Casein, IgE, Serum

Test Code
CASEN


Alias/See Also
Epic: LAB611
Mayo: CASE


CPT Codes
86008

Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 0.5 mL for every 5 allergens requested




Minimum Volume
0.3 mL

For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace


Other Acceptable Specimens

Collection Container: Red top




Instructions
Centrifuge and aliquot serum into a plastic vial.


Transport Container
Plastic vial


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


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis OK
Gross lipemia OK


Methodology
Fluorescence Enzyme Immunoassay (FEIA)


Setup Schedule
Monday through Friday


Report Available
Same day/1 to 3 days


Limitations
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 test results must be interpreted in the clinical context.

False-positive results for IgE antibodies may occur in patients with markedly elevated serum IgE (>2500 kU/L) due to nonspecific binding to allergen solid phases.


Reference Range

 

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 > or =100 Strongly positive
Reference values apply to all ages.

INTERPRETATION 
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.


Clinical Significance
USEFUL FOR 
Establishing a diagnosis of an allergy to casein

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

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

In vitro serum testing for IgE antibodies provides an indication of the immune response to allergens 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, 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).


Performing Laboratory
Mayo Clinic Laboratories - Rochester
3050 Superior Drive NW
Rochester, MN 55901


Additional Information
Casein, IgE, Serum

Last Updated: July 6, 2023
Last Review: N. Wolford, July 6, 2023


The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.