Autoimmune limbic encephalitis: A manifestation of systemic lupus erythematosus in the central nervous system

Autoimmune limbic encephalitis (ALE) associated with systemic lupus erythematosus (SLE) is a rare entity with few reports in the literature to date. In general, ALE associated with SLE has a satisfactory response to immunosuppressive treatment (RIT), but the pathogenesis of this association is poorly understood and may include an autoimmunity component. We report a case study describing the diagnosis and management of limbic encephalitis in a patient with active Systemic Lupus Erythematosus disease (SLE) and past medical history of cancer (endometrial adenocarcinoma in 2004 and papillary urothelial carcinoma in 2011 with curative treatment), followed over a one-year period. We discuss the possible association between limbic encephalitis and all past neoplastic and immune-mediated conditions of this patient. In this particularly case, autoimmunity was the most relevant factor associated with limbic encephalitis given negative neoplastic screening. Moreover, a good response was observed to immunotherapy, not seen with paraneoplastic limbic encephalitis, which is associated with poor response. In this case, the association of ALE with SLE is possible, since laboratory testing disclosed lupic activity and the patient had involvement of other systems (such as hematologic) during the period. However, the presence of other surface membrane antibodies are possible in the search for alternative etiologies.与系统性红斑狼疮（systemic lupus erythematosus, SLE）相关的自身免疫性边缘性脑炎（autoimmune limbic encephalitis, ALE）是一种罕见病症，迄今相关文献报道有限。总体而言，伴发于SLE的ALE对免疫抑制治疗（immunosuppressive treatment, RIT）应答良好，但二者关联的发病机制尚未完全阐明，推测可能涉及自身免疫异常环节。本文报告1例病例研究，对1例合并活动性系统性红斑狼疮且既往有恶性肿瘤病史（2004年确诊子宫内膜腺癌、2011年确诊乳头状尿路上皮癌，均已接受根治性治疗）的患者的边缘性脑炎诊断与管理过程进行了描述，并完成了为期1年的随访观察。本文还探讨了该患者既往所有肿瘤性疾病与免疫介导病症和边缘性脑炎之间的潜在关联。在本病例中，由于肿瘤筛查结果为阴性，自身免疫异常是与边缘性脑炎相关的最关键致病因素。此外，该患者对免疫治疗展现出良好应答，而副肿瘤性边缘性脑炎（paraneoplastic limbic encephalitis）患者的治疗应答往往不佳，二者存在显著差异。本病例提示，伴发于SLE的ALE是可能存在的：实验室检查结果显示狼疮活动，且患者随访期间出现了血液系统等其他系统受累表现。不过，在排查其他病因时，仍需考虑存在其他表面膜抗体阳性的可能性。