Immune Checkpoint Inhibitor-associated Triple M Overlap Syndrome, Thyroiditis, and Sjogren’s Syndrome in a Patient with Grave’s Disease and Rectal Adenocarcinoma
Amy Lin1, Arman Saied1, Anusha Akhai1, Scott Belliston2
1University of North Dakota School of Medicine and Health Sciences, 2Sanford Health
Objective:
N/A
Background:
Immune checkpoint inhibitors (ICI) play a key role in the treatment of many types of cancers due to their ability to enhance the body’s antitumor immune response. However, these agents also can lead to dysregulation of immune homeostasis, leading to immune-related adverse events (IRAEs) affecting multiple organ systems. Recent literature has suggested that patients with pre-existing autoimmune disease have a higher incidence of IRAEs. Our case expands the profile of concurrent multi-system IRAEs observed with ICI therapy and further supports the association between IRAEs and pre-existing autoimmunity.
Design/Methods:
N/A
Results:
This case presents an 83-year-old female patient with history of Grave’s disease and rectal adenocarcinoma who developed ptosis, diplopia, dysphagia, dysarthria, and weakness that began 6 weeks after starting immune checkpoint inhibitor therapy with pembrolizumab. On admission, she was found to have markedly elevated troponin, creatine phosphokinase, and TSH. Her neurologic examination was notable for bilateral exophoria in superior gaze, right abducens nerve palsy, flaccid dysarthria, as well as proximal bilateral upper and lower extremity weakness. Further laboratory workup revealed positive ANA and Anti-SS-B/LA titers, with negative anti-acetylcholine receptor and anti-MuSK antibodies.  Her symptoms, in combination with her laboratory workup, were felt to be clinically consistent with concurrent triple M overlap syndrome (myasthenia gravis, myositis, myocarditis), Sjogren’s syndrome, and thyroiditis, so she was started on IVIG, steroids, and levothyroxine. She experienced significant symptomatic improvement during admission.  
Conclusions:
While concurrent IRAEs have been recognized with ICI therapy, the simultaneous occurrence of ICI-associated triple M overlap syndrome, Sjogren’s syndrome, and thyroiditis has not been previously reported.  This case broadens the current understanding of the diverse autoimmune manifestations that can result from ICI therapy. We also highlight the association between pre-existing autoimmune disease and IRAEs, and propose the need for heightened awareness and monitoring for adverse effects in this population.  
Generative AI Usage
No, did not use generative AI in the drafting or editing in this abstract.
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