Immunoglobulin G (IgG) Subclass 2 Concentration (Serum/Plasma)

What Does IgG2 Serve in Your Body?

IgG2 is one of five subclasses of Immunoglobulin G (IgG), a type of antibody that plays a key role in fighting bacterial infections. It is particularly important for protecting against encapsulated bacteria, such as those causing pneumonia or meningitis. IgG2 antibodies help neutralize toxins and opsonize (mark) bacteria for destruction by immune cells.

When Might You Need This Test?

Doctors may order this test if you have symptoms or conditions linked to low IgG2 levels, such as recurrent infections, autoimmune diseases, or certain immune deficiencies. It may also be used to monitor treatment responses in patients with immune-related disorders.

Common Conditions Affecting IgG2 Levels

Low IgG2 levels can be associated with conditions like Common Variable Immunodeficiency (CVID), recurrent sinus or ear infections, or certain autoimmune diseases. High levels may rarely be seen in some inflammatory or autoimmune states, but this is less common.

What to Expect During the Test

A blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The test involves sending your blood sample to a lab for analysis using an immunoassay method to measure IgG2 concentration.