Synonyms: Immunoglobulin G
Related tests: serum electrophoresis, urine electrophoresis, kappa light chains, lambda light chains, IgM
Clinical significance
Class G immunoglobulins are the predominant antibodies in serum, making up about 75% of total immunoglobulins, and are particularly important in long-term defence against infections; an infecting agent initially causes a rise in specific IgM antibodies, which are later replaced by the even more specific IgG antibodies.
IgG crosses the placenta, protecting the foetus.
Most myelomas are of the IgG type.
Clinical indications
Further investigation when a monoclonal component is found on electrophoresis.
Sample type
The patient must have a blood sample taken.
Preparation
You must fast for at least 8 hours; a small amount of water is allowed.