探讨抗γ-氨基丁酸B型受体(GABA_BR)抗体与代谢型谷氨酸受体2(mGluR2)抗体双阳性自身免疫性脑炎(AE)的临床诊断特征。

回顾性分析1例2025年1月首次就诊于哈尔滨医科大学附属第一医院神经内科，后于2025年3月因症状加重再次住院，并经血清及脑脊液检查确诊为抗GABA_BR抗体与抗mGluR2抗体双阳性AE患者的临床资料，结合相关文献探讨其临床特征。

患者女性，54岁，以癫痫发作起病，病程中出现精神行为异常、视幻觉、认知功能下降及睡眠障碍等边缘叶脑炎综合征症状。头颅MRI示双侧海马长T₂信号；抗GABA_BR抗体阳性血清和脑脊液滴度分别为1∶1 000和1∶10，脑脊液抗mGluR2抗体阳性，滴度为1∶1，血清抗mGluR2抗体阴性。影像学筛查未见明确恶性肿瘤征象，但血清肿瘤标志物神经元特异性烯醇化酶(17.18 μg/L)及糖类抗原72-4(28.79 U/mL)水平轻度升高。经糖皮质激素联合血浆置换及吗替麦考酚酯治疗后症状显著改善。

抗GABA_BR与mGluR2抗体双阳性AE极为罕见，早期全面的抗体检测及免疫治疗可能有助于改善短期预后，并需长期随访以排除潜在的副肿瘤病因。抗mGluR2抗体的临床意义尚需进一步研究。

To investigate the clinical and diagnostic characteristics of autoimmune encephalitis (AE) double-positive for anti-γ-aminobutyric acid type B receptor (GABA_BR) and anti-metabotropic glutamate receptor 2 (mGluR2) antibodies.

A retrospective analysis was performed on the clinical data of a patient who was initially admitted to the Department of Neurology at the First Affiliated Hospital of Harbin Medical University in January 2025 and was readmitted in March 2025 due to symptom exacerbation, where a diagnosis of AE double-positive for anti-GABA_BR and anti-mGluR2 antibodies was confirmed via serological and CSF testing. Relevant literature was also reviewed to explore the clinical features of this condition.

A 54-year-old female patient presented with epileptic seizures as the initial symptom, and subsequently developed psychiatric and behavioral abnormalities, visual hallucinations, cognitive decline, and sleep disorders during the disease course, consistent with limbic encephalitis syndrome. Brain MRI showed bilateral hippocampal long T₂ signals. Anti-GABA_BR antibodies were positive in both serum and CSF, with titers of 1∶1 000 and 1∶10, respectively. Anti-mGluR2 antibodies were positive in CSF at a titer of 1∶1 but negative in serum. Systemic oncological screening revealed no definitive malignant lesions; however, serum tumor markers showed mild elevations in neuron-specific enolase (17.18 μg/L) and carbohydrate antigen 72-4 (28.79 U/mL). Symptoms improved significantly after treatment with glucocorticoids combined with plasma exchange and mycophenolate mofetil.

AE with double positivity for anti-GABA_BR and anti-mGluR2 antibodies is extremely rare. Early comprehensive antibody testing and immunotherapy may help improve short-term prognosis, and long-term follow-up is warranted to exclude a potential paraneoplastic etiology. The clinical significance of anti-mGluR2 antibodies needs further investigation.