Immunoglobulin G (IgG) Subclass 2 (Serum)

What Does This Test Measure?

IgG2 is one of five subclasses of Immunoglobulin G (IgG), the most common antibody in your blood. This subclass plays a key role in defending against specific types of bacteria and some viruses. Your body produces IgG2 in response to certain infections and vaccines. Levels can be influenced by immune system function, chronic infections, or certain medical conditions.

Why Might Your Doctor Order This Test?

Your doctor may order an IgG2 test if they suspect an immune-related condition, such as recurrent infections, poor response to vaccines, or certain autoimmune diseases. It can also help evaluate immune function in people with chronic illnesses or after receiving treatments that affect the immune system.

How Is This 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 measure IgG2 levels using an immunoassay method, which detects specific antibodies in your serum.

What Are Possible Results and What Do They Mean?

Results are typically reported as a concentration of IgG2 in the blood, though exact reference ranges can vary by lab. Low levels may suggest an impaired immune response, while high levels could indicate chronic infections, certain autoimmune conditions, or other immune-related factors. Your doctor will interpret the results in the context of your overall health and medical history.