MS Abstracts 02b-2g5

The symptoms, severity, and course of Multiple Sclerosis (MS) vary among patients, leading to complex treatment issues.

In recent years, research has focused on specific Adhesion Molecules that participate in the activation and function of Lymphocytes, especially the migration of these cells to sites of inflammation.

In particular, the Integrin, Very Late Activation Antigen-4 (VLA-4), has been implicated in mediating adhesion and migration of Immune Cells through interaction with its Ligand, Vascular Cell Adhesion Molecule-1 (VCAM-1).

VLA-4 is comprised of alpha4/beta1 and is critical in mediating Th-1 Cell migration in the animal model of MS, Experimental Autoimmune Encephalomyelitis, and has been the target of several recent clinical trials in MS.

The humanized MonoClonal AntiBody to alpha4 Integrin, Natalizumab (Tysabri, Biogen Idec/Elan), was recently approved in the United States for the treatment of Relapsing MS.

The authors discuss the mechanisms by which alpha4 Integrins alter Lymphocyte function as a rationale for Anti-alpha4 Integrin use in MS.

Background And Purpose
Increases in Apparent Diffusion Coefficient (ADC) from Diffusion-Weighted (DW) imaging are thought to be due to Axonal disruption, and changes have been well documented in Multiple Sclerosis lesions.

DW imaging of the Optic Nerves, however, presents many challenges. The goal of this study was to measure ADC in patients with Optic Neuritis by using Zonal Oblique MultiSection EchoPlanar Imaging.

Methods
The Optic Nerves of eighteen patients who had experienced an attack of Optic Neuritis 1 year previously and 11 control subjects were imaged with the Diffusion sequence.

Usable data were available from 16 patients and 10 control subjects.

The orbital Optic Nerves were segmented by a blinded observer by using a computer-assisted threshold-based contouring technique, and the mean ADC was determined.

Results
The mean ADC from diseased Optic Nerves was 1324 x 10(-6) mm2/s, compared with 990 x 10(-6) mm2/s from healthy ContraLateral Optic Nerves (P = .005 versus diseased Optic Nerves).

And 928 x 10(-6) mm2/s from control Optic Nerves (P = .006 versus diseased Optic Nerves and P = .40 versus healthy ContraLateral Optic Nerves).

The diseased Optic Nerve ADC correlated with both visual (e.g., r(S) = 0.73; P = .001 for logMAR Visual Acuity) and ElectroPhysiological parameters (e.g., r(S) = -0.57, P = .021 for Visual Evoked Potential Central field amplitude [VEP]).

Conclusion
It has been possible to apply DW imaging in a patient population, and, in the chronic phase following Optic Neuritis.

The correlation of mean ADC with the clinical and ElectroPhysiological parameters suggests that the ADC is giving a surrogate measure of Axonal disruption in the chronic, Postinflammatory Optic Nerve lesion.

The aim of this study was to use NeuroPsychological data to characterize two subtypes of Multiple Sclerosis (MS) patients in a large patient sample. We studied patients with Primary/Progressive MS (PPMS) and Secondary/Progressive MS (SPMS).

A group of 121 MS patients (36 PPS, 85 SPMS) and 40 healthy controls were administered a brief battery of Cognitive tests. Executive functioning, Memory and Attention were studied.

Results demonstrate that PPMS patients exhibited slightly more impairment than patients with SPMS, although this difference is not significant (50% vs 37%).

However, PPMS patients revealed a significantly poorer performance in Verbal Learning (p < 0.05) and in Verbal Fluency (p < 0.05).

Whereas PPMS patients had significantly shorter disease durations (p < 0.05), there was no statistical difference in disability between both groups. We conclude from our study that Cognitive deficits in Progressive MS are frequent.

Patients with PPMS tend to be more frequently and severely affected than SPMS patients. Our findings of high prevalence of Cognitive involvement in PPMS have not been reported previously.

Working Memory deficits are common in Multiple Sclerosis (MS) and have been identified behaviourally in numerous studies.

Despite recent advance in functional Magnetic Resonance Imaging (fMRI), few published studies have examined cerebral activations associated with Working Memory Dysfunction in MS.

The present study examines Brain activation patterns during performance of a Working Memory Task in individual with clinically definite MS, compared to healthy controls (HC).

fMRI was performed using a 1.5 Tesla GE scanner during a modified Paced Auditory Serial Addition Test (mPA-SAT).

Participants were 6 individuals with MS with Working Memory Impairment as evidenced on NeuroPsychological Testing, 5 individuals with MS without Working Memory Impairment, and 5 HC. Groups were demographically equivalent.

Data were analyzed using Statistical Parametric Mapping (SPM99) software, with a stringent significance level (alpha < .005, Voxel extent > or =8).

Both MS groups and the HC group were able to perform the task, with comparable performance in terms of numbers of correct responses.

Activation patterns within the HC and MS not-impaired groups were noted in similar Brain regions, consistent with published observations in healthy samples.

That is, activations were lateralized to the Left Hemisphere, involving predominantly Frontal regions.

In contrast, the MS impaired group showed greater Right Frontal and Right Parietal Lobe activation, when compared with the HC group.

Thus, it appears that Working Memory Dysfunction in MS is associated with altered patterns of Cerebral activation that are related to the presence of Cognitive Impairement, and not solely a function of MS.

Natalizumab is a humanized, MonoClonal AntiBody, that inhibits Adhesion Molecules (alpha(4)-Integrins) on the surface of Immune Cells.

These Adhesion Molecules are important for binding of Lymphocytes to Endothelial Cells of blood vessels and infiltration of inflammatory cells into tissues.

Natalizumab is currently being tested in large clinical trials for the treatment of Multiple Sclerosis (MS) and other Autoimmune Diseases (Inflammatory Bowel Diseases, Rheumatoid Arthritis).

After demonstrating the safety and potential effectiveness of Natalizumab in MS therapy during shorter treatment periods (< /=6 months) in clinical Phase I and II studies:

Two ongoing large, double-blinded, placebo-controlled Phase III trials (named AFFIRM and SENTINEL) are evaluating its efficacy for patients with Relapsing/Remitting MS in respect to primary clinical endpoints (relapse rate, disease progression).

Based a 1-year interim analysis of these studies, Natalizumab was recently authorized by the US Food and Drug Administration for treatment in reducing the frequency of clinical surges in Multiple Sclerosis, and an application was also made for its use in Europe.

After more than 2 years of combined Natalizumab (Tysabri) and Interferon-beta-1a (Avonex) therapy in the so-called Sentinel Study, there was one unexpected death and one appearance of Progressive Multifocal Leukoencephalopathy.

As a result, in February 2005 the manufacturers (Biogen/Elan) stopped all running studies of Natalizumab and removed the drug from the market.

New studies are underway to gain more understanding and especially to determine the risk to patients treated in the Sentinel Study.

This article summarizes and updates the results of previous and ongoing Natalizumab trials in the context of MS.

Background
Conflicting data have been reported on the association between IFN-ß therapy of Multiple Sclerosis (MS) patients and Thyroid Disease development.

Aims

1. To assess the actual occurrence of Thyroid dysfunction and Autoimmunity during long-term IFN-ß therapy
2. To establish the possible presence of predictive factors for Thyroid dysfunction development and duration
3. To suggest an effective follow-up protocol for patients receiving long-term IFN-ß therapy

Study protocol 106 MS patients (76 women) underwent IFN-ß 1a or 1b therapy for up to 84 months (median 42).

Thyroid function and AutoImmunity were assessed at baseline and every 3-6 months throughout the treatment course.

Results
Baseline Thyroid AutoImmunity was detected in 8.5% of patients and HypoThyroidism in 2.8%.

Thyroid Dysfunction (80% HypoThyroidism, 92% subclinical, 56% transient) developed in 24% (68% with AutoImmunity) of patients and AutoImmunity in 22.7% (45.5% with dysfunction), without significant differences between the two Cytokines; 68% of dysfunctions occurred within the first year.

AutoImmunity emerged as the only predictive factor for dysfunction development (RR 8.9), while sustained disease was significantly associated with male gender (P < 0.003).

Conclusions
Both incident Thyroid AutoImmunity and dysfunction frequently occur in MS patients during IFN-ß therapy, particularly within the first year of treatment.

Thyroid dysfunction is generally subclinical and transient in over than half of cases; preexisting or incident AutoImmunity emerged as the only significant predictive factor for Thyroid dysfunction development.

Thyroid function and AutoImmunity assessment is mandatory within the first year of IFN-ß therapy thereafter, serum TSH measurement only in patients with Thyroid Disease could be sufficient.

Nitric Oxide (NO) that is produced by inducible NO Synthase (iNOS) in Glial Cells is thought to contribute significantly to the pathogenesis of Multiple Sclerosis (MS).

Oligodendrocytes can be stimulated to express iNOS by Inflammatory Cytokines which are known to accumulate in the MS Brain.

The potentially pathological levels of NO produced under these circumstances can target a wide spectrum of IntraCellular components.

We hypothesized one of the critical targets for damage that leads to disease is Mitochondrial DNA (mtDNA).

In this study, we found that Cytokines, in particular a combination of TNF- (50ng/ml) and IFN (25ng/ml), cause elevated NO production in primary cultures of rat Oligodendrocytes.

Western blot analysis revealed a strong enhancement of iNOS expression 48 h after Cytokine treatment.

Within the same time period, NO-mediated mtDNA damage was shown by Southern blot analysis and by ligation mediated PCR.

Targeting the DNA repair Enzyme 8-OxoGuanine Glycosylase (hOGG1) to Mitochondria of Oligodendrocytes had a protective effect against this Cytokine-mediated mtDNA damage.

Moreover, studies using a TUNEL assay showed that MTS-hOGG1 transfected Oligodendrocytes had fewer Apoptotic Cells (17%+/-5.2) compared to cells containing vector only (31%+/-3.6) following treatment with the Cytokines.

Subsequent experiments revealed that targeting hOGG1 to Mitochondria reduces the activation of caspase 9 showing that this recombinant protein works to reduce Apoptosis that is occurring through a Mitochondrial based pathway.

PeriVascular Macrophages (PVM) constitute a subpopulation of resident Macrophages in the Central Nervous System (CNS) that by virtue of their strategic location at the Blood-Brain Barrier potentially lend themselves to a variety of important functions in both health and disease.

Functional evidence suggests that PVM play a supportive role during Experimental Autoimmune Encephalomyelitis in rodents. However, the function of PVM in the human CNS remains poorly characterized.

We first set out to investigate the validity of the AntiBody EDhu1, which recognizes human CD163, to specifically identify human PVM.

Second, we wanted to gain insight into the function of PVM in Antigen recognition and presentation and therefore we studied the expression of DC-SIGN, Mannose Receptor, MHC Class II.

And, several costimulatory molecules by PVM in the normal and inflamed human CNS (Multiple Sclerosis (MS) Brain lesions).

Conventional ImmunoHistoChemistry and double-labeled ImmunoFluorescence techniques were used. We show that CD163 specifically reveals PVM in the normal human CNS.

In MS lesions, CD163 staining reveals expression on foamy Macrophages and Microglia, besides an upregulation of the amount of PVM stained.

In contrast, Mannose Receptor expression is restricted to PVM in both normal and inflamed Brain tissue.

Furthermore, we show that a subpopulation of PVM in the human Brain express several molecules involved in Antigen recognition, presentation, and costimulation.

Therefore PVM, which occupy a strategic location at the BBB, are equipped to recognize Antigen and present it to T-Cells, supporting a role in the regulation of PeriVascular inflammation in the human CNS.

(c) 2005 Wiley-Liss, Inc.

Lipoic Acid (LA) is an antioxidant that suppresses and treats an animal model of Multiple Sclerosis (MS), Experimental Autoimmune Encephalomyelitis.

The purpose of this study was to determine the PharmacoKinetics (PK), tolerability and effects on Matrix Metalloproteinase-9 (MMP-9) and soluble InterCellular Adhesion Molecule-1 (sICAMP-1) of oral LA in patients with MS.

Thirty-seven MS subjects were randomly assigned to one of four groups: placebo, LA 600 mg twice a day, LA 1200 mg once a day and LA 1200 mg twice a day.

Subjects took study capsules for 14 days. We found that subjects taking 1200 mg LA had substantially higher peak Serum LA levels than those taking 600 mg and that peak levels varied considerably among subjects.

We also found a significant negative correlation between peak Serum LA levels and mean changes in Serum MMP-9 levels (T = -0.263, P =0.04).

There was a significant dose response relationship between LA and mean change in Serum sICAM-1 levels (P =0.03).

We conclude that oral LA is generally well tolerated and appears capable of reducing Serum MMP-9 and sICAM-1 levels.

LA may prove useful in treating MS by inhibiting MMP-9 activity and interfering with T-Cell migration into the CNS.

Purpose
To estimate the functional benefit in patients with severe Spasticity treated with Intrathecal Baclofen infusion through an implantable pump and to stress the need for functional assessment of these patients with a functional scale.

Patients And Methods
Between 1999 and 2003, 22 patients with a long history of severe and disabling pharmaceutically intractable Spasticity, underwent implantation of a pump for continuous Intrathecal Baclofen infusion.

The patients were subdivided into two categories according to the Etiology of Spasticity: 15 had Multiple Sclerosis and seven had suffered a Spinal Cord Injury at different levels (from C4 to T11).

Clinical status was assessed with the Ashworth and Penn spasm scales. Functional benefits were evaluated with the Barthel index score and pain relief with a self-reported visual analogue pain scale.

Results
Postoperatively, all patients presented improvement in Spasticity, reduction of spasm frequency, significant improvement in functional status, enhancement of life comfort and reduction of pain.

Conclusion
Reduction of Spasticity and spasms achieved with intrathecally delivered Baclofen, leads to functional improvement and pain relief.

InterNuclear Ophthalmoplegia (INO) is a sign of exquisite localizing value, often due to either Multiple Sclerosis or infarction.

To demonstrate that unusual causes of INO are more common than the 11% reported in previous series, this review considers a case series of 410 inpatients whom I personally examined during a 33-year period.

In this series, the cause of INO was infarction in 157 patients (38%), Multiple Sclerosis in 139 (34%), and unusual causes in 114 (28%).

Unusual causes included Trauma (20 cases), Tentorial Herniation (20 cases), Infection (17 cases), Tumor (17 cases), Iatrogenic Injury (12 cases), Hemorrhage (13 cases), Vasculitis (7 cases), and Miscellaneous (8 cases).

InterNuclear Ophthalmoplegia was unilateral in 136 of the infarct cases (87%), 38 of those with Multiple Sclerosis (27%), and 48 of the unusual cases (42%).

Because unusual causes compose more than one quarter of the cases, the differential diagnosis of INO should be Tripartite: Multiple Sclerosis, Stroke, and Other Causes.

Background
Neutralizing AntiBodies (NABs) occur frequently in patients receiving Interferon-IFN (IFN-ß) for Multiple Sclerosis (MS), but it is unclear whether occurrence of NABs is predictive for the persistence of NABs during continued IFN-ß therapy.

Methods
The authors used an AntiViral Neutralization Bioassay to measure NABs blindly from 6 months up to 78 months in patients with MS who were followed for at least 24 months during treatment with IFN-ß.

Patients were classified into three groups:
1. Persistently NAB-negative patients, defined as
   • patients without any positive samples at any time
2. Definitely NAB-positive patients, defined as
   • patients who had at least two consecutive positive samples
3. Patients with fluctuating NAB-positive and NAB-negative samples

Results
A total of 455 patients were included in the study.

Overall, 52.3% of the patients were persistently NAB-negative, 40.9% became definitely NAB-positive, and the remaining 6.8% were fluctuating.

More patients treated with IFN-ß-1a (Avonex) remained NAB-negative (p < 0.0001), whereas there was no difference between IFN-ß-1b (Betaferon) and IFN-ß-1a (Rebif).

Patients who have remained NAB-negative during the first 24 months of therapy rarely developed NABs. On the contrary, the majority of patients, who had been NAB-positive from 12 through 30 months after start of therapy, remained NAB-positive.

Conclusions
NABs should be measured in all patients treated with IFN-ß. If patients have been persistently NAB-negative for 24 months, measurements can be discontinued.

Patients who have been NAB-positive for a period of 18 months or more usually remain NAB-positive for a long time.