MS Abstracts 04b-2g6

Objective
Our objective was to test whether Natalizumab, an AntibBody against very Late Activating Antigen-4 (VLA-4), interferes with Central Nervous System Immune surveillance as assessed by Leukocyte cell numbers and cellular phenotypes in CerebroSpinal Fluid (CSF) and peripheral blood.

Methods
Cell numbers and cellular phenotypes in CSF and peripheral blood were analyzed in Multiple Sclerosis (MS) patients treated with Natalizumab, untreated MS patients, and patients with Other Neurological Disease (OND).

JC virus DNA in the CSF and peripheral blood was quantified by kinetic polymerase chain reaction.

Results
CSF Leukocyte counts, CD4⁺ and CD8⁺ T-Cells, CD19⁺ B-Cells, and CD138⁺ plasma cells were significantly lower in Natalizumab-treated MS patients compared with OND patients and untreated MS patients.

JC virus DNA was not detected in CSF or peripheral blood from Natalizumab-treated patients. Six months after cessation of Natalizumab therapy, low Lymphocyte counts in the CSF persisted.

The patient with the highest total Leukocyte and CD4⁺ and CD8⁺T-Cell counts in the CSF experienced a clinical relapse.

Interpretation
These data suggest that Natalizumab treatment results in a prolonged decrease of Lymphocytes in the CSF and are consistent with the hypothesis that Natalizumab impairs Immune surveillance of the Central Nervous System.

Resonance intensities of N-AcetylAspartate (NAA) relative to Creatine (Cr) were measured in a large central Brain Volume.

NAA/Cr in NAWM was estimated by regression of the NAA/Cr in each voxel against White Matter Fraction and extrapolation to a White Matter Fraction of 1.

The fractional size of the Semi-Solid Pool (F) was obtained from the binary spin bath model of MT by computing the model parameters from multiple MT-weighted and relaxometry acquisitions.

F in NAWM was significantly smaller in the patients [0.109 (0.009)] relative to controls [0.123 (0.007), P = 0.011], but did not differ between RR [0.1085] and SP [0.1087] patients [P > 0.99].

NAA/Cr and F in the NAWM were not correlated (r = 0.16, P > 0.7), mainly due to a lack of variation in F among patients.

This may indicate a floor to the extent of Myelin pathology that can occur in NAWM before a lesion appears.

Or, that Axonal damage is not strictly related to DeMyelination. The correlation between NAWM NAA/Cr and T₂w lesion volume was not significant (P > 0.1).

However, dividing the lesion volumes by the mean F in T₂w lesions resulted in a quantity that correlated well with NAWM NAA/Cr (r = -0.78, P = 0.038).

Possibly reflecting the association of Wallerian Degeneration in the NAWM with Axonal transection associated with DeMyelination within lesions.

Background
Histopathologic studies have shown that SubPial Cortical DeMyelination is extensive in chronic Multiple Sclerosis (MS).

Objective
To study whether SubPial Cortical DeMyelination in MS is associated with focal or diffuse White Matter (WM) pathologic features on Magnetic Resonance Imaging (MR imaging).

Design
Comparison of postmortem MR imaging findings with HistoPathologic findings.

Design & Setting
Brain donations from a general community.

Patients
Three patients with MS with extensive Cortical DeMyelination and 3 patients with minor Cortical DeMyelination were selected from an MS autopsy data set. The postmortem MR imaging and HistoPathologic data of the patients were compared.

Main Outcome Measures
Two observers blinded to the results of each other assessed the presence, extent, and distribution of focal and diffuse pathologic changes in WM by MR imaging and by HistoPathology.

Results
Extensive SubPial DeMyelination was not associated with a significant increase in the area of focal and diffuse WM pathologic changes as assessed by Luxol fast blue HistoChemistry or by MR imaging or with the presence or extent of JuxtaCortical abnormalities on MR imaging.

Conclusions
The lack of association of MS Gray Matter DeMyelination with diffuse or focal WM changes indicates that Gray Matter DeMyelination in MS occurs largely independent of WM pathologic changes.

The extent or distribution of WM abnormalities cannot be used to identify extensive Cortical DeMyelination in the clinical setting.

The pathogenesis of Multiple Sclerosis involves a breakdown in T-Cell tolerance to Myelin proteins like Myelin Basic Protein (MBP).

Most MBP-specific T-Cells are eliminated by Central tolerance in adult mice, however, the developmentally regulated expression of MBP allows MBP-specific Thymocytes in young mice to escape negative selection.

It is not known how these T-Cells that encounter MBP for the first time in the periphery are regulated.

We show that naive MBP-specific T-Cells transferred into T-Cell-deficient mice induce severe AutoImmunity.

Regulatory T-Cells prevent disease, however, suppression of the newly transferred MBP-specific T-Cells is abrogated by activating APCs in vivo.

Without APC activation, MBP-specific T-Cells persist in the periphery of protected mice but do not become anergic, raising the question of how long-term Tolerance can be maintained if APCs presenting endogenous MBP become activated.

Our results demonstrate that regulatory T-Cells induce naive MBP-specific T-Cells responding to nonactivated APCs to differentiate into a unique, tolerized state.

With the ability to produce IL-10 and TGF-beta1 in response to activated, but not nonactivated, APCs presenting MBP.

This Tolerant response depends on continuous activity of regulatory T-Cells because, in their absence, these uniquely Tolerized MBP-specific T-Cells can again induce AutoImmunity.

Objective
To compare the clinical disease progression in European (E) and North African (NA) patients with Multiple Sclerosis (MS) patients in France.

Methods
We compared the clinical features of MS in 211 NA patients and 2,945 E patients in a French population-based cohort with definite MS according to McDonald's Criteria.

Results
Among the NA patients with MS, 66.4% were women vs 72.9% of the E patients (p = 0.04), 15.6% had a Primary/Progressive form of MS vs 11.7% of the E patients (p = 0.08), and the mean age at onset was 29.9 +/- 9.8 years in the NA patients vs 32.9 +/- 10.6 years in the E patients (p < 0.0001).

In the NA patients, there was a higher proportion of patients with incomplete recovery from the first relapse (p < 0.0001), a shorter time between the first two relapses (p = 0.02), a higher number of relapses in the first 5 years (p = 0.03), and a shorter time to reach an Expanded Disability Status Scale score of 4.0 (p = 0.001) or 6.0 (p < 0.0001).

The only statistical difference in these factors between NA patients born in France and those born in North Africa was the mean age at onset of symptoms: it was earlier in NA patients born in France (p < 0.0001).

Conclusions
The course of Multiple Sclerosis is more aggressive in North African than in European patients.

Objective
To describe the characteristics of Late-Onset Multiple Sclerosis (MS) (LOMS, 50+ years) vs Adult-Onset MS (AOMS, 16 to < 50 years) and examine prognosis and associated risk factors.

Methods
Patients with definite MS, onset prior to July 1988, registered with a BCMS clinic before July 1998, with at least one Expanded Disability Status Scale (EDSS) score, were selected from the longitudinal population-based British Columbian (BC) MS database.

Clinical and demographic characteristics were compared between LO and AOMS. Progression was measured as time to reach sustained EDSS 6 and potential risk factors examined were sex, disease course (Primary/Progressive [PP] vs Relapsing [R]), and onset symptoms.

Results
Of those eligible (n = 2,837), LOMS comprized 132 (4.7%), with PPMS predominating (54.5% vs 10.6% in AOMS, p < 0.0005). Motor onset symptoms were more prevalent in LOMS and Sensory and Optic Neuropathy more prevalent in AOMS (p < 0.0005).

AOMS averaged 27.7 years (95% CI: 26.3 to 29.1) to EDSS 6 from onset vs 16.9 years (95% CI: 9.0 to 24.8) in LOMS, p < 0.0005. However, AOMS was associated with a younger age at EDSS 6 (58.4 years [95% CI: 57.1 to 59.6] vs 71.2 years [95% CI: 65.2 to 77.3] in LOMS, p < 0.0005).

There were no differences in progression between AO or LO for those with PPMS (p = 0.373) or R-MS (p = 0.438), although considerable variation was observed.

Conclusions
Late-Onset Multiple Sclerosis (LOMS) is not necessarily associated with a worse outcome:

First, progression in the Primary/Progressive or Relapsing patients differed little between Late-Onset vs Adult-Onset.

Secondly, those with LOMS were older when reaching Expanded Disability Status Scale 6.

The disease course has a far greater implication for disease prognosis than the presence of LOMS.

Background And Purpose
To prospectively determine the sensitivity in the detection of Multiple Sclerosis (MS) lesions by using Double Inversion Recovery (DIR), Fluid-Attenuated Inversion Recovery (FLAIR), and T₂-weighted Turbo Spin-Echo (T₂ TSE) MR imaging at 3T.

Methods
Seventeen patients presenting with a Clinically Isolated Syndrome (CIS) suggestive of MS, 9 patients with definite MS, and 6 healthy control subjects were included. Imaging was performed on a 3T MR system using DIR, FLAIR, and T₂ TSE sequences.

Lesions were counted and classified according to 5 anatomic regions: InfraTentorial, PeriVentricular, deep White Matter, JuxtaCortical, and mixed White Matter-Gray Matter.

The sensitivity at DIR was compared with the corresponding sensitivity at FLAIR and T₂ TSE sequence. The contrast between lesions and Normal-Appearing Gray Matter, Normal-Appearing White Matter, and CSF was determined for all sequences.

Results
Because of higher lesion-White Matter contrast, the DIR showed a higher number of lesions compared with the FLAIR (7% gain, P = 0.04) and the T₂ TSE (15% gain, P = 0.01).

The higher sensitivity was also significant for the InfraTentorial region compared with the FLAIR (56% gain, P = 0.02) and the T₂ TSE (44% gain, P = 0.02).

Compared with the FLAIR, no significant changes of the lesion load measurements were observed in the SupraTentorial Brain.

Slightly higher numbers of PeriVentricular and mixed Gray Matter-White Matter lesions on the DIR were counterbalanced by a slightly reduced sensitivity regarding JuxtaCortical lesions.

Conclusion
DIR Brain imaging at 3T provides the highest sensitivity in the detection of MS lesions especially in the InfraTentorial region.

Purpose
To determine observer performance in the detection of Multiple Sclerosis (MS) lesions on Magnetic Resonance (MR) images of the Brain.

And to assess the dependence of observer performance on lesion size, Parenchymal location, pulse sequence, and SupraTentorial versus InfraTentorial level.

Materials And Methods
This HIPAA-compliant protocol was approved by the institutional review board, and previously acquired MR data from a healthy volunteer and a patient with MS were used to derive parameter maps, with waiver of informed consent.

Parameter maps and image simulator software were used to generate 320 phantom brain images with simulated SupraTentorial and InfraTentorial MS lesions.

Images were displayed with T₂-weighting or Fluid-Attenuated Inversion Recovery (FLAIR) contrast.

Four readers independently evaluated the images, rating lesions on a five-point certainty scale.

Observer performance was measured by using the area under the alternative free-response receiver operating characteristic curve (A(1)), and significance was determined with the z test.

Results
Pooled A(1) scores were significantly better for FLAIR imaging (0.96 +/- 0.01 [standard error]) than for T₂-weighted MR imaging (0.89 +/- 0.04) SupraTentorially (P = .05).

But were similar for FLAIR imaging (0.90 +/- 0.06) and T₂-weighted MR imaging (0.88 +/- 0.05) InfraTentorially.

A(1) scores for Cortical, deep White Matter, and PeriVentricular lesions were 0.93 +/- 0.05, 0.97 +/- 0.02, and 0.89 +/- 0.04, respectively, for FLAIR imaging and 0.77 +/- 0.06, 0.99 +/- 0.01, and 0.89 +/- 0.05, respectively, for T₂-weighted MR imaging.

FLAIR scores were significantly higher than T₂-weighted scores for Cortical lesions. Linear correlation was found between A(1) and lesion size (r = 0.5).

Conclusion
SupraTentorially, performance was better with FLAIR imaging than with T₂-weighted MR imaging.

InfraTentorially, performance was moderate with both modalities. Observers did better with FLAIR imaging in the detection of Cortical lesions, and performance improved with increasing lesion size.

(c) RSNA, 2006.

Purpose
To investigate Normal-Appearing White (NAWM) and Cortical Gray (NAGM) Matter separately in Multiple Sclerosis (MS) in vivo using Diffusion Tensor Imaging (DTI).

Materials And Methods
In 64 MS patients (12 Primary/Progressive [PP], 38 Relapsing/Remitting [RR], 14 Secondary/Progressive [SP]) and 20 healthy controls, Whole-Brain Apparent Diffusion Coefficient (ADC) and Fractional Anisotropy (FA) maps were acquired.

A Stimulated Echo Acquisition Mode (STEAM) DTI sequence was used with minimal geometrical distortion in comparison to Echo-Planar Imaging (EPI).

NAWM and NAGM were identified using conventional Magnetic Resonance (MR) images, allowing a cautious assessment of FA in Cortex.

Results
Histogram analyses showed significant global FA decreases and ADC increases in MS NAWM compared to control WM. MS Cortical NAGM had no significant global ADC increase, but FA was decreased significantly.

In regional analyses, nearly all NAWM Regions-Of-Interest (ROIs) had significantly increased ADC compared to controls, but FA was not changed.

In nearly all Cortical NAGM ROIs, ADC was significantly increased and FA significantly reduced.

In multiple linear regression analyses in RR/SPMS patients, NAGM-ADC Histogram peak height was associated more strongly with clinical disability than T₂ lesion load.

Conclusion
Tissue damage occurs in both NAWM and Cortical NAGM. The Cortical damage appears to have more clinical impact than T₂ lesions.

Copyright 2006 Wiley-Liss, Inc.

IL-12 has long been considered important in the pathogenesis of Multiple Sclerosis, however, evidence from recent studies strongly supports the critical role of IL-12-related Proinflammatory Cytokine IL-23.

But not IL-12, in the development of Experimental Autoimmune Encephalomyelitis (EAE), an animal model of this disease.

The role of IL-23 in the CNS immunity of Multiple Sclerosis patients has not been elucidated; nor is it known whether human Microglia produce this Cytokine.

In this study we investigated the expression of IL-23p19 and p40, with its key subunit p19 as the focus, in histologically characterized CNS specimens from Multiple Sclerosis and control cases using in situ hybridization and ImmunoHistoChemistry.

A significant increase in mRNA expression and protein production of both subunits of IL-23 was found in lesion tissues compared with non-lesion tissues.

Double staining showed that activated Macrophages/Microglia were an important source of IL-23p19 in active and chronic active Multiple Sclerosis lesions.

We also detected IL-23p19 expression in mature Dendritic Cells which were preferentially located in the PeriVascular cuff of active lesions.

The finding that human Microglia produce IL-23 was further confirmed by the inducible production of IL-23p19 and p40 in cultured human Microglia in vitro upon different Toll-like receptor stimulations.

Taken together, these findings on the expression of IL-23p19 in Multiple Sclerosis lesions may lead to a better understanding of the events culminating in human Multiple Sclerosis.

Objective
To assess whether parasite infection is correlated with a reduced number of exacerbations and altered Immune reactivity in Multiple Sclerosis (MS).

Methods
A prospective, double-cohort study was performed to assess the clinical course and radiological findings in 12 MS patients presenting associated Eosinophilia.

All patients presented parasitic infections with positive stool specimens. In all parasite-infected MS patients, the Eosinophilia was not present during the 2 previous years.

Eosinophil counts were monitored at 3- to 6-month intervals. When counts became elevated, patients were enrolled in the study.

InterLeukin (IL) IL-4, IL-10 IL-12, Transforming Growth Factor (TGF)-beta, and Interferon-γ production by Myelin Basic Protein-specific Peripheral Blood Mononuclear Cells were studied using Enzyme-Linked Immunospot (ELISPOT).

FoxP3 and Smad7 expression were studied by reverse-transcriptase polymerase chain reaction.

Results
During a 4.6-year follow-up period, parasite-infected MS patients showed a significantly lower number of exacerbations, minimal variation in disability scores, as well as fewer Magnetic Resonance Imaging changes when compared with uninfected MS patients.

Furthermore, Myelin Basic Protein-specific responses in peripheral blood showed a significant increase in IL-10 and TGF-ß and a decrease in IL-12 and Interferon-γ-secreting cells in infected MS patients compared with noninfected patients.

Myelin Basic Protein-specific T-Cells cloned from infected subjects were characterized by the absence of IL-2 and IL-4 production, but high IL-10 and/or TGF-beta secretion, showing a Cytokine profile similar to the T-Cell subsets Tr1 and Th3.

Moreover, cloning frequency of CD4⁺CD25⁺ FoxP3⁺ T-Cells was substantially increased in infected patients compared with uninfected MS subjects.

Finally, Smad7 messenger RNA was not detected in T-Cells from infected MS patients secreting TGF-beta.

Interpretation
Increased production of IL-10 and TGF-ß, together with induction of CD25⁺CD4⁺ FoxP3⁺ T-Cells, suggests that regulatory T-Cells induced during parasite infections can alter the course of MS.

Ann Neurol 2007.

Copolymer-1 (Cop-1) has unique Immune regulatory properties and is a treatment option for Multiple Sclerosis (MS).

This study revealed that COP-I induced the conversion of peripheral CD4⁺CD25- to CD4⁺CD25⁺ regulatory T-Cells through the activation of transcription factor Foxp3.

COP-I treatment led to a significant increase in Foxp3 expression in CD4⁺ T-Cells in MS patients whose Foxp3 expression was reduced at baseline.

CD4⁺CD25⁺ T-Cell lines generated by COP-I expressed high levels of Foxp3 that correlated with an increased regulatory potential.

Furthermore, we demonstrated that the induction of Foxp3 in CD4⁺ T-Cells by Cop-1 was mediated through its ability to produce IFN-γ and, to a lesser degree, TGF-ß1, as shown by antibody blocking and direct Cytokine induction of Foxp3 expression in T-Cells.

It was evident that in vitro treatment and administration with Cop-1 significantly raised the level of Foxp3 expression in CD4⁺ T-Cells and promoted conversion of CD4⁺CD25⁺ regulatory T-Cells in wild-type B6 mice but not in IFN-γ knockout mice.

This study provides evidence for the role and mechanism of action of Cop-1 in the induction of CD4⁺CD25⁺ regulatory T-Cells in general and its relevance to the treatment of MS.