Taboada Phillip, Lee Matthew, Hoyer Remington, Gray Zane, Wang Jue
School of Medicine, University of Texas Southwestern Medical School, Dallas, USA.
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, USA.
Cureus. 2024 Aug 31;16(8):e68318. doi: 10.7759/cureus.68318. eCollection 2024 Aug.
Immune checkpoint inhibitors (ICIs) like pembrolizumab are increasingly used for treating renal cell carcinoma (RCC), offering benefits such as enhanced specificity and activation of immunological memory. However, ICIs can lead to immune-related adverse events (irAEs), including rare but serious neurologic consequences such as myasthenia gravis (MG). We present a case of pembrolizumab-induced MG with concurrent orbital myositis and myocarditis. A 69-year-old male with a history of pT3aN1 kidney cancer presented with abdominal pain, night sweats, and weight loss. Initial imaging revealed a retroperitoneal mass and a thyroid mass, and a biopsy confirmed papillary RCC. The patient began neoadjuvant therapy with pembrolizumab and axitinib. Three weeks post-initiation, he developed dysphagia, ptosis, and proptosis, which progressed with each pembrolizumab infusion. Hospitalization was required after the third cycle due to bilateral ptosis, heart block, and elevated troponins. Despite initial steroid treatment, symptoms persisted. Diagnoses of ICI-related MG (irMG) and myocarditis were established, and treatment included cessation of pembrolizumab, high-dose steroids, IVIGs, and a pacemaker for heart block. Post-discharge, the patient showed a slight improvement in ptosis but persistent dysphagia. MG induced by ICIs is a rare but severe complication with rapid onset and progression, often presenting with bulbar involvement and a significant risk of respiratory failure. The therapeutic regimen for our patient, including high-dose methylprednisolone and IVIG, aligns with current recommendations. This case underscores the importance of recognizing cardiac irAEs like myocarditis in patients on ICIs, as early intervention can significantly affect outcomes. Despite therapeutic interventions, complete resolution of irMG symptoms is rare, and persistent sequelae are common. This case highlights the critical need for vigilant monitoring and prompt management of neurologic and cardiac irAEs in patients undergoing ICI therapy. Clinicians should maintain a high index of suspicion for MG and myocarditis to improve diagnostic accuracy and patient outcomes.
帕博利珠单抗等免疫检查点抑制剂越来越多地用于治疗肾细胞癌（RCC），具有增强特异性和激活免疫记忆等益处。然而，免疫检查点抑制剂可导致免疫相关不良事件（irAE），包括重症肌无力（MG）等罕见但严重的神经系统后果。我们报告一例帕博利珠单抗诱导的MG并发眼眶肌炎和心肌炎病例。一名有pT3aN1期肾癌病史的69岁男性，出现腹痛、盗汗和体重减轻。初始影像学检查发现腹膜后肿块和甲状腺肿块，活检确诊为乳头状RCC。患者开始接受帕博利珠单抗和阿昔替尼新辅助治疗。开始治疗三周后，他出现吞咽困难、上睑下垂和眼球突出，每次输注帕博利珠单抗后症状都有进展。第三个周期后，由于双侧上睑下垂、心脏传导阻滞和肌钙蛋白升高，需要住院治疗。尽管最初进行了类固醇治疗，但症状仍持续存在。确诊为ICI相关MG（irMG）和心肌炎，治疗包括停用帕博利珠单抗、大剂量类固醇、静脉注射免疫球蛋白（IVIG）以及植入心脏起搏器治疗心脏传导阻滞。出院后，患者上睑下垂稍有改善，但吞咽困难持续存在。ICI诱导的MG是一种罕见但严重的并发症，起病迅速且进展快，常伴有延髓受累和呼吸衰竭的重大风险。我们患者的治疗方案，包括大剂量甲泼尼龙和IVIG，符合当前推荐。该病例强调了在接受ICI治疗的患者中识别心肌炎等心脏irAE的重要性，因为早期干预可显著影响治疗结果。尽管进行了治疗干预，但irMG症状完全缓解很少见，持续后遗症很常见。该病例突出了对接受ICI治疗的患者进行神经系统和心脏irAE的警惕监测和及时管理的迫切需求。临床医生应高度怀疑MG和心肌炎，以提高诊断准确性和患者治疗效果。
