Anti-glutamate receptor

Glutamate receptor

Glutamate receptors are synaptic receptors located primarily on the membranes of neuronal cells. Glutamate is one of the 20 amino acids used to assemble proteins and as a result is abundant in many areas of the body, but it also functions as a neurotransmitter and is particularly abundant in the...

 antibodies are autoantibodies

Autoantibody

An autoantibody is an antibody manufactured by the immune system that is directed against one or more of the individual's own proteins. It is derived from the Greek "auto" which means "self", "anti" which means "against" and "body"...

 detected in serum

Blood serum

In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...

 and/or cerebrospinal fluid

Cerebrospinal fluid

Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...

 samples of a variety of disorders such as encephalitis

Encephalitis

Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningoencephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue...

, epilepsy

Epilepsy

Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...

 and ataxia

Ataxia

Ataxia is a neurological sign and symptom that consists of gross lack of coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum...

. Recent clinical and experimental studies suggest that these antibodies are not simply epiphenomena and are involved in autoimmune disease

Autoimmune disease

Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...

 pathogenesis.

Anti-AMPAr

The first anti-glutamate receptor antibody was shown by McNamara JO and colleagues to be directed against the GluR3 subunit of the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid

AMPA

AMPA is a compound that is a specific agonist for the AMPA receptor, where it mimics the effects of the neurotransmitter glutamate....

 (AMPA) receptor. Since then anti-GluR3 antibodies have been demonstrated in temporal lobe epilepsy, epilepsia partialis continua

Epilepsia partialis continua

Epilepsia partialis continua is a rare type of brain disorder in which a patient experiences recurrent motor epileptic seizures that are focal , and recur every few seconds or minutes for extended periods .-Presentation:During these seizures, there is repetitive focal myoclonus or Jacksonian...

 and focal epilepsy.

Anti-NMDAr

The second large group of anti-glutamate receptor antibodies is associated with different subunits of N-methyl-D-aspartate

NMDA

N-Methyl-D-aspartic acid or N-Methyl-D-aspartate is an amino acid derivative which acts as a specific agonist at the NMDA receptor mimicking the action of glutamate, the neurotransmitter which normally acts at that receptor...

 (NMDA) receptor. Patients with limbic encephalitis

Limbic encephalitis

Limbic encephalitis is a form of encephalitis.In a small number of cases, the pathogens responsible for encephalitis attack primarily the limbic system , often causing memory deficits similar to those observed in Alzheimer's disease or Creutzfeldt-Jakob disease Limbic encephalitis is a form of...

, encephalitis, systemic lupus erythematosus

Systemic lupus erythematosus

Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...

, ataxia and epilepsia partialis continua may present with serum and cerebrospinal fluid antibodies to the delta2 or NR2 subunits of the NMDA receptor.

Antibodies against the NR1, NR2A and NR2B subunits of the NMDA receptor were described by Josep Dalmau, Erdem Tüzün and colleagues in women presenting with psychiatric symptoms, amnesia

Amnesia

Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...

, seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

s, dyskinesia

Dyskinesia

Dyskinesia is a movement disorder which consists of effects including diminished voluntary movements and the presence of involuntary movements, similar to tics or choreia. Dyskinesia can be anything from a slight tremor of the hands to uncontrollable movement of, most commonly, the upper body but...

s, autonomic dysfunction and loss of consciousness. So far, these antibodies appear to be associated with an accompanying ovarian or mediastinal teratoma

Teratoma

A teratoma is an encapsulated tumor with tissue or organ components resembling normal derivatives of all three germ layers. There are rare occasions when not all three germ layers are identifiable...

 expressing NMDA receptors. Notably, this is the second neuronal cell surface antigen (after anti-voltage-gated potassium channel

Voltage-gated potassium channel

Voltage-gated potassium channels are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state....

 (VGKC) antibodies described by Angela Vincent

Angela Vincent

Angela Vincent is a professor at Somerville College of Oxford University. She is the head of a research group, which is located in the Weatherall Institute of Molecular Medicine and working on a wide range of biological disciplines encompassing molecular biology, biochemistry, cellular immunology...

 and colleagues) associated with autoimmune encephalitis.

Anti-mGluR

Additionally, antibodies to the mGluR1

Metabotropic glutamate receptor 1

The glutamate receptor, metabotropic 1, also known as GRM1, is a human gene which encodes the metabotropic glutamate receptor 1 protein.-Function:...

 subunit of the metabotropic glutamate receptor 1

Metabotropic glutamate receptor 1

The glutamate receptor, metabotropic 1, also known as GRM1, is a human gene which encodes the metabotropic glutamate receptor 1 protein.-Function:...

 have been shown in a small group of ataxia patients. Anti-glutamate receptor antibodies are also detected in various non-immunological neurological diseases such as stroke

Stroke

A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

 and trauma

Physical trauma

Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

.