[pubmed] Myasthenia gravis associated with anti-MuSK antibodies developed after SARS-CoV-2 infection

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Eur J Neurol. 2021 Jan 9. doi: 10.1111/ene.14721. Online ahead of print.

ABSTRACT

INTRODUCTION: Since the onset of the novel coronavirus pandemic, several neurological complications secondary to SARS-CoV-2 infection have been reported, affecting central nervous system, peripheral nervous system and neuromuscular junction.

CASE REPORT: We present the case of a 77-year-old man who developed bulbar myasthenia gravis (MG) eight weeks after SARS-CoV-2 infection. The search for serum antibodies against the acetylcholine receptor, the muscle-specific tyrosine kinase (MuSK), and the low-density lipoprotein receptor-related protein 4 antibodies, performed by radioimmunoassay (RIA), resulted negative, while anti-MuSK antibodies were detected by cell-based assay (CBA). The patient was treated with pyridostigmine (60 mg four times a day) with unsatisfactory clinical response, followed by immunosuppressive therapy (azathioprine 1.5 mg/kg/day) with improvement of MG symptoms after two months of treatment.

DISCUSSION: Several viral diseases have been described as associated with the onset of MG, although the underlying mechanisms are not yet fully understood. Similarly, a growing number of scientific reports suggest a correlation between SARS-CoV-2 infection and autoimmune diseases. The interest of our case lies in the timing of the MG onset (after two months from infection), together with the unusual late onset of anti-MuSK MG. These elements suggest that coronavirus infection may act as a trigger of the disease. We confirm the importance of CBA in the serological diagnosis of RIA-negative MG.

PMID:33421278 | DOI:10.1111/ene.14721


Source: https://pubmed.ncbi.nlm.nih.gov/3342127 ... 4&v=2.14.2