What are other Names for this Test? (Equivalent Terms)

• IgE Blood Test

What is Immunoglobulin E Blood Test? (Background Information)

• Immunoglobulins (Igs) are a category of proteins produced by immune cells that aid in bodily defense against outside invaders. They recognize characteristic surface markings (antigens) on a foreign object and bind them away, before any damage is done to the body
• There are 5 five main types of immunoglobulins; each type, differing in its function and distribution throughout the body. The 5 types are:
  • IgA
  • IgG
  • IgE
  • IgD
  • IgM
• Immunoglobulins can reside either on the outside of cells, or freely circulate in blood. When circulating, they are also called antibodies (Abs)
• There are 3 categories of antibodies:
  • Circulating antibody: These antibodies circulate in blood and look for infection
  • Tissue antibody: These antibodies are present in tissues or organs all over the body and fights infections in the body
  • Secretory antibody: These antibodies are secreted in body fluids, such as saliva and mucus, and help prevent infection coming into the body from exposed mucus surface
• Plasma cells serve as antibody factories. They are specialized immune cells that, when stimulated by the immune system can produce and secrete up to 100 million antibodies per hour
• Immunoglobulin E (IgE) plays a role in allergic responses. It is also implicated in hypersensitivity reactions, in which the individual is abnormally-sensitive to an allergen
• The Immunoglobulin E Blood Test helps determine the levels of IgE in blood. It is used to test for allergies, parasitic diseases, and certain myelomas

What are the Clinical Indications for performing the Immunoglobulin E Blood Test?

Following are the clinical indications for performing the Immunoglobulin E Blood Test:

• Individuals with signs and symptoms of allergy
• Localized tissue swelling (which may be due to an allergic reaction); the swelling may be associated with pain
• Shortness of breath, fatigue
• Rash, itching
• Loss of appetite
• Vulnerability to infections: Individuals with decreased immune system are at an increased risk for infections
• Diarrhea
• Abdominal pain or discomfort
• Fever 

How is the Specimen Collected for Immunoglobulin E Blood Test?

Following is the specimen collection process for Immunoglobulin E Blood Test:

Sample required: Blood

Process of obtaining a blood sample in adults:

• A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit)
• The site is cleaned with 70% alcohol in an outward spiral, away from the zone of needle insertion
• The needle cap is removed and is held in line with the vein, pulling the skin tight
• With a small and quick thrust, the vein is penetrated using the needle
• The required amount of blood sample is collected by pulling the plunger of the syringe out slowly
• The wrap band is removed, gauze is placed on the collection site, and the needle is removed
• The blood is immediately transferred into the blood container, which has the appropriate preservative/clot activator/anti-coagulant
• The syringe and the needle are disposed into the appropriate “sharp container” for safe and hygienic disposal

Preparation required: No special preparation is needed prior to the test.

What is the Significance of the Immunoglobulin E Blood Test Result?

The interpretation of the Immunoglobulin E Blood Test value depends on the age of the individual. The normal range for the IgE Blood Test is as follows:

• 0-2 years: Less than 53 kU/L
• 2-3 years: Less than 93 kU/L
• 3-4 years: Less than 120 kU/L
• 4-5 years: Less than 160 kU/L
• 5-6 years: Less than 192 kU/L
• 6-7 years: Less than 224 kU/L
• 7-8 years: Less than 248 kU/L
• 8-9 years: Less than 260 kU/L
• 9-10 years: Less than 304 kU/L
• 10-18 years: Less than 328 kU/L
• 18 years and older: Less than 127 kU/L

A high value for the IgE Blood Test may indicate: 

• Atopic disease including:
  • Exogenous asthma, in 60% of cases
  • Hay fever, in 30% of cases
  • Atopic eczema
• Parasitic diseases including:
  • Ascariasis
  • Visceral larva migrans
  • Hookworm disease
  • Schistosomiasis
  • Echinococcus infestation

A low value for the IgE Blood Test may indicate:

• Hereditary deficiency
• Ataxia-telangiectasia
• Acquired immunodeficiency
• Non-IgE myeloma

The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.

Additional and Relevant Useful Information:

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/common-procedures/procedures-laboratory/quantitative-immunoglobulins-test/

Please visit our Laboratory Procedures Center for more physician-approved health information:

http://www.dovemed.com/common-procedures/procedures-laboratory/