Clemastine fumarate as a remyelinating therapy for multiple sclerosis (ReBUILD): a randomised, controlled, double-blind, crossover trial.

BACKGROUND: Multiple sclerosis is a degenerative inflammatory disease of the CNS characterised by immune-mediated destruction of myelin and progressive neuroaxonal loss. Myelin in the CNS is a specialised extension of the oligodendrocyte plasma membrane and clemastine fumarate can stimulate differentiation of oligodendrocyte precursor cells in vitro, in animal models, and in human cells. We aimed to analyse the efficacy and safety of clemastine fumarate as a treatment for patients with multiple sclerosis. METHODS: We did this single-centre, 150-day, double-blind, randomised, placebo-controlled, crossover trial (ReBUILD) in patients with relapsing multiple sclerosis with chronic demyelinating optic neuropathy on stable immunomodulatory therapy. Patients who fulfilled international panel criteria for diagnosis with disease duration of less than 15 years were eligible. Patients were randomly assigned (1:1) via block randomisation using a random number generator to receive either clemastine fumarate (5·36 mg orally twice daily) for 90 days followed by placebo for 60 days (group 1), or placebo for 90 days followed by clemastine fumarate (5·36 mg orally twice daily) for 60 days (group 2). The primary outcome was shortening of P100 latency delay on full-field, pattern-reversal, visual-evoked potentials. We analysed by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT02040298. FINDINGS: Between Jan 1, 2014, and April 11, 2015, we randomly assigned 50 patients to group 1 (n=25) or group 2 (n=25). All patients completed the study. The primary efficacy endpoint was met with clemastine fumarate treatment, which reduced the latency delay by 1·7 ms/eye (95% CI 0·5-2·9; p=0·0048) when analysing the trial as a crossover. Clemastine fumarate treatment was associated with fatigue, but no serious adverse events were reported. INTERPRETATION: To our knowledge, this is the first randomised controlled trial to document efficacy of a remyelinating drug for the treatment of chronic demyelinating injury in multiple sclerosis. Our findings suggest that myelin repair can be achieved even following prolonged damage. FUNDING: University of California, San Francisco and the Rachleff Family.

CD19 as a molecular target in CNS autoimmunity.

Multiple sclerosis (MS) and neuromyelitis optica (NMO) are the most prevalent neuroinflammatory diseases of the central nervous system (CNS). The immunological cascade of these disorders is complex, and the exact spatial and temporal role of different immune cells is not fully understood. Although MS has been considered for many years to be primarily T cell driven, it is well established that B cells and the humoral immune response play an important role in its pathogenesis. This has long been evident from laboratory findings that include the presence of oligoclonal bands in the CSF. In NMO, the importance of the humoral immune system appears even more obvious as evidenced by pathogenic antibodies against aquaporin 4 (AQP4). Besides their capacity to mature into antibody-producing plasma cells, B cells are potent antigen-presenting cells to T lymphocytes and they can provide soluble factors for cell activation and differentiation to other immune-competent cells. In MS and NMO, there are substantial data from clinical trials that B cell depletion with CD20-directed agents is effective and relatively safe. Plasma cells, which produce antibodies against molecular targets expressed by the host, but which also provide humoral immune responses against pathogens, are not targeted by anti-CD20 therapies. Therefore, the depletion of CD19-expressing cells would offer potential advantages with regard to efficacy, but potentially higher risks with regard to infectious complications. This review will outline the rationale for CD19 as a molecular target in CNS autoimmunity. The current stage of drug development is illustrated. Potential safety concerns will be discussed.

Immunomodulatory synergy by combination of atorvastatin and glatiramer acetate in treatment of CNS autoimmunity.

One approach to improving efficacy in MS therapy is to identify medications that provide additive or synergistic benefit in combination. Orally administered cholesterol-lowering HMG-CoA reductase inhibitors (known as statins), which exhibit immunomodulatory properties and are effective in treatment of the MS model EAE, are being tested in MS. As atorvastatin can enhance protective Th2 responses and has a different mechanism of action than glatiramer acetate (GA), a parenterally administered immunomodulatory agent approved for MS treatment, we tested whether the combination of these agents could be beneficial in EAE. Combination therapy using suboptimal doses of atorvastatin and GA prevented or reversed clinical and histologic EAE. Secretion of proinflammatory Th1 cytokines was reduced--and conversely Th2 cytokine secretion was increased--in these mice, but not in mice treated with each drug alone at the same doses. Monocytes treated with the combination of suboptimal doses of atorvastatin and GA secreted an antiinflammatory type II cytokine pattern and, when used as APCs, promoted Th2 differentiation of naive myelin-specific T cells. Our results demonstrate that agents with different mechanisms of immune modulation can combine in a synergistic manner for the treatment of CNS autoimmunity and provide rationale for testing the combination of atorvastatin and GA in MS.

Disease-modifying agents for multiple sclerosis: recent advances and future prospects.

Multiple sclerosis (MS) is a chronic autoimmune disease of the CNS. Currently, six medications are approved for immunmodulatory and immunosuppressive treatment of the relapsing disease course and secondary-progressive MS. In the first part of this review, the pathogenesis of MS and its current treatment options are discussed. During the last decade, our understanding of autoimmunity and the pathogenesis of MS has advanced substantially. This has led to the development of a number of compounds, several of which are currently undergoing clinical testing in phase II and III studies. While current treatment options are only available for parenteral administration, several oral compounds are now in clinical trials, including the immunosuppressive agents cladribine and laquinimod. A novel mode of action has been described for fingolimod, another orally available agent, which inhibits egress of activated lymphocytes from draining lymph nodes. Dimethylfumarate exhibits immunomodulatory as well as immunosuppressive activity when given orally. All of these compounds have successfully shown efficacy, at least in regards to the surrogate marker contrast-enhancing lesions on magnetic resonance imaging. Another class of agents that is highlighted in this review are biological agents, namely monoclonal antibodies (mAb) and recombinant fusion proteins. The humanized mAb daclizumab inhibits T-lymphocyte activation via blockade of the interleukin-2 receptor. Alemtuzumab and rituximab deplete leukocytes and B cells, respectively; the fusion protein atacicept inhibits specific B-cell growth factors resulting in reductions in B-cells and plasma cells. These compounds are currently being tested in phase II and III studies in patients with relapsing MS. The concept of neuro-protection and -regeneration has not advanced to a level where specific compounds have entered clinical testing. However, several agents approved for conditions other than MS are highlighted. Finally, with the advent of these highly potent novel therapies, rare, but potentially serious adverse effects have been noted, namely infections and malignancies. These are critically reviewed and put into perspective.

Rotational vertebral artery syndrome: 3D kinematics of nystagmus suggest bilateral labyrinthine dysfunction.

Whether the rotational vertebral artery syndrome (RVAS), consisting of attacks of vertigo, nystagmus and tinnitus elicited by head-rotation induced compression of the dominant vertebral artery (VA), reflects ischemic dysfunction of uni- or bilateral peripheral or central vestibular structures, is still debated. We report on a patient with bilateral high-grade carotid stenoses, in whom rightward headrotation led to RVAS symptoms including a prominent nystagmus. Three-dimensional kinematic analysis of the nystagmus pattern, recorded with search coils, revealed major downbeat nystagmus with minor horizontal and torsional components. Magnetic resonance angiography demonstrated a hypoplastic right VA terminating in the posterior inferior cerebellar artery, a dominant left VA, and a hypoplastic P1-segment of the left posterior cerebral artery (PCA) that was supplied by the left posterior communicating artery (PCoA). The right PCA and both anterior inferior cerebellar arteries were supplied by the basilar artery. The right PCoA originated from the right internal carotid artery. Color duplex sonography showed severe reduction of diastolic blood flow velocities in the left VA during RVAS attacks. The nystagmus pattern can be best explained by vectorial addition of 3D sensitivity vectors of stimulated right and left anterior and horizontal semicircular canals with slightly stronger stimulation on the left side. We hypothesize that in RVAS, compression of dominant VA leads to acute vertebrobasilar insufficiency with bilateral, but asymmetric ischemia of the superior labyrinth. With regard to RVAS etiology, our case illustrates a type of pure vascular RVAS. Severity of attacks markedly decreased after successful bilateral carotid endarterectomy.

Serum cholesterol levels do not influence outcome or recovery in acute ischemic stroke.

OBJECTIVE: To examine the influence of admission serum cholesterol levels (SCL) on severity of initial neurological deficit, neurological outcome at month 3 and neurological recovery in patients with acute first-ever ischemic stroke. METHODS: Prospectively collected data from 889 consecutive patients with first-ever acute ischemic stroke were retrospectively analysed. Patients who suffered a recurrent ischemic stroke (n=22) or died (n=30) during the follow-up period were excluded from this study. Age, gender, arterial hypertension, diabetes mellitus, smoking, stroke etiology, SCL and severity of neurological deficit, using the National Institute of Health Stroke Scale (NIHSS), at presentation (NIHSS0) and after 3 months (NIHSS1), were assessed. Neurological recovery was defined as difference in NIHSS score (Delta(NIHSS)), according to Delta(NIHSS)=NIHSS0 - NIHSS1. RESULTS: Data from 837 patients (66% men, age: 62 +/- 14 years) were analysed. NIHSS1 was 2.3 +/- 1.8 and Delta(NIHSS) was 3.4 +/- 3. Clinically insignificant correlations between SCL and NIHSS0 (r=-0.13, p=0.0002), NIHSS1 (r=-0.09, p=0.001) and Delta(NIHSS) (r=-0.1, p=0.03) were evident. Multivariate binary logistic regression analysis revealed smoking (p=0.008), stroke etiology (p=0.023) and NIHSS0 (p<0.001) but not age, gender, arterial hypertension, diabetes mellitus or SCL as predictors for Delta(NIHSS). CONCLUSION: Our data suggest that SCL in patients with acute ischemic stroke are not associated with neurological deficit on admission, outcome or neurological recovery.

Early recurrent ischemic stroke in stroke patients undergoing intravenous thrombolysis.

BACKGROUND: We assessed the incidence of early recurrent ischemic stroke in stroke patients treated with intravenous tissue-type plasminogen activator (tPA) and the temporal pattern of its occurrence compared with symptomatic intracranial hemorrhage (ICH). METHODS AND RESULTS: Prospectively collected, population-based data for 341 consecutive acute stroke patients (62% men; mean age, 66 years) treated with tPA according to the National Institute of Neurological Disorders and Stroke study protocol at 8 medical centers in Switzerland (3 academic and 5 community) between January 2001 and November 2004 were retrospectively analyzed. The primary outcome measure was neurological deterioration > or = 4 points on the National Institutes of Health Stroke Scale occurring within 24 hours of tPA treatment and caused either by recurrent ischemic stroke (defined as the occurrence of new neurological symptoms suggesting involvement of initially unaffected vascular territories and evidence of corresponding ischemic lesions on cranial computed tomography scans, in the absence of ICH) or by ICH. Early recurrent ischemic stroke was diagnosed in 2 patients (0.59%; 95% confidence interval, 0.07% to 2.10%) and symptomatic ICH in 15 patients (4.40%; 95% confidence interval, 2.48% to 7.15%). Both recurrent ischemic strokes occurred during thrombolysis, whereas symptomatic ICHs occurred 2 to 22 hours after termination of tPA infusion. CONCLUSIONS: Recurrent ischemic stroke is a rare cause of early neurological deterioration in acute stroke patients undergoing intravenous thrombolysis, with a different temporal pattern compared with that of symptomatic ICH.

Good outcomes in ischemic stroke patients treated with intravenous thrombolysis despite regressing neurological symptoms.

BACKGROUND AND PURPOSE: We evaluated the clinical course of 19 acute stroke patients with rapid early improvement of neurological deficit within the 3-hour window, treated with intravenous thrombolytics. RESULTS: No patient demonstrated a neurological deterioration during hospitalization. National Institutes of Health Stroke Scale (NIHSS) scores at therapy decision and discharge were 5 (4 to 6) and 0.5 (0 to 1.5), respectively. At 3-month follow-up, 1 patient had died; in remaining patients, NIHSS was 0 (0 to 1) and modified Rankin Scale 0.5 (0 to 1; < or =1 in 15 patients). CONCLUSIONS: Withholding of intravenous thrombolysis because of spontaneous early regression of neurological symptoms may not be justified.

Approved and future pharmacotherapy for multiple sclerosis.

BACKGROUND: Pharmacotherapy for relapsing-remitting multiple sclerosis (MS) advanced with the demonstration that interferon beta and glatiramer acetate improve the clinical course of this disease. Mitoxantrone is the first drug approved by the Food and Drug Administration for treatment of secondary progressive MS. Despite this progress, the agents presently available are only partially effective, are difficult to administer, and may have significant side effects. Several orally administered immunomodulatory agents are presently being evaluated for treatment of MS. One class of drugs, HMG CoA inhibitors (statins), is safe and well-tolerated and could become another mainstay of MS therapy. REVIEW SUMMARY: This article reviews the clinical evidence for approved MS therapies and discusses their mechanisms of action. Furthermore, the clinical and laboratory data suggesting a potential role for statins in MS therapy are discussed. CONCLUSIONS: Although treatment with interferon beta, glatiramer acetate, and mitoxantrone, the approved therapies, provide important treatment options for patients with relapsing-remitting MS and secondary progressive MS, the potential benefits of other medications, including statins, should be explored in controlled clinical trials.

Clonally expanded plasma cells in the cerebrospinal fluid of patients with central nervous system autoimmune demyelination produce "oligoclonal bands".

Clonally expanded plasma cells (cePC) and oligoclonal IgG (oligoclonal bands, OCB) in the cerebrospinal fluid (CSF) suggest an involvement of B cell mechanisms in autoimmune CNS demyelination. Due to their CSF-restricted occurrence, OCB are commonly believed to be the products of B cells inside the borders of the blood brain barrier. A comparison of CSF cell Ig transcriptomes and CSF-Ig proteomes recently demonstrated, that in multiple sclerosis patients CSF cells are the origin of CSF immunoglobulins. We expand these findings by applying anti-idiotypic antibodies to detect specific heavy chain CDR3 idiotopes of cePC-produced antibodies amongst OCB in the CSF of a patient each with MS and acute disseminated encephalomyelitis.

Live imaging of remyelination after antibody-mediated demyelination in an ex-vivo model for immune mediated CNS damage.

Mononuclear cell infiltrates, deposits of immunoglobulin and complement as well as demyelination and axonal damage are neuropathological hallmarks of Multiple Sclerosis (MS) lesions. An involvement of antibodies is further suggested by the presence of oligoclonal immunoglobulins in the cerebrospinal fluid of almost all MS patients. However, which mechanisms are most relevant for de- and remyelination and axonal loss in MS lesions is poorly understood. To characterize the regenerative abilities of demyelinated CNS tissue, we utilized murine organotypic cerebellar slice cultures expressing GFP in oligodendrocytes. The addition of a demyelinating monoclonal antibody specific for myelin oligodendrocyte glycoprotein and complement induced complete myelin destruction and oligodendrocyte loss, as demonstrated by confocal live imaging and staining for different myelin proteins. After removal of antibodies and complement we visualized the stages of remyelination, presumably originating from proliferating oligodendrocyte precursor cells and guided by morphologically intact appearing axons. Allowing for the detailed live imaging of de- and remyelination in an ex vivo situation closely resembling the three dimensional cytoarchitecture of the CNS, we provide a useful experimental system for the evaluation of new therapeutic strategies to enhance remyelination and repair in MS.

Clonally expanded plasma cells in the cerebrospinal fluid of MS patients produce myelin-specific antibodies.

Clonally expanded plasma cells (cePC) and their presumed products, oligoclonal immunoglobulin G bands (OCB), are characteristic findings in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS). While cePC and OCB strongly suggest an involvement of B cell-dependent immune mechanisms in the pathogenesis of MS, their actual pathological relevance and target antigens remain unknown. To further understand the potential role played by cePC, we generated a panel of monoclonal antibodies (MS-mAb) from CSF-derived cePC from four patients with early or definite MS. Single-cell RT-PCR of correctly paired heavy and light chain immunoglobulin genes from individual cePC ensured the subsequent resurrection of their original antigen specificity. Immunofluorescence stainings of MS lesion tissue with MS-mAb revealed myelin reactivity in the cePC repertoire of all four patients and intracellular filament reactivity in one patient. While myelin staining by MS-mAb was only rarely detectable in non-MS CNS white matter tissue, it was greatly enhanced at the edge of demyelinating lesions in MS brain tissue. Our findings provide conclusive evidence for the presence of an antigen-driven B cell response in the CSF of MS patients directed against epitopes present in areas of myelin degradation.

Relevant antibody subsets against MOG recognize conformational epitopes exclusively exposed in solid-phase ELISA.

A pathogenic role for circulating anti-myelin antibodies is difficult to establish in multiple sclerosis (MS). Here, we unravel a broad heterogeneity within the anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in humans and non-human primates, and demonstrate that detection of important epitopes of MOG within the pathogenic repertoire is exclusively dependent on presentation on a solid-phase MOG conformer. Results of ELISA and those of a liquid-phase assay were compared using a MOG protein with identical sequence but different conformations. We tested sera from 50 human subjects, plasma of Callithrix jacchus marmosets known to contain antibodies reactive to either conformational or linearized MOG, and monoclonal, conformation-dependent anti-MOG antibodies. We have found no antibody reactivity against the soluble MOG conformer in human serum, and show that this lack of detection is not due to technical artifacts. Rather, dominant epitopes of MOG are not displayed in soluble phase, as shown by a complete lack of binding of conformation-dependent mAb. In MP4-immune marmosets that exhibit demyelinating pathology due to spreading of antibody determinants to myelin-embedded MOG, only ELISA can detect pathogenic circulating anti-MOG antibodies. Thus, the accurate detection of important subsets of pathogenic anti-MOG antibodies requires methods in which MOG is displayed similarly to its natural conformation in myelin.

Pathogen specificity and autoimmunity are distinct features of antigen-driven immune responses in neuroborreliosis.

Neuroborreliosis (NB) is a chronic infectious disease of the central nervous system (CNS) caused by a tick-borne spirochete, Borrelia burgdorferi. In addition to direct effects of the causative infectious agent, additional immunity-mediated mechanisms are thought to play a role in the CNS pathology of NB. In order to further understand the involvement of humoral immune mechanisms in NB, we dissected the intrathecal antibody responses down to the single-plasma-cell level. Starting with single-cell reverse transcription-PCR of fluorescence-activated cell sorter-sorted cerebrospinal fluid plasma cells from an NB patient, we identified expanded clones and resurrected the antigen specificity of their secreted antibodies through recombinant expression of the correctly paired immunoglobulin heavy- and light-chain genes as monoclonal antibodies (MAbs). As expected, we found specificity for the causative infectious agent, B. burgdorferi, among the clonally expanded plasma cell (cePC)-derived MAbs. However, from an independent cePC of the same patient, we could derive MAbs specific for human CNS myelin, without detectable cross-reactivity with B. burgdorferi antigens. While reactivity against B. burgdorferi is a known feature of humoral immune responses in NB, we show (i) that immune responses specific for self antigens may be a distinct feature of CNS infections independent of pathogen reactivity and (ii) that humoral autoimmunity in NB (since found in cePC) is the result of a truly antigen-driven immune response. Our findings indicate that in NB mechanisms may be at play that induce distinct immune responses specific for pathogen and self antigens independent from "molecular mimicry."

Ultrasound diagnostics of the vertebrobasilar system.

Despite the fact that ischemic stroke in the vertebrobasilar system (VBS) is significantly less frequent than in the carotid system, abnormalities found in Doppler and duplex examinations are about as prevalent in the VBS as in the carotid system. Because of the potentially severe clinical deficits associated with stroke of the VBS and the increased risk for stroke under conditions, such as underlying symptomatic vertebrobasilar stenosis and general anesthesia, it is highly desirable to have reliable methods available to identify pathological changes of the VBS. Furthermore, because the VBS via the circle of Willis can play a significant role as collateral blood supply system when vessels of the anterior circulation have been compromised, the knowledge of the VBS is necessary to estimate the overall integrity of the remaining blood flow to the brain.

Antibody responses against galactocerebroside are potential stage-specific biomarkers in multiple sclerosis.

BACKGROUND: Galactocerebroside, the major glycolipid of central nervous system myelin, is a known target for pathogenic demyelinating antibody responses in experimental allergic encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). OBJECTIVE: To address the importance of anti-galactocerebroside (alpha-GalC) antibodies in MS and to evaluate them as biomarkers of disease. METHODS: alpha-GalC IgGs were quantified from sera of patients with MS and in marmoset EAE by a new immunosorbent assay. RESULTS: We report a significant difference in serum alpha-GalC IgG titers between patients with relapsing-remitting (RR)-MS and healthy controls (HCs; P < .001). The frequencies of alpha-GalC antibody-positive subjects (alpha-GalC titers > or = mean HC titers+3 SD) are also significantly elevated in RR-MS compared with HC (40% vs 0%; P = .0033). Immunoaffinity purified alpha-GalC IgGs from human serum bind to cultured human oligodendrocytes, indicating that the ELISA detects a biologically relevant epitope. Corroborating these findings, alpha-GalC antibody responses in marmoset EAE were similarly found to be specifically associated with the RR forms and not the peracute or progressive forms, in contrast with other anti-myelin antibodies (P = .0256). CONCLUSION: (1) alpha-GalC antibodies appear MS-specific and are not found in healthy subjects, unlike antibodies against myelin proteins; (2) when present, alpha-GalC antibodies identify mostly RR-MS and may be an indicator of ongoing disease activity. This novel assay is a suitable and valuable method to increase accuracy of diagnosis and disease staging in MS.

Molecular characterization of antibody specificities against myelin/oligodendrocyte glycoprotein in autoimmune demyelination.

Myelin/oligodendrocyte glycoprotein (MOG) is a target antigen for myelin-destructive Abs in autoimmune central nervous system demyelinating disorders. Little is known about the molecular and structural basis of these pathogenic Ab responses. Here, we have characterized anti-MOG Ab specificities in the marmoset model of experimental allergic encephalomyelitis, by means of a combinatorial IgG-Fab library. We found that a diverse population of Ig genes encodes for auto-Abs that exclusively recognize conformation-dependent antigenic targets on MOG. These antigenic domains correspond to exposed epitopes in vivo, as the Fab fragments recognize native MOG in situ in marmoset brain tissue. The Ab fragments described here represent Ab specificities that are common constituents of the humoral immune repertoire against MOG in outbred populations, as demonstrated by their ability to displace native anti-MOG Abs present in sera from MOG-immune marmosets and patients with multiple sclerosis. Furthermore, neuropathological analysis and characterization of Ab epitope specificities in animals immunized with MOG or MOG-derived peptides revealed that only conformation-dependent Abs are associated with demyelinating activity, suggesting that epitope recognition is an important factor for Ab pathogenicity. Our findings provide novel and unexpected knowledge on the diversity of anti-MOG Ab responses in nonhuman primates and humans, and will permit the dissection of pathogenic auto-Ab properties in multiple sclerosis.

Frontline: Epitope recognition on the myelin/oligodendrocyte glycoprotein differentially influences disease phenotype and antibody effector functions in autoimmune demyelination.

Preliminary observations of humoral immunity against the myelin oligodendrocyte glycoprotein (MOG) in experimental allergic encephalomyelitis (EAE) and human multiple sclerosis (MS) suggest that a subset of anti-MOG autoantibodies directed against conformational epitopes is of pathogenic predominance. Here, we provide proof that in marmoset EAE, autoantibodies reactive against conformational epitopes of MOG are not only responsible for aggravating demyelination, but also an essential factor for disease dissemination in space within the central nervous system, a hallmark for typical forms of human MS. In terms of effector mechanisms, IgG deposition and complement activation occur exclusively in association with presence of these conformational antibodies, while microglial/macrophage activation appears to be a common immunopathological finding regardless of the fine determinant specificity of anti-MOG antibodies. These findings highlight for the first time the complex heterogeneity of function and pathogenicity in the polyclonal anti-MOG antibody repertoire of outbred species. Because the linear and conformational antibody determinants of MOG are shared between marmosets and humans, these results are directly relevant to understanding effector mechanisms of organ damage in MS.