New Onset Generalized Myasthenia Gravis Evolving Following SARS-CoV-2 Infection

Abstract

During the SARS-CoV-2 (COVID-19) pandemic, the immunogenicity of the virus for various autoimmune complications has been observed. To date, a few reports have been published that raise the possibility of new onset myasthenia gravis (MG) associated with COVID-19 infection. We report a case of a 65-year-old male who developed his initial myasthenic presentation with mild dysarthria 14 days after COVID-19 infection symptomatic onset. His bulbar symptoms, diplopia, and ptosis progressed considerably over the next 1.5 months before he was diagnosed with non-thymomatous MG. Serological tests showed a high concentration of anti-acetylcholine receptor and anti-titin antibodies. He responded well to treatment with pyridostigmine and intravenous immunoglobulin. Reasonable latency from COVID-19 infection and gradual evolvement of myasthenic symptoms makes the causative association probable in this case. To our knowledge, this is the first report of anti-titin antibodies in new-onset MG associated with COVID-19 infection. In the article, we analyze the previously reported cases and summarize the information published to date. We discuss the possible immunological mechanisms behind new onset autoimmune disease following a viral infection and the associated features that raise the suspicion for such a possibility. We also hint at structural homologies between SARS-CoV-2 spike glycoprotein and titin epitopes.

“A new case of myasthenia gravis following COVID-19 Vaccination”

“…MG following SARS-CoV2 infection has been reported in the literatures; the causal relationship between the two conditions is difficult to understand. In all reported cases, the symptoms of MG have developed with latency from the SARS-CoV2 infection but not in the acute phase of the infection ( Jõgi et al, 2022 ). This indicates the autoimmune mechanism in the pathogenesis of the disease.…”

“…Another hypothesis is that infection in the context of the genetic predisposition makes a person susceptible to the disease. Particular HLA haplotypes such as HLA DQA1, DQB1 have been implicated in some cases of late onset MG ( Jõgi et al, 2022 ). An alternative theory has suggested that infection or some medications used to treat SARS-COVID19 infection (including Azithromycin and other macrolides) uncover the preexisting mild MG disease ( Jõgi et al, 2022 ).…”

“…Particular HLA haplotypes such as HLA DQA1, DQB1 have been implicated in some cases of late onset MG ( Jõgi et al, 2022 ). An alternative theory has suggested that infection or some medications used to treat SARS-COVID19 infection (including Azithromycin and other macrolides) uncover the preexisting mild MG disease ( Jõgi et al, 2022 ). However, MG exacerbation with various infections especially respiratory tract infections is more common in practice.…”

“…A few studies have shown an association between new onset MG and SARS-CoV2 infection. This correlation was partly explained by over activation of the immune response that leading to antibodies production by plasma cells against the neuromuscular junction structures ( Jõgi et al, 2022 ). In the reported cases of new onset MG following COVID19 infection, several autoantibodies have been detected ( Jõgi et al, 2022 ).…”

New-onset Myasthenia Gravis after SARS-CoV-2 infection: case report and literature review

“…The SARS-CoV-2 virus infection [2] has been correlated to several neurological manifestations, including neuropathy, myopathy, Guillain-Barré syndrome, anosmia, ageusia, and neuromuscular disorders [3]. Few cases of New-onset Myasthenia Gravis after COVID-19 have been reported [4][5][6][7][8][9][10][11][12][13]. The authors speculated that the new-onset MG after COVID-19 could be explained by molecular mimicry [4-6, 8-11, 13, 14] or by the breakdown of self-tolerance mechanisms [4,9,10,[12][13][14] as a consequence of the infection.…”