A Rare Case of Overlapping Durvalumab-induced Myositis, Takotsubo-like Morphological Changes Caused by Myocarditis, and Myasthenia Gravis

Abstract

Immune checkpoint inhibitors can cause a range of immune-related adverse events, including myositis, Takotsubo cardiomyopathy, and myasthenia gravis. We herein report a rare case of a 78-year-old man with concurrent durvalumab-induced myositis, Takotsubo-like morphological changes caused by myocarditis, and myasthenia gravis. The patient initially required invasive ventilation and exhibited symptoms of myasthenia gravis after treatment with high-dose steroids. However, he subsequently achieved successful recovery after the administration of intravenous immunoglobulin, plasmapheresis, and high-dose steroids. We advocate vigilant neurological monitoring of patients with immune checkpoint inhibitor-induced myositis, including the assessment of ptosis and other relevant signs, so that prompt treatment can be initiated at the time of emergence or progression of immune checkpoint inhibitor-induced myasthenia gravis.

Keywords: ICI-induced myasthenia gravis; Takotsubo cardiomyopathy; immune checkpoint inhibitors; immune-related adverse events; intravenous immunoglobulin; plasmapheresis.

Figure 1.

Electrocardiography data at the time of admission (A), just prior to coronary angiography on Day 1 (B) and Day 2 (C).

Figure 2.

Four-chamber view of the echocardiogram on Days 1 and 4.

Figure 3.

Left ventriculography showing atypical ballooning. Left ventricle in (A) diastole and (B) systole demonstrating apical akinesis (blue arrowheads) and basal hyperkinesis (red arrows). LVEF: left ventricle ejection fraction

Figure 4.

Clinical course of the patient until discharge. IVIg: intravenous immunoglobulin, mPSL: methylprednisolone, PSL: prednisolone

Figure 5.

Results of a repetitive nerve stimulation test of the left deltoid muscle. Waning is observed when the left axillary nerve is stimulated at a repetition frequency of 3 Hz.