IgG Subclass 4 (IgG4)

Understanding IgG Subclass 4 (IgG4)

IgG4 antibodies are the least abundant subclass of immunoglobulin G (IgG) in the blood, yet they play an important role in immune regulation. While IgG antibodies help the body respond to infections, abnormal IgG4 levels have been associated with certain immune-mediated conditions. One such condition is IgG4-related disease (IgG4-RD), a chronic disorder that can cause organ enlargement, inflammation, fibrosis, and, in some cases, tumor-like masses. Elevated IgG4 levels are also commonly seen in autoimmune condition...

What does IgG Subclass 4 (IgG4) measure?

The IgG Subclass 4 (IgG4) test measures the levels of immunoglobulin G subclass 4 (IgG4) antibodies in the blood. This test helps in the assessment and clinical evaluation of conditions such as autoimmune pancreatitis, sclerosing cholangitis, certain allergic conditions, and IgG4-related disease, a multisystem disorder characterized by inflammation and fibrosis affecting various organs. The test results are interpreted along with clinical history, imaging studies, and other histology correlation to support accurate...