Immunoglobulin IgG subclasses

Diagnostic Use

In normal adults, IgG constitutes approximately 75% of total serum immunoglobulin. Within the IgG class, the usual order of concentration of the 4 subclasses is IgG1>IgG2>IgG3>IgG4, but the actual concentration of each may vary markedly between individuals.

The four IgG subclasses show considerable differences in their properties, including ability to fix complement, to bind to macrophages and to pass through the placenta. Abnormal levels of one or more subclass may be associated with certain conditions, including anaphylaxis, autoimmune and gut diseases as well as hypo- and hyper gammaglobulinaemia. In particular, reduced production of IgG2 in children may be associated with recurrent infections.

It is also used to support the diagnosis of IgG4-related disease.


Protein Lab

Delphic Registration Code


Turnaround Time

1 week

Test Code