The Asthma Center

How Xolair works

In an allergen-induced asthmatic attack, inhaled allergens attach to a portion of specific IgE antibodies fixed on mast cells along the mucosal lining of the bronchial tubes. When a specific allergen is inhaled and attached to the matching IgE antibodies on a mast cell, an allergic reaction begins which results in a release of chemical mediators that cause you to develop asthma symptoms.

Injected Xolair® attaches to the circulating IgE antibody and helps remove this allergy antibody from circulation. Xolair® is actually an antibody derived from mice but genetically engineered so that it can be tolerated by humans. It works by binding circulating, free IgE antibodies, thus forming clumps of antibodies that are then of sufficient size to be removed from circulation by the body's own cleansing mechanism. These actions reduce the amount of IgE available to bind to mast cells. Since free circulating IgE attaches to mast cells and causes allergic asthmatic symptoms, decreasing this free circulating allergy antibody reduces the likelihood of allergic responses when exposed to inhaled allergens.

Allergic Cascade with Mast Cell, IgE and Mediator Release