Serum Immunoglobulin G (IgG) Subclass Electrophoresis (Qualitative)

What Is This Test Measuring?

IgG is the most common antibody in your blood, but it comes in several subtypes (subclasses): IgG1, IgG2, IgG3, and IgG4. This test checks the relative amounts of each subclass to see if one type is too high or too low, which can indicate immune-related health issues.

Why Might You Need This Test?

Doctors may order this test if you have symptoms like frequent infections, autoimmune diseases (such as lupus or rheumatoid arthritis), or conditions affecting antibody production. It can also help evaluate immune deficiencies or monitor treatment responses.

Sample Collection and Preparation

A blood sample is drawn from a vein in your arm. The blood is processed to separate serum (the liquid part without clots) for testing. No special preparation is needed, but fasting may be advised depending on your doctor’s instructions.

What Does the Result Mean?

Results are qualitative (descriptive rather than numeric), showing whether the subclass distribution appears normal or abnormal. For example, low IgG2 or IgG4 may suggest certain immune disorders, while high levels of one subclass could indicate inflammation or other conditions.