Neuroprotection in a novel mouse model of multiple sclerosis.

Multiple sclerosis is an immune-mediated, demyelinating and neurodegenerative disease that currently lacks any neuroprotective treatments. Innovative neuroprotective trial designs are required to hasten the translational process of drug development. An ideal target to monitor the efficacy of strategies aimed at treating multiple sclerosis is the visual system, which is the most accessible part of the human central nervous system. A novel C57BL/6 mouse line was generated that expressed transgenes for a myelin oligodendrocyte glycoprotein-specific T cell receptor and a retinal ganglion cell restricted-Thy1 promoter-controlled cyan fluorescent protein. This model develops spontaneous or induced optic neuritis, in the absence of paralytic disease normally associated with most rodent autoimmune models of multiple sclerosis. Demyelination and neurodegeneration could be monitored longitudinally in the living animal using electrophysiology, visual sensitivity, confocal scanning laser ophthalmoscopy and optical coherence tomography all of which are relevant to human trials. This model offers many advantages, from a 3Rs, economic and scientific perspective, over classical experimental autoimmune encephalomyelitis models that are associated with substantial suffering of animals. Optic neuritis in this model led to inflammatory damage of axons in the optic nerve and subsequent loss of retinal ganglion cells in the retina. This was inhibited by the systemic administration of a sodium channel blocker (oxcarbazepine) or intraocular treatment with siRNA targeting caspase-2. These novel approaches have relevance to the future treatment of neurodegeneration of MS, which has so far evaded treatment.

Immunoadsorption therapy in patients with multiple sclerosis with steroid-refractory optical neuritis.

BACKGROUND: In multiple sclerosis relapses refractory to intravenous corticosteroid therapy, plasma exchange is recommended. Immunoadsorption (IA) is regarded as an alternative therapy, but its efficacy and putative mechanism of action still needs to be established. METHODS: We prospectively treated 11 patients with multiple sclerosis who had optical neuritis and fulfilled the indications for apheresis therapy (Trial registration DE/CA25/00007080-00). In total, five IA treatments were performed using tryptophan-IA. Clinical activity (visual acuity, Expanded Disability Status Scale, Incapacity Status Scale), laboratory values and visual evoked potentials were measured before, during and after IA, with a follow-up of six months. Moreover, proteomic analyses were performed to analyze column-bound proteins as well as corresponding changes in patients' sera. RESULTS: After the third IA, we detected an improvement of vision in eight of eleven patients, whom we termed responders. Amongst these, the mean visual acuity improved from 0.15 ± 0.12 at baseline to 0.47 ± 0.32 after the third IA (P = 0.0252) up to 0.89 ± 0.15 (P < 0.0001) at day 180 ± 10 after IA. Soluble interleukin-2 receptor decreased in responders (P = 0.03), whereas in non-responders it did not. Proteomic analyses of proteins adsorbed to IA columns revealed that several significant immunological proteins as well as central nervous system protein fragments, including myelin basic protein, had been removed by IA. CONCLUSIONS: IA was effective in the treatment of corticosteroid-refractory optic neuritis. IA influenced the humoral immune response. Strikingly, however, we found strong evidence that demyelination products and immunological mediators were also cleared from plasma by IA.

The influence of immunomodulation on psycho-neuroimmunological functions in benign multiple sclerosis.

OBJECTIVES: In multiple sclerosis (MS), several neuroimmunomodulatory effectors are known, including melatonin. They are able to influence disease-related neurophysiogical changes (disability or impaired vision) as well as neuropsychological performance (e.g. cognition and depression). In this study we assessed the relationship between immunomodulation on psycho-neuroimmunological functions in benign multiple sclerosis. METHODS: We evaluated 26 young female patients with benign MS treated with/without immunomodulating therapies with regard to their physical disabilities (Expanded Disability Status Scale, EDSS), their visually evoked potentials (VEP), their plasma melatonin concentrations as well as their performance regarding emotional and cognitive tests and compared them with healthy matched controls. RESULTS: Patients with MS showed deficits in cognitive and emotional functions compared to healthy controls, which were in accordance with their increase in EDSS over time. However, in contrast to untreated patients, patients receiving immunotherapy showed significantly increased dysfunction with respect to actual mood (p = 0.02) and a tendency to increased depression scores (p = 0.072). However, neither treatment subgroup had cognitive deficits. In untreated patients, melatonin levels correlated with reduced scores in the cognitive tests (p = 0.045) but not with depression or VEP latencies. Patients with long-standing MS (>10 years) showed a significant correlation (p = 0.01) to their increased depression scores and their melatonin levels, but no correlation with VEP or cognitive dysfunction, compared to patients with shorter disease duration (< or =10 years). CONCLUSION: These results indicate that in MS all aspects of the psycho-neuroimmunological network can be affected. Despite the potential influence of immunomodulation on depression, no connection with melatonin representing the retinohypothalamic tract/pineal gland circuits could be detected. However, visual perception as well as visuoconstructive abilities were affected in MS patients. Neuropsychological tests in MS should concentrate on cognitive variables, which reflect the clinical status more accurately and may be used to monitor disease-modifying therapies.