Respiratory Profile, Region 2, Mid-Atlantic (DC, DE, MD, NC, VA), Serum

Test Code
RPR2


Alias/See Also
Epic: LAB3333
Mayo: RPR2


CPT Codes
82785-IgE 86003 x 23-Each individual allergen

Includes
Test Id Reporting Name Available Separately Always Performed
IGE Immunoglobulin E (IgE), S Yes Yes
DP House Dust Mites/D.P., IgE Yes Yes
DF House Dust Mites/D.F., IgE Yes Yes
CAT Cat Epithelium, IgE Yes Yes
DOGD Dog Dander, IgE Yes Yes
BERG Bermuda Grass, IgE Yes Yes
TIMG Timothy Grass, IgE Yes Yes
JOHN Johnson Grass, IgE Yes Yes
COCR Cockroach, IgE Yes Yes
PENL Penicillium, IgE Yes Yes
CLAD Cladosporium, IgE Yes Yes
ASP Aspergillus Fumigatus, IgE Yes Yes
ALTN Alternaria Tenuis, IgE Yes Yes
BXMPL Box Eld/Maple, S, IgE Yes Yes
BIR Silver Birch, IgE Yes Yes
CED Mountain Cedar, IgE Yes Yes
OAK Oak, IgE Yes Yes
ELM Elm, IgE Yes Yes
CTWD Cottonwood, IgE Yes Yes
PCANH Pecan Hickory, IgE Yes Yes
MULB Mulberry, IgE Yes Yes
SRW Short Ragweed, IgE Yes Yes
RRRP Rough Pigweed, IgE Yes Yes
SORR Red Sorrel, IgE Yes Yes


Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 1.7 mL




Minimum Volume
1.5 mL


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
 


Methodology
Fluorescence Enzyme Immunoassay (FEIA)


Setup Schedule
Monday through Friday


Report Available
Same day/1 to 3 days


Limitations
CAUTIONS 
An elevated concentration of total IgE is not diagnostic for allergic disease and must be interpreted in the clinical context of the patient, including age, sex, travel history, potential allergen exposure, and family history.

A normal concentration of total IgE does not eliminate the possibility of allergic disease. In patients with a high index of suspicion for allergic disease, testing for allergen-specific IgE may be warranted.

Testing for allergen-specific 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 

Specific IgE:

Class IgE kU/L Interpretation
<0.10  Negative 
0/1  0.10-0.34  Borderline/equivocal 
0.35-0.69  Equivocal 
0.70-3.49  Positive 
3.50-17.4  Positive 
17.5-49.9  Strongly positive 
50.0-99.9  Strongly positive 
> or =100  Strongly positive 
 
Reference values apply to all ages.

Total IgE:
Age Reference interval (in kU/L)
0-5 months < or =13
6-11 months < or =34
1 and 2 years < or =97
3 years < or =199
4-6 years < or =307
7 and 8 years < or =403
9-12 years < or =696
13-15 years < or =629
16 and 17 years < or =537
18 years and older < or =214


INTERPRETATION 

Elevated concentrations of total IgE may be found in a variety of clinical diseases, including allergic disease, certain primary immunodeficiencies, infections, inflammatory diseases, and malignancies.
 
Detection of allergen-specific 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.



Clinical Significance
USEFUL FOR 
Assessing sensitization to various inhalant allergens commonly found in the Mid-Atlantic region including the District of Columbia, Delaware, Maryland, North Carolina, and Virginia

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 
Immunoglobulin E (IgE) is one of the 5 classes of immunoglobulins and is defined by the presence of the epsilon heavy chain. It is the most recently described immunoglobulin, having first been identified in 1966. IgE exists as a monomer and is present in the circulation at very low concentrations, approximately 300-fold lower than that of IgG. The physiologic role of IgE is not well characterized, although it is thought to be involved in defense against parasites, specifically helminths.

The function of IgE is distinct from other immunoglobulins in that it induces activation of mast cells and basophils through the cell-surface receptor Fc epsilon RI. Fc epsilon RI is a high-affinity receptor specific for IgE present at a high density on tissue-resident mast cells and basophils. Because of this high-affinity interaction, almost all IgE produced by B cells is bound to mast cells or basophils, which explains the low concentration present in circulation. Cross-linking of the Fc epsilon RI-bound IgE leads to cellular activation, resulting in immediate release of preformed granular components (histamine and tryptase) and subsequent production of lipid mediators (prostaglandins and leukotrienes) and cytokines (interleukin-4 and interleukin-5).

Elevated concentrations of IgE may occur in the context of allergic disease. However, increases in the amount of circulating IgE can also be found in various other diseases, including primary immunodeficiencies, infections, inflammatory diseases, and malignancies. Total IgE measurements have limited utility for diagnostic evaluation of patients with suspected allergic disease. In this scenario, testing for the presence of allergen-specific IgE may provide more information.

Clinical manifestations of allergic disease result from activation of mast cells and basophils, which occurs when Fc epsilon RI-bound IgE antibodies interact with allergen.

In vitro serum testing for specific IgE antibodies may provide an indication of the immune response to an allergen 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. Sensitization to inhalant allergens (dust mite, mold, and pollen inhalants) primarily occurs in older children, adolescents, and adults, and usually manifests as respiratory disease (rhinitis and asthma).


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


Additional Information
Respiratory Profile, Region 2, Mid-Atlantic (DC, DE, MD, NC, VA), Serum

Last Updated: July 19, 2023
Last Review: N. Wolford, July 19, 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.