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Background and Objectives IgG4 autoantibodies to neurofascin-155 (Nfasc155) are associated with a subgroup of patients with chronic inflammatory demyelinating polyneuropathy (CIDP), currently named autoimmune nodopathy. We previously demonstrated that those antibodies alter conduction along myelinated axons by inducing Nfasc155 depletion and paranode destruction. In blood, IgG4 have the potency to exchange their moiety with other unrelated IgG4 through a process called Fab-arm exchange (FAE). This process results in functionally monovalent antibodies and may affect the pathogenicity of autoantibodies. Here, we examined this issue and whether FAE is beneficial or detrimental for Nfasc155 autoimmune nodopathy. Methods The bivalency and monospecificity of anti-Nfasc155 were examined by sandwich ELISA in 10 reactive patients, 10 unreactive CIDP patients, and 10 healthy controls. FAE was induced in vitro using reduced glutathione and unreactive IgG4, and the ratio of the kappa:lambda light chain was monitored. To determine the pathogenic potential of bivalent anti-Nfasc155 IgG4, autoantibodies derived from patients were enzymatically cleaved into monovalent Fab and bivalent F(ab')(2) or swapped with unreactive IgG4 and then were injected in neonatal animals. Results Monospecific bivalent IgG4 against Nfasc155 were detected in the serum of all reactive patients, indicating that a fraction of IgG4 have not undergone FAE in situ. These IgG4 were, nonetheless, capable of engaging into FAE with unreactive IgG4 in vitro, and this decreased the levels of monospecific antibodies and modulated the ratio of the kappa:lambda light chain. When injected in animals, monovalent anti-Nfasc155 Fab did not alter the formation of paranodes; by contrast, both native anti-Nfasc155 IgG4 and F(ab')(2) fragments strongly impaired paranode formation. The promotion of FAE with unreactive IgG4 also strongly diminished the pathogenic potential of anti-Nfasc155 IgG4 in animals and decreased IgG4 clustering on Schwann cells. Discussion Our findings demonstrate that monospecific and bivalent anti-Nfasc155 IgG4 are detected in patients and that those autoantibodies are the pathogenic ones. The transformation of anti-Nfasc155 IgG4 into monovalent Fab or functionally monovalent IgG4 through FAE strongly decreases paranodal alterations. Bivalency thus appears crucial for Nfasc155 clustering and paranode destruction.

Prognosis of myasthenia gravis (MG) in patients with thymoma is not well established. Moreover, it is not clear whether thymoma recurrence or unresectable lesions entail a worse prognosis of MG.

Altres ajuts: We thank the staff of the Department of Psychiatry of Hospital Universitari Santa Maria, Lleida; Núria Vidal D.Clin.Psy, (funded by a Spanish FIS-MSC Grant [PI11/01956]), from Hospital FREMAP Barcelona, Catalonia, Spain, who performed cognitive assessments;E. Vieta thanks the support of the Spanish Ministry of Economy and Competitiveness (PI15/00283) integrated into the Plan Nacional de I + D+I and cofinanced by ISCIII-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER); CIBERSAM; M.J. Portella thanks the suport of the Catalan Department of Health (SLT006_17_177).We also thank the patients and healthy controls who participated in the study for their kind cooperation. We also thank to Rebecca Oglesby MD, who kindly helped us with the language editing. Objective Mutations in CD59 cause CIDP-like polyneuropathy in children with inherited chronic hemolysis. We hypothesized that mutations in CD59 might be found in a subset of sporadic CIDP patients. Methods 35 patients from two centers, fulfilling the EFNS/PNS diagnostic criteria for CIDP were included. CD59 coding region was amplified by PCR and Sanger sequenced. Results One rare variant was detected in a patient which resulted in a synonymous change and predicted to be neutral. Pathogenic variants were absent in our cohort. Interpretation Our pilot study suggests that mutations in CD59 are absent in adult-onset sporadic CIDP.

Introduction: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated syndrome characterized clinically by weakness and/or numbness that evolves over 2 months or more. The heterogeneity of clinical features necessitates an individualized approach to disease monitoring that takes lessons learned from clinical trials and applies them to clinical practice. Areas covered: This review discusses the importance of clinimetrics and biomarkers in CIDP diagnosis and disease monitoring. Highlighted are the challenges of defining responses to immunotherapy, the usefulness, and limitations of utilizing evidence-based clinical outcome measures during routine clinical care, and the evolving understanding of how diagnostic and disease activity biomarkers may reshape our treatment and disease monitoring paradigms. Expert opinion: Although disability and impairment outcome measures are commonly used in CIDP to indicate disease status, the nonspecific nature of these metrics limits the ability to attribute a change in any given metric to a change in CIDP. This interpretive challenge may be magnified by inconsistencies in the direction of change as well as a strong placebo effect. There is a need to improve our understanding of minimally important changes in existing outcome measures as a means to personalize treatment and to better assess disease activity status with biomarker discovery.

Inflammatory neuropathies are a heterogeneous group of rare diseases of the peripheral nervous system that include acute and chronic diseases, such as Guillain-Barre syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The etiology and pathophysiological mechanisms of inflammatory neuropathies are only partly known, but are considered autoimmune disorders in which an aberrant immune response, including cellular and humoral components, is directed towards components of the peripheral nerve causing demyelination and axonal damage. Therapy of these disorders includes broad-spectrum immunomodulatory and immunosuppressive treatments, such as intravenous immunoglobulin, corticosteroids, or plasma exchange. However, a significant proportion of patients do not respond to any of these therapies, and treatment selection is not optimized according to disease pathophysiology. Therefore, research on disease pathophysiology aiming to reveal clinically and functionally relevant disease mechanisms and the development of new treatment approaches are needed to optimize disease outcomes in CIDP and GBS. This topical review describes immunological progress that may help guide therapeutic strategies in the future in these two disorders.

Background Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder characterised by muscle weakness and impaired sensory function. The present study provides a comprehensive literature review of the burden of illness of CIDP. Methods Systematic literature search of PubMed, Embase, and key conferences in May 2019. Search terms identified studies on the epidemiology, humanistic burden, current treatment, and economic burden of CIDP published since 2009 in English. Results Forty-five full texts and nineteen conference proceedings were identified on the epidemiology (n = 9), humanistic burden (n = 7), current treatment (n = 40), and economic burden (n = 8) of CIDP. Epidemiological studies showed incidence and prevalence of 0.2-1.6 and 0.8-8.9 per 100,000, respectively, depending on geography and diagnostic criteria. Humanistic burden studies revealed that patients experienced physical and psychosocial burden, including impaired physical function, pain and depression. Publications on current treatments reported on six main types of therapy: intravenous immunoglobulins, subcutaneous immunoglobulins, corticosteroids, plasma exchange, immunosuppressants, and immunomodulators. Treatments may be burdensome, due to adverse events and reduced independence caused by treatment administration setting. In Germany, UK, France, and the US, CIDP economic burden was driven by direct costs of treatment and hospitalisation. CIDP was associated with indirect costs driven by impaired productivity. Conclusions This first systematic review of CIDP burden of illness demonstrates the high physical and psychosocial burden of this rare disease. Future research is required to fully characterise the burden of CIDP, and to understand how appropriate treatment can mitigate burden for patients and healthcare systems.

Objective To analyze the microRNA profile in serum of patients with Adult Onset Pompe disease (AOPD). Methods We analyzed the expression of 185 microRNAs in serum of 15 AOPD patients and five controls using microRNA PCR Panels. The expression levels of microRNAs that were deregulated were further studied in 35 AOPD patients and 10 controls using Real-Time PCR. Additionally, the skeletal muscle expression of microRNAs which showed significant increase levels in serum samples was also studied. Correlations between microRNA serum levels and muscle function test, spirometry, and quantitative muscle MRI were performed (these data correspond to the study NCT01914536 at ClinicalTrials.gov). Results We identified 14 microRNAs that showed different expression levels in serum samples of AOPD patients compared to controls. We validated these results in a larger cohort of patients and we found increased levels of three microRNAs, the so called dystromirs: miR-1-3p, miR-133a-3p, and miR-206. These microRNAs are involved in muscle regeneration and the expression of these was increased in patients' muscle biopsies. Significant correlations between microRNA levels and muscle function test were found. Interpretation Serum expression levels of dystromirs may represent additional biomarkers for the follow-up of AOPD patients.

Objective To analyze the microRNA profile in serum of patients with Adult Onset Pompe disease (AOPD). Methods We analyzed the expression of 185 microRNAs in serum of 15 AOPD patients and five controls using microRNA PCR Panels. The expression levels of microRNAs that were deregulated were further studied in 35 AOPD patients and 10 controls using Real-Time PCR. Additionally, the skeletal muscle expression of microRNAs which showed significant increase levels in serum samples was also studied. Correlations between microRNA serum levels and muscle function test, spirometry, and quantitative muscle MRI were performed (these data correspond to the study NCT01914536 at ClinicalTrials.gov). Results We identified 14 microRNAs that showed different expression levels in serum samples of AOPD patients compared to controls. We validated these results in a larger cohort of patients and we found increased levels of three microRNAs, the so called dystromirs: miR-1-3p, miR-133a-3p, and miR-206. These microRNAs are involved in muscle regeneration and the expression of these was increased in patients' muscle biopsies. Significant correlations between microRNA levels and muscle function test were found. Interpretation Serum expression levels of dystromirs may represent additional biomarkers for the follow-up of AOPD patients.

Purpose of review Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous disorder that includes diverse clinical presentations and immunopathological mechanisms. Antibodies targeting proteins of the node of Ranvier are present in a subset of CIDP patients. These autoantibodies are pathogenic and associate with specific clinical phenotypes and therapeutic peculiarities. This review summarizes the novel insights that the discovery of novel autoantibodies has brought to the understanding of CIDP. Recent findings Several reports have confirmed the association of the antineurofascin 155 (NF155) antibodies with tremor, ataxia and poor response to IVIG, and with novel pathological features in CIDP patients. The association of nephrotic syndrome with anticontactin 1 (CNTN1) and antinodal neurofascin antibodies has also been described. Also, complement-fixing IgG3 antibodies targeting paranodal proteins have been associated with acute-onset CIDP. Importantly, detection of these autoantibodies has helped selecting CIDP patients for rituximab treatment. Finally, anti-CNTN1 and anti-NF155 antibodies have proven to be the first pathogenic autoantibodies described in CIDP. The discovery of autoantibodies against nodal and paranodal proteins has proven useful in clinical practice, has uncovered novel pathophysiological mechanisms, clinical phenotypes, therapeutic response and prognosis within the CIDP disease spectrum and has boosted the search for other clinically relevant autoantibodies.

Despite the well-recognized importance of immunoglobulin therapy individualization during the treatment of chronic inflammatory demyelinating polyneuropathy (CIDP), the pathway to best achieve optimization is unknown. There are many pharmacokinetic and immunobiologic variables that can potentially influence the appropriateness of any individual therapy. Although identification of specific autoantibodies and their targets has only been accomplished in a minority of patients with CIDP, already the diagnostic and treatment implications of specific autoantibody detection are being realized. Individual variability in IgG pharmacokinetic properties including IgG catabolic rates and distribution, as well as the IgG level necessary for disease control also require consideration during the optimization process. For optimization to be successful there must be a measure of treatment response that has a clinically meaningful interpretation. There are currently available well-defined and validated clinical assessment tools and outcome measures that are well suited for this purpose. While there remains much to learn on how best to manipulate immunopathology and immunoglobulin pharmacokinetics in the most favorable way, there currently exists an understanding of these principles to a degree sufficient to begin to develop rational and evidence-based treatment optimization strategies.

The chronic inflammatory neuropathies (CINs) are rare, very disabling autoimmune disorders that generally respond well to immune therapies such as intravenous immunoglobulin (IVIg). The most common forms of CIN are chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy, and polyneuropathy associated with monoclonal gammopathy of unknown significance. The field of CIN has undergone a major advance with the identification of IgG4 autoantibodies directed against paranodal proteins in patients with CIDP. Although these autoantibodies are only found in a small subset of patients with CIDP, they can be used to guide therapeutic decision-making, as these patients have a poor response to IVIg. These observations provide proof of concept that identifying the target antigens in tissue-specific antibody-mediated autoimmune diseases is important, not only to understand their underlying pathogenic mechanisms, but also to correctly diagnose and treat affected patients. This state-of-the-art Review focuses on the role of autoantibodies against nodes of Ranvier in CIDP, a clinically relevant emerging field of research. The role of autoantibodies in other immune-mediated neuropathies, including other forms of CIN, primary autoimmune neuropathies, neoplasms, and systemic diseases that resemble CIN, are also discussed.

Introduction Antibodies targeting the inward-rectifying potassium channel KIR4.1 have been associated with multiple sclerosis (MS) but studies using diverse techniques have failed to replicate this association. The detection of these antibodies is challenging; KIR4.1 glycosylation patterns and the use of diverse technical approaches may account for the disparity of results. We aimed to replicate the association using three different approaches to overcome the technical limitations of a single technique. We also performed a systematic review to examine the association of anti-KIR4.1 antibodies with MS. Methods Serum samples from patients with MS (n = 108) and controls (n = 77) were tested for the presence of anti-KIR4.1 antibodies using three methods: 1) by ELISA with the low-glycosylated fraction of recombinant KIR4.1 purified from transfected HEK293 cells according to original protocols; 2) by immunocytochemistry using KIR4.1-transfected HEK293 cells; and 3) by immunocytochemistry using the KIR4.1.-transfected MO3.13 oligodendrocyte cell line. We developed a systematic review and meta-analysis of the association of anti-KIR4.1 antibodies with MS according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results We did not detect anti-KIR4.1 antibodies in the MS patients or in controls using ELISA. Neither did we detect any significant reactivity against the antigen on the cell surface using the KIR4.1-transfected HEK293 cells or the KIR4.1-transfected MO3.13 cells. We included 13 prospective controlled studies in the systematic review. Only three studies showed a positive association between anti-KIR4.1 and MS. Clinical and statistical heterogeneity between studies precluded meta-analysis of their results. Conclusion We found no association between anti-KIR4.1 antibody positivity and MS. Although this lack of replication may be due to technical limitations, evidence from our study and others is mounting against the role of KIR4.1 as a relevant MS autoantigen.

Background and purposeThere is increasing interest in using patient-reported outcome measures (PROMs) in clinical studies to capture individual changes over time. However, PROMs have also been criticized because they are entirely subjective. Our objective was to examine the relationship between a subjective PROM and an objective outcome tool in patients with Guillain-Barre syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and gammopathy-related polyneuropathy (MGUSP). MethodsThe Inflammatory Rasch-built Overall Disability Scale (I-RODS (c), a multi-item scale that examines functionality) was completed by 137 patients with newly diagnosed (or relapsing) GBS (55), CIDP (59) and MGUSP (23) who were serially examined (GBS/CIDP, T0/T1/T3/T6/T12 months; MGUSP, T0/T3/T12). Possible association between the I-RODS findings and the vigorimeter scores, an objective linear instrument to assess grip strength, was examined. ResultsA significant correlating trend was found between the I-RODS and grip strength scores for the overall group and in each illness, independently. ConclusionThe objectivity of patients' subjective report on their functional state based on a strong correlation between the I-RODS and grip strength in patients with GBS, CIDP and MGUSP has been demonstrated. These findings provide further support to use the I-RODS and grip strength in future clinical studies in these conditions.

The ability to walk is considered a benchmark for good clinical recovery and prognosis, particularly in patients with Guillain-Barre syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). However, it has never been determined whether being able to walk represents general functionality. The purpose of this study was to examine whether the ability to walk outside independently reflects general functional improvement in patients with GBS, CIDP, and gammopathy-related neuropathy (MGUSP). A total of 137 patients with newly diagnosed (or relapsing) GBS (55), CIDP (59), and MGUSP (23) were serially examined (1-year). Predefined arbitrary cut-offs (so-called patients' Functional-Acceptable-Clinical-Thresholds [FACTs]) were taken at the 50th, 75th, and 90th percentile of the Inflammatory-Rasch-built-Overall-Disability-Scale (I-RODS (c)). We determined the proportion of patients able to walk outside independently that reached the postulated cut-offs. A mean total of 85%, 39%, and 12% of all patients able to walk reached 50th, 75th, and 90th percentile thresholds, respectively. These findings were not neuropathy type related. Our findings show that assessing only one construct of functionality (e.g., walking ability) does not reflect the full scope of daily/social functional deficits perceived by patients. The ability to walk shows a patient is doing better, but not necessarily doing well. The I-RODS (c) bypasses these limitations.

Objective: Myasthenia gravis (MG) is an autoimmune condition in which neurotransmission is impaired by binding of autoantibodies to acetylcholine receptors (AChR) or, in a minority of patients, to muscle specific kinase (MuSK). There are differences in the dominant IgG subclass, pathogenic mechanisms, and treatment responses between the two MG subtypes (AChR or MuSK). The antibodies are thought to be T-cell dependent, but the mechanisms underlying their production are not well understood. One aspect not previously described is whether defects in central and peripheral tolerance checkpoints, which allow autoreactive B cells to accumulate in the naive repertoire, are found in both or either form of MG. Methods: An established set of assays that measure the frequency of both polyreactive and autoreactive B cell receptors (BCR) in naive populations was applied to specimens collected from patients with either AChR or MuSK MG and healthy controls. Radioimmuno-and cell-based assays were used to measure BCR binding to AChR and MuSK. Results: The frequency of polyreactive and autoreactive BCRs (n = 262) was higher in both AChR and MuSK MG patients than in healthy controls. None of the MG-derived BCRs bound AChR or MuSK. Interpretation: The results indicate that both these MG subtypes harbor defects in central and peripheral B cell tolerance checkpoints. Defective B cell tolerance may represent a fundamental contributor to autoimmunity in MG and is of particular importance when considering the durability of myasthenia gravis treatment strategies, particularly biologics that eliminate B cells.

Clinical trials in multifocal motor neuropathy (MMN) have often used ordinal-based measures that may not accurately capture changes. We aimed to construct a disability interval outcome measure specifically for MMN using the Rasch model and to examine its clinimetric properties. A total of 146 preliminary activity and participation items were assessed twice (reliability studies) in 96 clinically stable MMN patients. These patients also assessed the ordinal-based overall disability sum score (construct, sample-dependent validity). The final Rasch-built overall disability scale for MMN (MMN-RODS(C)) was serially applied in 26 patients with newly diagnosed or relapsing MMN, treated with intravenous immunoglobulin (IVIg) (1-year follow-up; responsiveness study). The magnitude of change for each patient was calculated using the minimum clinically important difference technique related to the individually obtained standard errors. A total of 121 items not fulfilling Rasch requirements were removed. The final 25-item MMN-RODS(C) fulfilled all Rasch model's expectations and showed acceptable reliability and validity including good discriminatory capacity. Most serially examined patients improved, but its magnitude was low, reflecting poor responsiveness. The constructed MMN-RODS(C) is a disease-specific, interval measure to detect activity limitations in patients with MMN and overcomes the shortcomings of ordinal scales. However, future clinimetric studies are needed to improve the MMN-RODS(C)'s responsiveness by longer observations and/or more rigorous treatment regimens.

Background: Neuropsychological batteries are infrequently used to assess cognitive impairment in multiple sclerosis because they are time-consuming and require trained personnel. The Symbol Digit Modalities Test (SDMT) is suggested to be a useful screening tool to measure cognitive impairment in multiple sclerosis patients and is more valid and reliable over time than the Paced Auditory Serial Addition Test (PASAT). The purpose of this study was to evaluate which of these tests was more sensitive to cognitive impairment at one-year follow-up. Methods: A total of 237 patients with relapsing-remitting multiple sclerosis and 57 healthy controls underwent a complete neuropsychological assessment. One year later, we assessed 196 patients using the Brief Repeatable Battery of Neuropsychological Tests. We also administered other executive function and prospective memory tests, together with fatigue and depression questionnaires. Results: A total of 33.8% of patients were classified as cognitively impaired. The SDMT and the PASAT 3seconds test (PASAT3) had a sensitivity of 0.809 and 0.783, respectively, thereby classifying patients as cognitively impaired. Analysis of 196 patients one year later showed 31.6% had cognitive impairment compared with 27.6% at the first assessment. The sensitivity to detect cognitive impairment after one year was 0.824 for SDMT and 0.796 for PASAT3. When the predictors were removed from the comparative standard battery, SDMT still showed a slightly higher sensitivity. Both SDMT and PASAT3 correlated significantly with all tests, but SDMT showed higher correlation values. Furthermore, SDMT was completed by all subjects while PASAT3 was completed by 86.9% of patients and 94.7% of controls. Conclusions: SDMT is simpler to administer than PASAT3 and may be slightly more sensitive to MS cognitive impairment. It could thus be a suitable test to assess cognitive impairment routinely in people with relapsing-remitting multiple sclerosis. © 2014 Lopez-Gongora et al.; licensee BioMed Central.

Outcome measures are considered the most important tools to monitor patients' outcome in both clinical and research settings. Measuring the clinical state of patients is a fundamental part of our daily clinical practice and research that sometimes is taken for granted. In peripheral neuropathies, there are many scales available, but most of these are at the ordinal level. This paper will systematically address the types of scales available (being nominal, ordinal, interval, or ratio data-based) in terms of their strengths and weaknesses. The differences between classical test theory-based and modern test method-based outcome measures will be addressed with emphasis on Rasch methodology. Various steps will be highlighted as part of the evaluation and construction of outcome measures using the Rasch method, with the aim to increase the knowledge and utility of this technique. We argue that Rasch-built outcome measures should be used for future studies in neuromuscular disorders and their method of construction could be easily extrapolated to other neurological illnesses.

Purpose of review Autoimmune disorders of the peripheral nerves are diverse and heterogeneous. T cells, macrophages, and autoantibodies have been implicated in their pathogenesis. Autoantibodies to peripheral nerve molecules seem to play a role not only in the pathogenesis but provide diagnostic, prognostic, and therapeutic help. We review the state of the art and most relevant recent findings regarding autoantibodies in chronic inflammatory neuropathies, focusing on their clinical utility. Recent findings Research on autoantibodies in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) has received a recent boost with the description of antibodies against proteins of the node of Ranvier. Antibodies of the IgG4 isotype targeting the paranodal proteins contactin-1 (CNTN1) and neurofascin-155 (NF155) define specific CIDP subtypes and have diagnostic and prognostic implications. In multifocal motor neuropathy, anti-GM1 production is restricted to very few B-cell clones that could be the target of therapies aimed to remove or inactivate them. Moreover, novel ELISA and glycoarray techniques combining GM1 and galactocerebroside gangliosides improved the sensitivity of autoantibody detection. Detailed clinical and paraclinical features, including autoantibody reactivity patters, of autoimmune syndromes affecting simultaneously the central and peripheral nervous systems, are also described. Summary The heterogeneity of chronic inflammatory neuropathies is being unraveled with the description of specific autoantibodies and their association with small disease subtypes. The recently described paranodal autoantibodies anti-CNTN1 and NF155 have direct clinical value and seem to determine response to treatment. Further studies are needed to fully understand the primary contribution of the antibodies to the pathophysiology of the immune neuropathies.

This study aimed to define responder' through the concept of minimum clinically important differences using the individually obtained standard errors (MCID-SE) and a heuristic external criterion' responsiveness method in patients with Guillain-Barre syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). One hundred and fourteen newly diagnosed or relapsing patients (GBS: 55, CIDP: 59) were serially examined (1-year follow-up). The inflammatory Rasch-built overall disability scale (I-RODS), Rasch-transformed MRC sum score (RT-MRC), and Rasch-transformed modified-INCAT-sensory scale (RT-mISS) were assessed. Being-a-responder was defined as having a MCID-SE cut-off 1.96. Also, the correlations between patients' scores on each scale and the EuroQoL health-status thermometer' (external criterion) were determined (higher correlation indicated better responsiveness). In both diseases, the SEs showed a characteristic U'-shaped dynamic pattern across each scales' continuum. The number of patients showing a meaningful change were higher for the I-RODS>RT-MRC>RT-mISS and were in GBS higher than CIDP patients. The MCID-SE concept using Rasch-transformed data demonstrated an individual pattern of being-a-responder' in patients with immune-mediated neuropathies, and the findings were validated by the external criterion responsiveness method. The I-RODS showed greater responsiveness compared with the MRC and INCAT-sensory scales, and its use is therefore recommended in future trials in GBS and CIDP.

The Jamar dynamometer and Vigorimeter have been used to assess grip strength in immune-mediated neuropathies, but have never been compared to each other. Therefore, we performed a comparison study between these two devices in patients with immune-mediated neuropathies. Grip strength data were collected in 102 cross-sectional stable and 163 longitudinal (new diagnoses or changing condition) patients with Guillain-Barre syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), gammopathy-related polyneuropathy (MGUSP), and multifocal motor neuropathy (MMN). Stable patients were assessed twice (validity/reliability studies). Longitudinal patients were assessed 3-5times during 1year. Responsiveness comparison between the two tools was examined using combined anchor-/distribution-based minimum clinically important difference (MCID) techniques. Patients were asked to indicate their preference for the Jamar or Vigorimeter. Both tools correlated highly with each other (=0.86, p

The objectives of this study were to provide an overview of the outcome measures (OMs) applied in clinical trials in multifocal motor neuropathy (MMN) and to determine the responsiveness of a core set of selected OMs as part of the peripheral neuropathy outcome measures standardization (PeriNomS) study. The following OMs were serially applied in 26 patients with newly diagnosed or relapsing MMN, receiving intravenous immunoglobulin (assessments: T0/T3/T12months): 14 muscle pairs MRC (Medical Research Council) scale, the Neuropathy Impairment Scale motor-subset, a self-evaluation scale, grip strength, and MMN-RODS(C) (Rasch-built overall disability scale). All data, except the grip strength, were subjected to Rasch analyses before determining responsiveness. For grip strength, responsiveness was examined using a combined anchor- (SF-36 question-2) and distribution-based (1/2xSD) minimum clinically important difference (MCID) techniques, determining the proportion of patients exceeding both the identified cut-offs. For the remaining scales, the magnitude of change for each patient on each scale was determined using the MCID related to the individual SE (responder definition: MCID-SE1.96). Overall, a great assortment of measures has been used in MMN trials with different responsiveness definitions. For the selected OMs, responsiveness was poor and only seen in one fourth to one third of the patients, the grip strength being more responsive. Despite the efforts taken to standardize outcome assessment, further clinimetric responsiveness studies are needed in MMN.

We performed a comparison between Neuropathy Impairment Scale-sensory (NISs) vs. the modified Inflammatory Neuropathy Cause and Treatment sensory scale (mISS), and NIS-motor vs. the Medical Research Council sum score in patients with Guillain-Barre syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and IgM monoclonal gammopathy of undetermined significance-related polyneuropathy (MGUSP). The ordinal data were subjected to Rasch analyses, creating Rasch-transformed (RT)-intervals for all measures. Comparison between measures was based on validity/reliability with an emphasis on responsiveness (using the patient's level of change related to the individually obtained varying SE for minimum clinically important difference). Eighty stable patients (GBS: 30, CIDP: 30, and MGUSP: 20) were assessed twice (entry: two observers; 2-4weeks later: one observer), and 137 newly diagnosed or relapsing patients (GBS: 55, CIDP: 59, and IgM-MGUSP: 23) were serially examined with 12months follow-up. Data modifications were needed to improve model fit for all measures. The sensory and motor scales demonstrated approximately equal and acceptable validity and reliability scores. Responsiveness scores were poor but slightly higher in RT-mISS compared to RT-NISs. Responsiveness was equal for the RT-motor scales, but higher in GBS compared to CIDP; responsiveness was poor in patients with MGUSP, suggesting a longer duration of follow-up in the latter group of patients.

We investigated the molecular mechanisms involved in the pathogenesis of three inflammatory myopathies, dermatomyositis (DM), polymyositis (PM) and inclusion body myositis (IBM). We performed microarray experiments dagger using microdissected pathological muscle fibres from 15 patients with these disorders and five controls. Differentially expressed candidate genes were validated by immunohistochemistry on muscle biopsies, and the altered pathways were analysed in human myotube cultures. Up-regulation of genes involved in viral and nucleic acid recognition were found in the three myopathies but not in controls. In DM, retinoic acid-inducible gene 1 (RIG-I, DDX58) and the novel antiviral factor DDX60, which promotes RIG-I-mediated signalling, were significantly up-regulated, followed by IFIH1 (MDA5) and TLR3. Immunohistochemistry confirmed over-expression of RIG-I in pathological muscle fibres in 5/5 DM, 0/5 PM and 0/5 IBM patients, and in 0/5 controls. Stimulation of human myotubes with a ligand of RIG-I produced a significant secretion of interferon- (IFN; p < 0.05) and up-regulation of class I MHC, RIG-I and TLR3 (p < 0.05) by IFN-dependent and TLR3-independent mechanisms. RIG-I-mediated innate immunity, triggered by a viral or damage signal, plays a significant role in the pathogenesis of DM, but not in that of PM or IBM. Copyright (c) 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism characterized by episodes of weakness. Although TPP has been described in patients all over the world, it is especially frequent in Asiatic patients. Recently, two genomewide association studies have found a susceptibility locus on chromosome 17q24.3 near the KCNJ2 gene, which is responsible for another cause of periodic paralysis, the Andersen-Tawil syndrome (ATS). We report the first patient diagnosed with ATS with a de novo c. G899C mutation in the KCNJ2 gene in 2010 who developed an autoimmune hyperthyroidism and TPP in 2013. At the time of the ATS diagnosis other causes of periodic paralysis, including thyroid dysfunction, were ruled out. The condition of the patient, who had mild episodes of proximal weakness at follow-up, deteriorated dramatically in 2013, presenting continuous episodes of severe generalized weakness associated with low levels of potassium requiring frequent admissions to the hospital. After a few months, he also presented signs of hyperthyroidism, and a diagnosis of Grave's disease was made. In our opinion, this case clearly demonstrates that a dysfunction of the Kir2.1 potassium channel encoded by the KCNJ2 gene is a risk factor to develop TPP, and can be a useful tool to identify patients at risk in daily clinics.

Objective Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a frequent autoimmune neuropathy with a heterogeneous clinical spectrum. Clinical and experimental evidence suggests that autoantibodies may be involved in its pathogenesis, but the target antigens are unknown. Axoglial junction proteins have been proposed as candidate antigens. We examined the reactivity of CIDP patients' sera against neuronal antigens and used immunoprecipitation for antigen unraveling. Methods Primary cultures of hippocampal neurons were used to select patients' sera that showed robust reactivity with the cell surface of neurons. The identity of the antigens was established by immunoprecipitation and mass spectrometry, and subsequently confirmed with cell-based assays, immunohistochemistry with teased rat sciatic nerve, and immunoabsorption experiments. Results Four of 46 sera from patients with CIDP reacted strongly against hippocampal neurons (8.6%) and paranodal structures on peripheral nerve. Two patients' sera precipitated contactin-1 (CNTN1), and 1 precipitated both CNTN1 and contactin-associated protein 1 (CASPR1). Reactivity against CNTN1 was confirmed in 2 cases, whereas the third reacted only when CNTN1 and CASPR1 were cotransfected. No other CIDP patient or any of the 104 controls with other neurological diseases tested positive. All 3 patients shared common clinical features, including advanced age, predominantly motor involvement, aggressive symptom onset, early axonal involvement, and poor response to intravenous immunoglobulin. Interpretation Antibodies against the CNTN1/CASPR1 complex occur in a subset of patients with CIDP who share common clinical features. The finding of this biomarker may help to explain the symptoms of these patients and the heterogeneous response to therapy in CIDP. ANN NEUROL 2013;73:370380

Purpose of reviewMyasthenic disorders are a well characterized group of diseases of the neuromuscular junction. Their pathogenesis is diverse, including genetic and autoimmune mechanisms. We review recent findings on risk factors, pathogenesis and treatment of autoimmune myasthenia gravis.Recent findingsBetter knowledge of congenital myasthenia has led to the development of efficient diagnostic algorithms that have therapeutic implications. New epidemiological and genetic risk factors have been identified and are considered to play a role in the development of myasthenia gravis. The study of the role of innate immunity in myasthenia gravis has identified relevant pathways to explain myasthenia gravis causes. The description of the pathogenic role of IgG4 anti-MuSK antibodies has revealed heterogeneous immune mechanisms that should lead to more specific therapies. Rituximab seems to be particularly effective in MuSK(+) myasthenia gravis, and eculizumab arises as an option in refractory AChR(+) myasthenia gravis. Therapeutic algorithms need to be tailored to each myasthenia subtype.SummaryIncreasing knowledge about the environmental and genetic risk factors and basic immunopathogenesis of myasthenia gravis, including the role of innate immunity, regulatory T cell impairment and autoantibody heterogeneity, is providing a rationale for treatment with new biological agents. Current immunotherapies in myasthenia gravis undoubtedly provide benefits, but also cause side-effects. Controlled trials are, therefore, needed to confirm initial results from pilot studies.

Peripheral nerve disorders are a common complication in HIV patients, reaching 15% of them. Several patterns and aetiologies have been described, being lumbosacral poliradiculoneuropathy one of them. We describe an HIV-1-infected patient who developed lumbosacral poliradiculoneuropathy caused by Human herpesvirus 2 and review the literature about this uncommon condition.

Neurological complications (NC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are common and life-threatening in most cases. They may involve either the central (CNS) or peripheral nervous system (PNS). The aim of this study was to describe incidence and characteristics of NC after reduced-intensity conditioning allo-HSCT (allo-RIC), an unexplored setting. For this purpose, we reviewed 191 consecutive patients who underwent this procedure at our institution between January 1999 and December 2006. The median follow-up for survivors was 48 months (3-98 months). RIC included fludarabine (Flu) 150 mg/m2 in combination with busulfan (Bu) 8-10 mg/kg (n = 61), melphalan (Mel) 70-140 mg/m2 (n =119), cyclophosphamide (Cy) 120 mg/kg (n = 7), or low-dose total body irradiation (TBI) 2 Gy (n = 4). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A (CsA) in combination with methotrexate (MTX; n = 134) or mycophenolate mofetil (MMF; n = 52). Twenty-seven patients (14%) developed a total of 31 NC (23 CNS and 8 PNS) for a 4-year cumulative incidence of 16% (95% confidence interval [CI] 11-23). CNS complications included nonfocal encephalopathies in 11 patients, meningoencephalitis in 5 patients, and stroke or hemorrhage in 4. PNS complications consisted of 5 cases of mononeuropathies and 3 cases of polyneuropathies. Drug-related toxicity was responsible for 10 of the 31 events (32%) (8 caused by CsA). Interestingly, 14 of the 23 CNS events (61%) and only 1 of the 8 PNS complications (13%) appeared before day +100 (P = .01). Overall, patients presenting NC showed a trend for higher 1-year nonrelapse mortality (NRM) (37% versus 20%, P =.08). In patients with CNS involvement, 1-year NRM was significantly worse (42% versus 20%, P = .02). CNS NC also had a negative impact on 4-year overall survival (OS; 33% versus 45%, P = .05). In conclusion, our study showed that NC are observed after allo-RIC and have diverse features. NC affecting the CNS have earlier onset and worse outcome than those involving the PNS. Crown Copyright © 2009 American Society for Blood and Marrow Transplantation.

Introduction: The objective of this retrospective study was to describe the short- and long-term patterns of IVIg use, safety, and response to treatment in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Response to therapy was defined as an improvement of 1 point on the modified Rankin score at short- and mid-term visits. Patient status at long term was classified as remission, stability, or non-responder. Results: Eighty-six patients were included; 60.5% responded at short term and 54.6% at mid-term. At long term, 25.6% of patients were in remission, 65.1% were stable, and 9.3% were non-responders. The only variable associated with remission was a better response during the first 6 months of follow-up. Conclusions: A significant percentage of patients did not require any additional drugs in the long term. This suggests that treatment effect or disease outcome may be stable over time, and treatment regimens should therefore be individualized to avoid overtreatment. Muscle Nerve48: 870-876, 2013

Ovarian hyperstimulation syndrome (OHSS) is an uncommon but potentially life-threatening iatrogenic condition that may appear following ovulation induction in the course of some fertility treatments. This may lead to further complications, some of which may be severe, such as thromboembolic events. Though rarely, it can therefore be a potential cause of stroke.We report the case of a 34-year old woman under ovulation induction treatment who developed retinal and brain infarctions secondary to internal carotid occlusion. Oral anticoagulation was administered and recovery was good in spite of the persistence of carotid occlusion in follow-up magnetic ressonance imaging- angiographies.This is the first case of carotid occlusion following an OHSS reported in Spain and the eighth one published in the literature. Current literature on cerebrovascular complications in OHSS is also briefly reviewed.

Objective: To investigate the frequency and clinical correlates of anti-nerve autoantibodies in an unselected series of Italian patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) Methods: Sera from 276 CIDP patients fulfilling the EFNS/PNS criteria and included in the Italian CIDP database were examined for the presence of anti-nerve autoantibodies. Results were correlated with the clinical data collected in the database. Results: Anti-neurofascin155 (NF155) antibodies were found in 9/258 (3.5%) patients, anti-contactin1 (CNTN1) antibodies in 4/258 (1.6%) patients, and anti-contactin-associated protein1 (Caspr1) in 1/197 (0.5%) patients, while none had reactivity to gliomedin or neurofascin 186. Predominance of IgG4 isotype was present in 7of the 9 examined patients. Anti-NF155 patients more frequently had ataxia, tremor, and higher CSF protein levels than antibody-negative patients. Anti-CNTN1 patients more frequently had a GBS-like onset, pain, and ataxia and had more severe motor impairment at enrollment than antibody-negative patients. They more frequently received plasmapheresis, possibly reflecting a less satisfactory response to IVIg or steroids. IgM antibodies against one or more gangliosides were found in 6.5% of the patients (17/260) and were more frequently directed against GM1 (3.9%). They were frequently associated with a progressive course, with a multifocal sensorimotor phenotype and less frequent cranial nerve involvement and ataxia. Conclusions: Anti-paranodal and anti-ganglioside antibodies are infrequent in patients with CIDP but are associated with some typical clinical association supporting the hypothesis that CIDP might be a pathogenically heterogeneous syndrome possibly explaining the different clinical presentations.