Immunoglobulin G (IgG) Subclass 2 Concentration (Serum)

What Does This Test Measure?

IgG2 is one of five subclasses of Immunoglobulin G (IgG), a key protein in your immune system. It plays a role in defending against specific types of bacteria and some viruses. This test specifically looks at the concentration of IgG2 in your serum, which can vary based on your immune health and exposure to infections.

Why Might You Need This Test?

Doctors may order an IgG2 test if you have symptoms or conditions linked to immune deficiencies, such as recurrent infections, autoimmune diseases, or certain allergies. It can also be part of evaluating immune responses in people with chronic illnesses or those receiving immune-modulating treatments.

What to Expect Before the Test

No special preparation is usually needed for this blood test. You may be asked to fast for 8–12 hours before the draw if your lab requires it, but this is not always the case. Bring any medications or supplements you’re taking to your appointment.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis using an immunoassay method to measure IgG2 levels.