Background

Autoimmune mediated encephalitis (AME), which includes autoantibody-associated encephalitis and acute disseminated encephalomyelitis, is a common cause of encephalitis as well as infectious encephalitis in children. AME may be triggered by autoimmune responses to paraneoplastic syndromes and infections. Infectious encephalitis associated with an immunocompromised status caused by anti-cancer chemotherapy is well recognized; however, there have been few reports on the relationship between AME and chemotherapy.

Case report

A ten-year-old previously healthy, developmentally normal girl was diagnosed with a pure germinoma in the suprasellar region. Following 30 days of induction chemotherapy, she developed a depressed level of consciousness with accompanying right hemiplegia, aphasia, and unexplained fever. Cerebrospinal fluid (CSF) analysis revealed positive oligoclonal bands and elevated neopterin levels. Neither atypical cells suggesting tumor exacerbation nor pathogens known to cause encephalitis were identified in the CSF. She was administrated immunosuppressive therapy and her symptoms rapidly improved. No known autoantibodies associated with autoantibody-associated encephalitis were identified in blood or CSF. However, the presence of oligoclonal bands and elevated neopterin levels in the CSF, and the favorable response to immunosuppressive therapy were consistent with an AME diagnosis. Thirteen days after the third course of chemotherapy, the patient developed a depressed level of consciousness again. Due to the recurrence of encephalitis, re-administration of immunosuppressive therapy was performed, which led to improvement in her symptoms. Recurrence of encephalitis has not occurred for 1 year after completion of chemotherapy.

Conclusion

The chemotherapy-induced abnormal immune response might have triggered the AME.

中文翻译：

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生殖细胞瘤治疗期间化疗引起的自身免疫介导的脑炎

背景

自身免疫介导的脑炎（AME）包括自身抗体相关性脑炎和急性播散性脑脊髓炎，是儿童脑炎和感染性脑炎的常见病因。AME 可能由对副肿瘤综合征和感染的自身免疫反应触发。由抗癌化疗引起的与免疫功能低下状态相关的感染性脑炎已广为人知。然而，关于AME与化疗之间关系的报道很少。

案例报告

一名 10 岁以前健康、发育正常的女孩在鞍上区被诊断出患有纯生殖细胞瘤。诱导化疗 30 天后，她出现意识水平低下，伴有右侧偏瘫、失语和不明原因的发热。脑脊液 (CSF) 分析显示阳性寡克隆带和升高的新蝶呤水平。在脑脊液中既没有发现提示肿瘤恶化的非典型细胞，也没有发现已知引起脑炎的病原体。她接受了免疫抑制治疗，她的症状迅速改善。在血液或脑脊液中未发现与自身抗体相关脑炎相关的已知自身抗体。然而，脑脊液中寡克隆带的存在和新蝶呤水平升高，并且对免疫抑制治疗的良好反应与 AME 诊断一致。在第三个疗程化疗后 13 天，患者再次出现意识下降。因脑炎复发，再次给予免疫抑制治疗，症状有所改善。化疗完成后1年内未发生脑炎复发。

结论

化疗引起的异常免疫反应可能触发了 AME。