MYASTHENIA GRAVIS PRECIPITATED BY ASYMPTOMATIC COVID-19 INFECTION, VACCINE, OR BOTH? HOW GENETIC PREDISPOSITION AND IMMUNE RESPONSES PLAY A ROLE IN THE NEUROMUSCULAR JUNCTION

ABSTRACT

SESSION TITLE Autoimmune Disorders Both Primary and Secondary SESSION TYPE Rapid Fire Case Reports PRESENTED ON 10/18/2022 1015 am - 1110 am INTRODUCTION: SARS-CoV-2 has demonstrated an impact on the lungs, leads to hypercoagulable states, and has caused immune-mediated reactions. Myasthenia Gravis (MG) represents a neuromuscular junction autoimmune disorder, with only a few case reports associated with new-onset MG following COVID-19 vaccination. Very rarely, MG has been reported in coexistence with Primary Sjogren's Syndrome (PSS). Here we present a case of new-onset MG in a patient with a positive COVID-19 a nasopharyngeal RT-PCR swab test, who received 3 doses of the Moderna COVID-19 vaccine with the latest dose 2 weeks prior to presentation and demonstrated positive PSS antibodies (Abs). CASE PRESENTATION A 67-year-old male with no known past medical history presented with complaints of progressive weakness for 2 weeks, which began as diffuse malaise, and progressed to upper and lower extremity weakness with associated neck weakness, and dysphagia. Physical exam was remarkable for bilateral ptosis and difficulty ambulating. The patient was admitted to the ICU for suspected new-onset neuromuscular junction disorder and for close monitoring of his respiratory function. COVID-19 PCR was positive. MG and autoimmune disease workup was sent along with COVID-19 antibody testing. Chest X-Ray, CT head, and CT thorax were unremarkable. The patient was started on Pyridostigmine and IVIG, with low dose prednisone initiated on day 3 of admission. On the fifth day, symptoms improved significantly. Antibodies (Ab) against Acetylcholine (Ach) receptors were elevated and the diagnosis of MG was made. PSS Abs were also detected. Lyme, HIV, RPR, thyroid, and B12 levels were within the normal range which may mimic NMJ dysfunction. DISCUSSION: MG represents an autoimmune disorder due to autoantibodies against nicotinic AChR at the neuromuscular junction;however, these Abs can also target non-AChR muscle-specific receptor tyrosine kinase (MUSK). The exact mechanism of the autoimmune response with MG is not fully understood;however, there have been associations found with thymus gland hyperplasia and neoplasm when anti-AChR Abs are involved. Genetic predisposition is also likely to play a role. Viral and bacterial infections are established triggers for a myasthenic crisis in patients with pre-existing MG;however, there is yet to be a clear consensus regarding infections causing MG in otherwise healthy patients. As our pt did receive the COVID-19 vaccine, we have to consider an autoimmune reaction secondary to his administration. CONCLUSIONS: COVID-19 vaccines have demonstrated autoimmune responses such as myocarditis and myasthenic crisis in individuals. There have also been documented cases of MG in symptomatic COVID-19 infections. Given these findings, this patient may have experienced an environmental insult on top of a genetic predisposition and may warrant further investigation in patients with similar presentations. Reference #1 Sriwastava S, Tandon M, Kataria S, Daimee M, Sultan S. New onset of ocular myasthenia gravis in a patient with COVID-19 a novel case report and literature review. J Neurol. 2021 Aug;268(8)2690-2696. doi 10.1007/s00415-020-10263-1. Epub 2020 Oct 12. PMID 33047223;PMCID PMC7549728. Reference #2 Chavez A, Pougnier C. A Case of COVID-19 Vaccine Associated New Diagnosis Myasthenia Gravis. J Prim Care Community Health. 2021 Jan-Dec;1221501327211051933. doi 10.1177/21501327211051933. PMID 34709075;PMCID PMC8559213. Reference #3 Witberg G, Barda N, Hoss S, Richter I, Wiessman M, Aviv Y, Grinberg T, Auster O, Dagan N, Balicer RD, Kornowski R. Myocarditis after Covid-19 Vaccination in a Large Health Care Organization. N Engl J Med. 2021 Dec 2;385(23)2132-2139. doi 10.1056/NEJMoa2110737. Epub 2021 Oct 6. PMID 34614329;PMCID PMC8531986. DISCLOSURES No relevant relationships by Brooke Kania No relevant relationships by Anas Mahmoud No relevant relationships by Ahmed Salem No relevant elationships by Jessimar Sanchez No relevant relationships by Shivanck Upadhyay No relevant relationships by Deniz Yucel