Immunoglobulin G (IgG) Subclass 1, Serum Concentration

What Does This Test Measure?

IgG1 is part of the broader immunoglobulin family, which includes antibodies that play a critical role in your immune response. This test specifically looks at the concentration of IgG1 in your serum, which can vary depending on your health status, immune function, and exposure to infections or vaccines.

Why Might You Need This Test?

Doctors may order an IgG1 test to evaluate immune function, diagnose conditions like immunodeficiency, assess response to treatments, or investigate symptoms such as frequent infections, fatigue, or autoimmune issues. It can also help monitor certain chronic diseases or immune-related disorders.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate the serum, which is sent to a lab for analysis. The lab uses an immunoassay method to measure the IgG1 concentration.

What Are Possible Results?

Results are typically reported as a concentration value in milligrams per deciliter (mg/dL) or grams per liter (g/L). While specific reference ranges can vary by lab, lower than expected levels may indicate immune deficiencies, while higher levels might be seen in chronic infections or certain autoimmune conditions.