Thymectomy in Children and Adolescents with Acetylcholine Receptor Antibody Positive Juvenile Myasthenia Gravis

Background: Juvenile myasthenia gravis (JMG) is a rare autoimmune disorder of neuromuscular transmission caused by production of specific antibodies against the structures of the neuromuscular junction. Until now, data concerning effect and outcome after thymectomy in pediatric population, particularly in very young children, are spared.

Methods: We retrospectively analyzed a cohort of patients with positive acetylcholine receptor (AChR) antibodies JMG who underwent thymectomy since 20afFV02-02. For clinical evaluation before and after thymectomy, Osserman classification was used.

Results: Seventeen patients (14 females, 3 males) were identified, 7 of them were prepubertal at disease onset. Isolated ocular symptoms were present in seven at the onset, all developed generalized symptoms over time. All patients responded to pyridostigmine, but additional immunotherapy was required and included: corticosteroid therapy in 16/17, azathioprine in 10/17, in two mycophenolate mofetil and in one cyclosporine A. Five patients required intravenous immunoglobulins, four required plasma exchange, and one required immunoadsorption. Robot-assisted thymectomy was performed in 16/17 patients, one patient underwent thoracoscopic thymectomy. It was followed by subsequently clinical improvement in disease severity, 6 patients achieved complete remission. Early thymectomy (1 year after onset) led to a shortened period of corticosteroid therapy.

Conclusion: Because of existing therapeutic options, an early diagnosis of JMG is important. In children and adolescents, an early therapy and thymectomy have positive influence on the outcome in JMG with positive AChR antibodies. Early thymectomy led to a shortened period of immunotherapy and their possible side-effects on the growing organism. Robot-assisted thymectomy seems to be as effective as transsternal surgical approach.