Analysis of clinical infection⁃associated autoimmune encephalitis

Objective To summarize the clinical features of infection - associated autoimmune encephalitis (IAE) with different antibodies in Xinjiang region, and to explore the diagnostic value of relevant laboratory indicators for IAE. Methods A total of 47 patients with IAE diagnosed and treated in People's Hospital of Xinjiang Uiger Autonomous Region from January 2018 to October 2023 were enrolled, including 18 cases (38.30%) of anti - leucine - rich glioma - inactivated 1 (LGI1) antibody - associated encephalitis, 16 cases (34.04%) of anti - N - methyl - D - aspartate receptor (NMDAR) encephalitis, 8 cases (17.02%) of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated encephalitis, and 5 cases (10.64%) of anti-γ -aminobutyric acid receptor type B (GABABR) encephalitis. Social demographic data, clinical manifestations, laboratory and other examinations were collected, and receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of relevant laboratory indicators for IAE. Results The age of onset (χ2 = 9.500, P = 0.023), myasthenia (χ2 = 9.967, P = 0.019), vision loss (χ2 = 9.967, P = 0.019) and seizures (χ2 = 8.046, P = 0.045), cerebrospinal fluid (CSF) white blood cell count (χ2 = 15.237, P = 0.002) and chloride (F = 4.156, P = 0.011) in patients with anti - LGI1 antibody - associated encephalitis, anti - NMDAR encephalitis, anti - MOG antibody - associated encephalitis and anti - GABABR encephalitis were statistically significant. The age of onset in patients with anti-LGI1 antibody-associated encephalitis was larger than that in patients with anti-NMDAR encephalitis (Z = - 2.384, P = 0.017) and anti- MOG antibody-associated encephalitis (Z = - 2.420, P = 0.016). The CSF white blood cell count in patients with anti - NMDAR encephalitis was higher than that in patients with anti - LGI1 antibody - associated encephalitis (Z = - 3.307, P = 0.001) and anti-MOG antibody-associated encephalitis (Z = - 2.835, P = 0.005). CSF chloride was higher in patients with anti-NMDAR encephalitis (t = 3.159, P = 0.007) and anti-GABABR encephalitis (t = - 4.592, P = 0.007) than in patients with anti-LGI1 antibody-associated encephalitis. ROC curve showed that the area under the curve (AUC) of age of onset for diagnosis of anti-LGI1 antibodyassociated encephalitis was 0.722 (95%CI: 0.569-0.875, P = 0.012), the sensitivity was 0.556, the specificity was 0.821, and the cut-off value was 54.50 years old. The AUC of CSF white blood cell count in the diagnosis of anti-LGI1 antibody-associated encephalitis was 0.706 (95%CI: 0.558-0.855, P = 0.019), the sensitivity was 0.889, the specificity was 0.571, and the cut-off value was 4.50 × 106/L. The AUC in the diagnosis of anti - NMDAR encephalitis was 0.790 (95%CI: 0.643-0.937, P = 0.002), the sensitivity was 0.600, the specificity was 0.967, and the cut-off value was 13.50 × 106/L. The AUC of CSF chloride for the diagnosis of anti-LGI1 antibody-associated encephalitis was 0.748 (95%CI: 0.598-0.898, P = 0.005), with a sensitivity of 0.722 and a specificity of 0.714, and a cut-off value of 122.70 mmol/L. Conclusions IAE with different antibodies in Xinjiang region has specific clinical features. Age of onset, CSF white blood cell count and chloride have important value in the diagnosis of anti-LGI1 antibody-associated encephalitis, and CSF white blood cell count has important value in the diagnosis of anti-NMDAR encephalitis.