Neoplasms

Nervous System Diseases

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Rare Diseases

Myasthenia Gravis

Syndrome

Paraneoplastic Syndromes

Paraneoplastic Syndromes, Nervous System

Nervous System Neoplasms

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Autoimmune Diseases of the Nervous System

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Neuromuscular Junction Diseases

Neuromuscular Diseases

Micronutrients

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Bone Density Conservation Agents

Vitamins

Neostigmine

Vitamin D

Cholecalciferol

Vitamin D3

Calciferol

Unrelated patients with MG were included in the study. They were enrolled in the Neurology Department of Beijing Tongren Hospital, Capital Medical University and fulfilled the clinical and electromyography diagnostic criteria for acquired MG. Simply, all MG patients met the following diagnostic criteria: typical symptoms of fluctuating muscle weakness, positive result of neostigmine test, and decremental response to low-frequency repetitive nerve stimulation. Information on age at onset, AChR / MuSK Abs status (partly), thymus status, involved muscles at onset and Osserman type at the maximum worsening during 2 years follow-up were obtained and used as the grouping basis of sub-classifications. They were genotyped for VDR rs1544410, rs2228570, rs731236, and rs7975232 polymorphisms

The geography and ethnically matched control group consisted of 146 unrelated healthy subjects. They were genotyped for VDR rs1544410, rs2228570, rs731236, and rs7975232 polymorphisms.

Genomic DNA was extracted from peripheral blood samples using a Wizard Genomic DNA Purification Kit (Promega, Madison,Wisconsin, USA) as per the product instruction. VDR (rs731236, rs1544410, rs7975232, rs2228570) polymorphisms were genotyped by the improved Multiple Ligase Detection Reaction (iMLDR) developed by Genesky Biotechnologies Inc. (Shanghai, China).

Genotype analysis for VDR rs1544410, rs2228570, rs731236, and rs7975232 polymorphisms

The Vitamin D receptor gene (VDR) polymorphisms are the candidate genetic variants for susceptibility to autoimmune diseases. In the present study, the investigators aimed to assess the association between VDR polymorphisms and myasthenia gravis (MG) susceptibility and disease features in Chinese Han population.The patients with MG and healthy controls were genotyped for VDR rs1544410, rs2228570, rs731236, and rs7975232 polymorphisms using the improved multiple ligase detection reaction. Information on age at onset, acetylcholine receptor antibody (AChR-Ab) and muscle-specific kinase antibody (MuSK-Ab) status, thymus status, involved muscles at onset and Osserman type at the maximum worsening during 2 years follow-up were obtained and used as the grouping basis of sub-classifications. Intergroup comparisons of allele and genotype frequencies, haplotype distributions were performed between MG group and the control group, and between each pair of MG subgroups.

Association Study Between VDR Gene Polymorphisms and Risk and Features of MG in Han Chinese Population

Association Study Between Vitamin D Receptor Gene Polymorphisms and Risk and Features of Myasthenia Gravis in Han Chinese Population

The IPD that support the findings of this study are available from the central contact person upon reasonable request.

Codominant, dominant and recessive genetic models and haplotype analysis were applied to compare the difference between MG and control groups.

To study the precise effect of single nucleotide polymorphisms (SNPs) in the different population, the MG patients were divided into subgroups according to essential clinical variables, including onset age (≤50 or \>50 years), thymus status (thymoma or non-thymoma, by pathology), AChR / MuSK Abs (positive or negative), onset involvement (ocular or generalized) and Osserman type at the maximum worsening (type I or IIa-IIb or III-V). The investigators analyzed the distribution of genes in each group.

Beijing Tongren Hospital

Blood and Lymph Conditions

Musculoskeletal Diseases

Hyperplasia

Thymoma

Thymus Neoplasms

Thymus Hyperplasia

Muscle Weakness

Paresis

Asthenia

Muscular Diseases

Neuromuscular Manifestations

Neurologic Manifestations

Neoplasms by Histologic Type

Thoracic Neoplasms

Lymphatic Diseases

Patients with myasthenia gravis who are receiving medical treatment and treatment of crisis as plasmapheresis

Drug treatment of myasthenia gravis and treatment of crisis

Nourelhoda AA Haridy, Lecturer

Eman MH Khedr, Professor

Asmaa MM Hasan, Lecturer

This study aims to characterize the clinical features, frequency of different subgroups of MG, and identify predictors of treatment responsiveness among different subgroups of MG. The predictors are including primary outcome (percentage of changes in MG scales at baseline at time of enrollment and after 3 months) and secondary outcome (treatment-related adverse events). Also it aims to determine the frequency of patients with refractory MG.

This information will be used to understand the trends and mechanisms of disease relapse, and optimal management strategies.

Myasthenia gravis (MG) is a rare acquired autoimmune disease affecting the neuromuscular junction (NMJ), caused by autoantibodies that target the post-synaptic membrane. It's overall prevalence ranged from 150 to 250 cases per million. The most common autoantibodies are those directed to the nicotinic acetylcholine receptor (AChR), but there is smaller proportion of cases, in whom, other antibodies can be present and they included antibodies directed to muscle specific tyrosine kinase (MuSK) or to lipoprotein receptor-related protein 4 (Lrp-4). The manifestation of MG is in form of fatigable skeletal muscle weakness, affecting ocular, bulbar and limb muscles. In general, the disease diagnosis is confirmed by presence of this characteristic muscle weakness with positive autoantibodies in the serum. The main current treatment of the disease is symptomatic and immunomodulating therapies which are efficient in managing the disease manifestation. The disease prognosis is mostly favorable and about 15%, is considered medically refractory to the conventional therapy. MG can be classified into different subgroups according to different factors which included the autoantibody status, age of onset, and degree of muscle affection. These subgroups are significantly influencing the therapeutic decisions. Moreover, this proposed classification could explain the distinct immunopathological, clinical, therapeutic, and prognostic differences among these subgroups.

Current standard immunotherapies have a broad-spectrum of immune suppression, and potential side effects associated with their use can significantly impact quality of life, especially as they are usually needed life-long. Significant heterogeneity in treatment responsiveness and outcomes exists among the various subgroups of MG based on epidemiology, clinical presentation, autoantibody status, and comorbidities. In MG clinical trials, the evaluation is mainly depending on the short-term clinical efficacy, but the long-term benefits and impact on patient's quality of life and other disease burdens, (i.e., treatment-related side effects, financial impact), were not measured. The outcomes of MG were assessed in many studies and they included the reduction in quality of life, the negative impact on social and physical health, that related to the disease itself and the immunomodulators used for its treatment. Based on these factors, the investigators aimed to conduct this study to find the disease characteristics in the participants, the patient-tailored targeted treatment strategies, treatment outcomes, disease progression and quality of life.

Predictors and Prognostic Factors of Myasthenia Gravis Outcome

The MG Activities of Daily Living (MG- ADL) Scale an easily administered, 8-item questionnaire. Each item is graded on a 4- point symptom severity scale (0 = normal, 3 = most severe), with the total score ranging from 0 to 24. Test items emphasize the functional impact of muscle weakness (eg, the ability to comb one's hair or brush one's teeth instead of hand grip or outstretched arm strength tests) rather than its quantitation. The MG-ADL requires no special equipment or training and can be administered in 10 minutes. The MG-ADL test domains include ocular (2 items), oropharyngeal (3 items), respiratory (1 item), and extremity/limb (2 items).

Everyday clinical use led to the development of an abbreviated 15-item version, the MG-QOL15. These 15 items were derived from the mobility (9 items), symptoms (3 items), general contentment (1 item), and emotional well-being (2 items) domains of the 60-item version. Each of the items/statements (eg, "I have limited my social activity because of my condition") is scored by patients on a 5-point scale ranging from 0 ("not at all") to 4("very much") based on their experience over the previous 4 weeks; the item scores are summed to generate a total score ranging from 0 to 60.

The MG-MMT assesses the strength or function of 30 muscle groups typically affected by MG and includes a total of 18 items, with 12 assessed bilaterally, and 6 assessed as single items (lid closure, cheek puff, tongue protrusion, jaw closure, neck flexion, and neck extension). Each item is scored on a 5- point severity scale, based on the severity of muscle weakness \[0 = no weakness, 1 = weak/mild (25%) impairment, 2 = weak/moderate (50%) impairment, 3 = weak/severe (75%) impairment, 4 = paralyzed/unable to perform\]. Bilateral scores are summed for a total item score, and all item scores are summed for a total MG-MMT score. MG-MMT scores range from 0 to 120; domains include ocular (3 items, including eyelid closure), facial/oropharyngeal (3 items), axial strength (neck flexion/extension; 2 items), and limb strength (10 items).

The MG Composite (MGC) Scale is considered a mixed outcome measure that incorporates both physician-evaluated and patient-reported outcome items. In creating this composite scale, the developers sought to minimize the number of items (and thus administration time), to maximize the sensitivity and clinical relevance of each item, and to weight items (as recommended by the Myasthenia Gravis Foundation of America MGFA task force) commensurate with their impact on functional status, QOL, overall health status, and prognosis.13 The MGC Scale is composed of individual items from outcome measures (including the quantitative myasthenia gravis score (QMG), the MG-ADL, and the MG-MMT). Total score spans from 0 to 50.

Adverse effects of treatment of myasthenia gravis

Clinical statuses of patients are assessed and categorized according to Myasthenia Gravis Foundation of America (MGFA) postintervention status (PIS). It assesses the clinical state of MG patients at any time after institution of treatment for MG

Assiut University

Principal investigator, Lecturer of Neurology

The oVEMP technique is an accepted standard for testing otolith function in vestibular patients. It represents a quick, simple and non-invasive technique utilizing repetitive stimulation of the otolith organs with bone-conducted vibration to elicit an extraocular muscle response. Repetitive oVEMP stimulation leads to a characteristic decrement in patients with myasthenia, which can be quantified with surface electromyography from the inferior oblique muscle underneath the eye.

Ocular vestibular evoced myogenic potentials

Myasthenia gravis is an autoimmune disorder of neuromuscular transmission, characterized by fluctuating muscle weakness and fatigability. In isolated ocular myasthenia, when only the extraocular muscles are involved, most common ancillary tests, such as acetylcholine receptor autoantibodies and repetitive nerve stimulation, are often negative.

A simple, quick and non-invasive test for ocular myasthenia based on ocular vestibular evoked myogenic potentials (oVEMP) was recently developed.

The main goal of the study is to validate repetitive oVEMP stimulation in a blinded diagnostic accuracy study in order to facilitate early and accurate diagnosis of ocular myasthenia.

Blinded diagnostic accuracy study (index test vs. reference standard).

OVEMP in Myasthenia

Diagnostic Accuracy of Repetitive Ocular Vestibular Evoked Myogenic Potentials in Myasthenia Gravis (OMG Study)

oVEMP have been established as a standard clinical test of otolith function. Based on this technique, repetitive oVEMP stimulation, as a novel method for detecting ocular myasthenia gravis, was recently developed. Using this method, a response decrement in extraocular muscles can be quantified. The method is based on the conventional oVEMP montage with surface electrodes placed below the eyes. In order to elicit a response decrement, trains of ten bone-conducted vibration bursts at repetition rates of 20Hz will be applied with a hand-held 'minishaker' to the forehead. The oVEMP in response to these repetitive vibration stimuli will be measured in sustained upgaze from both inferior oblique muscles via surface electrodes. The magnitude of the decrement will be calculated as the difference between the amplitude of the second stimulus repetition and the mean amplitude of the fifth to ninth stimulus repetition. For further Information see: Valko et al. 2016 PMID:26791146

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization
Association Study Between VDR Gene Polymorphisms and Risk and Features of MG in Han Chinese Population	NCT05380128	Myasthenia Grav... Gene Polymorphi...	Genotype analys...	16 Years -	Beijing Tongren Hospital
Predictors and Prognostic Factors of Myasthenia Gravis Outcome	NCT05214612	Myasthenia Grav... Autoimmune Dise... Neuromuscular J... Thymoma Thymus Hyperpla... Nervous System ... Myasthenia Grav... Myasthenia Grav... Myasthenia Grav... Myasthenia Grav... Myasthenia Grav... Myasthenia Grav...	Drug treatment ...	16 Years -	Assiut University
OVEMP in Myasthenia	NCT03049956	Myasthenia Grav...	Ocular vestibul...	18 Years -	University of Zurich

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