Pembrolizumab導致的類重症肌無力疾病，眼肌炎和肝炎

田佳頤¹、歐陽豪¹、林志明¹²³、張世良³⁴

¹彰化基督教醫院 神經部；²靜宜大學 社會工作與兒童少年福利學；³大葉大學 藥用植物與保健學系；⁴中國醫藥大學 中醫系

Pembrolizumab-induced myasthenia gravis-like disorder, ocular myositis, and hepatitis

Chia-Yi Tian¹, Yang-Hao Ou¹, Chih-Ming Lin¹²³, Shih-Liang Chang³⁴

Department of Neurology, Changhua Christian Hospital, Changhua, Taiwan; Department of Social Work and Child Welfare, Providence University, Taichung, Taiwan; Department of Medicinal Botanicals and Health Applications, Da-Yeh University, Changhua, Taiwan; School of Chinese Medicine, China Medical University, Taichung, Taiwan

Introduction: Pembrolizumab and other immune checkpoint inhibitors are the emerging treatment for selected high-grade malignancies. Its antitumor activities rely on activation of cytotoxic T cell-mediated cell killing; however, its adverse effects are also related to enhanced cellular immunity. The management of these complications include cessation of the offending agent and the use of high-dose corticosteroid.

Case Report: A 75-year-old female with high-grade urothelial carcinoma of the left ureter, presented with an acute onset of bilateral ptosis sixteen days after her first infusion of pembrolizumab. It was found that she developed bilateral complete ptosis and limited extraocular muscle movements. Myasthenia gravis-related antibodies and repetitive stimulation test were negative. We diagnosed her with pembrolizumab-induced myasthenia gravis-like disorder and myositis based on clinical symptoms and elevation of muscle enzymes. We commenced methylprednisolone pulse therapy followed by oral steroid therapy with gradual resolution of the symptoms. Three months later, the patient received a second cycle of pembrolizumab with low-dose oral steroid without any complications.

Discussion: Pembrolizumab exert its antitumor activity by interfering the binding of programmed death-1 and its ligand PD-L1. As a result, enhanced cytotoxic T-cells are able to recognize tumor cells and induce cellular death. However, neurological complications may be serious and require prompt recognition and treatment. Our case demonstrated that concomitant use of low dose steroid and pembrolizumab may prevent such complications.