Lab Test

Barley (Allergen Specific IgE)

Barley (f6)

Test Codes

Antrim #31454, EPIC: LAB5575, SOFT: EBAR

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

A positive test result (class 1 or greater) is indicative of the presence of allergen-specific IgE and suggests an increased likelihood of allergic disease.

Clinical Disease

Sensitivity to grains including barley, rye, oats and wheat occur in over 100,000 people in the United States. This reaction is entitled Celiac Sprue Disease and is attributed to an allergic reaction to gluten, a protein component found in grains. Gluten is composed of two main components, the portion responsible for the reactivity known as prolamines and the crude leftover fibers known as glutenins. The primary prolamine group that accounts for the reactivity of barley is horedin.

Symptoms of barley allergy include chronic diarrhea, abdominal swelling and tenderness, weight loss, fatigue, iron deficiency, and other nutrient deficiencies resulting from malabsorption.

Individuals with food allergies usually have other allergies as well, including allergies to pollen or dust. Allergic response to barley may predispose an individual to an allergic reaction to other members of the grain family including wheat, rye, oats and also millet and buckwheat.

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.

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.

CPT Codes

86003
LOINC: 6037-6

Contacts

Last Updated

2/2/2023

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