Screening for autoantibodies against the IgLON5 antigen is performed in cases of suspected autoimmune encephalitis.
The IgLON5 protein is an adhesion molecule located on the cell surface of neurons with unknown functions. Antibodies against the IgLON5 antigen have been found in some cases of patients with encephalitis and neurodegeneration with abnormal sleep behaviors and obstructive sleep apnea. Other neurological symptoms observed in patients with IgLON5 autoantibodies are gait instability, dysarthria, dysphagia, ataxia, or chorea.
The antigen is an extracellular antigen with a molecular weight of 37 kDa and belongs to the immunoglobulin family.
In general, immunotherapy is often more effective in autoantibodies directed against extracellular antigens than in autoantibodies against intracellular antigens.