Test Code WEED4 Weed Panel # 4, Serum
Reporting Name
Weed Panel # 4Performing Laboratory
Mayo Clinic Laboratories in RochesterUseful For
Establishing a diagnosis of an allergy to giant ragweed, short ragweed, and Western ragweed
Defining the allergen responsible for eliciting signs and symptoms
Identifying allergens:
-Responsible for allergic response and/or anaphylactic episode
-To confirm sensitization prior to beginning immunotherapy
-To investigate the specificity of allergic reactions to insect venom allergens, drugs, or chemical allergens
Testing for IgE antibodies is not useful
Method Name
Fluorescence Enzyme Immunoassay (FEIA)
Ordering Guidance
This test uses a pooled allergen reagent; therefore, the multi-allergen Immunocap (panel cap) is reported with a single qualitative class result and concentration. This is the appropriate first-tier test for allergic disease.
For a listing of allergens available for testing, see Allergens - Immunoglobulin E (IgE) Antibodies.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL for every 5 allergens requested
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Type
SerumSpecimen Minimum Volume
For 1 allergen: 0.3 mL
For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 14 days | |
Frozen | 90 days |
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Reference Values
Class |
IgE kU/L |
Interpretation |
0 |
<0.10 |
Negative |
0/1 |
0.10-0.34 |
Borderline/equivocal |
1 |
0.35-0.69 |
Equivocal |
2 |
0.70-3.49 |
Positive |
3 |
3.50-17.4 |
Positive |
4 |
17.5-49.9 |
Strongly positive |
5 |
50.0-99.9 |
Strongly positive |
6 |
≥100 |
Strongly positive |
Reference values apply to all ages.
Interpretation
Positive results indicate the possibility of allergic disease induced by one or more allergens present in the multi-allergen cap.
Negative results may rule out allergy, except in rare cases of allergic disease induced by exposure to a single allergen.
Detection of IgE antibodies in serum (class 1 or greater) indicates an increased likelihood of allergic disease as opposed to other etiologies and defines the allergens that may be responsible for eliciting signs and symptoms.
The level of IgE antibodies in serum varies directly with the concentration of IgE antibodies expressed as a class score or kU/L.
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86003
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
WEED4 | Weed Panel # 4 | 73710-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
WEED4 | Weed Panel # 4 | 73710-6 |
Forms
If not ordering electronically, complete, print, and send an Allergen Test Request (T236) with the specimen.
Testing Algorithm
Includes testing for giant ragweed, short ragweed, and Western ragweed allergen.