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Test Code BLWRF Walnut-Food, IgE, with Reflex to Walnut-Food Components, IgE, Serum


Ordering Guidance


For a listing of allergens available for testing, see Allergens - Immunoglobulin E (IgE) Antibodies.



Specimen Required


Collection 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.


Useful For

Evaluation of patients with suspected walnut-food allergy

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
BLWX Walnut-Food Components, IgE, S No No

Testing Algorithm

Testing begins with analysis of walnut-food-specific total IgE. If walnut-food-specific total IgE result is negative (<0.10 kU/L), testing is complete.

 

If walnut-food-specific total IgE result is 0.10 kU/L or more, then walnut-food component (Jug r 1 and Jug r 3) testing will be performed at an additional charge.

Method Name

Fluorescent Enzyme Immunoassay (FEIA)

Reporting Name

Walnut-Food Component Reflex, 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

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

Reference values apply to all ages.

Day(s) Performed

Monday through Friday

Report Available

Same day/1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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

86003

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BLWRF Walnut-Food Component Reflex, S 6273-7

 

Result ID Test Result Name Result LOINC Value
BLW1 Walnut-Food, IgE, S 6273-7

Forms

If not ordering electronically, complete, print, and send an Allergen Test Request (T236) with the specimen.