Aquaporin 4 | Autoantibodies (liquor)

General Information

Aquaporin 4 is a membrane protein that functions as a water channel, particularly in astrocyte cells in the brain (astrocytes are glial cells that are the “support” cells of nerve cells).

Aquaporin-4 is responsible for the water balance of the cell – in accordance with changes in osmotic and hydrostatic pressure. Disruption of the regulatory function of this protein is associated with the development of cytotoxic and vascular (vasogenic) edema during ischemia/injury of brain tissue.

Aquaporin-4 autoantibodies develop in the autoimmune disease neuromyelitis optica.

The target of highly specific IgG autoantibodies detected in neuromyelitis optica is the astrocyte cell protein aquaporin-4.

Preparation of the patient: it is not necessary

Material for examination: Cerebrospinal fluid (CSF)

Interpretation of results

Increased titers of aquaphorin-4 autoantibodies are detected in the acute stage of the disease.

Autoantibody titers decrease during high-dose steroid treatment and during remissions that occur against the background of immunosuppression.