Autoimmune encephalitis-antibody targets and their potential pathogenicity in immunotherapy-responsive syndromes

Autoimmune encephalitis (AIE) associated with neural autoantibodies is increasingly recognized as a cause of subacute onset amnesia, confusion, and seizures. In the past decade, several key antibody targets have been identified in AIE. These include the N-methyl D-aspartate (NMDA) receptors, voltage-gated potassium channel complexes-in particular leucine-rich glioma inactivated 1 (LGI1) and glutamic acid decarboxylase (GAD). There is accumulating clinical and laboratory evidence that antibodies targeting the extracellular domains of cell-surface molecules are directly pathogenic. Each antibody target associates with a spectrum of clinical features and relative response to immunotherapies. These immunotherapies have been shown to improve short- and long-term clinical outcomes in affected patients. AIE is an important differential diagnosis to consider in patients presenting with symptoms of encephalitis as early diagnosis can lead to successful treatment.