Immunoglobulin Subclasses

Description: 
Measurement of IgG subclasses (IgG1, IgG2, IgG3 and IgG4) may be of value in patients with multiple recurrent infections in whom there is no overt immunoglobulin deficiency.
Clinical details: 
There are 4 subclasses of IgG (IgG1, IgG2, IgG3 and IgG4) defined on the basis of molecular characteristics. The IgG subclasses demonstrate age, sex and genetic variation. Isolated or compound deficiencies of all four subclasses have been described but, whilst some patients with deficiency exhibit clinical symptoms, others demonstrate no evidence of disease.
Reference range: 

IgG1 3.9 - 12.7 g/L IgG2 0.3 - 7.9 g/L IgG3 0.1 - 1.2 g/L IgG4 0.10 - 1.11 g/L Please contact the laboratory for paediatric ranges.

Units: 
g/L
Location: 
Sample type and Volume required: 
Clotted (yellow SST tube). Serum.
Turnaround time: 
1 week
Contacts:
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: 21/04/2026