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Order Code CH154
Turnaround Time 10 days
Test Includes

Immunoglobulin G Subclasses 1, 2, 3, 4
IgG (Immunoglobulin G)

Specimen Requirements
Specimen Source
Transport Container
(Specimen Container)

SST (Tiger Top)

Preferred Specimens
Minimum Volume (uL)
.5 mL
Collection Instructions
(Transport Temperature)
Transport Refrigerated (cold packs)
Specimen Stability
Temperature Period
Room temperature 72 hours
Refrigerated 7 days
Frozen 90 days
Reject Criteria

Gross hemolysis

Test Details
Immunoturbidimetric Assay, Tubidimetric
Clinical Significance

IgG are the most common isotype of Ig and include four subclasses which differ from one another in the following ways: their initial amino acid sequence, their physical and chemical properties and the different serum concentrations reached with age. Every subclass has a specific biological function: the response to proteic antigens is prevalently mediated by IgG1 and IgG3, while IgG2 mediates the response to polysaccharide antigens. It is still unclear whether IgG4 are protective or sensitising antibodies; IgG1 and IgG3 also have a major ability to bind to the cells that mediate the immune response, while only IgG4 activate the complement using an alternative route. Although low levels of IgG subclasses may be temporary, deficiencies are often associated with various diseases: 1) recidivating bacterial infections involving the respiratory and digestive tracts, primarily sustained by capsulated or pyogenic microorganisms; 2) IgA deficiency; 3) absence of immune response following vaccination; 4) allergic or autoimmune diseases; 5) diseases of the CNS. IgG subclass deficiencies must therefore be looked for every time these diseases are diagnosed, also because subjects may benefit from gammaglobulin replacement therapy.

Reference Ranges

See individual analytes

Alternative Names
IgG Subclasses Panel