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Test Code BLWX Walnut-Food Components, IgE, Serum


Specimen Required


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

 

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 to one of 2 walnut-food components

Testing Algorithm

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

Method Name

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

 

Fluorescent Enzyme Immunoassay (FEIA)

Reporting Name

Walnut-Food Components, IgE, S

Specimen Type

Serum

Specimen Minimum Volume

0.6mL

Specimen Stability Information

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

Reference Values

Only orderable as a reflex. For more information see BLWRF / Walnut-Food, IgE, with Reflex to Walnut-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 walnut-food IgE antibody is present (≥0.10 IgE kUa/L), additional specific component IgE antibody testing will be performed. If at least one potential specific allergenic walnut-food component IgE is detectable (≥0.10 IgE kUa/L), an interpretive report will be provided.

 

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

Clinical Reference

1. Salo PM, Arbes SJ Jr, Jaramillo R, et al. Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006. J Allergy Clin Immunol. 2014;134(2):350-359

2. Waserman S, Watson W. Food allergy. Allergy Asthma Clin Immunol. 2011;7 Suppl 1(Suppl 1):S73. Abrams EM, Sicherer SH. Diagnosis and management of food allergy. CMAJ. 2016;188(15):1087-1093

4. Weinberger T, Sicherer S. Current perspectives on tree nut allergy: a review. J Asthma Allergy. 2018;11:41-51

5. Lomas JM, Jarvinen KM. Managing nut-induced anaphylaxis: challenges and solutions. J Asthma Allergy. 2015;8:115-123

6. Maloney JM, Rudengren M, Ahlstedt S, Bock SA, Sampson HA. The use of serum-specific IgE measurements for the diagnosis of peanut, tree nut, and seed allergy. J Allergy Clin Immunol. 2008;122(1):145-151

7. Sicherer SH, Burks AW, Sampson HA. Clinical features of acute allergic reactions to peanut and tree nuts in children. Pediatrics. 1998;102(1):e6

8. Crespo JF, James JM, Fernandez-Rodriguez C, Rodriguez J. Food allergy: nuts and tree nuts [published correction appears in Br J Nutr. 2008 Feb;99(2):447-8]. Br J Nutr. 2006;96 Suppl 2:S95-S102

9. Yang L, Clements S, Joks R. A retrospective study of peanut and tree nut allergy: Sensitization and correlations with clinical manifestations [published online ahead of print, 2015 Feb 27]. Allergy Rhinol (Providence). 2015;doi:10.2500/ar.20105.6.0108

10. Pastorello EA, Farioli L, Pravettoni V, et al. Lipid transfer protein and vicilin are important walnut allergens in patients not allergic to pollen. J Allergy Clin Immunol. 2004;114(4):908-914

11. Rosenfeld L, Shreffler W, Bardina L, et al. Walnut allergy in peanut-allergic patients: significance of sequential epitopes of walnut homologous to linear epitopes of Ara h 1, 2 and 3 in relation to clinical reactivity. Int Arch Allergy Immunol. 2012;157(3):238-245

12. Masthoff LJ, Hoff R, Verhoeckx KC, et al. A systematic review of the effect of thermal processing on the allergenicity of tree nuts. Allergy. 2013;68(8):983-993

13. Costa J, Carrapatoso I, Oliveira MB, Mafra I. Walnut allergens: molecular characterization, detection and clinical relevance. Clin Exp Allergy. 2014;44(3):319-341

14. Valcour A, Lidholm J, Borres MP, Hamilton RG. Sensitization profiles to hazelnut allergens across the United States. Ann Allergy Asthma Immunol. 2019;122(1):111-116.e1

15. Asero R, Piantanida M, Pravettoni V. Allergy to LTP: to eat or not to eat sensitizing foods? A follow-up study. Eur Ann Allergy Clin Immunol. 2018;50(4):156-162

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

86008 x2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BLWX Walnut-Food Components, IgE, S 63486-5

 

Result ID Test Result Name Result LOINC Value
INBLW Walnut-Food IgE Ab Interpretation 69048-7
R1JUG Jug r 1 (Walnut-Food), IgE, S 81790-8
R3JUG Jug r 3 (Walnut Extract), IgE, S 81789-0