Young child with MuSK myasthenia gravis: treatment and remission with rituximab.

Abstract

Myasthenia gravis is an autoimmune disorder characterised by autoantibodies directed against postsynaptic receptors of the neuromuscular junction. Muscle-specific tyrosine kinase (MuSK) myasthenia gravis is a subtype of myasthenia gravis containing antibodies specific to the MuSK subunit of the motor endplate. MuSK myasthenia gravis tends to display a severe clinical course, and most patients are refractory to treatment. Paediatric MuSK myasthenia gravis is exceedingly rare and is typically managed with pyridostigmine, corticosteroids and intravenous immunoglobulin or plasmapheresis for acute crisis control. This report discusses a case of a 4-year-old girl diagnosed with MuSK myasthenia gravis who was treated with rituximab. She is one of the youngest children in the literature to receive rituximab for this condition, and she continues to show favourable outcomes. This case demonstrates the safety and efficacy of this treatment in paediatric patients diagnosed with MuSK myasthenia gravis.