Neurological autoimmune diseases are a group of disorders characterized by the abnormal immune response attacking the nervous system, including the brain, spinal cord and peripheral nerves. These diseases exhibit high heterogeneity, diverse clinical presentations, and are challenging to diagnose and manage due to a lack of effective treatments. In this study, the investigators will recruit eight kinds of autoimmune diseases of nervous system including Neuromyelitis Optica Spectrum Disorder (NMOSD), Myasthenia Gravis (MG), Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP), idiopathic inflammatory myopathy (IIM), and multiple sclerosis (MS), autoimmune encephalitis (AE), Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD). Through this study, the investigators aim to discover biomarkers with high sensitivity, specificity, and stability, which can support early diagnosis, disease monitoring, and personalized treatment for neurological autoimmune diseases, thereby improving the quality of life and prognosis for patients.