Abstract Details

Title A Rare Case of Checkpoint Inhibitor-induced Myasthenia Gravis

Topic Autoimmune Neurology

Presentation(s) P4 - Poster Session 4 (11:45 AM-12:45 PM)

Poster/Presentation
Number 14-011

Background Immune checkpoint inhibition has proven to be an effective focus for therapy against several types of cancer. In some cases, cancer survival is possible due to checkpoint immunomodulation by the malignant cells, leading to failed targeting by the immune system and continued proliferation. Medications such as Pembrolizumab counteract this defense mechanism by inhibiting interactions between transmembrane proteins found on cancerous cell surfaces, making them susceptible to immune surveillance that results in their suppression. Known side effects of Pembrolizumab include immunologic complications. We report a case of a patient treated with Pembrolizumab who developed checkpoint-inhibition-induced Myasthenia Gravis.

Objective Case report

Design/Methods

Patient was an 85-year-old female with recurrent squamous cell carcinoma of the vulva status post 2 cycles of Pembrolizumab. During a 3-week period, she developed progressive dysphagia, double vision, neck weakness and general malaise. Other reported symptoms were headache and urinary incontinence. The patient reported to the Emergency Department and was subsequently admitted to the Neurological ICU. Neurological exam showed neck extensor and flexor muscle weakness, diplopia, mild diplopia, and generalized weakness.

Results Brain MRI (Magnetic Resonance Imaging) showed no brainstem pathology. Lumbar Puncture showed (2 Nucleated cells), (81 glucose) and (38 protein). Serum MG antibodies (LRP4, AchR, MusK) were negative. Single-fiber EMG was consistent with neuromuscular junction disorder, most consistent with Myasthenia Gravis. Chest CT (Computed Tomography) was negative. Treatment included IVIG, prednisone, pyridostigmine, methotrexate, and plasmapheresis. Diplopia and neck musculature weakness improved. Due to her chronic medical conditions, the patient and family opted for hospice care.

Conclusions With rising interest in novel immunotherapies for cancer treatment, reporting on significant side effects becomes essential. There are few case reports on checkpoint inhibitor related Myasthenia Gravis. This case aims to provide knowledge on diagnostic and management strategies with patients that present with similar clinical findings to improve future patient care.

Authors/Disclosures
Ifrah Waris PRESENTER	Ms. Waris has nothing to disclose.
Anusha Gadipudi	Miss Gadipudi has nothing to disclose.
Ashley Vincenty-Acosta	Miss Vincenty-Acosta has nothing to disclose.
Axel M. Baez-Lugo, MD (Augusta University Medical Center)	Dr. Baez-Lugo has nothing to disclose.
Gerald Wallace IV, MD (Augusta University)	Dr. Wallace has nothing to disclose.