免疫チェックポイント阻害薬による免疫関連有害事象に伴う筋炎および重症筋無力症を発症し，急性呼吸不全に対して人工呼吸管理を必要とした1症例

Myositis and Myasthenia Gravis Associated with Immune-related Adverse Events due to Immune Checkpoint Inhibitor Treatment in a Patient Requiring Ventilatory Management for Acute Respiratory Failure

要旨

　がん治療の分子標的薬として使用される免疫チェックポイント阻害薬には，過度の免疫反応に起因するさまざまな病態（免疫関連有害事象）が現れることがある。ペムブロリズマブを投与後に，筋炎および重症筋無力症により人工呼吸管理を必要とした症例を経験した。換気不全および嚥下障害のため抜管困難と評価し，気管切開が必要であった。免疫関連有害事象に伴う筋炎，重症筋無力症による急性呼吸不全を呈する症例があることを集中治療医は認識しておく必要がある。

　Treatment with immune checkpoint inhibitors（ICIs）as molecularly targeted agents for cancer can be associated with complications（e. g., immune-related adverse events）that are the result of an excessive immune response. We report the case of a 65-year-old male who required mechanical ventilation due to myositis and myasthenia gravis after he was treated with the ICI pembrolizumab for advanced esophageal cancer. He had presented with acute respiratory failure with respiratory acidosis and was urgently admitted to the intensive care unit, where he was intubated and ventilated. It was difficult to extubate the patient due to muscle weakness with ventilatory failure and dysphagia, and a tracheostomy was performed. Anesthesiologists and intensivists involved in cancer care should be aware that myositis and myasthenia gravis associated with immune-related adverse events may present with acute respiratory failure.