BACKGROUND AND OBJECTIVES:The objective of the retrospective analysis was to test the hypothesis that changes in serum anti-myelin-associated glycoprotein (MAG) autoantibodies are associated with clinical response to immunotherapy in patients with anti-MAG neuropathy.METHODS:As of January 29, 2020, we used anti-myelin-associated glycoprotein-related search strings in the Medline database to identify studies that provided information on anti-MAG immunoglobulin M (IgM) autoantibodies and clinical outcomes during immunotherapies. The relative change in anti-MAG IgM titers, paraprotein levels, or total IgM was determined before, during, or posttreatment, and the patients were assigned to "responder," "nonresponder,"' or "acute deteriorating" category depending on their clinical response to treatment. The studies were qualified as "supportive" or "not supportive" depending on the percentage of patients exhibiting an association between relative change of anti-MAG antibody titers or levels and change in clinical outcomes.RESULTS:Fifty studies with 410 patients with anti-MAG neuropathy were included in the analysis. Forty studies with 303 patients supported the hypothesis that a "responder" patient had a relative reduction of anti-MAG antibody titers or levels that is associated with clinical improvements and "nonresponder" patients exhibited no significant change in anti-MAG IgM antibodies. Six studies with 93 patients partly supported, and 4 studies with 26 patients did not support the hypothesis.DISCUSSION:The retrospective analysis confirmed the hypothesis that a relative reduction in serum anti-MAG IgM antibodies is associated with a clinical response to immunotherapies; a sustained reduction of at least 50% compared with pretreatment titers or levels could be a valuable indicator for therapeutic response.

The acquired chronic demyelinating neuropathies include a growing number of disease entities that have characteristic, often overlapping, clinical presentations, mediated by distinct immune mechanisms, and responding to different therapies. After the discovery in the early 1980s, that the myelin associated glycoprotein (MAG) is a target antigen in an autoimmune demyelinating neuropathy, assays to measure the presence of antiMAG antibodies were used as the basis to diagnose the anti-MAG neuropathy. The route was open for describing the clinical characteristics of this new entity as a chronic distal large fiber sensorimotor neuropathy, for studying its pathogenesis and devising specific treatment strategies. The initial use of chemotherapeutic agents was replaced by the introduction in the late 1990s of rituximab, a monoclonal antibody against CD20(+) B-cells. Since then, other anti-B cells agents have been introduced. Recently a novel antigen-specific immunotherapy neutralizing the anti-MAG antibodies with a carbohydrate-based ligand mimicking the natural HNK-1 glycoepitope has been described.

Front cover: Auditory hair cell degeneration underlies hearing loss, and finding effective treatment has been a holy grail quest of hearing research. So far, a combination of antioxidants and other protective substances have proven successful to a limited extent. Our findings show that the combination of nuclear factor of activated T‐cells (NFAT) inhibitor and N‐acetylcysteine provides full protection from gentamicin damage in hair cells. The main advantage is that hair cell protection can be achieved using lower concentrations of each component, and thus decreasing their potential side effects. This approach could be beneficial as treatment not just in aminoglycoside‐induced ototoxicity, but in all cases of ROS‐induced cochlear damage, with noise‐induced hearing loss being one of them.

Anti-myelin-associated glycoprotein (MAG) neuropathy is a disabling autoimmune peripheral neuropathy that is caused by circulating monoclonal IgM autoantibodies directed against the human natural killer-1 (HNK-1) epitope. This carbohydrate epitope is highly expressed on adhesion molecules such as MAG, a glycoprotein present in myelinated nerves. We previously showed the therapeutic potential of the glycopolymer poly(phenyl disodium 3-O-sulfo-beta-d-glucopyranuronate)-(1 -> 3)-beta-d-galactopyranoside (PPSGG) in selectively neutralizing anti-MAG IgM antibodies in an immunological mouse model and ex vivo with sera from anti-MAG neuropathy patients. PPSGG is composed of a biodegradable backbone that multivalently presents a mimetic of the HNK-1 epitope. In this study, we further explored the pharmacodynamic properties of the glycopolymer and its ability to inhibit the binding of anti-MAG IgM to peripheral nerves. The polymer selectively bound anti-MAG IgM autoantibodies and prevented the binding of patients' anti-MAG IgM antibodies to myelin of non-human primate sciatic nerves. Upon PPSGG treatment, neither activation nor inhibition of human and murine peripheral blood mononuclear cells nor alteration of systemic inflammatory markers was observed in mice or ex vivo in human peripheral blood mononuclear cells. Intravenous injections of PPSGG to mice immunized against the HNK-1 epitope removed anti-MAG IgM antibodies within less than 1 hr, indicating a fast and efficient mechanism of action as compared to a B-cell depletion with anti-CD20. In conclusion, these observations corroborate the therapeutic potential of PPSGG for an antigen-specific treatment of anti-MAG neuropathy.

ObjectiveTo assess the clinicopathological and therapeutic features of patients with low (≥1000 to <10 000 Bühlmann Titre Units) (BTU), medium (10 000–70 000) or high (≥70 000) anti-myelin-associated glycoprotein (anti-MAG) antibody titres.MethodsWe retrospectively and prospectively analysed standardised report forms and medical records of 202 patients from 14 neuromuscular centres.ResultsMean age at onset and mean time between symptom onset to last follow-up were respectively 62.6 years (25–91.4) and 8.4 years (0.3–33.3). Anti-MAG antibody titres at diagnosis were low, medium or high in 11%, 51% and 38% of patients. Patients presented with monoclonal gammopathy of undetermined significance in 68% of cases. About 17% of patients presented with ‘atypical’ clinical phenotype independently of anti-MAG titres, including acute or chronic sensorimotor polyradiculoneuropathies (12.4%), and asymmetric or multifocal neuropathy (3%). At the most severe disease stage, 22.4% of patients were significantly disabled. Seventy-eight per cent of patients received immunotherapies. Transient clinical worsening was observed in 12% of patients treated with rituximab (11/92). Stabilisation after rituximab treatment during the 7–12-month follow-up period was observed in 29% of patients. Clinical response to rituximab during the 6-month and/or 7–12-month follow-up period was observed in 31.5% of patients and correlated with anti-MAG titre ≥10 000 BTU.ConclusionOur study highlights the extended clinical spectrum of patients with anti-MAG neuropathy, which appears unrelated to antibody titre. Besides, it may also suggest beneficial use of rituximab in the early phase of anti-MAG neuropathy.

We describe two cases of sensory mononeuritis that presented with similar past medical histories, and clinical and electrophysiological features. The two patients were females who had resided in areas endemic for leprosy (Brazil). Both developed a progressive, purely sensory, painful mononeuritis distally in the lower limbs with sensory nerve potentials asymmetrically reduced in amplitude. The sural nerve biopsy performed in Patient 1 showed granulomatous inflammation of the epineurial tissue, consistent with paucibacillary pure neural leprosy (PNL) while in Patient 2 there were signs of vascular inflammation consistent with non-systemic vasculitic neuropathy (NSVN). Patients 1 and 2 both improved following targeted treatment with rifampicin and dapsone vs. rituximab, respectively.

Anti-MAG (myelin-associated glycoprotein) neuropathy is a disabling autoimmune peripheral neuropathy caused by monoclonal IgM autoantibodies that recognize the carbohydrate epitope HNK-1 (human natural killer-1). This glycoepitope is highly expressed on adhesion molecules, such as MAG, present in myelinated nerve fibers. Because the pathogenicity and demyelinating properties of anti-MAG autoantibodies are well established, current treatments are aimed at reducing autoantibody levels. However, current therapies are primarily immunosuppressive and lack selectivity and efficacy. We therefore hypothesized that a significant improvement in the disease condition could be achieved by selectively neutralizing the pathogenic anti-MAG antibodies with carbohydrate-based ligands mimicking the natural HNK-1 glycoepitope 1. In an inhibition assay, a mimetic (2, mimHNK-1) of the natural HNK-1 epitope blocked the interaction of MAG with pathogenic IgM antibodies from patient sera but with only micromolar affinity. Therefore, considering the multivalent nature of the MAG-IgM interaction, polylysine polymers of different sizes were substituted with mimetic 2. With the most promising polylysine glycopolymer PL84(mimHNK-1)45 the inhibitory effect on patient sera could be improved by a factor of up to 230,000 per epitope, consequently leading to a low-nanomolar inhibitory potency. Because clinical studies indicate a correlation between the reduction of anti-MAG IgM levels and clinical improvement, an immunological surrogate mouse model for anti-MAG neuropathy producing high levels of anti-MAG IgM was developed. The observed efficient removal of these antibodies with the glycopolymer PL84(mimHNK-1)45 represents an important step toward an antigen-specific therapy for anti-MAG neuropathy.

The 230th European Neuromuscular Center (ENMC) international workshop occurred in Naarden, the Netherlands, from February 24th to 26th, 2017. The aims of the workshop were: 1) to create an IgM associated peripheral neuropathy study group and achieve consensus regarding the registration of patients with IgM associated peripheral neuropathy in a patient-based registry, 2) to improve future assessment of patients with IgM associated peripheral neuropathy from hematological markers to clinical trials, and 3) to discuss promising therapies for future clinical trials.

according to CIDP Disease Activity Status (CDAS) [4, 6] . Twelve healthy volunteers were used as controls (‘Ctrl’ group). Skin punch biopsies were performed 10 cm above the external malleoli and snap frozen in liquid nitrogen. RNA extraction, gene expression profiling, and MetaCore ® data analysis were performed according to the methods described previously [4] with the following filters: fold expression change >1.15, p < 0.05, Y chromosome linked genes and duplicate removal. Data analysis was made according to a 3 set comparison (C), where C1 stands for ‘IVIG vs. Ctrl’, C2 for ‘IVIG vs. NoIVIG’, and C3 for ‘NoIVIG vs. Ctrl’. This study was approved by the local Ethics Committee (protocol 235/10). We first analyzed the total number of differentially regulated genes between the 3 groups. Results showed 223 differentially regulated genes between patients treated with IVIG and the control group (C1; fig. 1 a). In contrast, numbers of differentially regulated genes were much higher when comparing NoIVIG patients to IVIG and the control group respectively: 1117 genes were differentially regulated between Dear Sir, Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common form of chronic autoimmune neuropathy [1] . The underlying immune-mediated mechanisms have not yet been fully elucidated [2], but gene expression analyses identified inflammatory molecular markers that are upregulated in skin nerve biopsies [3, 4] . Intravenous immunoglobulins (IVIG) are a first-line therapy for CIDP [5] . In order to gain insight in the anti-inflammatory effects of IVIG, 2 subgroups of patients treated with either IVIG or other immunosuppressive agents were selected from a previous gene expression profiling study [4] . The selected subgroups were further studied using a transcriptional microarray analysis in skin punch biopsies. Four patients (‘IVIG’ group) were treated with Privigen ® (2 g/kg administered over 5 days) 2–6 months before skin biopsy was performed. Three patients (‘NoIVIG’ group) received other treatments: prednisone (30 mg/day), azathioprine (2 mg/kg/ day) or tacrolimus (2 mg/day), respectively. All 7 patients had stable active disease Received: March 18, 2016 Accepted: May 17, 2016 Published online: June 11, 2016

AimsEvaluation of intraepidermal nerve fibres (IENFs) in skin biopsies is used in the diagnosis of small-fibre neuropathies. The number of IENFs is assessed manually under a microscope, with an inter-rater variability of similar to 25%. Unless the images are digitized, there is no documentation. Our aim was to develop a method for standardized semi-automated quantification (SAQ) and documentation of IENF density.Methods and resultsWe analysed samples from four different university centres that were immunostained according to local protocols. Images were acquired through the Z-plane with a whole slide scanner. orbit image analysis software was used to create an analysable image and develop a reliable algorithm for IENF detection. Rebuilt images revealed well-contrasted nerves, allowing detection of IENFs (automated). The software presented the detected nerves for confirmation by the operator (manual). As compared with the conventional microscopy count, the SAQ achieved correlation coefficients of 0.99 and 0.96 and interfacility variabilities of 19% and 23%, respectively. We found better reproducibility with fluorescence-stained specimens than with bright-field images.ConclusionsThe new semi-automated method has high experimenter-independent reproducibility when based on nerve detection by fluorescence and is easy to perform, even by untrained users. The IENF counting is electronically well documented.

Basel • Freiburg • Paris • London • New York • Chennai • New Delhi • Bangkok • Beijing • Shanghai • Tokyo • Kuala Lumpur • Singapore • Sydney Founded 1897 as ‘Monatsschrift für Psychiatrie und Neurologie’, continued 1957–1967 as ‘Psychiatria et Neurologia’ Founders: C. Wernicke and Th. Ziehen. Successors: K. Bonhoeffer (1912–1938), J. Klaesi (1939–1967), E. Grünthal (1953–1967), H.E. Kaeser (1968–1993)