The ACTRIMS + ECTRIMS + LACTRIMS conference is on, as many of you know. For my money, the presentations at this event are the most interesting of any conference over the last 5 years. Below are a whole lotta abstracts from today (so the embargo is off) that I find interesting. If you want to see more, go to:
– then select “Browse” from left-hand menu.
(thank you Bromley for the link)
Neurodegeneration and inflammation: which comes first?
Evidence for primary neurodegeneration in multiple sclerosis
Neuropathology, University Medical Centre, Göttingen, Germany.
Multiple sclerosis (MS) is generally regarded as an inflammatory demyelinating disease of the central nervous system. There is increasing evidence that MS also has a neurodegenerative component which appears to be the major cause of disability of MS patients. One of the major questions in MS pathogenesis is whether this neurodegenerative component occurs as a consequence of early inflammatory demyelination specifically in the progressive disease stage or whether neurodegeneration is an early phenomenon in MS lesions. There is increasing evidence from morphological studies that axonal pathology such as axonal transections or acute axonal damage occurs early in MS lesions but also in areas that are described as normal appearing white matter. This is supported by recent magnetic resonance imaging (MRI) and magnetic resonance spectroscopic (MRS) studies. In addition, cortical pathology with demyelination and neuroaxonal damage also appears to be an early event in lesion pathogenesis and contributes to the permanent clinical deficit of the patients. The presentation will give an overview on the current knowledge and evidence for primary neurodegenerative events in the pathogenesis of MS lesions.
Evidence for secondary neurodegeneration in multiple sclerosis
Pathology and Laboratory Medicine, University of British Columbia, Vancouver General Hospital, Vancouver , BC, Canada.
Neuropathological studies of multiple sclerosis (MS) have shown reduced numbers of axons in normal-appearing white matter (NAWM) attributed to Wallerian degeneration of axons within white matter plaques. This is also manifest as tractal degeneration in MS spinal cord.
Inflammatory cells in close proximity to degenerating axons in MS are considered to be mediators of axonal destruction. Components of the immune/inflammatory response, shown to have detrimental morphologic or physiologic effects on neurons/axons, have been documented by immunohistochemistry or molecular biological techniques in the MS plaque. These include CD4 lymphocytes and their proinflammatory and immunomodulatory cytokines, CD8 cytotoxic T-cells, activated microglia, macrophages (with proteases and other enzymes), matrix metalloproteinases, chemokines, anti-neuronal antibodies, complement, calpains, glutamate, cyclooxygenase-2, nitric oxide (NO), peroxynitrite and free radicals. NO is particularly toxic to demyelinated axons. Inflammation has also been detected in NAWM, where similar neurodegenerative factors may be operative. Degeneration of neuronal somata and neurites has been attributed to the effects of activated microglia in gray matter.
Blood–brain barrier dysfunction in MS plaques and NAWM, secondary to the inflammatory infiltrates, allows the introduction of previously-excluded systemic neurotoxins into the CNS parenchyma.
Demyelination itself is associated with secondary changes in axons, including dephosphorylation of neurofilaments and reduction in axonal diameter.
The redistribution of sodium channels along the demyelinated axolemma, evident in immunohistochemical studies, results in excessive energy demands on the axon and increased axoplasmic sodium concentration, the latter triggering the sodium–calcium exchanger leading to toxic levels of intra-axonal calcium. The insertion of calcium channels in the demyelinated axolemma has a similar effect.
In summary, histopathologic, immunohistochemical and molecular studies of plaques and non-plaque parenchyma indicate that neurodegeneration in MS may be secondary to the effects inflammation and demyelination.
Brain plasticity and repair
Mesenchymal stem cells as treatment for multiple sclerosis: immunomodulation versus tissue repair
A. Uccelli 1; S. Morando1; M. Esposito2; M. Principato1; D. Giunti1; S. Chiesa1; G. Martino2; G. Mancardi1; R. Furlan2
1. Neuroscience, Ophthalmology and Genetic, University of Genoa, Genoa, Italy.
2. San Raffaele Hospital, Milan, Italy.
While bone marrow derived mesenchymal stem cells (MSC) have been proposed for brain repair due to their multipotentiality, recent experimental data challenged their transdifferentiation capacity and suggested that they could modulate pathogenic immune responses.
The aim of this study was to address the in vivo effects of MSC on neural cells inside the inflamed central nervous system (CNS) as well as on key T cell subsets infiltrating both in the lymphoid organs and in the CNS.
We evaluated the MSC-mediated effects in MOG-induced experimental autoimmune encephalomyelitis (EAE) by immunological, histological and molecular analysis of CNS specimens.
We showed that irrespective of the lack of MSC neural differentiation, MSC decreased axonal sufferance through the inhibition of astrogliosis and microglia activation and the upregulation of genes involved in the BMP and Notch pathways. In addition, upon isolation of T cells from the brain of EAE-affected mice we detected an increase of CD4+ FoxP3 + T regulatory cells and a decrease of IL-17 producing T cells compared with control EAE mice.
Thus MSC may represent a valuable approach for the treatment of autoimmune diseases such as multiple sclerosis where tissue degeneration is associated with inflammation.
Antibodies: from pathogenesis to treatment
Monoclonal antibodies: the future
S. L. Hauser1
1. Neurology, University of California, San Francisco, San Francisco, CA, USA.
In contrast to earlier disease concepts of MS suggesting that pathogenic T cells were sufficient for full expression of the disease, it is now established that autoimmune B cells and humoral immune mechanisms also play major roles in mediating tissue damage. Current evidence indicates that diverse protein and lipid antigens are likely to be targets of humoral autoimmunity in MS.
In MS, memory B cells, which cross the blood-brain barrier, are believed to undergo restimulation, antigen-driven affinity maturation, clonal expansion, and differentiation to antibody-secreting plasma cells within the highly supportive CNS environment. Clonally expanded populations of memory B cells and plasma cells are also present in MS lesions and in cerebrospinal fluid, and can be detected even at the onset of clinical symptoms.
In a phase II trial in RRMS reported in 2007, Rituximab (Rituxan), a chimeric monoclonal antibody that targets CD20-positive B lymphocytes, reduced disease activity measured by MRI; secondary endpoints were also positive, including a reduction of clinical relapses. Suggestive efficacy was also observed in a phase 1 trial. In primary progressive MS, a phase II/III trial has been completed and preliminary results will be presented at this meeting.
The beneficial effects in the RRMS anti-CD20 trials occurred within weeks of the initial infusion, indicating that a direct effect on B cells - and not on autoantibodies – was responsible. Interference with B cell trafficking is one presumptive mechanism of action. The duration of action was also longer than the period of B cell depletion, suggesting that repopulating B-cells were less pathogenic. In a larger sense, the discovery that B-cell depletion has an impact on MS biology represents a paradigm shift in understanding how the inflammatory phase of MS develops; the data shift our perspective on the cause of MS, and open up a new area of investigation which may lead to development of increasingly selective therapies against humoral immune system pathways.
A Phase I/II dose-escalation trial of oral vitamin D3 with calcium supplementation in patients with multiple sclerosis
J. M. Burton1; S. Kimball2; R. Vieth2; A. Bar-Or3; H. Dosch4; L. Thibault5; S. Kilborn5; C. D'Souza6; R. Cheung4; M. Ursell7; P. O'Connor1
1. St. Michael's Hospital, Toronto, ON, Canada., 2. Mount Sinai Hospital, Toronto, ON, Canada., 3. Montreal Neurological Institute, Montreal, QC, Canada., 4. Hospital for Sick Children, Toronto, ON, Canada., 5. McGill University, Montreal, QC, Canada., 6. University of Toronto, Toronto, ON, Canada., 7. Etobicoke General Hospital, Etobicoke, ON, Canada.
Increasing distance from the equator, low UV radiation and low serum 25-hydroxyvitamin D [25(OH)D] are associated with increased multiple sclerosis (MS) prevalence and risk. While this relationship provides insight into prevention, it begs the question, ‘Is vitamin D3 (VD3), known to have immunoregulatory properties, beneficial in established MS?’ To answer this, a safe, effective dose must be determined.
To characterize the safety profile of high-dose oral VD3 in MS.
A prospective controlled 52-week trial matched MS patients for demographic and disease characteristics, randomizing them to treatment or control groups. Treatment patients started VD3 at 4000 IU/day and escalated over 28 weeks to 40 000 IU/day. This was followed by maintenance with 10 000 IU/day for 12 weeks, 4000 IU/day for 8 weeks and a 4-week wash-out, translating into roughly 14 000 IU/day over 52 weeks. Calcium (1200mg/day) was given throughout the trial. The primary endpoint was mean change in serum calcium in treatment patients at each VD3 dose, and a comparison of calcium between treatment and control groups. Secondary endpoints included 25(OH)D, urine calcium/creatinine (Ca/Cr) and PTH. Cytokines, lymphocyte response and matrix metalloproteinase-9 were also measured, as were Expanded Disability Status Scale (EDSS) and relapses.
Forty-nine patients were enrolled (25 treatment, 24 control) with mean age 40.5 years (21–54 years), EDSS 1.34 (0-6.0) and 25(OH)D 78nmol/l (38–154). No abnormalities or differences in serum calcium, urine Ca/Cr or PTH occurred, nor were there differences in calcium between groups. Despite a maximum mean 25(OH)D of 413nmol/l (66–729), no significant clinical or biochemical adverse events occurred. A greater proportion of treatment patients had stable/improved EDSS vs. control patients (p=0.018). Treatment patients also had fewer relapses and a greater reduction in relapse rate vs. controls. Immunological data will be presented.
High-dose VD3 (~10 000 IU/day, possibly higher) in MS is safe and tolerable, with evidence of clinical improvement.
Association of interferon beta and inosine in relapsing–remitting multiple sclerosis (ASIIMS): a multi-centre, randomized, double-blind, placebo-controlled phase II (proof of concept) trial in 157 patients
R. E. Gonsette1; C. Sindic2; M. D'Hooghe3; R. Medaer4; A. Michotte5; P. De Deyn6; P. Seeldrayers7; D. Guillaume8; R. Metz9; A. Maertens de Noordhout10; M. Dupuis11; P. Cras12; D. Decoo13; M. Van Zandijcke14
1. National Centre for Multiple Sclerosis, Melsbroek, Belgium., 2. UCL, Brussels, Belgium., 3. NCMS, Melsbroek, Belgium., 4. LUC, Dieprnbeek, Belgium., 5. VUB, Brussels, Belgium., 6. AZ Middelheim, Antwerp, Belgium., 7. CHU, Charleroi, Belgium., 8. CNRF, Fraiture, Belgium., 9. CH, Luxembourg, Luxembourg., 10. CHU, Liège, Belgium., 11. Clinique St-Pierre, Ottignies, Belgium., 12. UZ, Antwerp, Belgium., 13. EZ, Sijsele, Belgium., 14. AZ, Brugge, Belgium.
Neuronal and axonal loss occurs early in relapsing–remitting multiple sclerosis (RRMS) and is mediated by inflammatory processes as well as by oxidative stress and excitotoxicity. Effective anti-inflammatory drugs are available but the development of neuroprotective agents remains a challenge. Experimental and clinical observations suggest that uric acid (UA), a natural antioxidant, has a neuroprotective effect in EAE and possibly in MS. Oral administration of inosine, a precursor of UA, increases serum and CSF UA levels in MS patients and is well tolerated.
Combination therapy with an anti-inflammatory drug (IFNβ) and a potentially neuroprotective agent (inosine) might delay disability progression.
Patients with RRMS who had been on IFNβ for at least 6 months at baseline were randomized to IFNβ + inosine (n=79) or IFNβ + placebo (n=78) for 2 years. The two groups were not significantly different in terms of age (~37 years), disease duration (~6.2 years), mean EDSS (~2.3) and annual relapse rate (~0.8). The dose of inosine was adjusted to maintain serum UA levels in the range of asymptomatic hyperuricemia (females ≤8mg/dL; males ≤9mg/dL). Expanded Disability Status Scale (EDSS) and MSFC components were assessed every 3 months by a blinded evaluating physician. The primary end points were: percentage of patients with progression of disability (EDSS+1 confirmed at 3 months), time to sustained progression (Kaplan–Meier analysis) and mean EDSS.
The combination of IFNβ and inosine was safe and well tolerated. Urinary lithiasis occurred in 3.8% of treated patients and 1.3% of controls. No change in blood pressure was noted in patients with induced asymptomatic hyperuricemia. At 24 months no significant differences were observed between the two groups in any of the primary end points.
Combination therapy with IFNβ and inosine is not superior to IFNβ monotherapy. Potential reasons will be discussed. Inosine effects might be masked by those of IFNβ and the negative results of this combination therapy do not rule out a possible benefit of UA in naîve patients.
Treatment of multiple sclerosis with glatiramer acetate and albuterol: results of a clinical trial
P. Kivisäkk1; V. Viglietta2; B. Healy1; G. J. Buckle1; H. L. Weiner1; D. A. Hafler1; S. Khoury1
1. Brigham and Women's Hospital, Boston, MA, USA., 2. EMD Serono, Boston, MA, USA.
The mechanism of action of glatiramer acetate (GA) is thought to be by induction of anergy of GA reactive lines and enhanced production of Th2 cytokines. We hypothesized that albuterol may enhance the effects of GA in vivo or accelerate the induction of anergy and Th2 cytokine production.
In a randomized, double-masked, two-arm pilot study we investigated the effect of adding oral albuterol versus placebo to GA in relapsing–remitting multiple sclerosis (RRMS).
Eligibility criteria were clinically definite RRMS with positive brain magnetic resonance imaging (MRI), and an Expanded Disability Status Scale (EDSS) score between 0 and 3.5. No prior treatment with GA or oral myelin. No treatment with immunomodulating therapy within the past 3 months. No prior treatment with immunosuppressants. No steroid treatment 1 month prior to study entry. Subjects were randomized to two treatment arms: 20mg SQ of GA daily + 4mg PO of placebo daily for 2 years or 20mg SQ of GA daily + 4mg PO of albuterol daily, for 2 years.
The primary outcome measures were the change in the MS Functional Scale (MSFC), and the change in IL-13 and IFN-γ cytokine secretion by GA reactive T cell lines. Secondary outcome variables included changes in percentage of IL-12-producing monocytes by intra-cytoplasmic staining, time of first exacerbation, number and severity of exacerbations, and MRI evidence of progression.
Forty four subjects were randomized (21 in the GA+placebo arm and 23 in the GA+albuterol arm). There was a treatment effect of albuterol on MSFC at 6 months that diminished over time (p=0.026) and a trend for improved MSFC in the albuterol arm at 12 months. Analysis of the immunologic endpoints is ongoing.
Albuterol added to GA treatment in RRMS enhanced treatment response in the early time points and may be beneficial in accelerating the beneficial effects of therapy.
Immediate broad spectrum immunomodulating effects induced by bone marrow derived stem cells (MSC), in MS patients transplanted with MSC in a phase I/II clinical trial
A. Vaknin-Dembinsky1; I. Kassis1; C. Karageorgiou2; B. Gowda-Kurkalli3; J. Rachmilewitz3; Y. Libster1; T. Ben-Hur1; S. Slavin3; D. Karussis1
1. Neurology, Hadassah-Hebrew University Hospital, Jerusalem, Israel., 2. Gennimatas General Hospital, Athens, Greece., 3. Tel Aviv (Sourasky) Medical Center, Tel Aviv, Israel.
Bone marrow (BM) mesenchymal stem cells (MSC) possess strong neurotrophic effects and have become the focus of research as a potential method for inducing neuroprotection in diseases such as multiple sclerosis (MS). MSC were also proven to exert strong in vitro immunomodulatory effects.
To evaluate the immediate immunomodulatory effects of MSC in MS patients in a phase I/II clinical trial with intravenous and intrathecal administration of MSC.
A total of 14 MS patients were injected with autologous MSC, following their culture for 40-90 days. All patients received intrathecally a mean of 64.4, and 10 of them intravenously, a mean of 22 million cells. We performed an immunological analysis in 6 of the patients before the injection of the stem cells and 4 and 24 hours later. Peripheral blood monocytes were obtained and the following tests were perfomed: a) FACS analysis for the expression of markers of regulatory cells (CD4/CD25/FoxP3), myeloid dendritic cells activation markers (CD86, CD83 and HLA-DR), T-cell activation markers (CD69), b) lymphocyte proliferations assay and c) cytokine production.
All tested patients showed significant changes in all the above immunological tests, starting as early as 4 hours following the injection of MSC, including a 30-50% increase in the proportion of CD4+CD25+ regulatory T cells and 30-60% reduction of CD83 expression on myeloid dendritic cells. In addition, in vitro a significant decrease was noted in the proliferative responses upon stimulation of the lymphocytes with anti-CD3 or the PHA mitogen as well as a significant decrease in IL-17 secretion.
This is the first trial with intrathecal and intravenous injection of MSC in MS and revealed the strong immediate immunomodulatory effects induced by the injection of these cells. Further controlled studies and longer observation periods are needed to evaluate possible efficacy and long-term clinical and immunological effects of MSC transplantation.
Epigenetic marks in the brain of patients with secondary progressive multiple sclerosis
P. Casaccia1; F. Mastronardi2
1. Neuroscience, Mount Sinai School of Medicine, New York, NY, USA., 2. Hospital for Sick Children, Toronto, ON, Canada.
The gender prevalence of multiple sclerosis (MS), the low-level concordance in homozygous twins and the linkage to several genetic loci, suggest an epigenetic component to the definition of this demyelinating disorder. Epigenetics refers to the changes in gene expression that are consequent to secondary modifications of nucleosomal histones, the basic unit of chromatin, and/or DNA methylation.
Since modification of lysine residues in the tail of nucleosomal histones associated with repression are essential for developmental myelination in rodents, we asked whether specific patterns of post-translational modifications of the histones could be identified in human MS brains compared with non-MS controls.
Protein extracts were generated from the normal appearing white matter in brain samples obtained from the UCLA MS Brain Bank. Only samples from patients with secondary progressive MS, matched by age, sex, brain region and equivalent autolysis time were analyzed and compared with brain samples from non-neurological patients. Proteins were quantified and processed for Western-blot analysis using antibodies specific for lysine residues in the histone tails.
We detected decreased levels of epigenetic marks for repression of gene expression (that is, repressive methylation of lysine 9) and decreased expression of the enzymes responsible for deacetylation of nucleosomal histones (that is, histone deacetylases).
The epigenetic marks defining the oligodendrocyte lineage progression during development are decreased in the normal appearing white matter of patients with secondary progressive MS.