Test Code BETV2 BET v2 (Profilin), IgE, Serum
Ordering Guidance
For a listing of allergens available for testing, see Allergens - Immunoglobulin E (IgE) Antibodies.
BET v2 is also available as part of the PEANT / Peanut, IgE with Reflex to Peanut Components, IgE, Serum. This reflex test includes Ara h2, h1, h3, h6, h9, and Bet v2 (profilin) if the initial Peanut IgE test is detectable.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL for every 5 allergens requested
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Forms
If not ordering electronically, complete, print, and send an Allergen Test Request (T236) with the specimen.
Useful For
Evaluation of patients suspected birch pollen allergy
Evaluation of patients with suspected peanut allergy
Evaluation of patients with oral allergy syndrome to other pollens or plant-based foods
Special Instructions
Method Name
Fluorescence Enzyme Immunoassay (FEIA)
Reporting Name
BET v2 (Profilin), IgE, SSpecimen Type
SerumSpecimen Minimum Volume
For 1 allergen: 0.3 mL
For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 90 days | ||
Ambient | 7 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Clinical Information
Immunoglobulin E antibodies to the Bet v 2a profilin protein have been reported in 10% to 38% of birch pollen-allergic patients. Birch pollen is highly allergenic and is a significant cause of immediate hypersensitivity, affecting as much as 5% to 50% of the population of Western Europe. The presence of antibodies to Bet v 2, may also indicate sensitivity to other profilin containing pollens including ragweed pollen, mugwort pollen, and timothy grass pollen.
The profilin Bet v2 is related to, and cross-reactive with, antibodies to the potential peanut allergen profilin Ara h5. As profilin proteins are present in many other foods, sensitivity to profilin Bet v2 may be associated in broad allergen cross-reactivity among foods, including mango, peach, apple, hazelnut, celery, carrot, paprika, anise, fennel, coriander, cumin, tomato, and potato.
The most common manifestation of allergy to food in profilin related allergic individuals is oral allergy syndrome. Profilins are generally not resistant to heat and digestion. Individuals with birch pollen allergy and oral allergy syndrome are more frequently allergic to apples and peaches than to other foods. In cases of allergic reaction associated with oral allergy syndrome, rhinitis, itching, tingling, and other mild reactions on the oropharyngeal mucosa were reported to be the most common complaints.
Reference Values
Class |
IgE kU/L |
Interpretation |
0 |
<0.10 |
Negative |
0/1 |
0.10-0.34 |
Borderline/Equivocal |
1 |
0.35-0.69 |
Equivocal |
2 |
0.70-3.49 |
Positive |
3 |
3.50-17.4 |
Positive |
4 |
17.5-49.9 |
Strongly positive |
5 |
50.0-99.9 |
Strongly positive |
6 |
≥100 |
Strongly positive |
Concentrations ≥0.70 kU/L (Class 2 and above) will flag as abnormally high.
Interpretation
Profilins are potentially cross-reactive allergenic proteins found in many plant pollens and tissues. IgE antibodies to the profilin Bet v2, while associated with birch pollen sensitivity, also represent a minor peanut allergen marker as it is cross-reactive with the peanut profilin Ara h5. The presence of antibodies to profilin Bet v2 is typically associated with milder allergic reactions and oral allergy syndrome.
Specimen Retention Time
14 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86008
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
BETV2 | BET v2 (Profilin), IgE, S | 30985-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
BETV2 | BET v2 (Profilin), IgE, S | 30985-6 |
Day(s) Performed
Monday through Friday