[Autoimmune encephalitis: possibilities in the laboratory investigation]

Area of Science:

• Neuroimmunology
• Neurology
• Diagnostic Immunology

Background:

• Autoimmune responses against central nervous system (CNS) antigens are increasingly recognized in encephalitis with neurological or psychiatric symptoms.
• Paraneoplastic limbic encephalitis, often linked to intracellular antigens, carries a poor prognosis.
• Newer autoimmune encephalitis subtypes associated with cell surface receptor autoantibodies (NMDAR, LGI1, etc.) show better treatment response.

Purpose of the Study:

• To highlight the growing number of autoimmune encephalitis patients needing intensive neurological, psychiatric, and critical care.
• To emphasize the diagnostic importance of identifying specific autoantibodies in autoimmune encephalitis.

Main Methods:

• Analysis of 836 diagnostic test requests for autoimmune encephalitis from 717 patients over six years.
• Indirect immunofluorescence assay using a BIOCHIP with cell lines expressing six different receptor proteins on serum and cerebrospinal fluid (CSF) samples.

Main Results:

• IgG autoantibodies against receptor proteins were detected in 7.5% of patients.
• The most frequent autoantibodies identified were against NMDAR, followed by LGI1, GABA_BR, and CASPR2.

Conclusions:

• Early detection of autoantibodies significantly aids in diagnosing autoimmune encephalitis.
• Early diagnosis allows for effective treatment with plasmapheresis and immunosuppressive drugs.
• Autoantibody monitoring is valuable for assessing treatment efficacy and preventing disease progression.