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Peanut (Allergen Specific IgE)

Peanut (f13)

Test Codes

Antrim #31388, EPIC: LAB5681, SOFT: EPNU

Department

Special Testing Allergens

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

Hypersensitivity to peanuts is relatively common and peanut allergies are one of the most common sources of food-caused anaphylaxic death in the United States (1). Three percent of the American population is thought to have peanut allergies. Thirty percent of patients with food allergies are sensitive to peanuts. These patients lose their sensitivity to peanut allergens (1). Peanut-allergic individuals typically cannot tolerate other legumes such as peas, beans, and licorice. Symptoms may include nausea, vomiting, hives, angioedema, labored breathing, and/or anaphylactic shock.

When exposed to the peanut protein the patient's T-cells are unable to produce gamma interferon, which is important in inhibiting the synthesis of IgE. Peanut allergens are typically heat stable. Therefore, cooking or roasting peanuts will not abrogate their allergen potential. The primary allergen of peanuts is designated "Peanut-I" (2).

Certain factors such as alcohol consumption and exercise 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

1. Sachs MI and Yunginger JW, "Food-Induced Anaphylaxis." in "Food Allergy," Immunology and Allergy Clinics of North America: 11:4, 743-000, 1991.
2. 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. 40-42, 155, 345.

CPT Codes

86003
LOINC: 6206-7

Contacts

Last Updated

3/9/2023