Elevated levels of IgE are generally linked to allergic disease. However, the increase in IgE levels can also indicate many other conditions, such as primary immunodeficiencies (PIDs), infections, malignancies, and inflammatory diseases.
Immunoglobulins are the antibodies produced by B lymphocytes and plasma cells. They reside in the bloodstream and the mucous lining of body tissues. Antibodies counteract allergens and germs by binding to them and initiating allergic responses.
There are five types of antibodies, with Immunoglobulin E (IgE) recognizing and reacting to the allergen first. Unlike other immunoglobulins, the concentration of IgE antibodies is very low in the bloodstream of healthy individuals.
Increased serum IgE is associated with allergic and respiratory diseases, such as atopic dermatitis, allergic bronchopulmonary aspergillosis, asthma, persistent wheezing in children, and airway hyper-responsiveness.
Elevated levels of IgE are generally linked to allergic disease. However, the increase in IgE levels can also indicate many other conditions, such as primary immunodeficiencies (PIDs), infections, malignancies, and inflammatory diseases. Helminthic parasitic and allergic diseases: allergic rhinitis, asthma, and atopic dermatitis are the most common causes of high IgE levels.
Parasitic infections are one of the main causes of elevated serum IgE in predominantly agrarian countries, whereas allergies have become the bane of many industrialized countries as a result of improved standards of personal and community sanitation and hygiene.
Infection by parasitic worms (helminths) stimulates the production of anti-parasite IgE antibodies that results in highly elevated IgE levels. Both helminth infections and allergens have similar Th2 immune responses. Therefore, helminth infections can interfere with the accuracy of IgE tests for atopic conditions.
Elevated IgE levels can be detected in some individuals before an allergy develops. The presence of IgE antibodies in infancy to specific foods could be a precursor of atopic dermatitis, allergic rhinitis and asthma later in life.
Prurigo nodularis is a chronic skin condition which presents with itchy firm nodules throughout the body in primarily elderly patients. It is commonly associated with high IgE levels. Other skin conditions associated with pruritus (itch) are atopic dermatitis, bullous pemphigoid, lichen planus and others can also cause elevated IgE levels.
Primary immunodeficiencies, also known as Hyper-IgE syndrome (HIES), are also characterized by elevated IgE levels. Individuals with HIES display rash, eczema, persistent staphylococcal skin abscesses, recurrent respiratory, lung and sinus infections, candidiasis, and eosinophilia (a high level of disease-fighting white blood cells.) They are also at the risk of food allergies, anemia, and inflammation in the blood vessels. Eczema-like rashes early in life and skin abscesses are telltale signs.
There are two forms of HIES: autosomal dominant (AD-HIES) and autosomal recessive (AR-HIES). These conditions are triggered by deficiency or mutations in STAT3, DOCK8, TYK2, and PGM3 molecules.
Patients with HIES are also at higher risk of developing other malignancies, such as lymphatic cancer, autoimmune diseases, and HPV-positive cancers of head and neck.
With STAT3 deficiency, individuals are at risk for leukemia and cancers of the liver and lung. When the allergic branch of the immune system (Th2 side) is constantly fighting allergies, the germ-fighting branch (Th1 side) is suppressed. As a result, low Th1 function increases the risk of infections, chronic diseases, and malignancies.
Other disorders which can present with elevated IgE levels include kidney disease (nephrotic syndrome), smoking, alcohol use, and status post bone marrow transplantation.
Note, if your immunoglobulin level is high or low, it doesn't indicate that you may have one of these conditions. If you have questions about the IgE test, speak with a specialist.
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