GAD2 and encephalitis: After excluding cases with antibody overlap syndrome, unpaired serum and CSF specimens, coexistence of other immune diseases, and incomplete clinical information, a final cohort of 207 patients with confirmed AE was included in this study, which comprised of 109 cases of anti-NMDAR encephalitis, 48 cases of anti-LGI1 encephalitis, 14 cases of anti-GABABR encephalitis, 16 cases of anti-Caspr2 encephalitis, 16 cases of anti-GAD65 encephalitis, and 2 cases each of anti-IgLON5 encephalitis and anti-GFAP encephalitis.