Individual test · Labcorp 160531

Immunoglobulin G, Subclass 4

This test measures the level of Immunoglobulin G Subclass 4 (IgG4), a specific type of antibody found in your blood. It helps doctors evaluate your immune system's function, particularly if you have recurrent sinus or lung infections, asthma, or are undergoing allergy therapy. This measurement helps identify immune deficiencies or abnormal immune responses that may be contributing to your symptoms. However, this test alone cannot diagnose specific allergies or confirm the presence of a specific immune disease.