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 and the muscle-specific tyrosine kinase (MuSK), performed by radioimmunoassay (RIA), and the search of low-density lipoprotein receptor-related protein 4 antibodies, performed by immunohistochemistry, 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 2 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.
Keywords: SARS-CoV-2; anti-MuSK antibodies; cell-based assay; myasthenia gravis.
【저자키워드】 SARS-CoV-2, cell-based assay, anti-MuSK antibodies, myasthenia gravis., 【초록키워드】 Treatment, antibodies, immunohistochemistry, Coronavirus infection, pandemic, therapy, antibody, SARS-COV-2 infection, Infection, Diagnosis, Symptom, Novel coronavirus, Protein, Patient, nervous system, viral disease, Central nervous system, Neurological complications, serum antibody, receptor, myasthenia gravis, correlation, Autoimmune diseases, serological, Viral diseases, mechanism, immunosuppressive therapy, Low-density lipoprotein, Peripheral nervous system, Acetylcholine, immunosuppressive, Trigger, Neurological complication, followed by, tyrosine, secondary to, acetylcholine receptor, azathioprine, pyridostigmine, clinical response, low-density, serum antibodies, element, musk, neuromuscular junction, radioimmunoassay, described, performed, reported, the disease, eight, treated, affecting, CBA, RIA, the timing, 【제목키워드】 antibody,