TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: BETV2    
BET v2 (Profilin), IgE, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

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

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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 Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

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

> or =100

Strongly positive

Concentrations > or =0.70 kU/L (Class 2 and above) will flag as abnormally high.

Interpretation Provides information to assist in interpretation of the test results

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.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Results from IgE antibody testing must be interpreted in the context of patient’s clinical evaluation and history of allergen exposures.

 

The major allergen in birch pollen is Bet v1 (which is homologous to the peanut allergen Ara h8), as antibodies to the Bet v1 is found in as many as 95% in birch pollen patients. In cases of suspected birch pollen allergy, testing for antibodies to the profilin Bet v1 should be considered in addition to this test for profilin Bet v2 antibodies.

 

Positive results for IgE to peanut allergy markers, such as profilin Bet v2, are not diagnostic for peanut allergy and only indicate that the patient may be sensitized to peanut component or a cross-reactive allergen. Clinical correlation of results from in vitro IgE testing with patient history of allergic or anaphylactic responses to peanut is recommended.

 

Testing for IgE antibodies may not be useful in patients previously treated with immunotherapy to determine if residual clinical sensitivity exists, or in patients in whom the medical management does not depend upon identification of allergen specificity.

 

False-positive results for IgE antibodies may occur in patients with markedly elevated serum IgE (>2500 kU/L) due to nonspecific binding to allergen solid phases.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Anhoej C, Backer V, Nolte H: Diagnostic evaluation of grass- and birch-allergic patients with oral allergy syndrome. Allergy. 2001 Jun;56(6):548-552. doi: 10.1034/j.1398-9995.2001.056006548.x

2. Sekerkova A, Polackova M: Detection of Bet v1, Bet v2 and Bet v4 specific IgE antibodies in the sera of children and adult patients allergic to birch pollen: evaluation of different IgE reactivity profiles depending on age and local sensitization. Int Arch Allergy Immunol. 2011;154(4):278-85. doi: 10.1159/000321819

3. D'Amato G, Cecchi L, Bonini S, et al: Allergenic pollen and pollen allergy in Europe. Allergy. 2007 Sep;62(9):976-990. doi: 10.1111/j.1398-9995.2007.01393.x

4. Cabanos C, Tandang-Silvas MR, Odijk V, et al: Expression, purification, cross-reactivity and homology modeling of peanut profilin. Protein Expr Purif. 2010 Sep;73(1):36-45. doi: 10.1016/j.pep.2010.03.005

5. Bublin M, Breiteneder H: Cross-reactivity of peanut allergens. Curr Allergy Asthma Rep. 2014 Apr;14(4):426. doi: 10.1007/s11882-014-0426-8

6. Chan ES, Greenhawt MJ, Fleischer DM, Caubet JC: Managing cross-reactivity in those with peanut allergy. J Allergy Clin Immunol Pract. 2019 Feb;7(2):381-386. doi: 10.1016/j.jaip.2018.11.012

7. Simberloff T, Parambi R, Bartnikas LM, et al: Implementation of a standardized clinical assessment and management plan (SCAMP) for food challenges. J Allergy Clin Immunol Pract. 2017 Mar-Apr;5(2):335-344.e3. doi:10.1016/j.jaip.2016.05.021

Special Instructions Library of PDFs including pertinent information and forms related to the test