Objective Myasthenia gravis (MG) is a complex, autoimmune disorder in which antibodies inhibit neuromuscular connections. In most patients treatment with pyridostigmine, thymectomy and steroids improves muscular strength and skill. The aim of this report is to describe the benefit of rescue treatment of two patients with refractory MG and respiratory failure during conventional treatment.
Methods A 12-bed interdisciplinary paediatric intensive care unit. Patient 1, a 14-year-old girl with acetylcholine receptor antibody-positive MG was admitted with acute respiratory failure after conventional treatment with thymectomy, pyridostigmine, steroids, ciclosporin A and mycophenolate mofetil (MMF) over 3 years. Patient 2, a 13-year-old boy with a MUSK antibody-positive MG, chronic respiratory failure and tube feeding, had already received plasmaphereses and steroids without persistent improvement. Both patients were treated with plasmaphereses, rituximab, MMF and steroids.
Results In patient 1 the myasthenia score improved from 21/21 points to 6/24 points within 6 weeks. The acetylcholine receptor antibody level dereased to 25% of the initial value and remained stable at this level. Patient 2 showed improvement in myasthenia scoring from 21/21 points to 7/24 points within 3 months and 0/24 points after 8 months. Tube feeding was withdrawn after 3 months and nightly non-invasive ventilation after 8 months. MUSK antibodies dropped down to 20% of the initial value.
Conclusion In paediatric MG patients with severe respiratory failure on conventional treatment, combined treatment with plasmaphereses, rituximab, MMF and steroids leads to persistent remission of MG.