Vaccination as a possible trigger for immune-mediated necrotising myopathy.

Cavalcanti, Julia Francesca Bonato; Silva, Maria Beatriz Almeida; Alves de Siqueira Carvalho, Alzira

Immune-mediated necrotising myopathy is a rare autoimmune myopathy characterised by severe progressive muscle weakness, elevated levels of creatine kinase (CK), and necrosis with minimal inflammatory cell infiltration on muscle biopsy. We report a case of a previously healthy 42-year-old woman who presented with progressive muscle weakness 2 weeks after immunisation for yellow fever, tetanus/diphtheria and hepatitis B. Her symptoms started from the lower limbs and progressed to the upper limbs and cervical region associated with dysphagia, making her wheelchair bound. Electromyography showed a myopathic pattern, with a CK level of 12.177 U/L (reference value: 26-190 U/L), and biceps brachial muscle biopsy confirmed necrosis and regeneration fibres. The immunoblot test was positive for antisignal recognition particle. She was successfully treated with prednisone (1 mg/kg/day). Although considered safe, vaccines may cause allergic reactions or trigger autoimmune disorders. Currently, a causal relationship between them cannot be established.