SHM Converge Scientific Abstract ePoster Gallery-Immune Check Point Inhibitor Induced Myasthenia Gravis

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This case describes a 66-year-old woman with metastatic melanoma who developed immune checkpoint inhibitor–induced myasthenia gravis after starting ipilimumab and nivolumab three weeks earlier. She presented with progressive binocular vertical diplopia, ptosis that worsened during the day, and dysphagia with choking on liquids and pills. Because of concern for a neurologic or neuromuscular junction disorder, she underwent evaluation including brain MRI, lumbar puncture, chest imaging, and antibody testing. These studies were negative for metastatic disease, thymoma, and NMJ antibodies. EMG showed a myopathic process with patchy muscle membrane irritability, supporting the diagnosis of myasthenic crisis secondary to immune checkpoint inhibitors.<br /><br />She was treated with high-dose prednisone, IVIG, and pyridostigmine (Mestinon), with clinical improvement over five days. After discussion with her oncologist, her checkpoint inhibitor therapy was discontinued.<br /><br />The report emphasizes that nivolumab and ipilimumab can precipitate or worsen myasthenia gravis, often within the first 16 weeks of treatment. Typical symptoms include weakness, ptosis, diplopia, dyspnea, and dysphagia. Laboratory markers such as anti-AChR antibodies and CPK may be normal, so diagnosis often depends on clinical suspicion and electrodiagnostic testing, along with imaging to exclude thymoma or metastatic disease. Treatment may include corticosteroids, IVIG, plasmapheresis, anticholinesterase agents, and other immunosuppressants.<br /><br />Overall, the case highlights that immune checkpoint inhibitor–associated myasthenia gravis is rare but potentially life-threatening, and early recognition is critical to prevent serious complications and mortality.

Asset Subtitle

Michael D. McCafferty

Meta Tag

Author List Michael D. McCafferty, Nick Kurek

Category Clinical Vignettes

Concept Immune Checkpoint Inhibitor-Induced Myasthenia Gravis

Concept Ptosis

Concept Diplopia

Concept Swallowing Impairment

Concept Weakness

Distinguished Non-Finalist

Presenter Organization The Ohio State University

Presenting Author Michael D. McCafferty

Track Adult

Keywords

metastatic melanoma

immune checkpoint inhibitors

myasthenia gravis

nivolumab

ipilimumab

ptosis

diplopia

dysphagia

IVIG

pyridostigmine

Immune Checkpoint Inhibitor-Induced Myasthenia Gravis

Ptosis

Diplopia

Swallowing Impairment

Weakness