Screening for autoantibodies against the mGluR5 antigen is used in the investigation of patients with potential autoimmune encephalitis.
Metabotropic glutamate receptors are transmembrane proteins on the neuronal cell membranes. Unlike ionotropic receptors, metabotropic glutamate receptors (mGluRs) are not ion channels. Instead, they trigger cascades of biochemical processes, leading to the modification of other proteins, such as ion channels.
Antibodies against mGluR5 (metabotropic glutamate receptor 5, molecular weight 132 kDa) have been reported in limbic encephalitis with (or without) Hodgkin's lymphoma (Ophelia syndrome). Recognizing this disorder is important as it can occur in young people and is reversible.
Test of mGluR5 antibodies is performed in serum. There have been no reports of antibodies present in the CSF alone.
See also: mGluR1 Antibodies