Wheat (Allergen Specific IgE)
Wheat (f4)
Test Codes
Antrim #31390, EPIC: LAB2111656, SOFT: EWH
Department
Immunology
Specimen Collection Criteria
Collect: One Gold-top SST tube.
Twenty individual allergen assays or allergen screens can be performed on one 5 mL Gold-top SST tube. Each allergen assay requires 100 mcL of serum.
Physician Office/Draw Specimen Preparation
Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged collection tube within two hours of collection.
Preparation for Courier Transport
Transport: Centrifuged collection tube, refrigerated (2-8°C or 36-46°F).
Rejection Criteria
Plasma specimens.
Severely lipemic or hemolyzed specimens.
In-Lab Processing
Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Room temperature is acceptable for a maximum of two hours.
Storage
Specimen Stability for Testing:
Centrifuged SST Tubes and Microtainers® with Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable
Red-top Tubes and Microtainers® without Separator Gel
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable
Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 2 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 1 month
Specimen Storage in Department Prior to Disposal:
Refrigerated (2-8°C or 36-46°F): 7 days
Laboratory
Royal Oak Special Testing Laboratory
Performed
Monday – Friday.
Results available the next business day.
Reference Range
Allergy Reference Range: Less than 0.35 kU/L.
Range (kU/L) |
Class |
Interpretation |
Less than or equal to 0.34 |
0 |
Negative |
0.35-0.69 |
1 |
Low |
0.70-3.49 |
2 |
Medium |
3.50-17.49 |
3 |
High |
17.50-49.99 |
4 |
Very High |
50.0-100.0 |
5 |
Very High |
Greater than 100 |
6 |
Very High |
Test Methodology
Fluorescence Enzyme Immunoassay (FEIA).
Interpretation
The allergen class may not be predictive of clinical disease in some patients. The diagnosis of allergy should be based upon patient history and clinical findings. The diagnosis of allergy should not be based upon laboratory findings alone.
Clinical Utility
Positive assay results indicate a high probability of allergic disease. Negative assay results effectively rule out allergy induced by those allergens.
Clinical Disease
Forty different allergens have been identified for wheat. The primary protein allergens include albumin, wheat germ agglutinin, a concanavalin A-purified glycoprotein, a trypsin inhibitor, globulin, gliadin, and gluten. Cross-reactivity has been demonstrated between wheat and rye flour extract (1).
True food allergy is less common than popularly believed. It is estimated that only 1 to 4% of the general population suffers from a definite food allergy. Food allergy tends to be more common in children (up to 6%) than adults. In selected groups, such as children with eczema, the prevalence of food allergy may be as high as 25%.
The majority of the food allergies are due to the consumption of milk, egg, wheat, peanut, soy, tree nuts, fish and shellfish, however, allergic responses can occur with all types of food in a sensitized individual.
General symptoms of an allergy to food include nausea, vomiting, diarrhea, hives, itching, swelling of the mouth, tongue and/or lips, wheezing, and constriction of the airways in more severe reactions. Individuals with food allergies will typically show symptoms of an allergic response within 45 minutes of ingestion of food. Reactions to food ingestion occurring several hours after consumption is usually not related to allergies.
An anaphylactic reaction to food, which is life-threatening, occurs in approximately 1 million individuals each year according to the National Institutes of Health. Anaphylactic reactions are most commonly found in patients with allergies to peanuts, nuts, eggs, fish and shellfish. Anaphylactic responses occur approximately 5-15 minutes after food consumption and can lead to difficulty in breathing, constriction of the airways, and unconsciousness.
Certain factors such as alcohol consumption and exercise appear to enhance the reactivity to a food allergen in sensitized individuals. Individuals with food allergies usually have other allergies as well, including allergies to pollen or dust.
Reference
- Metcalfe, Dean D. M.D., Hugh A. Sampson, M.D., Ronald A. Simon, M.D., Food Allergy: Adverse Reactions to Foods and Food Additives. Blackwell Scientific Publications: Boston, 1991, pg. 43, 347-348.
CPT Codes
86003
LOINC: 6276-0
Contacts
Special Chemistry Laboratory – RO
248-551-8044
Name: Special Chemistry Laboratory – RO
Location:
Phone: 248-551-8044
Last Updated
7/21/2024
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