Immunoglobulin G Subclasses (1-4)

IgG subclass deficiency may be masked by a normal serum IgG concentration. The most common of the subclass deficiencies is IgG2 and this may also be associated with IgA deficiency. Isolated IgG4 deficiency is common in children and may not be clinically significant. The recently described systemic fibroinflammatory disorder, IgG4 related disease is associated with markedly increased IgG4 levels. IgG subclass is useful to test for individuals with recurrent infections and normal IgG, IgA and IgM.
Clinical details: 
IgG Subclass Deficiency, IgG4 Related Disease, Autoimmune Pancreatitis
Reference range: 

Immunoglobulin IgG 1 concentration 3.82 - 9.28
Immunoglobulin IgG 2 concentration 2.41 - 7.00
Immunoglobulin IgG 3 concentration 0.218 - 1.761
Immunoglobulin IgG 4 concentration 0.039 - 0.864

Adult ranges given, paediatric ranges on request.

Sample type and Volume required: 
Clotted (Gold top vacutainer)
Turnaround time: 
6 working days
Special sample instructions: 

All tests are compromised by prolonged transit times. For this reason, date of bleed and date of postage must be provided with each request.

Storage and transport: 
Serum stored at 4°C should be sent by first class post
Time limit for extra tests: 
10 days
Diagnostic Immunology and Allergy Department at King's College Hospital
General Enquiry : 020 3299 8752 / 020 3299 1171
King's College Hospital
Bessemer Wing - 1st Floor
Denmark Hill
London SE5 9RS
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 23/05/2023