[Characteristic analysis of autoimmune encephalitis with antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor]

The clinical data of 7 patients with anti-α-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid receptor (AMPAR) encephalitis admitted to the First Affiliated Hospital of Zhengzhou University from January 2015 to January 2024 were retrospectively collected, and 87 cases with complete literature data were included for summary analysis. Seven casess exhibited limbic encephalitis, including 3 with lung cancer and 1 with thymoma. All cases were treated with glucocorticoids and/or human immunoglobulin. Four cases with concurrent tumors were followed up for 1 to 25 months and all died. Among the 94 patients (7 admitted cases and 87 documented cases), there were 76 cases with tumor (80.9%), including 33 cases of thymoma (43.4%), 23 cases of lung cancer (30.3%), 9 cases of breast cancer (11.8%), and 6 cases of ovarian tumor (7.9%). The tumor was diagnosed in 13 cases (18.8%) before encephalitis, 40 cases (58.0%) within 1 month after encephalitis, 13 cases (18.8%) within 1-6 months, 2 case (2.9%) within 6-12 months, and 1 case (1.4%) after 1 year. Compared to the 18 patients without tumors who were followed up for>1 year, the 76 patients with tumors showed an increase in age and incidence of mental disorders (both P<0.05), while follow-up time and proportion of good prognosis were decreased (both P<0.05). Closely follow-up should be conducted within 1 year after anti-AMPAR encephalitis, especially in the lungs, thymus, breast, and ovaries. The prognosis of patients with tumors is poor, and older age and mental disorders may indicate the occurrence of tumors.