 30 healthy controls were prospectively enrolled. Students' t test, chi-square test, and Pearson correlations were used. The mean OPN level was 155.4+/-81.8 ng/ml in controls, and 15.9+/-36.2 ng/ml in MS patients (p<0.001).No statistical difference was observed among RR, SP and PPMS patients (p=0.162). No relationship was found between OPN levels and age at onset of disease (p=0.830), gender (p=0.785), MS subtypes (p=0.330), disease duration (p=0.744), or EDSS scores (p=0.633).About 34% of MS patients versus 10.3% of controls had osteoporosis (p=0.017).Osteopontin levels showed no significant correlation with osteoporosis in controls, but were lower in MS patients with osteoporosis in femur neck (r=0.85, p=0.010).The cumulative dose of corticosteroid treatment did not correlate with OPN levels (p=0.285).In conclusion, our results suggest that OPN may have a role as a shared cytokine in pathogenesis of MS and osteoporosis.

Pathological expression of CXCL12 at the blood-brain barrier correlates with severity of multiple sclerosis

Dysregulation of blood-brain barrier (BBB) function and transendothelial migration of leukocytes are essential components of the development and propagation of active lesions in multiple sclerosis (MS). Animal studies indicate that polarized expression of the chemokine CXCL12 at the BBB prevents leukocyte extravasation into the central nervous system (CNS) and that disruption of CXCL12 polarity promotes entry of autoreactive leukocytes and inflammation. In the present study, we examined expression of CXCL12 and its receptor, CXCR4, within CNS tissues from MS and non-MS patients. Immunohistochemical analysis of CXCL12 expression at the BBB revealed basolateral localization in tissues derived from non-MS patients and at uninvolved sites in tissues from MS patients. In contrast, within active MS lesions, CXCL12 expression was redistributed toward vessel lumena and was associated with CXCR4 activation in infiltrating leukocytes, as revealed by phospho-CXCR4-specific antibodies. Quantitative assessment of CXCL12 expression by the CNS microvasculature established a positive correlation between CXCL12 redistribution, leukocyte infiltration, and severity of histological disease. These results suggest that CXCL12 normally functions to localize infiltrating leukocytes to perivascular spaces, preventing CNS parenchymal infiltration. In the patient cohort studied, altered patterns of CXCL12 expression at the BBB were specifically associated with MS, possibly facilitating trafficking of CXCR4-expressing mononuclear cells into and out of the perivascular space and leading to progression of disease.

Molecular targets for disrupting leukocyte trafficking during multiple sclerosis

Autoimmune diseases of the central nervous system (CNS) involve the migration of abnormal numbers of self-directed leukocytes across the blood–brain barrier that normally separates the CNS from the immune system. The cardinal lesion associated with neuroinflammatory diseases is the perivascular infiltrate, which comprises leukocytes that have traversed the endothelium and have congregated in a subendothelial space between the endothelial-cell basement membrane and the glial limitans. The exit of mononuclear cells from this space can be beneficial, as when virus-specific lymphocytes enter the CNS for pathogen clearance, or might induce CNS damage, such as in the autoimmune disease multiple sclerosis when myelin-specific lymphocytes invade and induce demyelinating lesions. The molecular mechanisms involved in the movement of lymphocytes through these compartments involve multiple signalling pathways between these cells and the microvasculature. In this review, we discuss adhesion, costimulatory, cytokine, chemokine and signalling molecules involved in the dialogue between lymphocytes and endothelial cells that leads to inflammatory infiltrates within the CNS, and the targeting of these molecules as therapies for the treatment of multiple sclerosis.

Cell surface adhesion molecules and cytokine profiles in primary progressive multiple sclerosis

OBJECTIVE

We evaluated the utility of adhesion molecule (AM) and cytokine/chemokine expressions in blood and cerebrospinal fluid (CSF) as markers of disease activity in primary progressive multiple sclerosis (PPMS).

METHODS

The expressions of AMs and the levels of 17 cytokines in patients with PPMS (n = 25) were compared with those in secondary progressive MS (SPMS) (n = 18) and controls (n =11) and correlated with the volumes of focal and atrophic changes on MRI.

RESULTS

The expressions of very late activation antigen 4 (VLA-4), lymphocyte function-associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1) in blood and CSF were higher in PPMS than in controls. Comparison between PPMS and SPMS showed higher levels of ICAM-1 in blood and CSF in PPMS, while the level of the vascular adhesion molecule (VCAM-1) was higher only in blood. There was no difference in the levels of cytokines in serum or CSF between PPMS and SPMS or controls, but evidence suggesting intrathecal synthesis of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) was found in PPMS. The expressions of CSF VLA-4 in PPMS correlated with the total volume of cerebral lesions and the number of diffuse brain lesions in MRI, while the amount of LFA-1 in CSF correlated with the number of spinal T2 lesions. The level of serum MIP-1beta correlated with the T2 lesion load and EDSS score in PPMS.

CONCLUSIONS

The upregulated expressions of AMs in blood and CSF and evidence for intrathecal synthesis of MCP-1 and IL-8 in PPMS indicate the importance of inflammatory changes in the pathogenesis of PPMS.

During 3 years treatment of primary progressive multiple sclerosis with glatiramer acetate, specific antibodies switch from IgG1 to IgG4

In this study we analyzed the humoral immune response to glatiramer acetate in 16 GA-treated primary progressive MS patients and 9 placebo patients from the PROMiSe study. We have demonstrated that all multiple sclerosis patients (n=16) continuously treated with GA for 3 years developed anti-GA antibodies that peaked at month 3 and remained elevated during the whole study. We have also demonstrated that initially GA-reactive antibodies of the IgG1 subclass predominate, peaking at month 9 of therapy, but after 9 months IgG1 decreases while anti-GA antibodies of the IgG4 subclass increase and remain high for the 3 years of follow-up. These results support a shift from Th1 to Th2 in the antibody response to glatiramer acetate treatment.

TNF–α converting enzyme (TACE) protein expression in different clinical subtypes of multiple sclerosis

Tumor necrosis factor (TNF)-alpha converting enzyme (TACE, also called ADAM17) is a key sheddase that releases TNF-alpha from its inactive cell-bound precursor. TACE protein expression levels in peripheral blood mononuclear cells were measured by Western blot analysis in 20 healthy controls and 80 multiple sclerosis (MS) patients before and after treatment with IFNbeta [20 patients with primary progressive (PP) MS, 20 patients with secondary progressive (SP) MS, and 40 patients with relapsing- remitting (RR) MS (20 patients during clinical remission and 20 patients in relapse)]. TNF-alpha serum levels were also measured by enzyme-linked immunoassay in the MS patients and healthy controls. TACE protein expression levels were lower in healthy controls and PPMS patients compared with SPMS patients and RRMS patient during clinical remission. No differences in TACE protein levels were observed between RRMS patients in relapse and during remission. TACE protein levels were increased in PPMS patients treated with IFNbeta. Serum TNF-alpha levels were higher in RRMS patients in relapse compared with RRMS patients during remission, and positive and negative correlations were found between TACE protein expression and serum TNF-alpha levels in RRMS patients during relapse and during remission respectively. These findings point to different regulatory mechanisms of the TACE-TNF-alpha pathway in the clinical MS subtypes and expand the role of TACE in MS pathogenesis.

P-selectin glycoprotein ligand-1 variable number of tandem repeats (VNTR) polymorphism in patients with multiple sclerosis

P-selectin glycoprotein ligand-1 (PSGL-1) is an important adhesion molecule involved in lymphocyte recruitment into the brain, which represents a crucial step in the pathogenesis of multiple sclerosis (MS). Three hundred twenty-one MS patients and 342 controls were genotyped for the presence of a polymorphism in the PSGL-1 gene, consisting of a variable number of tandem repeats (VNTR) originating three possible alleles: A, B and C, in order to test whether they influence the susceptibility and the course of the disease. No significant differences among allelic frequencies of A, B and C alleles in MS as compared with controls were observed. Stratifying patients according to the course of the disease, a significantly increased frequency of the shortest C allele in PP-MS was found (7.1%), either in comparison with controls (P=0.011) or with all other MS patients, who had acute inflammatory attacks at onset and an initial RR form (P=0.036). Besides, none of SP-MS patients was a carrier of the C allele and B carriers converted later from RR to SP course as compared with A/A subjects (after 15.8 rather than 8.8 years, P=0.01). In conclusion, the C allele of the VNTR polymorphism in PSGL-1 is likely to be associated with PP-MS. As this allele has been demonstrated to have a very low efficiency in mediating lymphocyte binding to brain endothelium during attacks, its high frequency in PP-MS could be related to the absence of exacerbations in such patients.

Gene expression and genotyping studies implicate the interleukin 7 receptor in the pathogenesis of primary progressive multiple sclerosis

Multiple sclerosis (MS) is an enigmatic disease of the central nervous system resulting in sclerotic plaques with the pathological hallmarks of demyelination and axonal damage, which can be directly or indirectly orchestrated by cells from the peripheral circulation. The majority of patients with MS follow a relapsing-remitting course in the early stages of the disease (RRMS) but most ultimately enter a secondary progressive phase (SPMS). About 10% of patients follow a primary progressive course from the onset (PPMS). We measured gene expression in whole blood of people with and without chronic progressive MS (CPMS), PPMS and SPMS, to discover genes which may be differentially expressed in peripheral blood in active disease, and so identify pathologically significant genes and pathways; and we investigated genetic differences in the promoters of dysregulated genes encoded in genomic regions associated with MS. If SPMS and PPMS were independently compared to the controls, there was little overlap in the set of most dysregulated genes. Ribosomal protein genes, whose expression is usually associated with cell proliferation and activation, were dramatically over-represented in the set of most down-regulated genes in PPMS compared to SPMS (P < 10(-4), chi(2)). The T cell proliferation gene IL7R (CD127) was also underexpressed in PPMS, but was up-regulated in SPMS compared to the controls. One interleukin 7 receptor (IL7R) promoter single nucleotide polymorphism (SNP), -504 C, was undertransmitted in PPMS trios (P = 0.05, TDT), and carriers of this allele were under-represented in PPMS cases from two independent patient cohorts (combined P = 0.006, FE). The four known IL7R promoter haplotypes were shown to have similar expression levels in healthy controls, but not in CPMS (P < 0.01, t test). These data support the hypothesis that PPMS has significant pathogenetic differences from SPMS, and that IL7R may be a useful therapeutic target in PPMS.

Primary progressive multiple sclerosis

PURPOSE OF REVIEW

The present article reviews the currently ongoing scientific debate on the specific characteristics of primary progressive multiple sclerosis.

RECENT FINDINGS

The most important observations come from the studies using magnetic resonance imaging showing involvement of the normal-appearing brain tissue and also from the clinical and magnetic-resonance-imaging descriptions in longitudinal studies.

SUMMARY

Progress in the diagnosis of primary progressive multiple sclerosis has been made. Long- and short-term natural history are now better known, which will allow the designing of clinical trials in the near future. Magnetic-resonance-imaging studies have demonstrated damage of the normal-appearing brain tissue, which may explain in part the apparent clinical and radiological paradox, common to all clinical forms of multiple sclerosis but perhaps more evident in the primary progressive form. Preliminary results from exploratory trials seem to indicate that these patients should no longer be excluded from therapeutic trials.

Plasma osteopontin levels in multiple sclerosis

Osteopontin (OPN) is a pleiotropic integrin binding protein with functions in cell-mediated immunity, inflammation, tissue repair, and cell survival. Recent studies have shown that OPN may play an important role in the pathogenesis of experimental autoimmune encephalomyelitis and multiple sclerosis (MS). Here, we investigated the plasma levels of OPN in 221 MS patients and 36 healthy controls using an enzyme-linked immunoassay. The MS group comprised of 71 patients with primary and transitional progressive MS (PP/TP-MS), 35 patients with secondary progressive MS (SPMS), and 115 patients with relapsing-remitting MS (RRMS)[46 patients during clinical remission, 26 patients during relapse, and 43 patients treated with interferon-beta (IFNbeta)]. Levels of OPN in plasma were elevated in SPMS patients compared with healthy controls, RRMS patients in remission, and PP/TP-MS patients. Patients with RRMS during relapse presented higher OPN levels than patients with RRMS during clinical remission. When MS patients were classified based on progression of neurological disability, an inverse relation between levels of OPN and disability progression was observed only in patients with relapsing MS. In RRMS patients receiving therapy with IFNbeta, OPN plasma levels were similar to RRMS patients during remission. These findings suggest that OPN is involved in both acute and chronic disease activity, thus expanding the role of OPN in MS pathogenesis suggested by previous studies. Furthermore, the different profiles of OPN levels found in acute relapses and chronic progression and its apparent lack of influence in primary progressive MS phenotypes raise interesting questions on the actual role of OPN in the pathogenesis of MS.

Expression of adhesion molecules on peripheral lymphocytes predicts future lesion development in MS

The expression of adhesion molecules (alpha4beta1-integrin, LFA-1, ICAM-1) on T cells, measured by flow cytometry, was compared in different subtypes of multiple sclerosis (MS) and related to future lesion development as seen as delta T1 and T2 lesion load per year on magnetic resonance imaging (MRI). LFA-1 and alpha4beta1-integrin showed higher expression on CD4 and CD8 T lymphocytes in the secondary progressive compared to the relapsing-remitting (CD4: p<0.01, p=ns, p<0.05; CD8: p<0.001, p<0.001, p<0.001, respectively) and primary progressive MS phase (CD4: p<0.001, p<0.01, p<0.05; CD8: p<0.01, p<0.01, p<0.001, respectively). The adhesion molecule expression of alpha4- (r=0.31; p<0.05) and beta1-integrin (r=0.38; p<0.01) on CD4+ cells and of LFA-1beta on both CD4+ and CD8+ (r=0.28, p<0.05) and r=0.29; p<0.05, respectively) cells was significantly related to increase in T2 lesion load. Our study provides further evidence for the involvement of integrins in lesion development, shown as T2 lesions on MRI in MS.

The pathology of primary progressive multiple sclerosis

The pathological hallmark of chronic multiple sclerosis includes focal demyelination, gliosis, inflammation and axonal injury. There is limited information on whether these pathological features differ across the clinical phenotypes of the disease (relapsing-remitting, secondary progressive, and primary progressive). This review will focus on the pathological aspects of PPMS and pathogenic implications. A better understanding of the differences in PPMS pathology and pathogenesis will lead to more effective treatment strategies.

Immunologic factors in primary progressive multiple sclerosis

Primary progressive multiple sclerosis (PPMS) is clinically characterized by progression without remission or relapse, in contrast to relapsing forms of MS. Pathologic and imaging findings also indicate that PPMS differs from relapsing forms. Recent studies examining potential immunologic differences among MS forms suggest that cytokine and adhesion molecule expression profiles, but not chemokine receptor profiles, in PPMS patients resemble those in healthy controls more than those in patients with relapsing MS. However, the significance of these findings remains to be fully elucidated, and there is little additional evidence as yet of marked differences among MS forms based on immunologic characteristics. Of interest are the recent demonstrations that activated immune cells produce brain-derived neurotrophic factor (BDNF), a neuroprotective factor, in MS lesions, that BDNF receptors are located in MS tissue, and that glatiramer acetate (GA)-specific T cells produce BDNF irrespective of T helper cell Th1 or Th2 phenotype. These findings both support the concept of a protective inflammation in MS and suggest an additional mechanism of action for the clinical effects of GA therapy in MS. Whether and to what extent this mechanism is present in different MS forms remain to be clarified.

Interferon beta-1b modulates serum sVCAM-1 levels in primary progressive multiple sclerosis

Endothelial activation is a key feature of multiple sclerosis (MS) pathogenesis. It is modulated by interferon beta-1b (IFNB-1b) treatment in relapsing-remitting MS (RRMS) patients. This particular pharmacodynamic effect still has to be proven in primary progressive MS (PPMS). In the current study, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) and sE-selectin were analyzed longitudinally in 18 PPMS patients before, during and after 12 months of treatment with IFNB-1b. During drug therapy there was a significant early and sustained increase of sVCAM-1 (overall P < 0.0001). Flu-like symptoms induced by IFNB-1b and also concomitant infections were associated with higher sVCAM-1 levels. Neutralizing antibodies to IFNB-1b were associated with lower sVCAM-1 levels. In conclusion, IFNB-1b modulates the adhesion cascade in patients with PPMS in a similar way it does in RRMS. Nevertheless, a clinical effect of IFNB in PPMS still has to be proven in a randomized controlled clinical trial.

The pathogenesis of primary progressive multiple sclerosis: antibody-mediated attack and no repair?

Primary progressive multiple sclerosis (MS) differs from the more common form of MS which has an initial relapsing-remitting course in a number of ways, including pathological features, clinical course, differential diagnosis and response to treatment. The lesions in primary progressive MS tend to be more diffuse, less inflammatory and less likely to remyelinate than those occurring in relapsing-remitting MS and secondary progressive MS; there are also fewer focal lesions in the brain in primary progressive MS. Recent evidence suggests that antibodies to central nervous system (CNS) antigens have an important role in disease progression. Such antibodies could cause demyelination, inhibit remyelination and cause axonal destruction. Ongoing immune attack by autoantibody and lack of CNS repair could be responsible for the gradually increasing disability in primary progressive MS. Further research on the B-cell and autoantibody response in primary progressive MS might lead to advances in diagnosis and treatment. Inhibition of autoantibody production by inducing B-cell apoptosis with rituximab is a potential new therapy for primary progressive MS.

Recruitment of neutrophils across the blood-brain barrier: the role of posttraumatic hepatic ischemia

PURPOSE: To study the effects of total hepatic ischemia, and reperfusion on the accumulation of neutrophils in the brain of rats submitted to normovolemic conditions as well as to controlled hemorrhagic shock state. METHODS: Thirty two adult male Wistar rats, were divided into four groups: the Control group, was submitted to the standard procedures for a period of 60 min of observation; Shock group, was submitted to controlled hemorrhagic shock (mean arterial blood pressure=40mmHg, 20min) followed by volemic resuscitation (lactated Ringer's solution + blood, 3:1) and reperfusion for 60min; Pringle group, was submitted to total hepatic ischemia for 15min and reperfusion for 60min. The total group was submitted to controlled hemorrhagic shock for 20min followed by volemic resuscitation (lactated Ringer's solution + blood, 3:1), total hepatic ischemia for 15min and reperfusion for 60min. Measurements of serum lactate and base excess were used to characterize the hemorrhagic shock state with low tissue perfusion. The counting of neutrophils on the brain was performed after the euthanasia of animals. RESULTS: The values for the counting of neutrophils on the brain indicate that did not occur difference among studied groups (p=0.196) (Control 0.12± 0.11, Shock 0.12± 0.13, Pringle 0.02± 0.04, Total 0.14± 0.16). CONCLUSION: Hemorrhagic shock associated to total hepatic ischemia for 15 minutes, followed by 60 minutes of reperfusion, did not causes significant neutrophils accumulation in the brain of rats.

Approach to discriminate subgroups in multiple sclerosis with cerebrospinal fluid (CSF) basic inflammation indices and TNF-alpha, IL-1beta, IL-6, IL-8

Lumbar CSF and serum pairs of untreated multiple sclerosis patients (MS; n=47) were analyzed on admission. On average, higher CSF leukocyte (lymphocyte and monocyte) counts, IgG index, CSF IgG contents, but not of TNF-alpha, IL-1beta, IL-6, IL-8 in CSF and serum, were revealed in all MS or patients with long disease course (LO-MS) compared with controls. In primary progressive MS (PP-MS) cell counts were low, but IgG contents were high, when compared to relapsing-remitting MS (RR-MS). In clinically probable MS (CP-MS) both contents were low, in clinically definite MS (CD-MS) high. Spearman's correlation with the four monokines and the basic indices in CSF revealed activation patterns known for microglia/macrophages in the four MS subgroups, for astrocytes in CP-MS and RR-MS, for CSF lymphocytes in CP-MS and PP-MS, for cells of blood-brain barrier (BBB) in CP-MS, for intrathecal IgG synthesis in PP-MS and for lymphocyte transfer in CD-MS. Correlations between CSF and serum parameters indicated CNS disease processes to be associated with systemic processes of inflammation (acute, chronic) in CD-MS, RR-MS, and PP-MS in different ways. CSF IgG content, IgG index and systemic markers of inflammation correlated with overall disability scores in LO-MS; increasing levels may indicate a bad outcome.

Expression of beta2 adrenoreceptors on peripheral blood mononuclear cells in patients with primary and secondary progressive multiple sclerosis: a longitudinal six month study

BACKGROUND

Beta(2) adrenoreceptor expression on peripheral blood mononuclear cells is increased in progressive multiple sclerosis. This increase has been correlated with disease activity in relapsing-remitting multiple sclerosis.

OBJECTIVE

To determine the beta(2) adrenoreceptor expression in primary and secondary progressive multiple sclerosis in relation to findings on magnetic resonance imaging (MRI) and clinical disease activity.

METHODS

10 patients with multiple sclerosis were studied (five with primary progressive and five with secondary progressive forms of the disease) over a period of six months. Monthly clinical and MRI assessments of the brain and spinal cord were carried out. Beta(2) adrenoreceptor expression was assessed monthly using a ligand binding assay with [(125)I]iodocyanopindolol. Expression of beta(2) adrenoceptors on peripheral blood mononuclear cells was also assessed in five normal controls over a similar period.

RESULTS

The mean (SEM) value of beta(2) adrenoreceptor density for the five normal controls was 1346 (183) sites/cell, with affinity Kd of 120 (40) pM. MRI disease activity in primary progressive multiple sclerosis was reported on two occasions and on those occasions the expression of beta(2) adrenoreceptors was increased in excess of 1900 sites/cell; in the remaining 28 observations beta(2) adrenoreceptor expression was within the normal range (800 to 1900 sites/cell). In patients with secondary progressive disease, MRI disease activity was observed on 16 occasions. In these patients expression of beta(2) adrenoreceptors was increased in excess of 2000 sites/cell in all measurements except in one subject who did not show MRI activity throughout the six months period of study. The affinity of the receptors was within the normal range in all cases.

CONCLUSIONS

Increased expression of beta(2) adrenoreceptors was correlated with MRI disease activity in two patients with primary progressive multiple sclerosis. In secondary progressive multiple sclerosis, increased expression of beta(2) adrenoreceptors tended not to correlate with MRI disease activity. This may reflect a persistent Th1 immune reaction in the secondary progressive form of the disease.

Differential efficacy of a synthetic antagonist of VLA-4 during the course of chronic relapsing experimental autoimmune encephalomyelitis

The integrin VLA-4 has been shown to play a key role in the entry of antigen-specific T cells into the CNS during autoimmune demyelination. Treatment of animals with experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis, with antibodies to VLA-4 is known to suppress acute disease. In the present study, a synthetic antagonist of VLA-4 (TBC 3486) was injected subcutaneously into mice adoptively sensitized for chronic relapsing EAE. TBC 3486 was administered daily for 14 days at early (before acute signs) and late time points (during chronic disease). Early treatment led to marked delay in disease onset and reduction in clinical severity and demyelination. After termination of treatment, clinical severity remained lower than in controls for more than 1 week. TBC 3486-treated animals showing no clinical signs (at the height of disease in controls) displayed moderate levels of inflammation but little damage to myelin. Late administration of TBC 3486 to animals with chronic EAE had no effect clinically. Immunocytochemistry and Western blotting of CNS tissue from acutely treated animals supported a moderate shift toward a Th2-type cytokine profile after treatment. Thus, TBC 3486 effectively delayed and reduced the acute (but not chronic) phase of EAE, and this amelioration correlated with changes in the inflammatory molecule profile.

Issues and practices in multiple sclerosis

The objective of this roundtable discussion of experts in the field of multiple sclerosis (MS) was to summarize the current understanding of MS and its therapeutic options. The experts discussed subjects ranging from the etiology of MS to the current standards for patient care. Specific topics included the subtypes of MS, with a focus on the benign subtype, brain atrophy, the role of magnetic resonance imaging or "neuroimaging studies," disease-modifying therapies, biological markers as indicators of drug efficacy, and combination therapies. In addition, the experts speculated as to what will be available in the near future for the improved diagnosis and management of MS. This review summarizes the main points of this discussion and is intended to serve as a reference for neurologists involved in the care of patients with MS.

Expression of chemokine receptors in the different clinical forms of multiple sclerosis

Chemokines and their receptors are important in the trafficking of peripheral leukocytes into the central nervous system, a major event in the pathogenesis of multiple sderosis (MS). Evidence based on clinical, pathological and magnetic resonance imaging grounds supports some divergence between forms of MS with relapses [relapsing-remitting (RR) and secondary progressive (SP)] and the primary progressive (PP) form. To elucidate whether different pathogenic mechanisms are involved in PPMS, we compared membrane expression of a group of CC and CXC chemokine receptors (CCR1, CCR5, CXCR3, CXCR4) in peripheral blood of 68 MS patients (25 PPMS, 23 SPMS and 20 RRMS) and 26 healthy controls. We found a significant increase in surface expression of CCR5 in CD4+, CD8+, CD19+ and CD14+ cells as well as an increased percentage of CXCR3 and CXCR4 in CD14+ cells in MS patients compared to controls. Increased levels of CXCL10 (IP-10) and CCL5 (RANTES) in cerebrospinal fluid were also observed in a subgroup of MS patients. These results support that chemokines and their receptors are involved in the pathogenesis of MS However, a pattem of chemokine-chemokine receptor expression characteristic of each clinical form of the disease failed to be observed.

Differentiation of multiple sclerosis subtypes: implications for treatment

There has been tremendous progress in the immunomodulatory treatment of multiple sclerosis (MS) during recent years. With the introduction of interferon-beta, glatiramer acetate and mitoxantrone (recently registered for MS in the US), there are at least three therapeutic strategies that have proven effective in large phase III studies. However, not all patients with MS respond well to treatment with these drugs. This may largely be a consequence of disease heterogeneity. From a clinical perspective, patients with different disease courses show different treatment responses. Patients with relapsing-remitting MS are more likely to respond to immunomodulatory therapy than those with a progressive disease course. Studies of patients with secondary progressive MS have yielded inconsistent results and, so far, there has been no positive phase III study of immunomodulatory therapy in patients with primary progressive MS. Pathological evidence indicates that subtyping based on clinical findings alone does not reflect actual disease heterogeneity. In a large series of biopsy and autopsy specimens, at least four subtypes could be identified with respect to oligodendrocyte/myelin pathology and immunopathology. As long as the only method of identifying subtypes of disease is histopathology, differential therapy will remain a future goal. Thus, there is an urgent need for in vivo markers of immunopathogenesis in an individual patient that would allow treatment to be specifically directed towards a given pathological focus. However, at least from a theoretical point of view, some therapeutic approaches appear very attractive. Plasmapheresis and/or intravenous immunoglobulins could most plausibly be the best approach for the immunopathological subtype of MS, which is characterised by antibody and complement deposition next to demyelinated axons, in order to remove antibodies. The subtype of MS that is associated with heavy macrophage activation, T cell infiltration and expression of inflammatory mediator molecules, including tumour necrosis factor-alpha, may be most likely to respond to immunomodulation with interferon-beta or glatiramer acetate. There are other subtypes of MS in which viral infection or oligodendrocyte degeneration, rather than autoimmunity, appear to play a role. It is possible that these could benefit from antiviral therapy, oligodendrocyte protection or oligodendrocyte transplantation, although therapies based on these latter approaches have yet to be developed.

Primary progressive multiple sclerosis: increasing clarity but many unanswered questions

Heterogeneity in the clinical course of multiple sclerosis (MS) is well recognised and patients following a primary progressive course, 10-15% of the MS population, have a distinct clinical and paraclinical phenotype. This review examines recent advances in our understanding of this subgroup of patients and examines the new criteria to be applied in diagnosis. It also highlights developments in genetic, immunological, magnetic resonance and pathological aspects of the disease, whilst also outlining the results of recent therapeutic trials.

Metabolic differences between multiple sclerosis subtypes measured by quantitative MR spectroscopy

We used quantitative magnetic resonance (MR) spectroscopic imaging with T1-based image segmentation to evaluate the subtypes of multiple sclerosis (MS) (eight patients each group of relapsing-remitting [RR], secondary progressive [SP] and primary progressive [PP]). There was no significant difference in age between the PP group with the RP, SP or control group. We found that the metabolite ratio of choline/NA from the periventricular white matter region was not significantly different between the RR and SP groups. Using an ANOVA, the ratios of periventricular choline/NA or creatine/NA of these combined groups were significantly higher than the PP and control groups. Quantification of these data suggest that the major cause of the elevation of these parameters is due to an increase in choline and creatine in the RR group while NA is decreased in the SP group. Thus, early PP disease appears to be relatively intact with respect to neuronal loss.

The pathology of primary progressive multiple sclerosis

The present review will focus on the current knowledge of the pathology of primary progressive multiple sclerosis lesions. Multiple sclerosis (MS) is an inflammatory demyelinating disease with a broad clinical variability. The main disease courses are relapsing-remitting, secondary progressive and primary progressive MS. Pathological studies examining the specific underlying pathology of a defined clinical subtype are rare. Here, we focus on the pathological characteristics of the MS lesions and summarize the current findings of the pathology of primary progressive MS with respect to inflammation, oligodendrocyte myelin pathology, axon destruction and immunopathology of the lesions.

Two-year follow-up study of primary and transitional progressive multiple sclerosis

This study documents changes in clinical and magnetic resonance imaging (MRI) characteristics in a large cohort of patients with primary and transitional progressive multiple sclerosis (PP and TPMS) over 2 years. Patients with PPMS and TPMS were recruited from six European centres and underwent clinical and MRI examination at three time points: baseline, year one and year two. Of the 190 patients recruited clinical data were available on 125 patients (66%, five centres) and MRI data were available on 113 patients (59%, four centres) at 2 years. Significant increases were seen in T2 load and T1 hypointensity, while brain and cord volume decreased. In PPMS significantly higher lesion loads were found in those who presented with non-cord syndromes when compared to cord presentation and there was a trend to greater brain atrophy in those who deteriorated clinically over the course of the study compared to those who remained stable. Significant cord atrophy was only seen in those with a cord presentation. Measurable changes in MRI parameters can be detected in PPMS patients over a relatively short period of time. MRI quantification is likely to be useful in elucidating disease mechanisms in PPMS and in the execution of clinical trials.

Intracellular cytokine profile in T-cell subsets of multiple sclerosis patients: different features in primary progressive disease

OBJECTIVE

To evaluate the expression of cytokines in both CD4+ and CD8+ T cells derived from peripheral blood of untreated multiple sclerosis (MS) patients with either relapsing-remitting (RR), secondary progressive (SP) or primary progressive (PP) MS and healthy controls (HC).

BACKGROUND

MS is an immune-mediated disease and cytokines hove been hypothesized to contribute significantly to disease progression. Compared to the relapse-onset (RR, SP) form of the disease, PPMS patients have different clinical, immunological and pathological features. Surprisingly, the ability of their circulating T cells to produce immunoregulatory cytokines has not been extensively studied so far.

METHODS

Seventy-two MS patients (24 RR, 26 SP, 22 PP) and 34 HC were studied. Stimulated peripheral blood derived CD4+ and CD8+ T MS patients express significantly more CD4+ and CD8+ T cells were analyzed for IFN-gamma, IL-2, TNF-alpha, IL-4, IL-10 and IL-13 production.

RESULTS

cells producing IFN-gamma compared to HC. Compared to the other forms of the disease, PPMS patients display a significant decrease in CD4+ T cells producing IL-2, IL-13 and TNF-alpha and a significant increase in CD8+ T cells producing IL-4 and IL-10.

CONCLUSIONS

The data presented here demonstrate that patients with PPMS express less pro- and more anti-inflammatory cytokine producing T cells compared to the relapse-onset form of the disease, confirming the view on PPMS as a distinct disease entity.

Similar pro- and anti-inflammatory cytokine production in the different clinical forms of multiple sclerosis

Cytokines play an important role in the initiation and maintenance of the inflammatory reaction in multiple sclerosis, a chronic inflammatory demyelinating disease of the central nervous system. Magnetic resonance imaging evidence supports clinical divergence between forms of multiple sclerosis with relapses and the primary progressive form without relapses, which shows fewer and smaller inflammatory lesions. With the aim of understanding better the relative role of pro-inflammatory and/or anti-inflammatory cytokines in primary progressive multiple sclerosis in comparison to relapsing forms, we analysed in 65 patients (24 primary progressive, 20 relapsing-remitting and 21 secondary progressive) and 29 healthy controls, the production of cytokines (IFN-gamma, TNF-alpha, IL-6, IL-10 and IL-12) by peripheral blood mononuclear cells after in vitro stimulation. We found a similar percentage of cytokines producing cells between healthy controls and the different clinical forms of multiple sclerosis patients.

Apoptosis in neurones exposed to cerebrospinal fluid from patients with multiple sclerosis or acute polyradiculoneuropathy

Primary cultures of murine cerebellar granule neurones were exposed to cerebrospinal fluid from patients with subtypes of multiple sclerosis or acute polyradiculoneuropathy (Guillain-Barré syndrome) for 2 days. Cells were then stained with Hoechst 33342 or terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) to detect apoptotic bodies. The results were compared with control cultures exposed to cerebrospinal fluid from patients with no known neurological disease or deficit. There was no significant difference in the level of apoptosis induced between these controls and cultures not exposed to cerebrospinal fluid at all. Cultures exposed to cerebrospinal fluid samples from patients with relapsing-remitting multiple sclerosis did not have higher levels of apoptosis than cells exposed to controls, regardless of whether the sample was taken during relapse or remission. However, a significant increase in apoptosis was observed in cultures exposed to cerebrospinal fluid from patients with primary progressive multiple sclerosis, and apoptosis correlated with disease severity. This supports the existence of biochemical differences between subgroups of multiple sclerosis. A significant increase in apoptosis was also induced by cerebrospinal fluid samples from patients with acute polyradiculoneuropathy, suggesting the presence of neurotoxic factor(s) here also. The relevance to disease pathology is unclear.

Multiple sclerosis: current pathophysiological concepts

Multiple sclerosis (MS) is an often disabling disease primarily affecting young adults that exhibits extraordinary clinical, radiological, and pathological heterogeneity. We review the following: (a) known environmental and genetic factors that contribute to MS susceptibility; (b) current knowledge regarding fundamental pathophysiological processes in MS, including immune cell recruitment and entry into the central nervous system (CNS), formation of the plaque, and orchestration of the immune response; (c) descriptive and qualitative distinct pathological patterns in MS and their implications; (d) the evidence supporting the causative role of direct toxins, cell-mediated and humorally mediated immune mechanisms, and the concept of a "primary oligodendrogliopathy" in demyelination and axonal injury; (e) the potential benefits of inflammation; (f) the prospects for remyelination; and (g) therapeutic implications and approaches suggested by putative pathophysiological mechanisms.