Supplementary Material for: Successful Management of Immune-Mediated Myelitis in a Renal Cancer Patient: A Case Report

Introduction: Immune checkpoint inhibitors (ICIs) have revolutionized metastatic renal cell carcinoma (mRCC) treatment, significantly improving survival outcomes. However, ICIs are linked to immune-related adverse events (irAEs), which can impact multiple organs. Neurological irAEs, such as myelitis, are rare but potentially severe. Case Presentation: We describe a 54-year-old male with high-grade clear cell renal carcinoma treated with nivolumab and ipilimumab. After four cycles, he developed hypophysitis, adrenal insufficiency, and hypothyroidism, managed with hydrocortisone and levothyroxine, while continuing nivolumab monotherapy. In August 2022, he experienced right eyelid ptosis and right-hand weakness. Cranial MRI showed improvement in the sellar lesion, and chronic sensorimotor polyneuropathy was diagnosed, ruling out myasthenia gravis. Nivolumab treatment continued. By December 2022, after seven cycles, the patient developed back pain and dysesthesias, with MRI confirming transverse myelitis from C7 to T3. Nivolumab was discontinued, and high-dose corticosteroids (1g methylprednisolone daily for 5 days) led to clinical improvement. A 12-week taper followed, with no symptom recurrence. Disease progression in April 2023 led to a switch to pazopanib, maintaining a partial response for six months. Conclusion: This case emphasizes the serious nature of neurological irAEs from ICIs and the critical need for early detection and management. It also highlights the increased risk of subsequent irAEs after an initial event, underscoring the importance of vigilant monitoring.

引言：免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）彻底革新了转移性肾细胞癌（metastatic renal cell carcinoma, mRCC）的治疗方案，显著改善了患者的生存结局。然而，ICIs可引发免疫相关不良事件（immune-related adverse events, irAEs），累及多器官系统。神经系统免疫相关不良事件（如脊髓炎）虽罕见，但病情可能危重。
病例报告：本文报告1例54岁高级别透明细胞肾细胞癌患者，接受纳武利尤单抗（nivolumab）联合伊匹木单抗（ipilimumab）治疗。完成4个周期治疗后，患者出现垂体炎、肾上腺功能不全及甲状腺功能减退症，予氢化可的松与左甲状腺素钠治疗的同时，继续予以纳武利尤单抗单药维持治疗。2022年8月，患者出现右眼睑下垂及右手无力症状。颅脑磁共振成像提示鞍区病变较前改善，结合检查确诊为慢性感觉运动性多发性神经病，排除重症肌无力，继续予以纳武利尤单抗治疗。2022年12月，完成7个周期治疗后，患者出现背痛及感觉异常，磁共振成像证实存在C7至T3节段横贯性脊髓炎。遂停用纳武利尤单抗，予大剂量糖皮质激素（每日1g甲泼尼龙（methylprednisolone），连续5天）治疗后，患者临床症状改善。随后予以12周的激素逐渐减量方案，期间未出现症状复发。2023年4月患者出现疾病进展，换用帕唑帕尼（pazopanib）治疗，后续6个月维持部分缓解。
结论：本病例凸显了ICIs所致神经系统免疫相关不良事件的严重性，强调早期识别与管理的关键必要性。同时提示初始免疫相关不良事件发生后，后续发生不良事件的风险升高，需加强对患者的密切监测。