MYASTHENIA GRAVIS

Management of respiratory failure in immune checkpoint inhibitors-induced overlap syndrome: a case series and review of the literature

BACKGROUND

Checkpoint inhibitor-induced overlap syndrome ([OS] myocarditis, and myositis with or without myasthenia gravis) is rare but life-threatening.

CASES PRESENTATION

Here we present a case series of four cancer patients that developed OS. High troponinemia raised the concern for myocarditis in all the cases. However, the predominant clinical feature differed among the cases. Two patients showed marked myocarditis with a shorter hospital stay. The other two patients had a prolonged ICU stay due to severe neuromuscular involvement secondary to myositis and myasthenia gravis. Treatment was based on steroids, plasmapheresis, intravenous immunoglobulin, and immunosuppressive biological agents.

CONCLUSION

The management of respiratory failure is challenging, particularly in those patients with predominant MG. Along with intensive clinical monitoring, bedside respiratory mechanics can guide the decision-making process of selecting a respiratory support method, the timing of elective intubation and extubation.

Myasthenic crisis

Myasthenic crisis is a complication of myasthenia gravis characterized by worsening of muscle weakness, resulting in respiratory failure that requires intubation and mechanical ventilation. Advances in critical care have improved the mortality rate associated with myasthenic crisis. This article reviews the epidemiology of myasthenic crisis and discusses patient evaluation. Therapeutic options including mechanical ventilation and pharmacological and surgical treatments are also discussed.

Autoimmune myasthenia gravis: emerging clinical and biological heterogeneity

Acquired myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction in which patients experience fluctuating skeletal muscle weakness that often affects selected muscle groups preferentially. The target of the autoimmune attack in most cases is the skeletal muscle acetylcholine receptor (AChR), but in others, non-AChR components of the neuromuscular junction, such as the muscle-specific receptor tyrosine kinase, are targeted. The pathophysiological result is muscle endplate dysfunction and consequent fatigable muscle weakness. Clinical presentations vary substantially, both for anti-AChR positive and negative MG, and accurate diagnosis and selection of effective treatment depends on recognition of less typical as well as classic disease phenotypes. Accumulating evidence suggests that clinical MG subgroups might respond differently to treatment. In this Review, we provide current information about the epidemiology, immunopathogenesis, clinical presentations, diagnosis, and treatment of MG, including emerging therapeutic strategies.