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Test Code NUTHX Hazelnut-Food Components, IgE, Serum


Specimen Required


Only orderable as a reflex. For more information see NUTHR / Hazelnut-Food, IgE with Reflex to Hazelnut-Food Components, IgE, Serum.

 

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Secondary ID

618848

Useful For

Evaluation of patients with suspected hazelnut-food allergy to one of 4 hazelnut-food components

Testing Algorithm

If hazelnut-food specific total IgE is 0.10 kU/L or more, then testing for four hazelnut-food components (Cor a 1, Cor a 8, Cor a 9, Cor a 14) is performed at an additional charge.

Method Name

Only orderable as a reflex. For more information see NUTHR / Hazelnut-Food, IgE with Reflex to Hazelnut-Food Components, IgE, Serum.

 

Fluorescent Enzyme Immunoassay (FEIA)

Reporting Name

Hazelnut-Food Components, IgE, S

Specimen Type

Serum

Specimen Minimum Volume

0.6 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  90 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Clinical Information

Allergies to tree nuts are relatively prevalent and can result in severe reactions. The main culprits in tree nut allergies include walnut, almond, pistachio, cashew, pecan, hazelnut, macadamia, Brazil nut, and pine nuts. Tree nut allergy often appears in young children and estimates of prevalence range from 0.1% to greater than 5% of the population, dependent on geographical region.

 

In the case of nut-induced allergic reactions, as with many other foods, symptoms usually present within minutes of ingestion. Over 80% of reactions to tree nuts involve allergy related respiratory symptoms. Tree nut allergies are one of the most dangerous types of allergic reaction with 20% to 40% of cases of related anaphylaxis and 70% to 90% of fatalities attributable to nut exposure, including peanut exposure.

 

Hazelnut allergy can occur upon ingestion as a systemic food allergy that can be associated with severe reactions or as oral allergy syndrome, often associated with pollen allergy (pollen-food allergy syndrome). It is the most common tree nut allergy in Europe. Sensitization to birch pollen is strongly associated with hazelnut sensitization with 84% of those with birch pollen allergy being sensitized to hazelnuts.

 

Components of hazelnut allergy can be used to stratify risk of severe systemic reactions. Hazelnut allergy can be severe or can be pollen related and less severe. The component protein Cor a 1 is heat and digestion labile and is often cross-reactive with birch pollen sensitivity due to cross-reactivity between homologous allergens of hazelnut and birch pollens (PR-10 proteins Cor a 1 and Bet v 1). Sensitization to Cor a 1 component protein is mainly associated with local reactions posing a lower risk of severe systemic reaction. Pollen-related hazelnut allergy is often observed in adults, with symptoms limited to the oropharyngeal cavity. However, systemic symptoms and even anaphylaxis have been infrequently reported with sensitivity to Cor a 1.

 

Cor a 8 is a heat and digestion stabile nonspecific lipid transfer protein that exhibits sensitization in 8% to 17% of hazelnut allergy cases in the United States, with high prevalence in areas that lack birch trees. Cor a 8 sensitization can be associated with clinically silent hazelnut tolerant individuals, oral allergy syndrome or in some cases severe allergy. Peach allergy may be associated with sensitivity for Cor a 8.

 

Cor a 9 and 14 are heat and digestion stable protein component that are associated with higher risks or severe, systemic reaction. Cor a 9 and Cor a 14 sensitization serve as excellent diagnostic markers for identifying direct hazelnut allergy and for prediction of potentially severe symptoms. Sensitization to Cor a 9 (a legume like globulin) was observed in 10% of hazelnut allergic individuals and has been established to be associated with severe systemic reactions. Other studies have put the sensitization rate or Cor a 9 to be as much as 35%. Cor a 9 may show crossreactivity to11S globulin protein components of walnut (Jug r 4), peanut (Ara h 3), Brazil nut (Ber e 2), soybean (Gly m 6), cashew (Ana o 2), almond (Pru du 6) and pistachio (Pis v 2).  Sensitization to Cor a 14 (a 2S albumin allergen) has been observed in 6% of allergic individuals and is associated with moderate and severe systemic reactions. Cor a 14 is highly heat and digestion resistant and serves as an excellent prediction for clinical allergy. Cor a 14 sensitization has been reported in 15% of individuals with severe symptoms, 5.6% of individuals with moderate symptoms, and 4% of those with localized symptoms. Its cross reactivity is limited to walnut (Jug r 1) and pecan (Car i 1) protein components. Cor a 14-sIgE determination was a better predictor of oral food challenge sensitivity than other hazelnut component allergens (Cor a 1, Cor a 8 and Cor a 9).

Reference Values

Only orderable as a reflex. For more information see NUTHR / Hazelnut-Food, IgE with Reflex to Hazelnut-Food Components, IgE, Serum.

 

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 of 0.70 kU/L or more (class 2 and above) will flag as abnormally high.

Reference values apply to all ages.

Interpretation

When detectable total hazelnut-food IgE antibody is present (≥0.10 IgE kUa/L), additional specific component IgE antibody testing will be performed. If a potential specific allergenic hazelnut-food component IgE is detectable (≥0.10 IgE kUa/L), an interpretive report will be provided.

 

When the sample is negative for total hazelnut-food IgE antibody (<0.10 IgE kUa/L), further testing for specific hazelnut-food component IgE antibodies will not be performed. A negative IgE result for total cashew antibody may indicate a lack of sensitization to the potential hazelnut-food allergenic components.

CPT Code Information

86003

86008 x 3

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NUTHX Hazelnut-Food Components, IgE, S 63486-5

 

Result ID Test Result Name Result LOINC Value
INUTH Hazelnut-Food IgE Ab Interpretation 69048-7
A1COR Cor a 1 (Hazelnut-Food), IgE, S 69421-6
A8COR Cor a 8 (Hazelnut-Food), IgE, S 58753-5
A9COR Cor a 9 (Hazelnut-Food), IgE, S 65765-0
A14CO Cor a 14 (Hazelnut-Food), IgE, S 81788-2