230th ENMC International Workshop:: Improving future assessment and research in IgM anti-MAG peripheral neuropathy: A consensus collaborative effort, Naarden, The Netherlands, 24-26 February 2017.

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230th ENMC International Workshop:: Improving future assessment and research in IgM anti-MAG peripheral neuropathy: A consensus collaborative effort, Naarden, The Netherlands, 24-26 February 2017.

Neuromuscul Disord. 2017 Aug 02;:

Authors: Pruppers MHJ, Merkies ISJ, Lunn MPT, Notermans NC, IMAGiNe Study Group

PMID: 28927829 [PubMed - as supplied by publisher]

Autoantibodies in chronic inflammatory neuropathies: diagnostic and therapeutic implications.

Autoantibodies in chronic inflammatory neuropathies: diagnostic and therapeutic implications.

Nat Rev Neurol. 2017 Jul 14;:

Authors: Querol L, Devaux J, Rojas-Garcia R, Illa I

Abstract
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.

PMID: 28708133 [PubMed - as supplied by publisher]

Autoantibodies to nodal isoforms of neurofascin in chronic inflammatory demyelinating polyneuropathy.

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Autoantibodies to nodal isoforms of neurofascin in chronic inflammatory demyelinating polyneuropathy.

Brain. 2017 May 28;:

Authors: Delmont E, Manso C, Querol L, Cortese A, Berardinelli A, Lozza A, Belghazi M, Malissart P, Labauge P, Taieb G, Yuki N, Illa I, Attarian S, Devaux JJ

Abstract
Chronic inflammatory demyelination polyneuropathy is a heterogeneous and treatable immune-mediated disorder that lacks biomarkers to support diagnosis. Recent evidence indicates that paranodal proteins (contactin 1, contactin-associated protein 1, and neurofascin-155) are the targets of autoantibodies in subsets of patients showing distinct clinical presentations. Here, we identified neurofascin-186 and neurofascin-140 as the main targets of autoantibodies in five patients presenting IgG reactivity against the nodes of Ranvier. Four patients displayed predominantly IgG4 antibodies, and one patient presented IgG3 antibodies that activated the complement pathway in vitro. These patients present distinct clinical features compared to those with anti-neurofascin-155 IgG4. Most patients had a severe phenotype associated with conduction block or decreased distal motor amplitude. Four patients had a subacute-onset and sensory ataxia. Two patients presented with nephrotic syndromes and one patient with an IgG4-related retroperitoneal fibrosis. Intravenous immunoglobulin and corticosteroids were effective in three patients, and one patient remitted following rituximab treatment. Clinical remission was associated with autoantibody depletion and with recovery of conduction block and distal motor amplitude suggesting a nodo-paranodopathy. Our data demonstrate that the pathogenic mechanisms responsible for chronic inflammatory demyelination polyneuropathy are broad and may include dysfunctions at the nodes of Ranvier in a subgroup of patients.

PMID: 28575198 [PubMed - as supplied by publisher]

Absence of antibodies against KIR4.1 in multiple sclerosis: A three-technique approach and systematic review.

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Absence of antibodies against KIR4.1 in multiple sclerosis: A three-technique approach and systematic review.

PLoS One. 2017;12(4):e0175538

Authors: Navas-Madroñal M, Valero-Mut A, Martínez-Zapata MJ, Simón-Talero MJ, Figueroa S, Vidal-Fernández N, López-Góngora M, Escartín A, Querol L

Abstract
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.

PMID: 28414733 [PubMed - in process]

Compromised fidelity of B-cell tolerance checkpoints in AChR and MuSK myasthenia gravis.

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Compromised fidelity of B-cell tolerance checkpoints in AChR and MuSK myasthenia gravis.

Ann Clin Transl Neurol. 2016 Jun;3(6):443-54

Authors: Lee JY, Stathopoulos P, Gupta S, Bannock JM, Barohn RJ, Cotzomi E, Dimachkie MM, Jacobson L, Lee CS, Morbach H, Querol L, Shan JL, Vander Heiden JA, Waters P, Vincent A, Nowak RJ, O'Connor KC

Abstract
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.

PMID: 27547772 [PubMed]

Clinical Characteristics of Patients With Double-Seronegative Myasthenia Gravis and Antibodies to Cortactin.

Clinical Characteristics of Patients With Double-Seronegative Myasthenia Gravis and Antibodies to Cortactin.

JAMA Neurol. 2016 Jul 5;

Authors: Cortés-Vicente E, Gallardo E, Martínez MÁ, Díaz-Manera J, Querol L, Rojas-García R, Illa I

Abstract
Importance: Double-seronegative myasthenia gravis (dSNMG) includes patients with myasthenia gravis (MG) without detectable antibodies to the nicotinic acetylcholine receptor (AChR) or to muscle-specific tyrosine kinase (MuSK). The lack of a biomarker hinders the diagnosis and clinical management in these patients. Cortactin, a protein acting downstream from agrin/low-density lipoprotein receptor-related protein 4 (LRP4)/MuSK, has been described as an antigen in dSNMG.
Objective: To describe the frequency and clinical features of patients with dSNMG who have cortactin antibodies.
Design, Setting, and Participants: A retrospective cross-sectional study was conducted at Hospital de la Santa Creu i Sant Pau, an institutional practice referral center in Barcelona, Spain, between May 1, 2015, and November 30, 2015. We included 250 patients with a definitive diagnosis of MG with available serum samples at the time of diagnosis. Descriptive and comparative data analyses were performed.
Exposures: Cortactin antibodies were measured by enzyme-linked immunosorbent assay and Western blot; AChR, MuSK, and anti-striated muscle antibodies were detected using a standard method; and LRP4 antibodies were tested using a cell-based assay.
Main Outcomes and Measures: The primary outcome was the frequency of patients with dSNMG who have cortactin antibodies. Secondary outcomes were demographic, clinical, neurophysiological, and laboratory data.
Results: Of 250 patients (mean [SD] age at onset, 49.7 [21.2] years; 56% female), 38 (15.2%) had dSNMG, 201 (80.4%) had MG with AChR antibodies, and 11 (4.4%) had MG with MuSK antibodies. Cortactin antibodies were identified in 28 patients with MG: 9 of 38 (23.7%) who had dSNMG, 19 of 201 (9.5%) who had MG with AChR antibodies (significantly lower than those with dSNMG: 9.5% vs 23.7%; P = .02), and 0 of 11 who had MG with MuSK antibodies; 0 of 29 controls had cortactin antibodies. At onset, among the 9 patients with dSNMG and cortactin antibodies, 6 had ocular MG and 3 had Myasthenia Gravis Foundation of America clinical classification IIA. Two patients with ocular MG developed generalized MG. The group with dSNMG and cortactin antibodies, compared with those who had MG with AChR antibodies, more frequently had mild forms at onset (100.0% vs 62.7%; P = .03), had fewer bulbar signs at maximal worsening (0% vs 41.3%; P = .01), and were younger at onset (median [interquartile range], 34.9 [9.5] vs 53.9 [38.5] years; P = .03); the group with dSNMG and cortactin antibodies also more frequently had ocular MG at onset than those with MG and AChR antibodies, although the difference was not statistically significant (66.7% vs 40.8%; P = .17). Of 17 patients with ocular dSNMG, 4 (23.5%) had antibodies to cortactin.
Conclusions and Relevance: In this study, patients with cortactin antibodies and dSNMG had an ocular or mild generalized phenotype of MG. Including the detection of cortactin antibodies in the routine diagnosis of dSNMG may be helpful in ocular MG.

PMID: 27379450 [PubMed - as supplied by publisher]

Correlation of the patient’s reported outcome Inflammatory-RODS with an objective metric in immune-mediated neuropathies.

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Correlation of the patient's reported outcome Inflammatory-RODS with an objective metric in immune-mediated neuropathies.

Eur J Neurol. 2016 Apr 29;

Authors: Draak TH, Gorson KC, Vanhoutte EK, van Nes SI, van Doorn PA, Cornblath DR, van den Berg LH, Faber CG, Merkies IS, PeriNomS Study Group

Abstract
BACKGROUND AND PURPOSE: There 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-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and gammopathy-related polyneuropathy (MGUSP).
METHODS: The Inflammatory Rasch-built Overall Disability Scale (I-RODS©, 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.
RESULTS: A significant correlating trend was found between the I-RODS and grip strength scores for the overall group and in each illness, independently.
CONCLUSION: The 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.

PMID: 27129110 [PubMed - as supplied by publisher]

Contactin-1 IgG4 antibodies cause paranode dismantling and conduction defects.

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Contactin-1 IgG4 antibodies cause paranode dismantling and conduction defects.

Brain. 2016 Mar 26;

Authors: Manso C, Querol L, Mekaouche M, Illa I, Devaux JJ

Abstract
Paranodal axoglial junctions formed by the association of contactin-1, contactin-associated protein 1, and neurofascin-155, play important functions in nerve impulse propagation along myelinated axons. Autoantibodies to contactin-1 and neurofascin-155 define chronic inflammatory demyelinating polyradiculoneuropathy subsets of patients with specific clinical features. These autoantibodies are mostly of the IgG4 isotype, but their pathogenicity has not been proven. Here, we investigated the mechanisms how IgG subclasses to contactin-1 affect conduction. We show that purified anti-contactin-1 IgG1 and IgG4 bind to paranodes. To determine whether these isotypes can pass the paranodal barrier, we incubated isolated sciatic nerves with the purified antibody or performed intraneural injections. We found that IgG4 diffused into the paranodal regionsin vitroor after intraneural injections. IgG4 infiltration was slow and progressive. In 24 h, IgG4 accessed the paranode borders near the nodal lumen, and completely fill the paranodal segments by 3 days. By contrast, control IgG, anti-contactin-1 IgG1, or even anti-contactin-associated-protein-2 IgG4 did not pass the paranodal barrier. To determine whether chronic exposure to these antibodies is pathogenic, we passively transferred anti-contactin-1 IgG1 and IgG4 into Lewis rats immunized with P2 peptide. IgG4 to contactin-1, but not IgG1, induced progressive clinical deteriorations combined with gait ataxia. No demyelination, axonal degeneration, or immune infiltration were observed. Instead, these animals presented a selective loss of the paranodal specialization in motor neurons characterized by the disappearance of the contactin-associated protein 1/contactin-1/neurofascin-155 complex at paranodes. Paranode destruction did not affect nodal specialization, but resulted in a moderate node lengthening. The sensory nerves and dorsal root ganglion were not affected in these animals. Electrophysiological examination further supported these results and revealed strong nerve activity loss affecting predominantly small diameter or slow conducting motor axons. These deficits partly matched with those found in patients: proximal motor involvement, gait ataxia, and a demyelinating neuropathy that showed early axonal features. The animal model thus seemed to replicate the early deteriorations in these patients and pointed out that paranodal loss in mature fibres results in conduction defects, but not conduction slowing. Our findings indicate that IgG4 directed against contactin-1 are pathogenic and are reliable biomarkers of a specific subset of chronic inflammatory demyelinating polyneuropathy patients. These antibodies appear to loosen the paranodal barrier, thereby favouring antibody progression and causing paranodal collapse.

PMID: 27017186 [PubMed - as supplied by publisher]

Does ability to walk reflect general functionality in inflammatory neuropathies?

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Does ability to walk reflect general functionality in inflammatory neuropathies?

J Peripher Nerv Syst. 2016 Mar 10;

Authors: Draak TH, Gorson KC, Vanhoutte EK, van Nes SI, van Doorn PA, Cornblath DR, van den Berg LH, Faber CG, Merkies IS, PeriNomS Study Group

Abstract
BACKGROUND: The "ability to walk" is considered a benchmark for good clinical recovery and prognosis, particularly in patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). However, it has never been determined whether being "able to walk" represents general functionality.
OBJECTIVE: To examine whether the ability to walk outside independently reflects general functional improvement in patients with GBS, CIDP, and gammopathy-related neuropathy (MGUSP).
METHODS: 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(©) ). We determined the proportion of patients able to walk outside independently that reached the postulated cut-offs.
RESULTS: 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.
CONCLUSION: 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(©) bypasses these limitations.

PMID: 26968437 [PubMed - as supplied by publisher]

[Retinal and brain infarctions secondary to acute carotid thrombosis in ovarian hyperstimulation syndrome].

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[Retinal and brain infarctions secondary to acute carotid thrombosis in ovarian hyperstimulation syndrome].

Neurologia. 2008 Jun;23(5):319-21

Authors: Querol L, Martínez-Corral M, Martí E, Martí-Fábregas J

Abstract
INTRODUCTION: 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.
CLINICAL CASE: 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.
CONCLUSIONS: 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.

PMID: 18247184 [PubMed - indexed for MEDLINE]