Immunoglobulin G (IgG) Subclass 2 Concentration (Serum)

What Is IgG2 Used For?

IgG2 is one of five subclasses of IgG antibodies, each playing a role in immune defense. IgG2 is particularly important for protecting against certain bacteria, such as those causing respiratory infections. Measuring IgG2 can help doctors assess immune function, especially in conditions like recurrent sinus infections, pneumonia, or other immune-related disorders.

Why Might You Need This Test?

Your doctor may order an IgG2 test if you have frequent or severe infections, particularly those involving the sinuses, lungs, or skin. It may also be used in research or clinical studies evaluating immune responses, especially in people with suspected immune deficiencies.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then sent to a lab where it is processed to separate serum. The IgG2 level is measured using an immunoassay method, which detects specific antibodies in your serum.

What Are Common Results and What Do They Mean?

Results are reported as a mass concentration (e.g., grams per liter). While specific reference ranges vary by lab, lower than expected IgG2 levels may suggest an immune system that struggles to produce enough of this subclass, potentially increasing susceptibility to certain infections.