Myasthenia Gravis Treatment: From Old Drugs to Innovative Therapies with a Glimpse into the Future.

Myasthenia gravis (MG) is a rare autoimmune disease that causes debilitating muscle weakness due to impaired neuromuscular transmission. Since most (about 80-90%) MG patients present autoantibodies against the acetylcholine receptor, standard medical therapy consists of symptomatic treatment with acetylcholinesterase inhibitors (e.g., pyridostigmine). In addition, considering the autoimmune basis of MG, standard therapy includes immunomodulating agents, such as corticosteroids, azathioprine, cyclosporine A, and cyclophosphamide. New strategies have been proposed for the treatment of MG and include complement blockade (i.e., eculizumab, ravulizumab, and zilucoplan) and neonatal Fc receptor antagonism (i.e., efgartigimod and rozanolixizumab). The aim of this review is to provide a detailed overview of the pre- and post-marketing evidence on the five pharmacological treatments most recently approved for the treatment of MG, by identifying both preclinical and clinical studies registered in clinicaltrials.gov. A description of the molecules currently under evaluation for the treatment of MG is also provided.

An evaluation of rozanolixizumab-noli for the treatment of anti-AChR and anti-MuSK antibody-positive generalized myasthenia gravis.

INTRODUCTION: Myasthenia gravis (MG) is an auto-immune disease characterized by fluctuating symptoms of muscle weakness and fatigue. Corticosteroids and corticosteroid-sparing broad-spectrum immunosuppression play a great role in the treatment of myasthenia gravis. However, debilitating side effects and long time to treatment effect highlight the need for development of novel target-specific medications. Rozanolixizumab is a highly specific neonatal Fc receptor (FcRn) inhibitor that acts on immunoglobulin G (IgG) homeostasis. Results from the MycarinG Phase III randomized controlled trial demonstrated significant efficacy of rozanolixizumab in generalized MG in terms of primary outcome and all secondary endpoints, tolerability, and safety compared to placebo. AREAS COVERED: We included different trials on myasthenia gravis and rozanolixizumab which include Phase II (NCT03052751) and Phase III MycarinG (NCT03971422) studies. EXPERT OPINION: Clinical trials have demonstrated that rozanolixizumab has strong efficacy with a 78% reduction in pathogenic IgG like plasma exchange (PLEX) and has therapeutic benefits comparable with PLEX and IVIG. It has less treatment adverse events and is easily accessible through subcutaneous infusion. The safety and effectiveness of rozanolixizumab need to be assessed further in the real-world context in post-marketing studies. If current trial information holds true, rozanolixizumab may become a medication of choice for MG in succeeding years.

M1 acetylcholine receptors in somatostatin interneurons contribute to GABAergic and glutamatergic plasticity in the mPFC and antidepressant-like responses.

Alterations in glutamatergic and GABAergic function in the medial prefrontal cortex (mPFC) are prevalent in individuals with major depressive disorder, resulting in impaired synaptic plasticity that compromises the integrity of signal transfer to limbic regions. Scopolamine, a non-selective muscarinic receptor antagonist, produces rapid antidepressant-like effects by targeting M1-type acetylcholine receptors (M1R) on somatostatin (SST) interneurons. So far, these effects have been investigated with relatively short-term manipulations, and long-lasting synaptic mechanisms involved in these responses are still unknown. Here, we generated mice with conditional deletion of M1R (M1f/fSstCre+) only in SST interneurons to determine the role of M1R in modulating long-term GABAergic and glutamatergic plasticity in the mPFC that leads to attenuation of stress-relevant behaviors. We have also investigated whether the molecular and antidepressant-like effects of scopolamine could be mimicked or occluded in male M1f/fSstCre+ mice. M1R deletion in SST-expressing neurons occluded the rapid and sustained antidepressant-like effects of scopolamine, as well as scopolamine-induced increases in c-Fos+/CaMKIIα cells and proteins necessary for glutamatergic and GABAergic function in the mPFC. Importantly, M1R SST deletion resulted in resilience to chronic unpredictable stress in behaviors relevant to coping strategies and motivation, and to a lesser extent, in behaviors relevant to avoidance. Finally, M1R SST deletion also prevented stress-induced impairments in the expression of GABAergic and glutamatergic markers in the mPFC. These findings suggest that the antidepressant-like effects of scopolamine result from modulation of excitatory and inhibitory plasticity via M1R blockade in SST interneurons. This mechanism could represent a promising strategy for antidepressant development.

Conventional and emerging treatments and controversies in myasthenia gravis.

INTRODUCTION: Myasthenia gravis (MG) is caused by IgG antibodies against different proteins at the neuromuscular junction. Anti-acetylcholine receptor (AChR) Abs are detected in the great majority of patients. MG management consists of long-term immunotherapy, based on steroids and immunosuppressants, short-term treatments and therapeutic thymectomy. Targeted immunotherapies that reduce B cell survival, inhibit complement activation, and decrease serum IgG concentration have been evaluated in trials and have entered clinical practice. AREAS COVERED: Herein, the efficacy and safety data of conventional and novel therapeutic options are reviewed and their indications in the disease subtypes are discussed. EXPERT OPINION: Even though conventional treatment is generally effective, 10-15% of patients have refractory disease and there are safety concerns related to long-term immunosuppression. Novel therapeutic options offer several advantages but also have limitations. Safety data based on long-term treatment are not yet available for some of these agents. The mechanisms of action of new drugs and the immunopathogenesis of different MG subtypes must be considered in therapy decision making. Integrating new agents in the treatment scenario of MG can significantly improve disease management.

Age of onset and factors affecting treatment responses in ocular myasthenia gravis.

BACKGROUND: Ocular myasthenia gravis (OMG) is an autoimmune disease which causes ptosis, diplopia, or both. It can be categorized as early or late onset, with differing presenting characteristics and prognoses. Currently, there is limited information available to compare characteristics and outcomes in onset groups in Thailand. OBJECTIVE: To describe and compare baseline characteristics and outcomes in OMG patients classified by onset groups and to investigate the factors associated with the disease, especially in terms of treatment responses classified according to the MGFA Post-Intervention Status (MGFA-PIS). METHODS: OMG patients diagnosed between January 2014 and March 2021 at Rajavithi Hospital, Thailand, were categorized into 2 groups based on age of onset, and baseline characteristics were analyzed and compared. The treatment responses of each group in terms of time to achievement of minimal manifestations (MM) were analyzed. RESULTS: Eighty-one patients (38 with early and 43 with late onset) were included, and the mean (SD) follow-up time was 35.85 months (17.25). There was no significant difference between the baseline characteristics of the two groups. A low dose of pyridostigmine was more commonly used in the early-onset group (p = 0.01), while the mean dose of corticosteroids was significantly lower in the late-onset patients (p < 0.001). We found that seropositivity of acetylcholine receptor antibody decreased the odds ratio of achievement of MM (OR 0.185, 95% CI 0.043-0.789, p = 0.023) and receiving a high dose of pyridostigmine (≥ 120 mg/day) increased the odds ratio of achieving it (OR 8.296, 95% CI 2.136-32.226, p = 0.002). CONCLUSIONS: A higher dose of pyridostigmine may be necessary for achievement of favorable treatment response. AChRAb seropositivity is a predictor for unfavorable treatment response in Thai populations.

Efgartigimod Alfa in Generalised Myasthenia Gravis: A Profile of Its Use.

Intravenous efgartigimod alfa (also known as efgartigimod alfa-fcab in the USA; Vyvgart®) is the first neonatal Fc receptor antagonist approved in several countries worldwide, including the USA and EU for the treatment of generalised myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) antibody positive, and in Japan for the treatment of gMG regardless of antibody status. In the double-blind, placebo-controlled phase 3 ADAPT trial in patients with gMG, efgartigimod alfa significantly and rapidly reduced disease burden and improved muscle strength and quality of life compared with placebo. The clinical benefits of efgartigimod alfa were durable and reproducible. Furthermore, in an interim analysis of the ongoing open-label phase 3 ADAPT+ extension trial, efgartigimod alfa provided consistent clinically meaningful improvements in patients with gMG. Efgartigimod alfa was generally well tolerated, with most adverse events being mild to moderate in severity.

Generalised myasthenia gravis (gMG) is a chronic, autoimmune neuromuscular disorder that can significantly impair quality of life. Several novel targeted therapeutic approaches have emerged to provide faster onset of action compared with conventional immunosuppressive therapy, favourable tolerability profile and the potential for a sustained disease control for patients with gMG. Intravenous efgartigimod alfa (also known as efgartigimod alfa-fcab in the USA; Vyvgart^®) is the first neonatal Fc receptor antagonist approved in several countries worldwide, including the USA and EU for the treatment of gMG in adults who are anti-acetylcholine receptor (AChR) antibody positive, and in Japan for the treatment of gMG regardless of antibody status. In the pivotal clinical trial in patients with gMG, efgartigimod alfa rapidly reduced disease burden and improved muscle strength and quality of life. The beneficial effects of efgartigimod alfa occurred early and were durable and reproducible. Longer term, efgartigimod alfa provided consistent clinically meaningful improvements in patients with gMG. Efgartigimod alfa is generally well tolerated, with most adverse events being mild to moderate in severity. Thus, efgartigimod alfa is a novel, effective and generally well-tolerated treatment option for patients with gMG.

An update of the pharmacological treatment options for generalized myasthenia gravis in adults with anti-acetylcholine receptor antibodies.

PURPOSE: This review aims to provide an update on current pharmacological agents for the management of generalized myasthenia gravis (MG). SUMMARY: MG is an autoimmune disease characterized by impaired neuromuscular transmission and muscle weakness. Most patients have autoimmune antibodies to the nicotinic acetylcholine receptor, with treatments aimed at eliminating or decreasing levels of autoantibodies. Limitations of current treatments for generalized MG include limited efficacy and serious adverse effects, indicating a continued need for new treatments. Efgartigimod alfa, a biologic newly approved by the Food and Drug Administration, provides a novel treatment option for patients with chronic generalized MG. CONCLUSION: While the landscape for treatment of generalized MG has expanded over recent years, there is still an unmet need for patients for whom multiple lines of treatment have failed. The introduction of neonatal Fc receptor antagonists such as efgartigimod alfa may have an immediate impact in patients for whom standard-of-care therapy has failed.

Treatment considerations in myasthenia gravis for the pregnant patient.

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune disease where muscle antibodies form against the acetylcholine receptor (AChR), MuSK, or LRP4 at the neuromuscular junction leading to weakness. Patients worry about consequences for pregnancy, giving birth, nursing, and child outcome. AREAS COVERED: This review lists the pharmacological treatments for MG in the reproductive age and gives recommendations. Consequences for pregnancy, giving birth, breastfeeding, and child outcome are discussed. EXPERT OPINION: Pyridostigmine, corticosteroids in low doses, and azathioprine are regarded as safe during pregnancy and should be continued. Mycophenolate mofetil, methotrexate, and cyclophosphamide should not be used in reproductive age. Rituximab should not be given during pregnancy. Other monoclonal IgG antibodies such as eculizumab and efgartigimod should be given only when regarded strictly necessary to avoid long-term and severe incapacity. Intravenous and subcutaneous immunoglobulin and plasma exchange are safe treatments during pregnancy and are recommended for exacerbations with moderate or severe generalized weakness. Most MG women have spontaneous vaginal deliveries. Indications for Cesarean section are obstetrical and similar to non-MG women. Neonatal myasthenia manifests as a transient weakness caused by the mother's IgG muscle antibodies and affects 10% of the babies. MG women should be supported in their wish to have children.

Precision targeting of autoantigen-specific B cells in muscle-specific tyrosine kinase myasthenia gravis with chimeric autoantibody receptor T cells.

Muscle-specific tyrosine kinase myasthenia gravis (MuSK MG) is an autoimmune disease that causes life-threatening muscle weakness due to anti-MuSK autoantibodies that disrupt neuromuscular junction signaling. To avoid chronic immunosuppression from current therapies, we engineered T cells to express a MuSK chimeric autoantibody receptor with CD137-CD3ζ signaling domains (MuSK-CAART) for precision targeting of B cells expressing anti-MuSK autoantibodies. MuSK-CAART demonstrated similar efficacy as anti-CD19 chimeric antigen receptor T cells for depletion of anti-MuSK B cells and retained cytolytic activity in the presence of soluble anti-MuSK antibodies. In an experimental autoimmune MG mouse model, MuSK-CAART reduced anti-MuSK IgG without decreasing B cells or total IgG levels, reflecting MuSK-specific B cell depletion. Specific off-target interactions of MuSK-CAART were not identified in vivo, in primary human cell screens or by high-throughput human membrane proteome array. These data contributed to an investigational new drug application and phase 1 clinical study design for MuSK-CAART for the treatment of MuSK autoantibody-positive MG.

Demographics and ocular findings in children with myasthenia.

PURPOSE: To report the demographics and ocular features of myasthenia gravis in the paediatric population. METHODS: Retrospective revision of the medical records of all patients younger than 18 years of age with myasthenia who were examined at Great Ormond Street Hospital between the 1st of January 2016 and 1st of January 2020. RESULTS: A total of 49 children were assessed during the 4-year period. There was a female predominance, with only 12 males (24.5%). 26 children (53.1%) had juvenile myasthenia gravis (JMG) while 18 (36.7%) had congenital myasthenic syndrome (CMS). 4 patients (8.2%) were diagnosed with probable CMS while 1 (2.0%) was classified as probable JMG. The mean age at diagnosis was 5.3 years old (SD 3.9) whereas the mean age at onset was 3.7 years old (SD 3.9). Almost half of the children (49%) had ocular involvement, present in 19 patients in the JMG group (70.4%) and in 5 children (22.7%) in the CMS cohort. Ptosis was the most common sign at presentation, seen in 32 patients (65.3%). Nine patients (18.4%) presented with a squint and another 7 (14.3%) developed it later on. Anti-acetylcholine receptor antibodies were positive in 18 of the 26 JMG patients (69.2%) whereas identifiable mutations were found in the 18 CMS patients (100%). Pyridostigmine was the drug of choice in our series, used by thirty-three patients (67.3%). The majority of the patients (73.5%) improved after treatment. CONCLUSIONS: JMG was the most common type of paediatric MG, specifically the ocular form. Ptosis was the most common sign at presentation. The majority of the patients improved after medical treatment.

A systematic review and in silico study of potential genetic markers implicated in cases of overactive bladder.

OBJECTIVE: The contribution of genetic factors to the presence of an overactive bladder is recognized. This study aimed to (1) assemble and synthesize available data from studies assessing differential gene expression in patients with overactive bladder vs controls without overactive bladder and (2) determine possible correlations and functional pathways between genes. DATA SOURCES: We searched PubMed, Ovid or Medline, and Wiley Cochrane Central Register of Controlled Trials databases between January 1, 2000, and December 15, 2021. STUDY ELIGIBILITY CRITERIA: Studies were included if gene expression was detected and quantified using molecular approaches performed on human bladder tissue specimens directly and excluded if the gene expression analysis was carried out from blood and urine specimens alone. METHODS: A systematic review was completed to identify publications that reported differently expressed gene candidates among patients with overactive bladder vs healthy individuals. Gene networking connections and pathway analysis were performed employing Metascape software, where inputs were identified from our systematic review of differentially expressed genes in overactive bladder. RESULTS: A total of 9 studies were included in the final analysis and 11 genes were identified as being up-regulated (purinergic receptor P2X 2 [P2RX2], smoothelin [SMTN], growth-associated protein 43 [GAP43], transient receptor potential cation channel subfamily M member 8 [TRPM8], cadherin 11 [CDH1], gap junction protein gamma 1 [GJC1], cholinergic receptor muscarinic 2 [CHRM2], cholinergic receptor muscarinic 3 [CHRM3], and transient receptor potential cation channel subfamily V member 4 [TRPV4]) or down-regulated (purinergic receptor P2X 2 [P2RX3] and purinergic receptor P2X 5 [P2RX5]) in patients with overactive bladder. Gene network analysis showed that genes are involved in chemical synaptic transmission, smooth muscle contraction, blood circulation, and response to temperature stimulus. Network analysis demonstrated a significant genetic interaction between TRPV4, TRPM8, P2RX3, and PR2X2 genes. CONCLUSION: Outcomes of this systematic review highlighted potential biomarkers for treatment efficacy and have laid the groundwork for developing future gene therapies for overactive bladder in clinical settings.

[Effects of rituximab on prognosis in myasthenia gravis: A single-center experience from Turkey]. / A rituximab hatása a myasthenia gravis prognózisára: egy központú, törökországi tapasztalat.

Background and purpose: Management of treatment-resistant patients with myasthenia gravis (MG) remains an important issue. This study aimed to evaluate the effects of rituximab (RTX) treatment on the prognosis of patients with acetylcholine receptor autoantibody-positive (AChR-Ab+), muscle-specific kinase autoantibody-positive (MuSK-Ab+), or seronegative or double seropositive MG. Methods: Nineteen patients treated with RTX between 2015 and 2020 were included in this study. Demographic and clinical characteristics, prognosis, and prognostic predictors of MG were evaluated retrospectively. The Myas-thenia Gravis Foundation of America Post-Inter-vention Status (MGFA-PIS) before RTX treatment (pre-RTX) and after RTX treatment (post-RTX) were recorded. Results: A total of 10 patients (52.6%) were AchR Ab+, 6 patients (31.6%) were MuSK Ab+, 1 patient (5.3%) was seronegative, and 2 patients (10.5%) were double seropositive. Steroid dose was pre-RTX 38.9±5.7 (25-45), it was post-RTX 10.5±10.3 (0-30) (p<0.001). Post-RTX steroid treatment was discontinued in 6 of 19 patients (p=0.041). Only three patients received intravenous immunoglobulin at the post-RTX follow-up (p<0.001). In post-RTX 12th month, the MGFA-PIS score was as minimally manifestation or better in 9 patients (47.3%) and improved or was better in 18 patients (94.7%) (p-value 0.004; <0.001, respectively). Conclusion: The improvement in MGFA-PIS scores post-RTX was similar in MuSK-Ab+ and AChR-Ab+ patients. The data are insufficient in seronegative and double seropositive patients and RTX must be considered in the treatment of suitable patients with MuSK-Ab+ and AChR-Ab+ refractory MG.

Outcomes and characteristics of myasthenia gravis: A 10-year retrospective cross-sectional study at King Fahad Medical City.

OBJECTIVES: To investigate the distribution of muscle weakness in Myasthenia gravis (MG) and the therapeutic response in each category. METHODS: This is a retrospective cross-sectional study included all MG patients presented to our clinic between 2010 and 2020. The demographic, clinical, serological, electrophysiological, radiological, and histopathological data of the patients were recorded. The details of the treatment administered were also documented. Muscle weakness was divided into: ocular, bulbar, and generalized. RESULTS: The mean age of the 147 patients included in this study was 34.2±16.6 years. The most common presentation was ocular MG (57.1%). There was no significant association between the gender of the patients and the MG subgroups. Antibodies against AChR were reported in 95.2%, 75%, and 87% of the patients with ocular, bulbar, and generalized myasthenia, respectively. Anti-MuSK antibodies were detected in 20% of the patients with bulbar weakness. Most of the patients with ocular (91.7%) and bulbar (90%) presentation developed generalized weakness. At the end of the follow-up, 82.6%, 70.2%, and 57.5% of the patients with generalized, ocular, and bulbar presentations, respectively demonstrated well-controlled weakness. CONCLUSION: The most common initial presentation was ocular weakness. Most patients with ocular and bulbar presentation developed generalized weakness during the follow up period. The most frequently reported autoantibody was against AChR. Most patients with generalized, ocular, and bulbar presentation demonstrated well-controlled weakness at the end of the follow up period.

Like a Game of Chess, Every Move Matters: The Role of Antibodies in the Myasthenia Gravis Treatment Landscape.

Symptoms and disease pathophysiology of myasthenia gravis (MG) vary considerably with each patient, and their individual preferences and priorities add to the need for individualized treatment of this autoimmune disease. Research in MG has grown substantially in recent years. New treatments have the potential of being both effective and well tolerated, addressing the trade-off of choosing either efficacy or tolerability when selecting treatments. Promising investigational treatments that may become available in the future may allow more patients than ever before to achieve an asymptomatic state, with the ultimate goal being to turn off abnormal antibody production.

Abdeg technology for the treatment of myasthenia gravis: efgartigimod drug experience.

INTRODUCTION: Myasthenia gravis is characterized by fluctuating muscle weakness that improves with rest and worsens with effort or throughout the day. AREAS COVERED: Efgartigimod is a human IgG1-derived Fc fragment modified at five residues to increase its affinity for the neonatal Fc receptor by Abdeg technology. Thus, efgartigimod binds to the neonatal Fc receptor and decreases the levels of IgG, including autoantibodies of this isotype. For acetylcholine receptor (AChR) antibody-positive patients, efgartigimod had a higher proportion of MG-ADL responders than placebo in the first treatment cycle. The mean changes of multiple outcomes from baseline were better for efgartigimod than placebo from weeks 1 to 7 in the first treatment cycle. The decrease of IgG and AChR autoantibodies was 61.3% and 57.6% one week after the first treatment cycle ends, respectively. The most common adverse events were headache, nasopharyngitis, nausea, and diarrhea, which occurred in the same proportion in the efgartigimod and placebo groups. Urinary and upper respiratory tract infections were twice as frequent in efgartigimod-treated patients. EXPERT OPINION: Efgartigimod was efficacious and safe for generalized myasthenia patients with AChR antibody-positive patients. These findings need to be confirmed in AChR antibody-negative patients, and long-term safety studies are currently ongoing.

Myasthenia gravis patients have a high level of autoantibodies, which can cause fluctuating muscle weakness. In this regard, efgartigimod is a new drug approved to treat myasthenia gravis that decreases antibody levels and symptom improvement. Furthermore, this drug was safe for these patients.[Figure: see text].

Role of complement, anti-complement therapeutics, and other targeted immunotherapies in myasthenia gravis.

INTRODUCTION: Several patients with myasthenia gravis (MG) do not adequately respond to available drugs or exhibit poor tolerance, necessitating the need for new therapies. AREAS COVERED: The paper discusses the rapidly evolving target-specific immunotherapies that promise long-standing remissions in the management of MG. It is specifically focused on the role of complement, anti-complement therapeutics, and the anti-FcRn and B cell monoclonals. EXPERT OPINION: Anti-AChR antibodies cause internalization of the receptors and activate complement leading to in situ MAC formation that damages the post-synaptic membrane of the neuromuscular junction. Inhibiting MAC formation by antibodies targeting key complements subcomponents is a reasonable therapeutic goal. Indeed, the anti-C5 monoclonal antibodies, Eculizumab, Ravulizumab, and Zilucoplan, have been successfully tested in MG with Eculizumab first and now Ravulizumab FDA-approved for refractory MG based on sustained long-term benefits. Among the biologics that inhibit FcRn, Efgartigimod caused rapid reduction of the circulating IgG in the lysosomes, and induced sustained clinical remission with good safety profile leading to FDA-approved indication. Anti-B cell agents, like Rituximab, can induce sustained long-term remissions, especially in IgG4 antibody-mediated Musk-MG, by targeting short-lived antibody-secreting plasmablasts. These biologics offer effective targeted immunotherapies with good tolerance promising to change the therapeutic algorithm in the chronic MG management.

Vitamin B12 as a cholinergic system modulator and blood brain barrier integrity restorer in Alzheimer's disease.

So far, the cholinergic hypothesis of Alzheimer's disease (AD) remains the fundamental explanation for the complex etiopathology of AD. However, therapeutics raising synaptic acetylcholine (Ach) or having cholinergic receptors agonistic activity had shown limited clinical efficacy, possibly, due to lacking capability to aggregate cholinergic receptors within the degenerated cholinergic neurons. Vitamin-B12 (B12) is an epigenetic modifier. It has a specific CNS transport system via the cubam receptors. The later enclose a cholinergic aggregator; agrin protein, suggesting that B12 administration may cause cholinergic receptors aggregation. Further, B12 involvement in homocysteine (Hcy) metabolism may restore blood brain barrier (BBB) integrity disrupted by elevated Hcy levels in AD. Here in, using a pharmacological model of cholinergic amnesia, three different B12 doses were compared to the standard of care; donepezil (DON) regarding cholinergic system modulation, and their effect on Hcy metabolic pathways. Further, AD-associated cerebro-vascular pathology was assessed by morphometric analyses of cerebro-vasculature morphology and ultrastructure using scanning and transmission electron-microscopes, respectively. Consequent effect on key AD-hallmarks and behavioral cognitive tests was also examined. The highest B12-tested dose (B12-HD) showed the greatest hippocampal cholinergic modulation with dose-dependent preferential upregulation of one cholinergic receptor over the other. Altered Hcy metabolism was proved to be a consequence of cholinergic disruption that was variably reversed by different B12 doses. In spite of equipotent effect of DON and B12-HD therapies in decreasing ß-amyloid synthesis, B12-HD-treated group revealed the greatest restoration of BBB integrity indicating superior capability of ß-amyloid clearance. Therefore, B12-HD therapy may represent a promising AD-modifying agent with extra-ability over conventional cholinergic modulators to aggregate cholinergic receptors.

Novel treatment strategies for acetylcholine receptor antibody-positive myasthenia gravis and related disorders.

The presence of autoantibodies directed against the muscle nicotinic acetylcholine receptor (AChR) is the most common cause of myasthenia gravis (MG). These antibodies damage the postsynaptic membrane of the neuromuscular junction and cause muscle weakness by depleting AChRs and thus impairing synaptic transmission. As one of the best-characterized antibody-mediated autoimmune diseases, AChR-MG has often served as a reference model for other autoimmune disorders. Classical pharmacological treatments, including broad-spectrum immunosuppressive drugs, are effective in many patients. However, complete remission cannot be achieved in all patients, and 10% of patients do not respond to currently used therapies. This may be attributed to production of autoantibodies by long-lived plasma cells which are resistant to conventional immunosuppressive drugs. Hence, novel therapies specifically targeting plasma cells might be a suitable therapeutic approach for selected patients. Additionally, in order to reduce side effects of broad-spectrum immunosuppression, targeted immunotherapies and symptomatic treatments will be required. This review presents established therapies as well as novel therapeutic approaches for MG and related conditions, with a focus on AChR-MG.

Antibody Therapies in Autoimmune Neuromuscular Junction Disorders: Approach to Myasthenic Crisis and Chronic Management.

Myasthenia gravis (MG) is a neurological autoimmune disorder characterized by muscle weakness and fatigue. It is a B cell-mediated disease caused by pathogenic antibodies directed against various components of the neuromuscular junction (NMJ). Despite the wide range of adverse effects, current treatment is still based on non-specific immunosuppression, particularly on long-term steroid usage. The increasing knowledge regarding the pathogenic mechanisms of MG has however allowed to create more target-specific therapies. A very attractive therapeutic approach is currently offered by monoclonal antibodies (mAbs), given their ability to specifically and effectively target different immunopathological pathways, such as the complement cascade, B cell-related cluster of differentiation (CD) proteins, and the human neonatal Fc receptor (FcRn). Up to now, eculizumab, a C5-directed mAb, has been approved for the treatment of generalized MG (gMG) and efgartigimod, a FcRn inhibitor, has just been approved by the U.S. Food and Drug Administration for the treatment of anti-acetylcholine receptor (AChR) antibody positive gMG. Other mAbs are currently under investigation with encouraging preliminary results, further enriching the new range of therapeutic possibilities for MG. This review article provides an overview of the present status of mAb-based therapies for MG, which offer an exciting promise for better outcomes by setting the basis of a precision medicine approach.

Laryngeal myasthenia gravis following influenza vaccination: a case report and literature review.

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disease of acquired neuromuscular junction transmission disorder mediated by auto-antibodies. Extranophthalmic muscles are the most susceptible to MG, while the larynx muscle may also be affected. MG can be aggravated by various types of drugs. In the present study, a patient with laryngeal MG who received an influenza vaccination 5 days before onset was treated, which has not been previously reported. CASE PRESENTATION: A 58-year-old Asian woman developed mild dysphagia and severe dysarthria five days after receiving a trivalent inactivated influenza vaccine. The patient's quantitative MG score was 4 (1 for swallowing and 3 for speech), and the patient's neurological symptoms varied. The serum acetylcholine receptor (AChR) antibody titer was 0.67 nmol/L (normal range below 0.2 nmol/L), and other immunological and thyroid function tests were negative. As revealed by chest computed tomography (CT), there was no thymus abnormality. Based on the patient's history, clinical features, and examination results, the patient was diagnosed with laryngeal MG. The patient received pyridostigmine oral administration (60 mg/d) and steroid therapy (Prednisone, oral, 60 mg/d). The patient's symptoms began to improve after 7 days of treatment, and were significantly relieved after 2 weeks. CONCLUSION: Influenza vaccination might cause an unexpected abnormal autoimmune response in MG as a very rare event. Further research is needed to assess the possible causal relationship between the influenza vaccine and neurological complications, also in addition to the safety of the vaccine.