Walnut-Food, IgE, with Reflex to Walnut-Food Components, IgE, Serum
Use
This test is useful for the evaluation of patients suspected of having a walnut-food allergy. The test starts by determining the presence of total walnut-food-specific IgE antibody. If detectable total walnut-food-specific IgE antibody is found (≥0.10 kU/L), reflex testing is performed for IgE antibodies against specific walnut-food components, Jug r 1 and Jug r 3. This helps in assessing the potential strength and type of allergenic response, providing detailed information about the patient's sensitivity to specific walnut allergens. Walnut allergy can lead to severe allergic reactions, including anaphylaxis, and persistent allergies to walnut can be lifelong.
Special Instructions
Specimen collection should involve careful identification of specimens, ensuring correct handling and processing. Electronic orders should utilize the corresponding Allergens - Immunoglobulin E (IgE) Antibodies form for instruction clarity. If ordering manually, use the Allergen Test Request form (T236).
Limitations
While positive results for IgE antibodies to walnut or specific components suggest sensitization, they are not diagnostic for walnut allergy and should be interpreted within the clinical context. IgE testing might not be helpful in individuals previously treated with immunotherapy or in whom allergy management does not depend on allergen specificity. High IgE levels can lead to false positives due to nonspecific binding. Additionally, negative results do not guarantee a lack of clinical allergy. The cross-reacting carbohydrate determinants may cause false positives.
FDA ApprovedNew York Approved
Methodology
Immunoassay (FEIA)
Biomarkers
LOINC Codes
- 6273-7
- 6273-7
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 collection is using a serum gel tube, but a red top tube is acceptable.
Causes for Rejection
Gross hemolysis and gross lipemia are acceptable. No specific rejection criteria stated for icterus.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 14 days |
| Frozen | 90 days |