探讨抗二肽基肽酶样蛋白-6(DPPX)抗体相关脑炎的诊断学特征。

回顾性分析2021年6月25日内蒙古包钢医院神经内科收治的1例血清抗DPPX抗体阳性患者的既往及现有临床资料，总结抗DPPX抗体相关脑炎的诊断学特征并复习相关文献。

患者男性，53岁，因"右眼渐进性失明10 d"入院。眼科查体示双侧瞳孔不等大，左侧3.0 mm，右侧4.0 mm，右侧直接、间接光反射消失；右眼无光感，左眼0.4；眼底、黄斑区及眼底荧光造影未见异常；右眼视诱发未引出。头颅磁共振成像(MRI)未见新发梗死及占位性病变；动态脑电图大致正常；血清抗DPPX抗体＋＋(1∶20滴度稀释)，其他N-甲基-D-天冬氨酸(NMDA)受体脑炎抗体均阴性；脑脊液余项检查大致正常。住院期间给予营养神经治疗，住院6 d后下方视野有所恢复，有光感。出院诊断为抗DPPX抗体脑炎。患者既往于2018年3月8日因左侧肢体肌力减弱住院治疗，左侧肢体肌力为4级，左上肢痛觉减退，余查体阴性。头颅MRI未见新发梗死；颈部MRI示颈5/6水平髓内占位，诊断为星形细胞瘤，未予特殊治疗，自行康复锻炼，2020年3月左侧肢体肌力及感觉均完全恢复正常。

本例抗DPPX抗体脑炎患者以偏侧肢体肌力减弱起病，且两次临床症状均有不同程度自行缓解情况，进一步证明该病可能存在自限性。

To explore the diagnostic characteristics of anti-dipeptidyl-peptidase-like protein 6 (DPPX) antibody associated encephalitis.

A retrospective analysis was conducted on the past and current clinical data of a patient with serum anti-DPPX antibody positive admitted to the Neurology Department of Inner Mongolia Baogang Hospital on June 25, 2021. The diagnostic characteristics of anti-DPPX antibody related encephalitis were summarized and relevant literatures were reviewed.

The patient, a 53 year old male, was hospitalized due to progressive blindness in the right eye for 10 days. Ophthalmic examination showed that the pupils of both sides had unequal sizes, 3.0 mm on the left side and 4.0 mm on the right side, and the direct and indirect light reflection of right eye disappeared. Light perception of right eye disappeared, and the vision of the left eye was 0.4. The fundus, macular area and fundus fluorescein showed no abnormality. Visual evoked response in the right eye was not elicited. No new infarctions or occupying lesions were found on cranial MRI. The dynamic electroencephalogram was generally normal. Serum anti-DPPX antibody + + (diluted at 1∶20 titers), all other N-methyl-D-aspartic acid (NMDA) receptors encephalitis antibodies were negative. The remaining items of the cerebrospinal fluid examination were generally normal. During hospitalization, nutritional nerve therapy was given, and after 6 days of hospitalization, the lower field of vision and light perception recovered and there was a sense of light. The discharge diagnosis was anti-DPPX antibody encephalitis. The patient was admitted to the hospital for treatment on March 8, 2018 due to left limb strength. At the time of admission, a neurological examination showed that the left limb strength was level 4, with reduced pain sensation in the left upper limb and negative results on other examinations. Complete cranial MRI showed no new infarctions. Neck MRI showed a intramedually mass at the C5/6 level of the neck, diagnosed as astrocytoma. No special treatment was given, and only self rehabilitation exercise was performed. In March 2020, the left limb strength and sensation fully returned to normal.

The patient with anti-DPPX antibody encephalitis in this case started with weak unilateral limb strength, and both clinical symptoms showed varying degrees of self relief, further proving that the disease may exhibit self-limiting characteristics.