The impact of HLA-DRB1 alleles in a Hellenic, Pediatric-Onset Multiple Sclerosis cohort: Implications on clinical and neuroimaging profile.

BACKGROUND: Pediatric-Onset Multiple Sclerosis (POMS) is considered a complex disease entity and several genetic, hormonal, and environmental factors have been associated with disease pathogenesis. Linkage studies in Caucasians have consistently suggested the human leukocyte antigen (HLA) polymorphisms, as the genetic locus most strongly linked to MS, with the HLA-DRB1*15:01 allele, being associated with both adult and pediatric MS patients. Here we aim to investigate the prevalence of the HLA-DRB1 alleles among a Hellenic POMS cohort and any possible associations with clinical and imaging disease features. MATERIALS AND METHODS: 100 POMS patients fulfilling the IPMSSG criteria, 168 Adult-Onset MS (AOMS) patients, and 246 Healthy Controls (HCs) have been enrolled. HLA genotyping was performed with a standard low-resolution sequence-specific oligonucleotide (SSO) technique. RESULTS: POMS patients display a significantly increased HLA-DRB1*03 frequency compared to both HCs [24% vs. 12.6%, OR [95%CI]: 2.19 (1.21-3.97), p=0.016) and AOMS (24% vs. 13.1%, OR [95%CI]: 2.1 (1.1-3.98), p=0.034] respectively. HLA-DRB1*03-carriers display reduced risk for brainstem lesion development (OR [CI 95%]:0.19 (0.06-0.65), p=0.011). A significantly lower frequency of HLA-DRB1*07 (4% vs 13.4%, OR (95% CI): 0.27 (0.09-0.78), p= 0.017) and HLA-DRB1*11 (37% vs 52%, OR [95% CI]: 0.54 (0.34-0.87), p= 0.016) was observed in POMS compared to HCs. CONCLUSION: The HLA-DRB1*03 allele was associated with a higher risk for POMS, replicating our previous findings, and with a lower risk for brainstem lesion development, a common clinical and neuroimaging feature in POMS, while HLA-DRB1*07 and HLA-DRB1*11 display a protective role. These findings expand the existing knowledge of HLA associations and POMS.

First-line disease modifying treatments in pediatric-onset multiple sclerosis in Greece: therapy initiation at more advanced age is the main cause of treatment failure, in a retrospective observational study, with a cohort from a single Multiple Sclerosis Center.

OBJECTIVES: Long-term immunomodulatory therapy of pediatric onset-multiple sclerosis (POMS) is based mainly on published case series and internationally agreed guidelines. Relevant studies in the Greek population are absent from the literature. The purpose of this study is to present data on the efficacy and safety of the 1st line immunomodulatory drugs in the treatment of POMS patients. MATERIALS AND METHODS: The present study included 27 patients meeting the IPMSSG criteria for POMS and who are monitored at the outpatient clinic of the Multiple Sclerosis and Demyelinating Diseases Unit (MSDDU), of the 1st Neurological Department, University Hospital of Aeginition. All patients received 1st line immunomodulatory drugs as initial therapy. Clinical, laboratory, and imaging parameters of the disease were recorded before and after treatment. RESULTS: Post-treatment, a significant reduction of the relapse number (mean ± SD: 2.0 ± 1.0 vs 1.2 ± 1.6, p = 0.002), EDSS progression (mean ± SD: 1.5 ± 0.8 vs 0.9 ± 0.7, p = 0.005) and ARR (mean ± SD: 1.5 ± 0.7 vs 0.4 ± 0.5, p = 0.0001) was observed, while no changes were observed in the EDSS score, (mean ± SD: 1.8 ± 0.6 vs 1.9. 0.6, p = 0.60). Advanced age at treatment initiation increased the risk for drug discontinuation before 24 months of therapy (HR = 0.6, 95% CI (0.35-0.99), p = 0.04). CONCLUSIONS: Most pediatric patients are forced to switch to either more efficacious 1st line or 2nd line drugs. Additionally, our study suggests that older age at the time of the 1st line treatment initiation, contributes to earlier drug discontinuation.

Fingolimod as a first- or second-line treatment in a mini-series of young Hellenic patients with adolescent-onset multiple sclerosis: focus on immunological data.

BACKGROUND: Pediatric onset multiple sclerosis(POMS) is characterized by a highly active profile, often warranting treatment with high efficacy disease-modulating therapies (DMTs). Fingolimod, an oral sphingosine-1-phosphate receptor modulator, is the first Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved DMT for the treatment of POMS. OBJECT: Our aim is to present real-world data of seven fingolimod-treated POMS-patients, recruited in a single MS center in Greece. METHODS: Clinical and imaging/laboratory data from 7 Hellenic patients fulfilling the International Pediatric Multiple Sclerosis Study Group (IPMSSG) criteria for POMS diagnosis, who have received fingolimod treatment, were selected. Human leukocyte antigen (HLA) genotyping was performed with standard low-resolution sequence-specific oligonucleotide techniques. RESULTS: Three patients were treatment-naïve adolescents who received fingolimod as first-line treatment. Two experienced ongoing clinical and radiological disease activity and have been switched to natalizumab. The remaining cases were post-adolescent adults with POMS, where the vast majority experienced total/near-total disease remission. Fingolimod was generally well-tolerated. Two patients with high disease activity carried the HLA-DRB1*03 allele, while five patients were carriers of at least one of the HLA-DRB1*04, HLA-DRB1*13, and HLA-DRB1*14 alleles, which when not combined with HLA-DRB1*03 showed a trend towards a more favorable clinical course. Fingolimod responders showed a trend towards increased CD(16-56)+NK cell counts in immunophenotyping assays. CONCLUSIONS: Our preliminary results support that response of POMS patients to fingolimod may be partially dependent on age and previous DMT, with younger and treatment-naïve patients presenting worse outcomes. The role of immunogenetics and immunophenotyping in personalized treatment warrants investigation in larger and more diverse populations.

Autoimmune Neurogenic Dysphagia.

Autoimmune neurogenic dysphagia refers to manifestation of dysphagia due to autoimmune diseases affecting muscle, neuromuscular junction, nerves, roots, brainstem, or cortex. Dysphagia is either part of the evolving clinical symptomatology of an underlying neurological autoimmunity or occurs as a sole manifestation, acutely or insidiously. This opinion article reviews the autoimmune neurological causes of dysphagia, highlights clinical clues and laboratory testing that facilitate early diagnosis, especially when dysphagia is the presenting symptom, and outlines the most effective immunotherapeutic approaches. Dysphagia is common in inflammatory myopathies, most prominently in inclusion body myositis, and is frequent in myasthenia gravis, occurring early in bulbar-onset disease or during the course of progressive, generalized disease. Acute-onset dysphagia is often seen in Guillain-Barre syndrome variants and slowly progressive dysphagia in paraneoplastic neuropathies highlighted by the presence of specific autoantibodies. The most common causes of CNS autoimmune dysphagia are demyelinating and inflammatory lesions in the brainstem, occurring in patients with multiple sclerosis and neuromyelitis optica spectrum disorders. Less common, but often overlooked, is dysphagia in stiff-person syndrome especially in conjunction with cerebellar ataxia and high anti-GAD autoantibodies, and in gastrointestinal dysmotility syndromes associated with autoantibodies against the ganglionic acetyl-choline receptor. In the setting of many neurological autoimmunities, acute-onset or progressive dysphagia is a potentially treatable condition, requiring increased awareness for prompt diagnosis and early immunotherapy initiation.

Progress in the therapy of myasthenia gravis: getting closer to effective targeted immunotherapies.

PURPOSE OF REVIEW: To provide an update on immunomodulating and immunosuppressive therapies in myasthenia gravis and highlight newly approved, or pending approval, therapies with new biologics. RECENT FINDINGS: Preoperative IVIg is not needed to prevent myasthenic crisis in stable myasthenia gravis patients scheduled for surgery under general anesthesia, based on controlled data. Rituximab, if initiated early in new-onset myasthenia gravis, can lead to faster and more sustained remission even without immunotherapies in 35% of patients at 2 years. Biomarkers determining the timing for follow-up infusions in Rituximab-responding AChR-positive patients are discussed. Most patients with MuSK-positive myasthenia gravis treated with Rituximab have sustained long-term remission with persistent reduction of IgG4 anti-MuSK antibodies. Eculizumb in the extension REGAIN study showed sustained long-term pharmacological remissions and reduced exacerbations. Three new biologic agents showed promising results in phase-II controlled myasthenia gravis trials: Zilucoplan, a subcutaneous macrocyclic peptide inhibiting complement C5; Efgartigimod, an IgG1-derived Fc fragment binding to neonatal FcRn receptor; and Rozanolixizumab, a high-affinity anti-FcRn monoclonal antibody. Finally, the safety of ongoing myasthenia gravis immunotherapies during COVID19 pandemic is discussed. SUMMARY: New biologics against B cells, complement and FcRn receptor, are bringing us closer to successful targeted immunotherapies in the chronic management of myasthenia gravis promising an exciting future for antibody-mediated neurological diseases.

The immunobiology of autoimmune encephalitides.

Autoimmune encephalitides, with an estimated incidence of 1.5 per million population per year, although described only 15 years ago, have already had a remarkable impact in neurology and paved the field to autoimmune neuropsychiatry. Many patients traditionally presented with aberrant behavior, especially of acute or subacute onset, and treated with anti-psychotic therapies, turn out to have a CNS autoimmune disease with pathogenic autoantibodies against synaptic antigens responding to immunotherapies. The review describes the clinical spectrum of these disorders, and the pathogenetic role of key autoantibodies directed against: a) cell surface synaptic antigens and receptors, including NMDAR, GABAa, GABAb, AMPA and glycine receptors; b) channels such as AQP4 water-permeable channel or voltage-gated potassium channels; c) proteins that stabilize voltage-gated potassium channel complex into the membrane, like the LGI1 and CASPR2; and d) enzymes that catalyze the formation of neurotransmitters such as Glutamic Acid Decarboxylase (GAD). These antibodies, effectively target excitatory or inhibitory synapses in the limbic system, basal ganglia or brainstem altering synaptic function and resulting in uncontrolled neurological excitability disorder clinically manifested with psychosis, agitation, behavioral alterations, depression, sleep disturbances, seizure-like phenomena, movement disorders such as ataxia, chorea and dystonia, memory changes or coma. Some of the identified triggering factors include: viruses, especially herpes simplex, accounting for the majority of relapses occurring after viral encephalitis, which respond to immunotherapy rather than antiviral agents; tumors especially teratoma, SCLC and thymomas; and biological cancer therapies (immune-check-point inhibitors). As anti-synaptic antibodies persist after viral infections or tumor removal, augmentation of autoreactive B cells which release autoantigens to draining lymph nodes, molecular mimicry and infection-induced bystander immune activation products play a role in autoimmunization process or perpetuating autoimmune neuroinflammation. The review stresses the importance of early detection, clinical recognition, proper antibody testing and early therapy initiation as these disorders, regardless of a known or not trigger, are potentially treatable responding to systemic immunotherapy with intravenous steroids, IVIg, rituximab or even bortezomid.

Quantitative clinical and autoimmune assessments in stiff person syndrome: evidence for a progressive disorder.

BACKGROUND: Stiff Person Syndrome (SPS) is an under-diagnosed disorder that affects mobility and the quality of life of affected patients. The aim of the study is to describe the natural history of SPS, the extent of accumulated disability and the associated clinical and immunological features in patients followed for up to 8 years in a single center. METHODS: Our collective cohort included 57 SPS patients. Additionally, 32 of these patients were examined every 6 months for a two-year period in a longitudinal study protocol, to assess disease progression using quantitative measures of stiffness and heightened sensitivity. RESULTS: The most frequent initial symptom was leg stiffness, followed by paraspinal muscle rigidity and painful spasms in 95% of the patients. Although none of the patients required assistance for ambulation during the first 2 years of disease onset, 46 patients (80%) lost the ability to walk independently during our follow-up, despite symptomatic medications. In the longitudinal cohort, the number of stiff areas increased (p < 0.0001), consistent with worsening functional status and quality of life. High-titer anti-GAD antibodies were present in serum and CSF with elevated intrathecal GAD-specific IgG synthesis, but they did not correlate with clinical severity or progression. CONCLUSIONS: This large study on SPS patients, combining an eight-year follow-up at a single center by the same leading neurologist and his team, is the first to provide longitudinal data in a large patient subgroup using objective clinical measures. One of the main findings is that SPS is a progressive disease leading to physical disability over time.

A double-blind, placebo-controlled study of rituximab in patients with stiff person syndrome.

OBJECTIVE: In stiff person syndrome (SPS), an antibody-mediated impaired γ-aminobutyric acidergic (GABAergic) neurotransmission is believed to cause muscle stiffness and spasms. Most patients improve with GABA-enhancing drugs and intravenous immunoglobulin, but some respond poorly and remain disabled. The need for more effective therapy prompted a trial with the anti-CD20 monoclonal antibody rituximab. METHODS: This was a placebo-controlled randomized trial of rituximab (2 biweekly infusions of 1g each). The primary outcome was a change in stiffness scores at 6 months. Secondary outcomes were changes in heightened-sensitivity and quality of life scores. Enrolling 24 patients was calculated to detect 50% change in stiffness scores. RESULTS: Randomization was balanced for age, sex, disease duration, and glutamic acid decarboxylase autoantibody titers. No significant changes were noted at 6 months after treatment in all outcomes. Specifically, no differences were noted in the stiffness index, the primary outcome, or sensitivity scores, the secondary outcome, at 3 or 6 months. Quality of life scores improved significantly (p < 0.01) at 3 months in both groups, but not at 6 months, denoting an early placebo effect. Blinded self-assessment rating of the overall stiffness for individual patients revealed improvement in 4 patients in each group. At 6 months, improvement persisted in 1 patient in the placebo group versus 3 of 4 in the rituximab group, where these meaningful improvements were also captured by video recordings. INTERPRETATION: This is the largest controlled trial conducted in SPS patients and demonstrates no statistically significant difference in the efficacy measures between rituximab and placebo. Rituximab's lack of efficacy could be due to a considerable placebo effect; insensitivity of scales to quantify stiffness, especially in the less severely affected patients; or drug effectiveness in only a small patient subset. Ann Neurol 2017;82:271-277.

Pathogenesis of immune-mediated neuropathies.

Autoimmune neuropathies occur when immunologic tolerance to myelin or axonal antigens is lost. Even though the triggering factors and the underling immunopathology have not been fully elucidated in all neuropathy subsets, immunological studies on the patients' nerves, transfer experiments with the patients' serum or intraneural injections, and molecular fingerprinting on circulating autoantibodies or autoreactive T cells, indicate that cellular and humoral factors, either independently or in concert with each other, play a fundamental role in their cause. The review is focused on the main subtypes of autoimmune neuropathies, mainly the Guillain-Barré syndrome(s), the Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), the Multifocal Motor Neuropathy (MMN), and the IgM anti-MAG-antibody mediated neuropathy. It addresses the factors associated with breaking tolerance, examines the T cell activation process including co-stimulatory molecules and key cytokines, and discusses the role of antibodies against peripheral nerve glycolipids or glycoproteins. Special attention is given to the newly identified proteins in the nodal, paranodal and juxtaparanodal regions as potential antigenic targets that could best explain conduction failure and rapid recovery. New biological agents against T cells, cytokines, B cells, transmigration and transduction molecules involved in their immunopathologic network, are discussed as future therapeutic options in difficult cases. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.

Molecular treatment effects of alemtuzumab in skeletal muscles of patients with IBM.

BACKGROUND: Mechanisms of inflammation and protein accumulation are crucial in inclusion body myositis (IBM). Recent evidence demonstrated that intravenous immunoglobulin failed to suppress cell-stress mediators in IBM. Here we studied the molecular changes in skeletal muscle biopsies from patients with IBM before and after treatment with alemtuzumab. METHODS: Relevant inflammatory and degeneration-associated markers were assessed by quantitative-PCR and immunohistochemistry in repeated muscle biopsy specimens from patients with IBM, which had been treated in a previously published uncontrolled proof-of-concept trial with alemtuzumab. RESULTS: There were no significant changes of the mRNA expression levels of the pro-inflammatory chemokines CXCL-9, CCL-4, and the cytokines IFN-γ, TGF-ß, TNF-α, and IL-1ß. Similarly, the degeneration-associated molecules ubiquitin, APP and αB-crystallin did not substantially change. Although no overall beneficial treatment effect was noted except for a 6-month stabilization, some patients experienced a transient improvement in muscle strength. In such responders, a trend towards reduced expression of inflammatory markers was noted. In contrast, the expression remained unchanged in the others who did not experience any change. The expression levels of IL-1ß and MHC-I correlated with the positive clinical effect. By immunohistochemistry, some inflammatory mediators like CD8, CXCL-9, and MHC-I were downmodulated. However, no consistent changes were noted for ubiquitin, nitrotyrosin and ß-amyloid. CONCLUSIONS: Alemtuzumab showed a trend towards downregulation of the expression of some inflammatory molecules in skeletal muscle of IBM patients but has no effect on several crucial markers of cell stress and degeneration. The data are helpful to explain the molecular treatment effects of future lymphocyte-targeted immunotherapies in IBM.

Follow-up nerve conduction studies in CIDP after treatment with IGIV-C: Comparison of patients with and without subsequent relapse.

INTRODUCTION: Electrodiagnostic studies (EDX) are not performed routinely before treatment suspension in CIDP, and no data exist regarding their value in predicting clinical relapse. METHODS: Serial EDX (baseline and after IGIV-C therapy) were analyzed from subjects in the ICE clinical trial who responded to IGIV-C treatment and were subsequently re-randomized to placebo in an extension phase. Comparisons were made between subjects who relapsed and those who did not. RESULTS: A total of 55% (6/11) of the Relapse group had an increase in total number of demyelinating findings (DF) versus 8% (1/13) in the No Relapse group (P = 0.023). In the Relapse group, 100% had ≥ 1 new DF and 73% (8/11) had ≥ 4 new DF versus 60% (8/13) and 8% (1/13), respectively, in the No Relapse group. CONCLUSIONS: An increased total number of DF or the occurrence of ≥ 4 new DF may indicate a higher risk of clinical relapse after treatment cessation in IGIV-C-responsive patients.

Treatment for inclusion body myositis.

BACKGROUND: Inclusion body myositis (IBM) is a late-onset inflammatory muscle disease (myopathy) associated with progressive proximal and distal limb muscle atrophy and weakness. Treatment options have attempted to target inflammatory and atrophic features of this condition (for example with immunosuppressive and immunomodulating drugs, anabolic steroids, and antioxidant treatments), although as yet there is no known effective treatment for reversing or minimising the progression of inclusion body myositis. In this review we have considered the benefits, adverse effects, and costs of treatment in targeting cardinal effects of the condition, namely muscle atrophy, weakness, and functional impairment. OBJECTIVES: To assess the effects of treatment for IBM. SEARCH METHODS: On 7 October 2014 we searched the Cochrane Neuromuscular Disease Group Specialized Register, the Cochrane Central Register for Controlled Trials (CENTRAL), MEDLINE, and EMBASE. Additionally in November 2014 we searched clinical trials registries for ongoing or completed but unpublished trials. SELECTION CRITERIA: We considered randomised or quasi-randomised trials, including cross-over trials, of treatment for IBM in adults compared to placebo or any other treatment for inclusion in the review. We specifically excluded people with familial IBM and hereditary inclusion body myopathy, but we included people who had connective tissue and autoimmune diseases associated with IBM, which may or may not be identified in trials. We did not include studies of exercise therapy or dysphagia management, which are topics of other Cochrane systematic reviews. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. MAIN RESULTS: The review included 10 trials (249 participants) using different treatment regimens. Seven of the 10 trials assessed single agents, and 3 assessed combined agents. Many of the studies did not present adequate data for the reporting of the primary outcome of the review, which was the percentage change in muscle strength score at six months. Pooled data from two trials of interferon beta-1a (n = 58) identified no important difference in normalised manual muscle strength sum scores from baseline to six months (mean difference (MD) -0.06, 95% CI -0.15 to 0.03) between IFN beta-1a and placebo (moderate-quality evidence). A single trial of methotrexate (MTX) (n = 44) provided moderate-quality evidence that MTX did not arrest or slow disease progression, based on reported percentage change in manual muscle strength sum scores at 12 months. None of the fully published trials were adequately powered to detect a treatment effect. We assessed six of the nine fully published trials as providing very low-quality evidence in relation to the primary outcome measure. Three trials (n = 78) compared intravenous immunoglobulin (combined in one trial with prednisone) to a placebo, but we were unable to perform meta-analysis because of variations in study analysis and presentation of trial data, with no access to the primary data for re-analysis. Other comparisons were also reported in single trials. An open trial of anti-T lymphocyte immunoglobulin (ATG) combined with MTX versus MTX provided very low-quality evidence in favour of the combined therapy, based on percentage change in quantitative muscle strength sum scores at 12 months (MD 12.50%, 95% CI 2.43 to 22.57). Data from trials of oxandrolone versus placebo, azathioprine (AZA) combined with MTX versus MTX, and arimoclomol versus placebo did not allow us to report either normalised or percentage change in muscle strength sum scores. A complete analysis of the effects of arimoclomol is pending data publication. Studies of simvastatin and bimagrumab (BYM338) are ongoing. All analysed trials reported adverse events. Only 1 of the 10 trials interpreted these for statistical significance. None of the trials included prespecified criteria for significant adverse events. AUTHORS' CONCLUSIONS: Trials of interferon beta-1a and MTX provided moderate-quality evidence of having no effect on the progression of IBM. Overall trial design limitations including risk of bias, low numbers of participants, and short duration make it difficult to say whether or not any of the drug treatments included in this review were effective. An open trial of ATG combined with MTX versus MTX provided very low-quality evidence in favour of the combined therapy based on the percentage change data given. We were unable to draw conclusions from trials of IVIg, oxandrolone, and AZA plus MTX versus MTX. We need more randomised controlled trials that are larger, of longer duration, and that use fully validated, standardised, and responsive outcome measures.

ANTECEDENTES: La miositis por cuerpos de inclusión (MCI) es una enfermedad muscular inflamatoria (miopatía) de aparición tardía asociada con atrofia muscular y debilidad progresivas de los miembros proximales y distales. Las opciones de tratamiento se han intentado dirigir a las características inflamatorias y atróficas de esta afección (por ejemplo, con fármacos inmunosupresores e inmunomoduladores, esteroides anabólicos y tratamientos antioxidantes), aunque hasta ahora no hay un tratamiento eficaz conocido para la reversión o la reducción de la progresión de la miositis por cuerpos de inclusión. En esta revisión se han considerado los efectos beneficiosos, los efectos adversos y los costos del tratamiento dirigido a los efectos fundamentales de la afección, a saber, la atrofia muscular, la debilidad y el deterioro funcional. OBJETIVOS: Evaluar los efectos del tratamiento para la MCI. MÉTODOS DE BÚSQUEDA: El 7 octubre 2014, se hicieron búsquedas en el registro especializado del Grupo Cochrane de Enfermedades Neuromusculares (Cochrane Neuromuscular Disease Group), en el Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials) (CENTRAL), MEDLINE y en EMBASE. Además, en noviembre 2014 se realizaron búsquedas de ensayos en curso o terminadas pero no publicados en los registros de ensayos clínicos. CRITERIOS DE SELECCIÓN: Se consideraron para inclusión en la revisión los ensayos aleatorios o cuasialeatorios, incluidos los ensayos cruzados (crossover), del tratamiento para la MCI en adultos en comparación con placebo u otro tratamiento. Se excluyeron específicamente los pacientes con MCI familiar y miopatía por cuerpos de inclusión hereditaria, pero se incluyeron los pacientes con enfermedades del tejido conjuntivo y autoinmunitarias asociadas con MCI, que pueden o no identificarse en los ensayos. No se incluyeron los estudios de terapia con ejercicios o tratamiento de la disfagia, que son los temas de otras revisiones sistemáticas Cochrane. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Se utilizaron procedimientos metodológicos Cochrane estándar. RESULTADOS PRINCIPALES: La revisión incluyó diez ensayos (249 participantes) que utilizaron diferentes regímenes de tratamiento. Siete de los diez ensayos evaluaron agentes únicos y tres evaluaron agentes combinados. Muchos de los estudios no presentaron datos suficientes para el informe del resultado primario de la revisión, que fue el cambio porcentual en la puntuación de fuerza muscular a los seis meses. Los datos agrupados de dos ensayos de interferón beta­1a (n = 58) no identificaron diferencias importantes en las puntuaciones normalizadas de la suma de la fuerza muscular manual desde el inicio hasta los seis meses (diferencia de medias [DM] ­0,06; IC del 95%: ­0,15 a 0,03) entre IFN beta­1a y placebo (pruebas de calidad moderada). Un único ensayo de metotrexato (MTX) (n = 44) proporcionó pruebas de calidad moderada de que el MTX no detuvo ni enlenteció la progresión de la enfermedad, sobre la base del cambio porcentual informado en las puntuaciones de la suma de la fuerza muscular manual a los 12 meses. Ninguno de los ensayos publicados completamente tuvo poder estadístico suficiente para detectar un efecto del tratamiento. Se consideró que seis de los nueve ensayos publicados completamente aportaron pruebas de calidad muy baja con respecto a la medida de resultado primaria. Tres ensayos (n = 78) compararon la inmunoglobulina intravenosa (combinada en un ensayo con prednisona) con placebo, pero no fue posible realizar el metanálisis debido a las variaciones en el análisis de los estudios y a la presentación de los datos del ensayo, sin acceso a los datos primarios para el reanálisis. Otras comparaciones también se informaron en ensayos individuales. Un ensayo abierto de inmunoglobulina anti­linfocitos T (IgAT) combinada con MTX versus MTX proporcionó pruebas de calidad muy baja a favor del tratamiento combinado, sobre la base del cambio porcentual en las puntuaciones cuantitativas de la suma de la fuerza muscular a los 12 meses (DM 12,50%; IC del 95%: 2,43 a 22,57). Los datos de los ensayos de oxandrolona versus placebo, azatioprina (AZA) combinada con MTX versus MTX y arimoclomol versus placebo no permitieron informar sobre el cambio porcentual o normalizado en las puntuaciones de la suma de la fuerza muscular. Un análisis completo de los efectos del arimoclomol está pendiente de la publicación de los datos. Están en curso estudios de simvastatina y bimagrumab (BYM338). Todos los ensayos analizados informaron eventos adversos. Solamente uno de los diez ensayos interpretó la significación estadística de los eventos adversos. Ninguno de los ensayos incluyó criterios preespecificados para los eventos adversos significativos. CONCLUSIONES DE LOS AUTORES: Los ensayos de interferón beta­1a y MTX proporcionaron pruebas de calidad moderada de que no tienen efectos sobre la progresión de la MCI. Las limitaciones generales del diseño de los ensayos, que incluyen el riesgo de sesgo, los escasos números de participantes y la corta duración, hacen difícil determinar si alguno de los tratamientos farmacológicos incluidos en esta revisión fue eficaz. Un ensayo abierto de ATG combinada con MTX versus MTX aportó pruebas de calidad muy baja a favor del tratamiento combinado sobre la base de los datos de cambio porcentual facilitados. No fue posible establecer conclusiones de los ensayos de IgIV, oxandrolona y AZA más MTX versus MTX. Se necesitan más ensayos controlados aleatorios de mayor tamaño, con una duración más prolongada y que utilicen medidas de resultado completamente validadas, estandarizadas y de interés.

Mechanistic effects of IVIg in neuroinflammatory diseases: conclusions based on clinicopathologic correlations.

The mechanisms of action of IVIg on immunoregulatory and neuroinflammatory network have been predominantly based on in vitro experiments and animal studies, rather than direct effects on human tissues. Based on clinicopathologic correlations and tissues obtained before and after IVIg therapy, the better documented and clinically-relevant in-vivo actions of IVIg include effects on: a) Antibodies. An extracted antigen-specific anti-immunoglobulin (idiotypic) fraction appears partially responsible for its effect in myasthenia gravis and GBS; b) Complement. Sera from Dermatomyositis (DM) patients responding to IVIg, inhibit complement consumption and intercept MAC formation leading to disappearance of MAC deposits in the repeated muscle biopsies and normalization of muscle tissue; c) Genes. In repeated muscle biopsies from DM patients who improved after IVIg, but not from Inclusion-Body-Myositis (IBM) who did not improve, there is a 2-fold alteration of 2206 tissue genes associated with inflammation, fibrosis, tissue remodeling and regeneration; and d) degenerative-proinflammatory molecules and ß-amyloid, implicated in neurodegenerative CNS diseases and IBM. In repeated muscle biopsies of IBM patients who did not respond to IVIg, the mRNA or protein expression for chemokines, IFN-γ, TGF-ß, IL-10, Ubiquitin and aB-crystallin is reduced, but not for the key molecules ICOS, ICOSL, IL-6, IL1-ß, perforin, APP, nitric oxide synthase and nitrotyrosine, in spite of good IVIg penetration in muscles. Collectively, the selective effectiveness of IVIg in human diseases seems to correlate in vivo with inhibition of causative inflammatory mediators. Study of accessible tissues before and after therapy and clinicopathologic correlations, may help explain the differential effect of IVIg in autoimmune or neuroinflammatory diseases.

Stiff Person Syndrome and GAD Antibody-Spectrum Disorders.

OBJECTIVE: Antibodies against glutamic acid decarboxylase (GAD), originally associated with stiff person syndrome (SPS), define the GAD antibody-spectrum disorders that also include cerebellar ataxia, autoimmune epilepsy, limbic encephalitis, progressive encephalomyelitis with rigidity and myoclonus (PERM), and eye movement disorders, all of which are characterized by autoimmune neuronal excitability. This article elaborates on the diagnostic criteria for SPS and SPS spectrum disorders, highlights disease mimics and misdiagnoses, describes the electrophysiologic mechanisms and underlying autoimmunity of stiffness and spasms, and provides a step-by-step therapeutic scheme. LATEST DEVELOPMENTS: Very-high serum GAD antibody titers are diagnostic for GAD antibody-spectrum disorders and also predict the presence of GAD antibodies in the CSF, increased intrathecal synthesis, and reduced CSF γ-aminobutyric acid (GABA) levels. Low serum GAD antibody titers or the absence of antibodies generates diagnostic challenges that require careful distinction in patients with a variety of painful spasms and stiffness, including functional neurologic disorders. Antibodies against glycine receptors, first found in patients with PERM, are seen in 13% to 15% of patients with SPS, whereas amphiphysin and gephyrin antibodies, seen in 5% of patients with SPS spectrum disorders, predict a paraneoplastic association. GAD-IgG from different SPS spectrum disorders recognizes the same dominant GAD intracellular epitope and, although the pathogenicity is unclear, is an excellent diagnostic marker. The biological basis of muscle stiffness and spasms is related to autoimmune neuronal hyperexcitability caused by impaired reciprocal γ-aminobutyric acid-mediated (GABA-ergic) inhibition, which explains the therapeutic response to GABA-enhancing agents and immunotherapies. ESSENTIAL POINTS: It is essential to distinguish SPS spectrum disorders from disease mimics to avoid both overdiagnoses and misdiagnoses, considering that SPS is treatable if managed correctly from the outset to prevent disease progression. A step-by-step, combination therapy of GABA-enhancing medications along with immunotherapies ensures prolonged clinical benefits.

Stiff-person syndrome and related disorders - diagnosis, mechanisms and therapies.

Stiff-person syndrome (SPS) is the prototypical and most common autoimmune neuronal hyperexcitability disorder. It presents with stiffness in the limbs and axial muscles, stiff gait with uncontrolled falls, and episodic painful muscle spasms triggered by anxiety, task-specific phobias and startle responses, collectively leading to disability. Increased awareness of SPS among patients and physicians has created concerns about diagnosis, misdiagnosis and treatment. This Review addresses the evolving diagnostic challenges in SPS and overlapping glutamic acid decarboxylase (GAD) antibody spectrum disorders, highlighting the growing number of overdiagnoses and focusing on the progress made in our understanding of SPS pathophysiology, antibodies against GAD and other inhibitory synaptic antigens, and the fundamentals of neuronal hyperexcitability. It considers the role of impaired GABAergic or glycinergic inhibition in the cortex and at multiple levels in the neuraxis; the underlying autoimmunity and involvement of GAD antibodies; immunopathogenic mechanisms beyond antibodies, including environmental triggers; familial and immunogenetic susceptibility; and potential T cell cytotoxicity. Finally, the mechanistic rationale for target-specific therapeutic interventions is presented along with the available therapeutic approaches, including enhancers of GABA signalling drugs and immunotherapies.

Severe Stiff-Person Syndrome After COVID: The First Video-Documented COVID Exacerbation and Viral Implications

OBJECTIVES: To describe a patient with mild GAD-positive stiff-leg syndrome (SLS) who developed severely disabling stiff-person syndrome (SPS) 1 week after mild COVID-19 and discuss the impact of viral implications. METHODS: Video-documented serial clinical observations at baseline, after acute COVID-19, and after IVIG treatments. RESULTS: A 39-year-old man with left-SLS was stable during a 2-year follow-up with low-dose antispasmodics, working fully and functioning normally, even able to run. One week after mild COVID-19, he started to experience generalized SPS symptomatology that steadily worsened the following 2-3 weeks, becoming unable to walk, requiring a walker, with significant thoracolumbar and bilateral leg stiffness and spasms. GAD ab were very high. After 3 monthly IVIg infusions he showed improvements, but his gait remains significantly stiff. All clinical changes, from baseline to post-Covid, and then post- IVIg have been video-documented. DISCUSSION: This is the first, clearly documented, severe GAD-positive SPS after COVID-19. Although viral or postviral causation can be incidental, the temporal connection with acute COVID-19, the severe disease worsening after symptom-onset, and the subsequent steady improvement after IVIg, suggest viral-triggered autoimmunity. Because COVID-19 reportedly can trigger or worsen GAD-associated diabetes type 1 through proinflammatory mediators, and SPS has been reportedly triggered by West Nile Virus, possibly through molecular mimicry, this case of acutely converting GAD-SLS to GAD-SPS suggest the need to explore viral etiologies in patients with GAD-SPS experiencing acute, long-lasting episodic exacerbations of stiffness and spasms.