ABSTRACT
Background/Aims Myasthenia gravis (MG) is an antibody-mediated autoimmune disease targeting proteins at the postsynaptic membrane of the neuromuscular junction. MG is thought to occur in genetically susceptible individuals following an environmental trigger. SARS-CoV-2 infection has been associated with new-onset autoimmune disease, new-onset MG, and exacerbations of pre-existing MG, with molecular mimicry between SARS-CoV-2 epitopes and autoantigen-induced autoreactivity thought to be part of the underlying mechanism. We report a case of newonset ocular MG following first dose Pfizer-BioNTech BNT162b2 SARS-COV2 vaccination which was referred to rheumatology as suspected mononeuritis multiplex. Methods A 53-year-old man of East Asian ethnicity presented to the emergency department (ED) with sudden onset diplopia and left lateral gaze restriction 7 days after receiving his first dose of the Pfizer-BioNTech BNT162b2 SARS-COV2 vaccination. He had longstanding myopia and dry eyes but no other medical history, no regular medications or significant family history. He was a current smoker, with a 50-pack year history. He did not drink alcohol or use any recreational drugs. He was found to have an isolated left VI cranial nerve (CN) palsy with an otherwise normal ocular and physical examination. Blood tests were unremarkable apart from raised cholesterol, and he was discharged with a suspected self-limiting microvascular CN lesion. Three weeks later he presented to ED with worsening diplopia, increasingly restricted eye movements, headache, nausea, vomiting and blurred vision. Ophthalmology assessment noted new right sided CN III and VI palsy, persistent left CN VI palsy, and vertical diplopia in all fields of gaze. Neurological and physical examination were normal. Bloods including an autoimmune screen were unremarkable. SARS-CoV-2 Spike antibodies were positive consistent with SARS-CoV-2 vaccination but not infection. Intracranial and thoracic imaging were unremarkable. He was referred to and seen by both rheumatology and neurology as a case of suspected mononeuritis multiplex. Results A diagnosis of ocular MG was confirmed with positive serum acetylcholine receptor antibodies, and he was started on prednisolone, and pyridostigmine to good effect. Daily forced vital capacity (FVC) showed no respiratory muscle involvement, and nerve conduction studies and electromyography were normal, excluding secondary generalisation. Conclusion A review of the literature found 14 reported cases of new-onset MG all within 4 weeks following SARS-CoV-2 vaccine. Whilst these cases provide interesting insights into the pathogenesis of autoimmune conditions such as MG, they are not epidemiological studies to inform vaccine safety. Ultimately, current evidence suggests that the risks of SARS-COV-2 infection outweigh the risk of vaccine-related adverse events, therefore we suggest clinicians should be aware of potential new-onset autoimmune conditions, but support the safety of SARSCOV2 vaccination. Further, research into possible immunological mechanisms behind this phenomenon, including identifying potential epitopes inducing molecular mimicry, could help establish the likelihood of a causative link.
ABSTRACT
Background: Myasthenia gravis (MG) is an autoimmune disease of unknown etiology. Infections are known as a major cause of MG exacerbations. A few studies have shown an association between new onset MG and SARS-CoV-2 infection. Case presentation: We have reported a case of new onset myasthenia gravis in a 68-year-old man presented with bulbar symptoms a few days after receiving COVID-19 vaccine (Sinopharm vaccine). The disease was confirmed by high titer of antibody against acetylcholine receptor and electrophysiological examinations. Conclusion(s): Among the adverse effects reported with the COVID-19 vaccine, new onset myasthenia gravis is very rare. The underlying mechanism is unknown but the immune response after vaccination and molecular mimicry theory has been proposed.Copyright © 2022
ABSTRACT
Objective: To report a patient presenting with bulbar symptoms in the setting of COVID-19 infection leading to a new diagnosis of Myasthenia Gravis. Background: There have been many reports of neurological complications in patients with COVID-19 infection including Guillain Barre syndrome, Bell's palsy and transverse myelitis. There are limited case series describing the effects of COVID-19 in patients with known Myasthenia Gravis, but there have only been rare reports of new onset Myasthenia Gravis in the setting of COVID-19 infection. Design/Methods: Electronic medical records of the patient were reviewed. Results: 78 year old man presented to the hospital with new onset of dysphagia, dysarthria, bilateral ptosis and left facial droop. The patient was given intravenous alteplase for possible stroke. On admission the patient also tested positive for COVID-19. His symptoms persisted post-alteplase. On exam he was noted to have fatigable ptosis, weakness of brow elevation, eye closure, horizontal movements of the tongue and intermittent dysarthria, raising the concern for myasthenia gravis. A trial of Mestinon led to improved symptoms. Serum acetylcholine receptor antibodies were positive, confirming the Myasthenia Gravis diagnosis. He received 5 sessions of intravenous immunoglobulin (IVIG) due to persistent bulbar symptoms. He initially responded well to treatment but later decompensated with respiratory failure requiring intubation. He was then treated with plasmapheresis for 5 days with symptom improvement and was successfully extubated. Conclusions: Our patient with a new diagnosis of myasthenia gravis with simultaneous COVID-19 infection eventually progressed into myasthenic crisis. This case raises the possibility of myasthenia and/or myasthenic crisis being a neurological complication of COVID-19 infection. Mechanisms behind this have been postulated to include molecular mimicry, the inflammatory cascade of COVID-19 leading to immune dysregulation, or viral illness triggering previously asymptomatic patients. Awareness of new onset myasthenia associated with COVID-19 infection can lead to earlier diagnosis and treatment.
ABSTRACT
Objective: To define clinical features, disease course, and collect biospecimens in patients with myasthenia gravis (MG), including understudied subgroups such as seronegative, muscle-specific kinase antibody (MuSK), and LRP4 antibody positive MG. Background: The MG Rare Disease Clinical Research Network (MGNet) was funded by the National Institutes of Health (NIH) to gain better understanding of the clinical course of MG and develop improved approaches to diagnosis and treatment. As part of this initiative a multicenter prospective natural history study and biorepository was developed: Exploring Outcomes and Characteristics of Myasthenia Gravis 2 (EXPLORE-MG2). Design/Methods: EXPLORE-MG2 is a web-based observational registry that incorporates NIH recommended common data elements for MG. Key eligibility criteria include: ≥18 years old;diagnosed with MG within 2-years of study enrollment based on clinical presentation and seropositivity for MG associated autoantibodies, and/or abnormal neurophysiology test or positive edrophonium test. Biospecimen collection focuses on immunosuppressive naïve patients and rare MG subgroups. Participants will be followed for at least 2-years with study visits occurring approximately every 6 months in the context of usual clinical care. The study has been open to enrollment since January 2021 with 6 sites currently activated/participating. Results: A total of 62 patients have been enrolled and 152 biospecimens were collected as of 10/1/2021. The mean age was 57 years (range 20-84);47% were female, 66% were acetylcholine receptor antibody-positive, 16% were MuSK MG, and 18% were seronegative. Enrollment of new participants and follow-up of existing participants are ongoing to reach our current goal of 400 enrolled participants. We will present updated enrollment data and demographics at the meeting. Conclusions: The EXPLORE-MG2 study is active after a COVID-19 pandemic related delay. Samples and clinical data will be available to researchers for current and future investigation. Data from EXPLORE-MG2 will improve clinical trial readiness for future studies and facilitate development of treatment-responsive biomarkers.