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Test Code WEED1 Weed Panel # 1

Performing Laboratory

Mayo Medical Laboratories in Rochester

Reporting Name

Weed Panel # 1

Specimen Type

Serum


Specimen Required


Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 0.5 mL

Additional Information: See Allergens-IgE Antibodies in Special Instructions.


Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross OK

Icterus

NA

Other

NA

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  90 days

Specimen Minimum Volume

0.3 mL

Day(s) and Time(s) Performed

Monday through Friday; 9 a.m.-8 p.m., Saturday; 8 a.m.-3 p.m.

Specimen Retention Time

14 days

Analytic Time

Same day/1 day

Reference Values

Class

IgE kU/L

Interpretation

0

<0.35

Negative

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.

Useful For

Testing for IgE antibodies may be useful to establish the diagnosis of an allergic disease and to define the allergens responsible for eliciting signs and symptoms.

 

Testing also may be useful to identify allergens which may be responsible for allergic disease and /or anaphylactic episode, to confirm sensitization to particular allergens prior to beginning immunotherapy, and to investigate the specificity of allergic reactions to insect venom allergens, drugs, or chemical allergens.

Testing Algorithm

Includes testing for English plantain, lamb's quarters, mugwort, Russian thistle, and short ragweed allergen.

Method Name

Fluorescence Enzyme Immunoassay (FEIA)

Test Classification

This test has been cleared or approved by the U.S. 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
WEED1 Weed Panel # 1 24480-6

 

Result ID Test Result Name Result LOINC Value
WEED1 Weed Panel # 1 24480-6

Clinical Information

Clinical manifestations of immediate hypersensitivity (allergic) diseases are caused by the release of proinflammatory mediators (histamine, leukotrienes, and prostaglandins) from immunoglobulin E (IgE)-sensitized effector cells (mast cells and basophils) when cell-bound IgE antibodies interact with allergen.

 

In vitro serum testing for IgE antibodies provides an indication of the immune response to allergen(s) that may be associated with allergic disease.

 

The allergens chosen for testing often depend upon the age of the patient, history of allergen exposure, season of the year, and clinical manifestations. In individuals predisposed to develop allergic disease(s), the sequence of sensitization and clinical manifestations proceed as follows: eczema and respiratory disease (rhinitis and bronchospasm) in infants and children less than 5 years due to food sensitivity (milk, egg, soy, and wheat proteins) followed by respiratory disease (rhinitis and asthma) in older children and adults due to sensitivity to inhalant allergens (dust mite, mold, and pollen inhalants).

Cautions

Testing for IgE antibodies is not useful in patients previously treated with immunotherapy to determine if residual clinical sensitivity exists, or in patients in whom the medical management does not depend upon identification of allergen specificity.

 

Some individuals with clinically insignificant sensitivity to allergens may have measurable levels of IgE antibodies in serum, and results must be interpreted in the clinical context.

 

False-positive results for IgE antibodies may occur in patients with markedly elevated serum IgE (>2,500 kU/L) due to nonspecific binding to allergen solid phases.

Clinical Reference

Homburger HA: Chapter 53: Allergic diseases. In Clinical Diagnosis and Management by Laboratory Methods. 21st edition. Edited by RA McPherson, MR Pincus. WB Saunders Company, New York, 2007, Part VI, pp 961-971

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 is then 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, Uppsala, Sweden Rev 02/2005)