Immunoglobulin G, subclasses (1 - 4)-13549
Test info
IgG (1, 2, 3, 4)
Study patients with recurrent bacterial infections or allergy
Specimen
Immediatley following collection, mix sample by gently inverting 5 times
- Allow sample to clot for a minimum of 30 minutes
- Spin within two (2) hours of sample collection
Gold serum separator (SST) tube
- Allow sample to clot
- Spin within two (2) hours of sample collection
- Transfer serum to a Transfer vial/tube with cap - 12mL (LabCorp), labelled as serum
Refrigerated (preferred) - 7 days
Frozen - 13 days
Freeze/thaw cycles - stable x 3
Ambient - 3 days
- Gross lipemia
- Hemolysis
Performance
Immunologic
Clinical and Interpretive info
See report
There are four subtypes, of which IgG(1) and IgG(2) comprise 85% of the total. IgG(1) and IgG(3) fix complement best; IgG(3) is hyperaggregable and effects serum viscosity disproportionately.
IgG antibody responses to certain antigens occur to a greater extent in one type of IgG subclass than another. Therefore, some patients with normal total IgG levels may have problems with pyogenic infections because they do not produce IgG(2) or combinations of IgG(2), IgG(3), and/or IgG(4). Some clinically significant IgG subclass deficiencies occur in patients who have IgA deficiency.
The four subclasses of IgG differ in the constant regions of their heavy chains. A patient may have a normal totalIgG yet still have a significant decrease in one subclass. IgG(1) deficiencies are associated with EBV infections, IgG(2) with sinorespiratory infections and infections with encapsulated bacteria, IgG(3) with sinusitis and otitis media, and IgG(4) with allergies, ataxia telangiectasia, and sinorespiratory infections. See tables in individual subclass listings.
Billing
82787 x 4