Immunoglobulin E

Immunoglobulin E (IgE ) is an antibody to fight off parasites in the first place. He is also responsible for allergies.

Of all antibody isotypes IgE was detected as the last, namely until 1966, by the couple Kimishige and Teruko Ishizaka. This late discovery is explained by the comparatively very low concentrations of free IgE antibodies in the serum. IgG1 antibodies typically occur during about 9 mg / ml of serum in concentrations as IgE concentrations are from about 30 ng / ml serum. IgE antibodies are the only antibodies, which are present predominantly cell- bound.

The IgE has the ability to bind to Fc receptors on mast cells or basophils and stay there for years in the body. Derogation of an allergen, it causes the mast cell to distribute substances that trigger an allergy - mainly histamine. It plays a more important role in the defense against parasites and worms. It is based on a mediated by eosinophils, IgE - dependent cytotoxicity. It makes less than 1 % of all immunoglobulins of the body and has the typical shape of the Y, similar to the IgG or the IgD, but a longer base.

Importance in medical diagnostics

The amount of total IgE plays a significant role in the evaluation of allergic diseases, especially of eosinophilic pulmonary infiltrates, eosinophilic gastroenteritis, allergic alveolitis (eg farmer's lung ) or vasculitis such as granulomatosis with polyangiitis, Churg -Strauss syndrome and allergic bronchopulmonary aspergillosis. In the parasitic IgE is often increased. In immunodeficiencies such as the T- cell defect or the hyper-IgE syndrome, as well as in forms of urticaria, angioedema, or unclear rashes uses the IgE determination.