Evidence-based guideline update: Plasmapheresis in neurologic disorders: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology

Utility of Plasmapheresis in Autoimmune-Mediated Encephalopathy in Children: Potentials and Challenges

Autoimmune-mediated encephalopathy in children continues to constitute a diagnostic and therapeutic challenge in pediatric population. Utility and usefulness in this clinical setting of plasmapheresis have seldom been evaluated in current pediatric literature. Children with immune-mediated encephalopathies represent a uniquely different group among patients presenting to intensive care units or neurological services worldwide. Arriving at a final diagnosis is not an easy task for treating physicians. It is very crucial to consider early use of first-line immunotherapy modalities, save those children's lives and improve outcomes. Plasmapheresis is an emerging, potentially beneficial first-line therapy in such patients. However, indications, value, logistics, and procedural difficulties are often faced. This study is mainly meant to review the current knowledge in regard to the clinical value of plasmapheresis in children with immune-mediated encephalopathy.

Plasmapheresis and immunoadsorption in patients with steroid refractory multiple sclerosis relapses

Patients suffering from multiple sclerosis (MS) are treated with high-dose intravenous steroids during acute relapses. In case of steroid refractory relapses, patients are treated with plasmapheresis or immunoadsorption. Until now data concerning the efficacy of both procedures are scarce. Visual evoked potentials (VEP), visual acuity and degree of remission of deficits caused by a relapse that had led to admission in MS patients (n = 48) treated with PLEX, IA or both in a single university centre setting were evaluated retrospectively. In a grouped analysis of patients treated with combined PLEX/IA, PLEX or IA alone, patients in all groups profited as assessed by VEP. Visual acuity also showed a trend towards a better performance, but lacked significance. In a subgroup analysis only concerning patients with initially pathological VEP there was a significant beneficial effect in the groups treated with PLEX/IA as well as in the group summarizing all patients. The combination of PLEX and IA provides a valid treatment option in steroid-refractory MS-relapses, and IA should be considered in acute relapses especially in patients with side effect of PLEX.

Current and future immunotherapy targets in autoimmune neurology

Randomized controlled treatment trials of autoimmune neurologic disorders are generally lacking and data pertaining to treatment are mostly derived from expert opinion, large case series, and anecdotal reports. The treatment of autoimmune neurologic disorders comprises oncologic therapy (where appropriate) and immunotherapy. In this chapter, we first describe the standard acute and chronic immunotherapies and provide a practical overview of their use in the clinic (mechanisms of action, dosing, monitoring, and side effects). Novel approaches to treatment of autoimmune neurologic disorders, through new drug discovery or repurposing, are dependent on improved mechanistic understanding of immunopathology. Such approaches, with emphasis on monoclonal antibodies, are discussed using the paradigm of three autoimmune neurologic disorders whose immunopathogenesis is better understood, specifically myasthenia gravis, neuromyelitis optica, and chronic inflammatory demyelinating polyradiculoneuropathy. It is important to realize that the treatment strategy and management plan must be individualized for each patient. In general these are influenced by the following: clinical severity, antibody type, presence or absence of cancer, and prior treatment response, if known.

Plasma Exchange in a Patient with Tumefactive, Corticosteroid-Resistant Multiple Sclerosis

Tumefactive multiple sclerosis (MS) is an aggressive form of MS that can be difficult to treat with standard therapies. In severe MS relapses, plasma exchange (PLEX) has shown some benefit, but reports of its use in patients with tumefactive MS are limited. This article describes the successful use of PLEX in a patient with tumefactive MS. A 46-year-old right-handed woman with a recent diagnosis of MS presented with drowsiness, dysarthria, horizontal nystagmus, and quadriparesis. Her brain magnetic resonance images demonstrated multiple tumefactive demyelinating lesions in the medulla, bilateral periventricular white matter, and corona radiata white matter. She was initially treated with a 10-day course of intravenous methylprednisolone without benefit; therefore, PLEX was initiated. After the second exchange, the patient started to improve and was discharged initially to rehabilitation and then home. She was started on disease-modifying therapy with natalizumab and did not experience further relapses but had slow clinical decline during the next year, which led to discontinuation of natalizumab treatment. PLEX may be used as second-line treatment in corticosteroid-resistant MS relapses, but there are limited reports of its use in patients with tumefactive MS. This patient presented with aggressive disease with multiple tumefactive lesions and did not respond to standard treatment with corticosteroids. PLEX was successful in improving her symptoms, allowing her to return home, although the disease progressed during the next year.

Hyperchloremic metabolic acidosis following plasma exchange during myasthenia gravis crisis

BACKGROUND

Therapeutic plasma exchanges are increasingly used, notably during myasthenia gravis crisis. Repeated exchanges may induce severe adverse events.

CASE

We reported a case of symptomatic hyperchloremic metabolic acidosis following a therapeutic plasma exchange. Analysis of 4% albumin substitution solution revealed a chloride concentration of 145 mmol/L, which could explain this acidosis.

DISCUSSION

Infusion of high volume of 4% albumin during plasma exchanges may produce hyerchloremic metabolic acidosis.

CONCLUSION

Special attention should be paid when repeated plasma exchanges are performed. J. Clin. Apheresis 31:479-480, 2016. © 2015 Wiley Periodicals, Inc.

Plasma exchange for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an uncommon progressive or relapsing paralysing disease caused by inflammation of the peripheral nerves. If the hypothesis that it is due to autoimmunity is correct, removal of autoantibodies in the blood by plasma exchange should be beneficial.

OBJECTIVES

To assess the effects of plasma exchange for treating CIDP.

SEARCH METHODS

On 30 June 2015, we searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register for Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL Plus, and LILACS. We also scrutinised the bibliographies of the trials, contacted the trial authors and other disease experts, and searched trials registries for ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs in participants of any age comparing plasma exchange with sham treatment or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the trials, extracted the data, and assessed risk of bias. Where possible the review authors combined data according to the methods of the Cochrane Neuromuscular Disease Review Group.

MAIN RESULTS

PRIMARY OUTCOME MEASURE

one cross-over trial including 18 participants showed after four weeks, 2 (95% confidence interval (CI) 0.8 to 3.0) points more improvement on an 11-point disability scale with plasma exchange (10 exchanges over four weeks) than with sham exchange. Rapid deterioration after plasma exchange occurred in eight of 12 who had improved.

SECONDARY OUTCOME MEASURES

when we combined the results of this cross-over trial and a trial with 29 participants treated in a parallel-group design, there were 31 points (95% CI 16 to 45) more improvement on an impairment scale (maximum score 280) after plasma exchange (six exchanges over three weeks) than after sham exchange. There were significant improvements in both trials in an electrophysiological measure, the proximally evoked compound muscle action potential, after three or four weeks. Nonrandomised evidence indicates that plasma exchange induces adverse events in 3% to 17% of procedures. These events are sometimes serious. Both trials had a low risk of bias. A trial that showed no significant difference in the benefit between plasma exchange and intravenous immunoglobulin is included in the Cochrane review of intravenous immunoglobulin for this condition.

AUTHORS' CONCLUSIONS

Moderate- to high-quality evidence from two small trials shows that plasma exchange provides significant short-term improvement in disability, clinical impairment, and motor nerve conduction velocity in CIDP but rapid deterioration may occur afterwards. Adverse events related to difficulty with venous access, use of citrate, and haemodynamic changes are not uncommon. We need more research to identify agents that will prolong the beneficial action of plasma exchange.

Neuromuscular issues in systemic disease

The neuromuscular system can be involved in several systemic conditions. Clinical manifestations can appear at onset or throughout the course of the disease process. New investigational methods, including imaging of peripheral nerves, new laboratory tests, and antibodies, are available. In addition to symptomatic therapies, specific treatment options, such as for familial amyloid neuropathy and Fabry's disease, are becoming increasingly available. Pathomechanisms vary depending on the underlying disease process. In addition to metabolic, hormonal, immune, and antibody-mediated mechanisms, in some generalized diseases, genetic causes need to be considered. This review focuses on different aspects of the peripheral nervous system including the nerve roots, plexuses, mononeuropathies and generalized neuropathies, neuromuscular junction disorders, muscle, and autonomic nervous system.

Four different synthetic peptides of proteolipid protein induce a distinct antibody response in MP4-induced experimental autoimmune encephalomyelitis

Here we studied the autoantibody specificity elicited by proteolipid protein (PLP) in MP4-induced experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis (MS). In C57BL/6 (B6) mice, antibodies were induced by immunization with one of the two extracellular and by the intracellular PLP domain. Antibodies against extracellular PLP were myelin-reactive in oligodendrocyte cultures and induced mild spinal cord demyelination upon transfer into B cell-deficient J(H)T mice. Remarkably, also antibodies against intracellular PLP showed binding to intact oligodendrocytes and were capable of inducing myelin pathology upon transfer into J(H)T mice. In MP4-immunized mice peptide-specific T(H)1/T(H)17 responses were mainly directed against the extracellular PLP domains, but also involved the intracellular epitopes. These data suggest that both extracellular and intracellular epitopes of PLP contribute to the pathogenesis of MP4-induced EAE already in the setting of intact myelin. It remains to be elucidated if this concept also applies to MS itself.

Fully human monoclonal antibody inhibitors of the neonatal fc receptor reduce circulating IgG in non-human primates

The therapeutic management of antibody-mediated autoimmune disease typically involves immunosuppressant and immunomodulatory strategies. However, perturbing the fundamental role of the neonatal Fc receptor (FcRn) in salvaging IgG from lysosomal degradation provides a novel approach - depleting the body of pathogenic immunoglobulin by preventing IgG binding to FcRn and thereby increasing the rate of IgG catabolism. Herein, we describe the discovery and preclinical evaluation of fully human monoclonal IgG antibody inhibitors of FcRn. Using phage display, we identified several potent inhibitors of human-FcRn in which binding to FcRn is pH-independent, with over 1000-fold higher affinity for human-FcRn than human IgG-Fc at pH 7.4. FcRn antagonism in vivo using a human-FcRn knock-in transgenic mouse model caused enhanced catabolism of exogenously administered human IgG. In non-human primates, we observed reductions in endogenous circulating IgG of >60% with no changes in albumin, IgM, or IgA. FcRn antagonism did not disrupt the ability of non-human primates to mount IgM/IgG primary and secondary immune responses. Interestingly, the therapeutic anti-FcRn antibodies had a short serum half-life but caused a prolonged reduction in IgG levels. This may be explained by the high affinity of the antibodies to FcRn at both acidic and neutral pH. These results provide important preclinical proof of concept data in support of FcRn antagonism as a novel approach to the treatment of antibody-mediated autoimmune diseases.

Plasmapheresis in neurological disorders: Experience from a tertiary care hospital in South India

BACKGROUND

Therapeutic plasma exchange (PE) or plasmapheresis is the treatment of choice in many neurological disorders. Even though it is safe in experienced hands, there is a major concern about its safety among physicians.

OBJECTIVES

To analyze our experience with 230 patients who underwent PE for various neurological disorders.

MATERIALS AND METHODS

Retrospective review of PE procedures done during a period of 48 months, from July 2007 to June 2011 in a tertiary care teaching hospital in South India. Indications, clinical results and technical factors are discussed.

RESULTS

The main indication for PE was GBS (203 patients; 88.3%). Age of patients ranged from 14-65 (mean = 42.3 years). The most common complications were paraesthesias and/or cramps (36.1%) and hypotension (32.2%). Four pregnant patients who underwent PE had good recovery with one intrauterine death. There was no mortality.

CONCLUSION

The analysis of 240 cases of PE done in our department shows that the procedure is safe, with only minimal procedure related complications and no mortality.

Optimizing IgG therapy in chronic autoimmune neuropathies: a hypothesis driven approach

Prolonged intravenous immunoglobulin (IVIG) therapy is used for the chronic autoimmune neuropathies chronic idiopathic demyelinating polyneuropathy and multifocal motor neuropathy, but the doses and treatment intervals are usually chosen empirically due to a paucity of data from dose-response studies. Recent studies of the electrophysiology and immunology of these diseases suggest that antibody-induced reversible dysfunction of nodes of Ranvier may play a role in conduction block and disability which responds to immunotherapy more rapidly than would be expected for demyelination or axonal damage per se. Clinical reports suggest that in some cases, the effects of each dose of IVIG may be transient, wearing-off before the next dose is due. These observations lead us to hypothesize that that therapeutic IgG acts by competing with pathologic autoantibodies and that individual patients may require different IgG levels for optimal therapeutic effects. Frequent IVIG dosing and weekly subcutaneous IgG have been tried as ways of continuously maintaining high serum IgG levels, resulting in stabilization of neuromuscular function in small case series. Frequent grip strength and disability measurements, performed by the patient at home and reported electronically, can be used to assess the extent and duration of responses to IgG doses. Individualization of IgG treatment regimens may optimize efficacy, minimize disability, and identify nonresponders.

Therapeutic plasma apheresis as a treatment for 35 severely ill children and adolescents with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections

BACKGROUND

Because of its reported similarities to Sydenham chorea, therapeutic plasma apheresis (TPA) has been proposed as a potential treatment of pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). To date, support for the use of TPA has been limited to a few anecdotal reports and a small placebo-controlled trial demonstrating dramatic symptom improvements at 1 month and 1 year follow-up. To evaluate the safety and efficacy of TPA further, we undertook a retrospective review of all PANDAS patients treated with TPA at Georgetown University Hospital between August 2009 and October 2013.

METHODS

Forty patients were identified, and sufficient information was available from medical records and telephone interview for 35 cases (88%). All 35 (23 boys; 12 girls) met diagnostic criteria for PANDAS (Swedo et al. 1998 ) and had severe symptoms. The TPA procedures were performed at Georgetown University Hospital using a protocol that processes a total of 4.5 blood volumes over 3-5 days (three treatments of 1.5 volumes each). Overall symptom improvements at 6 months post-TPA and long-term follow-up were estimated by parents, who also rated changes in individual symptoms to provide information about patterns of improvement.

RESULTS

All patients were reported to have received at least some benefit from TPA, with average improvement of 65% at 6 months post-TPA and 78% at longer-term follow-up. A decrease in the number of reported symptoms also occurred, with particular improvements in obsessive-compulsive disorder (OCD), anxiety, tics, and somatic symptoms, including dysgraphia, sleep difficulties, and urinary urgency or frequency. Contrary to expectations, preceding duration of illness was not correlated with degree of improvement following TPA, suggesting that acuity of illness is not a factor affecting response. Only two adverse events were reported: both involved reopening of the site where the central line had been placed and resolved immediately following application of pressure and re-dressing of the puncture site.

CONCLUSIONS

Therapeutic plasma apheresis is an invasive medical intervention that should be reserved for treatment of children and adolescents who are severely affected by PANDAS. In such patients, it appears to be a safe, well-tolerated, and beneficial treatment option.

Severe Sydenham's chorea (chorea paralytica) successfully treated with plasmapheresis

Sydenham’s chorea is often regarded as a relatively benign and self-limiting condition. Treatment is typically symptomatic, although occasionally immunomodulatory therapies are required in severe forms. Here we report a girl who was affected with the severe variant, chorea paralytica, who responded dramatically and rapidly to plasmapheresis, having failed other therapies.

Consensus recommendations for the diagnosis and treatment of multiple sclerosis: the Middle East North Africa Committee for Treatment and Research In Multiple Sclerosis (MENACTRIMS)

With evolving diagnostic criteria and the advent of new oral and parenteral therapies for MS, most current diagnostic and treatment algorithms need re-evaluation and updating. The diagnosis of MS relies on incorporating clinical and paraclinical findings to prove dissemination in space and in time, and exclude alternative diseases that can explain the findings at hand. The differential diagnostic workup should be guided by clinical and laboratory red flags to avoid unnecessary tests. Appropriate multiple sclerosis (MS) therapy selection is critical to maximize patient benefit. The current guidelines review the scientific evidence supporting treatment of acute relapses, radiologically isolated syndrome, clinically isolated syndrome, relapsing remitting MS, secondary progressive MS, and primary progressive MS. The purpose of these guidelines is to provide practical recommendations and algorithms for the diagnosis and treatment of MS based on current scientific evidence and clinical experience.

Prognostic factors and complication rates for double-filtration plasmapheresis in patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute immune-mediated demyelinating polyradiculoneuropathy that could lead to disabilities if not properly treated. There are only limited data on the prognostic factors and complications when using double-filtration plasmapheresis in these patients. We reviewed the medical records of 60 GBS patients who underwent double-filtration plasmapheresis as the first-line therapy at a tertiary care teaching hospital. The severity of disease was evaluated at different time points using disability scores. Functional outcome was defined as good (GBS disability score 0 to 2) or poor (GBS disability score 3 to 6) at 28 days after admission. The cohort included 22 women and 38 men with a mean age of 50 ± 18 years. In univariate logistic regression analysis, potential factors associated with poor outcome include an older age (P = 0.101), the absence of preceding respiratory tract infection (P = 0.043), mechanical ventilation (P = 0.016), a lower hematocrit (p = 0.072), a lower serum sodium level (P = 0.153) and a higher disability score on admission (P < 0.001). In multivariate analysis, a higher disability score on admission was associated with a poorer outcome (OR, 5.61; 95% CI, 2.34 to 13.43; P < 0.001), whereas the presence of prodromal upper respiratory tract infection correlated with a better outcome (OR, 0.13; 95% CI, 0.03-0.59; P = 0.009). Among 60 patients, eleven (18.3%) have various complications attributed to plasmapheresis treatment. Six patients (10.0%) developed deep vein thrombosis and two experienced catheter-related infection (3.3%). Hypotension, allergy and hemolysis occurred in one patient each (1.7%). In conclusion, we describe our experiences of using DFPP in the treatment of GBS. The pretreatment severity score was the most significant predictor of treatment outcome, suggesting that early referral and timely treatment are important. Potential complications such as catheter-related infection and deep vein thrombosis should be monitored carefully.

Rapid and reversible responses to IVIG in autoimmune neuromuscular diseases suggest mechanisms of action involving competition with functionally important autoantibodies

Intravenous immunoglobulin (IVIG) is widely used in autoimmune neuromuscular diseases whose pathogenesis is undefined. Many different effects of IVIG have been demonstrated in vitro, but few studies actually identify the mechanism(s) most important in vivo. Doses and treatment intervals are generally chosen empirically. Recent studies in Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy show that some effects of IVIG are readily reversible and highly dependent on the serum IgG level. This suggests that in some autoantibody-mediated neuromuscular diseases, IVIG directly competes with autoantibodies that reversibly interfere with nerve conduction. Mechanisms of action of IVIG which most likely involve direct competition with autoantibodies include: neutralization of autoantibodies by anti-idiotypes, inhibition of complement deposition, and increasing catabolism of pathologic antibodies by saturating FcRn. Indirect immunomodulatory effects are not as likely to involve competition and may not have the same reversibility and dose-dependency. Pharmacodynamic analyses should be informative regarding most relevant mechanism(s) of action of IVIG as well as the role of autoantibodies in the immunopathogenesis of each disease. Better understanding of the role of autoantibodies and of the target(s) of IVIG could lead to more efficient use of this therapy and better patient outcomes.

Evaluation of the quality of guidelines for myasthenia gravis with the AGREE II instrument

Background

Clinical practice guidelines (CPGs) are systematically developed statements to assist practitioners in making decisions about appropriate healthcare in specific clinical circumstances. The methodological quality of CPGs for myasthenia gravis (MG) are unclear.

Objective

To critically evaluate the methodological quality of CPGs for MG using AGREE II instrument.

Method

A systematical search strategy on PubMed, EMBASE, DynaMed, the National Guideline Clearinghouse (NGC) and the Chinese Biomedical Literature database (CBM) was performed on September 20th 2013. All guidelines related to MG were evaluated with AGREE II. The software used for analysis was SPSS 17.0.

Results

A total of 15 CPGs for MG met the inclusion criteria (12 CPGs in English, 3 CPGs in Chinese). The overall agreement among reviews was moderate or high (ICC >0.70). The mean scores (mean ± SD) for al six domains were presented as follows: scope and purpose (60.93% ±16.62%), stakeholder involvement (40.93% ±20.04%), rigor of development (37.22% ±30.46%), clarity of presentation (64.26% ±16.36%), applicability (28.19% ±20.56%) and editorial independence (27.78% ±28.28%). Compared with non-evidence-based CPGs, evidence-based CPGs had statistically significant higher quality scores for all AGREE II domains (P<0.05). All domain scores appear slightly higher for CPGs published after AGREE II instrument development and validation (P>0.05). The quality scores of CPGs developed by NGC/AAN were higher than the quality scores of CPGs developed by other organizations for all domains. The difference was statistically significant for all domains with the exception of clarity of presentation (P = 0.07).

Conclusions

The qualities of CPGs on MG were generally acceptable with several flaws. The AGREE II instrument should be adopted by guideline developers, particularly in China.

Chronic inflammatory demyelinating polyradiculoneuropathy and variants: where we are and where we should go

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic and often disabling sensory motor neuropathy postulated as caused by an immune attack against peripheral nerve myelin. In addition to a classic sensory–motor polyneuropathy, other phenotypes of CIDP have been described including the Lewis- Sumner syndrome, distal acquired demyelinating symmetric (DADS) neuropathy, pure motor CIDP, pure sensory CIDP including chronic immune sensory polyradiculopathy (CISP), and focal CIDP. These phenotypes are currently considered to be variants of CIDP, even if the possibility that they represent different demyelinating neuropathies cannot be fully excluded considering differences in their response to therapy. Several data support the role of the immune system in the pathogenesis of CIDP even if the precise targets and actors (antibodies and lymphocytes) of this immune response remain uncertain. Recent studies have shown that the therapeutic response may differ in patients with peculiar clinical presentations supporting the hypothesis that different pathogenetic mechanisms may underlie the heterogeneity of CIDP. The majority of patients with CIDP show improvement after immune therapies including corticosteroids, plasma exchange, and high-dose intravenous immunoglobulin (IVIg). It remains unclear why none of the other immune therapies that were reported to be variably effective in other immune disorders proved to be effective also in CIDP.

Post-infectious autoimmune disorders: Sydenham's chorea, PANDAS and beyond

Infections, and the resulting immune response to these infections, have recently received increased recognition as pathogenic mechanisms for neuropsychiatric disorders. Sydenham's chorea (SC), a widely recognized post-streptococcal autoimmune disorder, represents a model for this proposed pathogenesis. In SC, a dysregulated immune response to a streptococcal infection is hypothesized to result in inflammation of neuronal networks, particularly the basal ganglia nuclei. The resulting dysfunction in the basal ganglia nuclei are hypothesized to lead to a constellation of adventitious movements and psychiatric symptoms, which investigations have shown are amenable to immunomodulatory therapies. PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal infections) has been proposed as a variant of SC, and is hypothesized to share a pathogenic mechanism, despite a unique symptom profile of predominantly psychiatric symptoms. In this review, we present the clinical aspects of both disorders, the data for potential shared etiopathogenesis between them, and the evidence for the therapeutic use of immunomodulatory therapies for the symptoms of SC and PANDAS. This article is part of a Special Issue entitled SI: Neuroimmunology in Health And Disease.

Categorization of multiple sclerosis relapse subtypes by B cell profiling in the blood

Introduction

B cells are attracting increasing attention in the pathogenesis of multiple sclerosis (MS). B cell-targeted therapies with monoclonal antibodies or plasmapheresis have been shown to be successful in a subset of patients. Here, patients with either relapsing-remitting (n = 24) or secondary progressive (n = 6) MS presenting with an acute clinical relapse were screened for their B cell reactivity to brain antigens and were re-tested three to nine months later. Enzyme-linked immunospot technique (ELISPOT) was used to identify brain-reactive B cells in peripheral blood mononuclear cells (PBMC) directly ex vivo and after 96 h of polyclonal stimulation. Clinical severity of symptoms was determined using the Expanded Disability Status Scale (EDSS).

Results

Nine patients displayed B cells in the blood producing brain-specific antibodies directly ex vivo. Six patients were classified as B cell positive donors only after polyclonal B cell stimulation. In 15 patients a B cell response to brain antigens was absent. Based on the autoreactive B cell response we categorized MS relapses into three different patterns. Patients who displayed brain-reactive B cell responses both directly ex vivo and after polyclonal stimulation (pattern I) were significantly younger than patients in whom only memory B cell responses were detectable or entirely absent (patterns II and III; p = 0.003). In one patient a conversion to a positive B cell response as measured directly ex vivo and subsequently also after polyclonal stimulation was associated with the development of a clinical relapse. The evaluation of the predictive value of a brain antigen-specific B cell response showed that seven of eight patients (87.5%) with a pattern I response encountered a clinical relapse during the observation period of 10 months, compared to two of five patients (40%) with a pattern II and three of 14 patients (21.4%) with a pattern III response (p = 0.0005; hazard ratio 6.08 (95% confidence interval 1.87-19.77).

Conclusions

Our data indicate actively ongoing B cell-mediated immunity against brain antigens in a subset of MS patients that may be causative of clinical relapses and provide new diagnostic and therapeutic options for a subset of patients.

Autoimmunity and inflammation in status epilepticus: from concepts to therapies

The understanding of immunological mechanisms underlying some forms of epilepsy and encephalitis has rapidly increased for the last 10 years leading to the concept of status epilepticus of autoimmune origin. Actual treatment recommendations regarding autoimmune status epilepticus are based on retrospective case studies, pathophysiological considerations and experts' opinion. In addition, there are no clear indicators to predict outcome. In situations where autoimmune mechanisms are suspected in patients with status epilepticus, there is evidence that earlier treatment is related to better outcome. Increased awareness is mandatory to decrease the number of patients with major neurological problems or fatal outcome, which is overall about 50%. We here summarize findings of all pediatric and adult patients reported to date, and review the current state of knowledge in the field of immune therapeutic approaches of status epilepticus.

Multiple sclerosis: current knowledge and future outlook

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by demyelination and axonal loss. The etiology of MS is unknown; however, environmental and genetic factors play a key role in the development of MS. Diagnostic criteria have been adapted to facilitate earlier diagnosis with increased sensitivity and specificity. Our understanding of the pathophysiology of MS has deepened considerably in recent years, resulting in different therapies to modify the disease course. Furthermore, several drugs have lately shown efficacy in phase III studies and their approval is expected in the near future. As treatment options expand, a future challenge will be to find the optimal treatment for the individual patient.

SUMMARY

This mini-review gives an overview of the current knowledge of MS with emphasis on the latest diagnostic criteria and both current and upcoming treatment options. Key Messages: Treatment of MS changes rapidly as the knowledge and therapeutic options in MS expand. Clinical Impact: Diagnosis of MS is based on McDonald criteria. MS therapy can be divided into relapse, disease-modifying and symptomatic treatment. Relapses are commonly treated with intravenous methylprednisolone. First-line therapy consists of either interferon-β, glatiramer acetate or teriflunomide. In general, agents used as escalation therapies (natalizumab, fingolimod and mitoxantrone) are more potent than the agents used for first-line therapy; however, these have potentially serious side effects and should be used with care.

Identification of a B cell-dependent subpopulation of multiple sclerosis by measurements of brain-reactive B cells in the blood

B cells are increasingly coming into play in the pathogenesis of multiple sclerosis (MS). Here, we screened peripheral blood mononuclear cells (PBMC) from patients with clinically isolated syndrome (CIS), MS, other non-inflammatory neurological, inflammatory neurological or autoimmune diseases, and healthy donors for their B cell reactivity to CNS antigen using the enzyme-linked immunospot technique (ELISPOT) after 96 h of polyclonal stimulation. Our data show that nine of 15 patients with CIS (60.0%) and 53 of 67 patients with definite MS (79.1%) displayed CNS-reactive B cells, compared to none of the control donors. The presence of CNS-reactive B cells in the blood of the majority of patients with MS or at risk to develop MS along with their absence in control subjects suggests that they might be indicative of a B cell-dependent subpopulation of the disease.

Therapeutic Plasma Exchange in Neurologic Diseases: An Experience with 91 Patients in Seven Years

INTRODUCTION

In this study, we report the results of our experience of therapeutic plasma exchange (TPE) for neuroimmunologic disorders performed at our hospital over a seven-year period.

METHODS

We retrospectively reviewed the medical records of 91 patients (53 male, 38 female) who had been treated at our center with TPE.

RESULTS

60 patients with Guillain-Barrè syndrome (GBS), 23 with myasthenia gravis (MG), 4 with chronic inflammatory demyelinating polyneuropathy (CIDP) and 1 patient each with polymyositis, septic encephalopathy, acute disseminated encephalomyelitis (ADEM) and Opsoclonus-Myoclonus syndrome (OMS) received TPE. 26.7% of GBS patient's made complete recovery, 61.7% had partial recovery and 11.7% patients died due to respiratory failure. Despite our best efforts and effective TPE treatments, 13.4% of MG patients deceased, however, 78% had full recovery. Three patients with CIDP were discharged with full and 1 patient with partial recovery. The patient with ADEM had partial recovery with TPE at first, but deceased 2 months later due to pneumonia-related respiratory insufficiency. While, patient with polymyositis had slight-partial recovery, we obtained full recovery with TPE in septic encephalopathy and OMS patients. The side effects and complications of treatments with TPE, which included hypotension, hypocalcaemia and anemia, were mild and manageable.

CONCLUSION

The improvement rates were encouraging and we concluded that significant benefit can be achieved with TPE for the treatment of neuroimmunological disorders.

Plasmapheresis eliminates the negative impact of AAV antibodies on microdystrophin gene expression following vascular delivery

Duchenne muscular dystrophy is a monogenic disease potentially treatable by gene replacement. Use of recombinant adeno-associated virus (AAV) will ultimately require a vascular approach to broadly transduce muscle cells. We tested the impact of preexisting AAV antibodies on microdystrophin expression following vascular delivery to nonhuman primates. Rhesus macaques were treated by isolated limb perfusion using a fluoroscopically guided catheter. In addition to serostatus stratification, the animals were placed into one of the three immune suppression groups: no immune suppression, prednisone, and triple immune suppression (prednisone, tacrolimus, and mycophenolate mofetil). The animals were analyzed for transgene expression at 3 or 6 months. Microdystrophin expression was visualized in AAV, rhesus serotype 74 sero-negative animals (mean: 48.0 ± 20.8%) that was attenuated in sero-positive animals (19.6 ± 18.7%). Immunosuppression did not affect transgene expression. Importantly, removal of AAV binding antibodies by plasmapheresis in AAV sero-positive animals resulted in high-level transduction (60.8 ± 18.0%), which is comparable with that of AAV sero-negative animals (53.7 ± 7.6%), whereas non-pheresed sero-positive animals demonstrated significantly lower transduction levels (10.1 ± 6.0%). These data support the hypothesis that removal of AAV binding antibodies by plasmapheresis permits successful and sustained gene transfer in the presence of preexisting immunity (natural infection) to AAV.

Plasma exchange induces vitamin D deficiency

BACKGROUND

Plasma exchange is used in the treatment of diseases mediated by pathogenic circulating proteins, or for transplant desensitization. Its non-targeted nature results in the depletion of physiologically important molecules, and it is often complicated by hypocalcaemia.

AIM

To determine the effects of plasma exchange on vitamin D binding protein (DBP) and associated vitamin D metabolites.

DESIGN

Single-centre prospective cohort study of 11 patients.

METHODS

DBP and vitamin D metabolites were measured before and immediately after five plasma exchanges, and 7 and 28 days after discontinuation of plasma exchange.

RESULTS

Plasma exchange reduced plasma DBP concentration from 196.9 ± 53.2 to 98.5 ± 34 μg/ml (P = 0.0001), 1,25-dihydroxyvitamin D from 103 ± 52 to 42 ± 4 pmol/l (P = 0.003) and 25-hydroxyvitamin D from 49.7 ± 29 to 22 ± 9.4 nmol/l (P = 0.0017), through their removal in effluent. After 7 days, DBP and 1,25-dihydroxyvitamin D were not significantly different from baseline, but 25-hydroxyvitamin D remained significantly lower after 7 days (26.4 ± 9.8 nmol/l, P = 0.02) and 28 days (30.8 ± 15.5 nmol/l, P = 0.048). Corrected calcium decreased from 2.23 ± 0.11 to 1.98 ± 0.08 mmol/l (P = 0.0007) immediately after five treatments. Plasma calcium was significantly associated with 1,25-dihydroxyvitamin D (r(2) = 0.79, P < 0.0001).

CONCLUSION

Plasma exchange induced an acute reversible decrease in plasma 1,25-dihydroxyvitamin D, DBP, calcium and a sustained decrease in plasma 25-hydroxyvitamin D.

Assessing relapses and response to relapse treatment in patients with multiple sclerosis: a nursing perspective

There are currently no assessment tools that focus on evaluating patients with multiple sclerosis (MS) who are experiencing a relapse or that evaluate patients' response to acute relapse treatment. In practice, assessments are often subjective, potentially resulting in overlooked symptoms, unaddressed patient concerns, unnoticed or underrecognized side effects of therapies (both disease modifying and symptomatic), and suboptimal therapeutic response. Systematic evaluation of specific symptoms and potential side effects can minimize the likelihood of overlooking important information. However, given the number of potential symptoms and adverse events that patients may experience, an exhaustive evaluation can be time-consuming. Clinicians are thus challenged to balance thoroughness with brevity. A need exists for a brief but comprehensive objective assessment tool that can be used in practice to 1) help clinicians assess patients when they present with symptoms of a relapse, and 2) evaluate outcomes of acute management. A working group of expert nurses convened to discuss recognition and management of relapses. In this article, we review data related to recognition and management of relapses, discuss practical challenges, and describe the development of an assessment questionnaire that evaluates relapse symptoms, the impact of symptoms on the patient, and the effectiveness and tolerability of acute treatment. The questionnaire is designed to be appropriate for use in MS specialty clinics, general neurology practices, or other practice settings and can be administered by nurses, physicians, other clinicians, or patients (self-evaluation). The relapse assessment questionnaire is currently being piloted in a number of practice settings.

Myasthenia gravis and pregnancy

Myasthenia gravis is an autoimmune disease of the neuromuscular junction characterized by painless fluctuating skeletal muscle weakness. Disease exacerbations are more likely to occur in the first trimester or puerperium. A number of medications commonly used in obstetric practice can exacerbate the disease. The effect of pregnancy on myasthenia varies substantially from woman to woman and also from pregnancy to pregnancy in the same woman. Mainstay treatments involve acetylcholine esterase inhibitors, corticosteroids and other immunosuppressants, and adequate rest. Newborns may suffer in utero or neonatal consequences, usually transient, of transplacental antibody exposure.

Differential diagnosis of amyotrophic lateral sclerosis from Guillain-Barré syndrome by quantitative determination of TDP-43 in cerebrospinal fluid

The aim of this study was to investigate whether an increased level of TAR DNA-binding protein 43 (TDP-43) in the cerebrospinal fluid (CSF) could be a biomarker for amyotrophic lateral sclerosis (ALS) and facilitate differential diagnosis of ALS from peripheral motor neuropathy. TDP-43 is the major constituent of neuronal and glial inclusions that neuropathologically characterize both ALS and tau-negative frontotemporal lobar degeneration. Recent discoveries of various missense mutations in the TDP-43 gene in familial ALS indicate a pivotal role of the aberrant accumulation of TDP-43 in neurodegeneration. Increased TDP-43 in the CSF could be a hallmark of ALS and other TDP-43 proteinopathy. Sandwich enzyme-linked immunosorbent assay (ELISA) was established to measure the concentration of TDP-43 in biological fluids. Culture supernatants of cells transfected with various TDP-43 constructs were used to confirm that the ELISA detected TDP-43. TDP-43 in the culture supernatant of TDP-43 transfected cells was detected by immunoprecipitation with subsequent immunoblotting and concentrations were successfully measured by sandwich ELISA. We then measured TDP-43 concentrations in the CSF of patients with ALS and Guillain-Barré syndrome (GBS). TDP-43 concentrations in CSF were significantly higher in ALS than in GBS (p = 0.016). The sensitivity of the diagnostic test was 71.4% and the specificity was 84.6%. Quantitative determination of TDP-43 concentrations in the CSF by sandwich ELISA is a potential laboratory test for differentiating ALS from peripheral motor neuropathies such as GBS.

Immunotherapy of multiple sclerosis: the state of the art

It is widely accepted that the main common pathogenetic pathway in multiple sclerosis (MS) involves an immune-mediated cascade initiated in the peripheral immune system and targeting CNS myelin. Logically, therefore, the therapeutic approaches to the disease include modalities aiming at downregulation of the various immune elements that are involved in this immunologic cascade. Since the introduction of interferons in 1993, which were the first registered treatments for MS, huge steps have been made in the field of MS immunotherapy. More efficious and specific immunoactive drugs have been introduced and it appears that the increased specificity for MS of these new treatments is paralleled by greater efficacy. Unfortunately, this seemingly increased efficacy has been accompanied by more safety issues. The immunotherapeutic modalities can be divided into two main groups: those affecting the acute stages (relapses) of the disease and the long-term treatments that are aimed at preventing the appearance of relapses and the progression in disability. Immunomodulating treatments may also be classified according to the level of the 'immune axis' where they exert their main effect. Since, in MS, a neurodegenerative process runs in parallel and as a consequence of inflammation, early immune intervention is warranted to prevent progression of relapses of MS and the accumulation of disability. The use of neuroimaging (MRI) techniques that allow the detection of silent inflammatory activity of MS and neurodegeneration has provided an important tool for the substantiation of the clinical efficacy of treatments and the early diagnosis of MS. This review summarizes in detail the existing information on all the available immunotherapies for MS, old and new, classifies them according to their immunologic mechanisms of action and proposes a structured algorithm/therapeutic scheme for the management of the disease.

Therapeutic plasma exchange in neurology: 2012

In treating neuroimmunological diseases, neurologists have a number of different drugs to choose from ranging from corticosteroids to IVIg to more specific cell based therapies, the latter most frequently from the world of oncology. In some diseases, therapeutic plasma exchange, a procedure rather than a drug, is used. The most obvious advantage of therapeutic plasma exchange is the usually rapid onset of action presumably due to removal of pathogenic auto-antibodies. In some diseases, a single course of therapeutic plasma exchange is used while in others prolonged treatment with therapeutic plasma exchange is used. This article will review the use of therapeutic plasma exchange in neurology and will draw heavily upon recent consensus statements from the American Society for Apheresis and the American Academy of Neurology and by Cochrane reviews.