TOTAL IgE

Clinical Significance:

Immunoglobulin E (lgE) is a trace protein in serum and normally accounts for less than 0.001 % of total serum immunoglobulins. Total lgE levels may vary due to a variety of different factors, including genetic disposition and allergen exposure. Many allergies are mediated by lgE immunoglobulins which act as point of contact between the allergen and specialized cells. High affinity lgE specific receptors are found on the surface membranes of mast cells and basophils. Once lgE has been bound by these receptors, it plays a key role in the generation of immediate hypersensitivity reactions. lgE has been linked to atopic disease and there is a strong correlation between increased lgE and asthma.

1. In deciding a course of therapy it is important to distinguish between lgE mediated and non-lgE mediated reactions, which is possible by measuring total circulating lgE levels.
2. Measurement of total lgE is of value in early detection and diagnosis of allergy.
3. lgE is used for its predictive value as an indicator of the likelihood of the development of allergic disease in asymptomatic infants and children.
4. Useful as a prognostic indicator in adults with certain types of chronic allergic illness.
5. Diagnosis of bronchopulmonary aspergillosis (normal values of lgE excludes its diagnosis in active lung disease).
6. Parasitic infiltration of Gl tract and parenchymatous organs leads to elevated lgE levels E.g.: Echinococcosis

Increased in :
Allergic disorders

• Asthma
• Allergic Rhinitis or Hayfever
• Inhalant allergy
• Atopic Rhinitis or Sinusitis
• Atopic Dermatitis
• Urticaria
• Bronchopulmonary Aspergillus
• Hypersensitivity pneumonitis
• Drug Allergy
• Food Allergy

Parasitic infection

• Ascariasis
• Visceral Larva Migrans
• Toxocara
• Capillariasis
• Echinococcosis
• Hookworm
• Amebiasis

Immunologic disorders

• Hyper-lgE and recurrent pyoderma (Job-Buckley Syndrome)
• Thymic dysplasia or deficiency
• Wiskott-Aldrich Syndrome
• Pemphigoid
• Periarteritis nodosa
• Hypereosinophilic syndrome

Neoplasm (i.e. lgE Myeloma)

Decreased in:

• Congenital Hypogammaglobulinemia
• Acquired Hypogammaglobulinemia
• Sex-linked hypogammaglobulinemia
• Ataxia-telangiectasia
• lgE Deficiency