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HelpTest Code LAB2482 Grapefruit, IgE, Serum
Additional Codes
SQ: GFRUTM
MAYO: GRFR
Reporting Name
Grapefruit, IgEUseful For
Establishing a diagnosis of an allergy to grapefruit
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
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumOrdering Guidance
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 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 |
Special Instructions
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.
Day(s) Performed
Monday through Friday
Test 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 |
|---|---|---|
| GRFR | Grapefruit, IgE | 6131-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| GRFR | Grapefruit, IgE | 6131-7 |
Method Description
Specific IgE from the patient's serum reacts with the allergen of interest, which is covalently coupled to an ImmunoCAP. After washing away nonspecific IgE, enzyme-labeled anti-IgE antibody is added to form a complex. After incubation, unbound anti-IgE is washed away, and the bound complex incubated with a developing agent. After stopping the reaction, the fluorescence of the eluate is measured. Fluorescence is proportional to the amount of specific IgE present in the patient's sample (ie, the higher the fluorescence value, the more IgE antibody is present).(Package insert: ImmunoCAP System Specific IgE FEIA. Phadia; Rev 06/2020)
Report Available
Same day/1 to 3 daysReject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
Method Name
Fluorescence Enzyme Immunoassay (FEIA)
Forms
If not ordering electronically, complete, print, and send an Allergen Test Request (T236) with the specimen.