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26428 Walnut Tree, IgE, Serum (WALN)

Walnut Tree, IgE, Serum (WALN)
Test Code: WALNSO
Synonyms/Keywords

​California Black Walnut, California Walnut, Carya basilike (Greek), Carya Persica (Greek), Juglans Californica, Jupiter's Nuts, Walnut Tree, IgE, Serum (WALN)

Useful For

​Establishing a diagnosis of an allergy to walnut tree

Defining the allergen responsible for eliciting signs and symptoms

Identifying allergens:

-Responsible for allergic disease and/ or anaphylactic episode

-To confirm sensitization prior to beginning immunotherapy

Specimen Requirements
Fasting RequiredSpecimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​SerumSerum Separator Tube (SST)Red Top Tube (RTT)​​0.3 mL​0.3 mL
Collection Processing Instructions

​For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace

0.5 mL for every 5 allergens requested

Specimen Stability Information
Specimen TypeTemperatureTime
​Serum ​​Refrigerated (preferred)​14 Days
​Frozen​90 Days
Interference

​Testing for IgE antibodies is not 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.

Some individuals with clinically insignificant sensitivity to allergens may have measurable levels of IgE antibodies in serum, and results must be interpreted in the clinical context.

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.

Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Mayo Clinic Laboratories​Monday through Friday​1-3 Days​Fluorescence Enzyme Immunoassay (FEIA)
Reference Lab
Test Information

​Clinical manifestations of immediate hypersensitivity (allergic) diseases are caused by the release of proinflammatory mediators (histamine, leukotrienes, and prostaglandins) from immunoglobulin E (IgE)-sensitized effector cells (mast cells and basophils) when cell-bound IgE antibodies interact with allergen.

In vitro serum testing for IgE antibodies provides an indication of the immune response to allergen(s) that may be associated with allergic disease.

The allergens chosen for testing often depend upon the age of the patient, history of allergen exposure, season of the year, and clinical manifestations. In individuals predisposed to develop allergic disease(s), the sequence of sensitization and clinical manifestations proceed as follows: eczema and respiratory disease (rhinitis and bronchospasm) in infants and children less than 5 years due to food sensitivity (milk, egg, soy, and wheat proteins) followed by respiratory disease (rhinitis and asthma) in older children and adults due to sensitivity to inhalant allergens (dust mite, mold, and pollen inhalants).

Reference Range Information

Performing LocationReference Range













Mayo Clinic Laboratories
ClassIgE kU/LInterpretation
0<0.10Negative
0/1 0.10-0.34Borderline/equivocal
10.35-0.69Equivocal
20.70-3.49Positive
33.50-17.4Positive
417.5-49.9Strongly positive
550.0-99.9Strongly positive
6> or =100Strongly positive

Reference values apply to all ages.


Interpretation

​Detection of IgE antibodies in serum (Class 1 or greater) indicates an increased likelihood of allergic disease as opposed to other etiologies and defines the allergens that may be responsible for eliciting signs and symptoms.

The level of IgE antibodies in serum varies directly with the concentration of IgE antibodies expressed as a class score or kU/L.

Outreach CPTs
CPTModifier
(if needed)
QuantityDescriptionComments
86003​​1
Synonyms/Keywords

​California Black Walnut, California Walnut, Carya basilike (Greek), Carya Persica (Greek), Juglans Californica, Jupiter's Nuts, Walnut Tree, IgE, Serum (WALN)

Ordering Applications
Ordering ApplicationDescription
​COM​Walnut Tree, IgE, Serum (WALN)
​Cerner​Walnut Tree, IgE, Serum (WALN)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting RequiredSpecimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
​SerumSerum Separator Tube (SST)Red Top Tube (RTT)​​0.3 mL​0.3 mL
Collection Processing

​For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace

0.5 mL for every 5 allergens requested

Specimen Stability Information
Specimen TypeTemperatureTime
​Serum ​​Refrigerated (preferred)​14 Days
​Frozen​90 Days
Interference

​Testing for IgE antibodies is not 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.

Some individuals with clinically insignificant sensitivity to allergens may have measurable levels of IgE antibodies in serum, and results must be interpreted in the clinical context.

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.

Useful For

​Establishing a diagnosis of an allergy to walnut tree

Defining the allergen responsible for eliciting signs and symptoms

Identifying allergens:

-Responsible for allergic disease and/ or anaphylactic episode

-To confirm sensitization prior to beginning immunotherapy

Reference Range Information

Performing LocationReference Range













Mayo Clinic Laboratories
ClassIgE kU/LInterpretation
0<0.10Negative
0/1 0.10-0.34Borderline/equivocal
10.35-0.69Equivocal
20.70-3.49Positive
33.50-17.4Positive
417.5-49.9Strongly positive
550.0-99.9Strongly positive
6> or =100Strongly positive

Reference values apply to all ages.


Interpretation

​Detection of IgE antibodies in serum (Class 1 or greater) indicates an increased likelihood of allergic disease as opposed to other etiologies and defines the allergens that may be responsible for eliciting signs and symptoms.

The level of IgE antibodies in serum varies directly with the concentration of IgE antibodies expressed as a class score or kU/L.

For more information visit:
Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Mayo Clinic Laboratories​Monday through Friday​1-3 Days​Fluorescence Enzyme Immunoassay (FEIA)
Reference Lab
For billing questions, see Contacts
Outreach CPTs
CPTModifier
(if needed)
QuantityDescriptionComments
86003​​1
For most current information refer to the Marshfield Laboratory online reference manual.