ImmunoCAP is a very sensitive blood test for allergies. It measures the concentration of immunoglobulin E (IgE), which is an indicator of allergic sensitization.
ImmunoCAP can test for hundreds of allergens, such as weeds, trees, pollen, mold, food, and animal dander—all with just one blood sample taken. ImmunoCAP results can help your doctor determine yours or your child’s individual allergy profile. He or she can then use this profile to work with you to create an individualized treatment plan. This might include medications and tips to help you reduce exposure to specific allergic triggers, including rhinitis triggers, asthma triggers, and food allergy triggers. Your doctor can test for specific allergic triggers with just one sample of blood.
Among allergy blood tests, ImmunoCAP is widely considered to be the most accurate and precise—the best test, the gold standard. In fact, ImmunoCAP has been specifically endorsed for use by doctors in allergy management guidelines from the National Institutes of Health.
Allergy Blood Testing
The allergen-specific IgE antibody test is a blood test used to screen for an allergy to a specific substance or substances if a person presents with acute or chronic allergy-like symptoms. This is especially true if symptoms are recurrent and appear to be tied to triggers, such as exposures to particular foods or environments, and if other family members are known to have allergies.
A variety of different types of allergy tests may be performed by exposing a person to different substances under careful medical supervision . The usefulness of these tests, however, can be affected by skin conditions, such as significant dermatitis or eczema, and by medications, such as histamines and some anti-depressants. With some tests there is also the potential for severe reactions, including a severe reaction that may be life-threatening. In these cases, the allergen-specific IgE antibody test may be ordered as an alternative, as it is performed on a blood sample and does not have an effect on the person being tested.
The allergen-specific IgE antibody test may also be done to monitor immunotherapy (desensitization) or to see if a child has outgrown an allergy. It can only be used in a general way, however, as the level of IgE present does not correlate to the severity of an allergic reaction, and someone who has outgrown an allergy may have a positive IgE for many years afterward.
One or more allergen-specific IgE antibody tests are usually ordered when a person has signs or symptoms that suggest an allergy to one or more substances. Signs and symptoms may include:
- Red itchy eyes
- Coughing, nasal congestion, sneezing
- Itching and tingling in the mouth
- Abdominal pain, or vomiting and diarrhea
A test may also be ordered occasionally to help evaluate the effectiveness of immunotherapy or to determine whether a child has outgrown an allergy.
Negative results indicate that a person probably does not have a “true allergy,” an IgE-mediated response to that specific allergen, but the results of allergen-specific IgE antibody tests must always be interpreted and used with caution and the advice of the doctor. Even if an IgE test is negative, there is still a small chance that a person does have an allergy.
Elevated results usually indicate an allergy, but even if the specific IgE test is positive, a person may or may not ever have an actual physical allergic reaction when exposed to that substance. The amount of specific IgE present does not necessarily predict the potential severity of a reaction. A person’s clinical history and additional medically supervised allergy tests may be necessary to confirm an allergy diagnosis.
Sometimes your doctor will look at other blood tests for an indirect indication of an ongoing allergic process, including a total IgE level or a complete blood count (CBC) and white blood cell differential (specifically eosinophils and basophils). Increases in these test results may suggest an allergy, but they may also be elevated for other reasons.
ImmunoCAP Specific IgE blood testing is a valuable tool for clinicians. It is an in vitro quantitative assay that measures allergen-specific IgE. ImmunoCAP aids with the clinical diagnosis of IgE-mediated allergic disorders when used in conjunction with patient history and other clinical findings.
Clinical practice guidelines for asthma, rhinitis, and food allergy all recommend allergy testing to aid management of these diseases. ImmunoCAP Specific IgE blood test results allow you to:
- Develop a plan for personalized, effective treatment guided by quantitative results
- Counsel patients on targeted exposure reduction to specific triggers
- Consider referral to an appropriate specialist
Normal or negative results may help rule out allergies, and other possible etiologies should be considered.
mmunoCAP Specific IgE blood testing is easy for clinicians to utilize:
- Requires only a single blood sample
- Patients do not need to stop taking their allergy medications
- Can be performed for hundreds of allergens
- Widely available in laboratories across the United States
Among allergy blood tests, ImmunoCAP is widely considered to be the the most accurate, precise, and reliable—the gold standard.
For more information :-
- “Precision and accuracy of commercial laboratories’ ability to classify positive and/or negative allergen-specific IgE results”
- “Analytic precision and accuracy of commercial immunoassays for specific IgE: Establishing a standard”
- “A comparison of skin prick tests, intradermal skin tests, and RASTs in the diagnosis of cat allergy”