New-onset Immune-mediated Necrotizing Myopathy and Trigeminal Neuropathy after SARS-CoV-2 mRNA Vaccination in a Patient with Rheumatoid Arthritis and Sjögren's Syndrome

Elderly-onset inflammatory myopathy associated with Sjögren's syndrome following SARS-CoV-2 vaccination

As vaccination against SARS-CoV-2 has progressed, various autoimmune diseases, including inflammatory myopathies, have been reported to develop after vaccination. Sjögren's syndrome (SS) sometimes presents as extra-glandular manifestations including inflammatory myopathy. In this report, we describe a case of inflammatory myopathy associated with SS that occurred in an atypically elderly patient after receiving the first dose of the SARS-CoV-2 mRNA vaccine (BNT162b2). The inflammatory myopathy was pathologically classified into non-specific myositis and characterised by predominant infiltration of the B cell lineage in this case. Combined treatment with glucocorticoid, intravenous immunoglobulin, and immunosuppressant resulted in an improvement in swallowing function and muscle strength. While we recognise the efficacy and safety of SARS-CoV-2 vaccines, we also emphasise the importance of recognising that individuals with an immunogenetic predisposition such as positivity of anti SS-A antibody may show disease activity including inflammatory myopathy following vaccination in SS, even at an atypically old age.

Immune-mediated necrotizing myopathy: A comprehensive review of the pathogenesis, clinical features, and treatments

Immune-mediated necrotizing myopathy (IMNM) is a rare and newly recognized autoimmune disease within the spectrum of idiopathic inflammatory myopathies. It is characterized by myositis-specific autoantibodies, elevated serum creatine kinase levels, inflammatory infiltrate, and weakness. IMNM can be classified into three subtypes based on the presence or absence of specific autoantibodies: anti-signal recognition particle myositis, anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase myositis, and seronegative IMNM. In recent years, IMNM has gained increasing attention and emerged as a research hotspot. Recent studies have suggested that the pathogenesis of IMNM is linked to aberrant activation of immune system, including immune responses mediated by antibodies, complement, and immune cells, particularly macrophages, as well as abnormal release of inflammatory factors. Non-immune mechanisms such as autophagy and endoplasmic reticulum stress also participate in this process. Additionally, genetic variations associated with IMNM have been identified, providing new insights into the genetic mechanisms of the disease. Progress has also been made in IMNM treatment research, including the use of immunosuppressants and the development of biologics. Despite the challenges in understanding the etiology and treatment of IMNM, the latest research findings offer important guidance and insights for delving deeper into the disease's pathogenic mechanisms and identifying new therapeutic strategies.