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Unit Code 82711:
Bahia Grass, IgE

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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 responsible for

anaphylaxis, 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.

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).

Reference Values

Class     IgE kU/L               Interpretation

   0          <0.35                      Negative

   1          0.35-0.70               Equivocal

   2          0.71-3.5                 Positive

   3          3.51-17.5               Positive

   4          17.6-50.0               Strongly positive

   5          50.1-100.0            Strongly positive

   6           >100.0                   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 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.

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 (>2500 kU/L) due to nonspecific binding

to allergen solid phases.

Special Instructions and Forms

• Allergens - IgE Antibodies 

Clinical Reference

Homburger HA:  Methods in laboratory immunology. In Allergy Principles

and Practice. Vol. 1. 5th edition. Edited by E Middleton, Jr, CE Reed, EF

Ellis, et al. St Louis, MO, Mosby Year Book Inc, 1998, pp 417-429

Key