Walnut-Food Components, IgE, Serum
Use
The Walnut-Food Components, IgE, Serum test is used for evaluating patients suspected of having a walnut-food allergy, particularly to the major allergen components, Jug r 1 and Jug r 3. Allergies to tree nuts, including walnuts, are prevalent and can cause severe reactions that appear rapidly after ingestion. Tree nut allergies are among the most dangerous, capable of causing anaphylaxis, and are often persistent throughout a patient's lifetime. Jug r 1 is a major component that induces systemic allergic reactions to walnuts and has a high positive predictive value for diagnosing walnut allergy. Jug r 3 is also a major allergen associated with severe allergic reactions. Both components are important for determining walnut allergy, and cross-reactivity with other nut allergens is possible.
Special Instructions
Not provided.
Limitations
Negative results for IgE antibodies to walnuts and its components do not exclude clinically significant allergic responses. Positive results suggest sensitization but are not definitive for allergy diagnosis. Specific IgE testing may not be useful in patients previously treated with immunotherapy or those for whom allergen identification does not affect management. False positives can occur due to nonspecific binding, especially in patients with high serum IgE levels.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Fluorescent Enzyme Immunoassay (FEIA))
Biomarkers
Jug r 1
ProteinJug r 3
Protein
LOINC Codes
- 63486-5 - Nut allergen pnl Ser
- 69048-7 - Immunologist review
- 81790-8 - English walnut (rJug r) 1 IgE Qn
- 81789-0 - English walnut (rJug r) 3 IgE Qn
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.6 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial. Preferred serum gel container; acceptable red top.
Causes for Rejection
Gross hemolysis, gross lipemia, and gross icterus are acceptable.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 14 days |
| Frozen | 90 days |