IgG Substance Concentration in Serum (Qualitative or Screening)

What IgG Testing Measures

IgG is the most abundant antibody in your blood and plays a key role in defending against bacteria and viruses. This test helps determine if your immune system is producing enough IgG, which is crucial for fighting infections long-term. It may be used to check for immune deficiencies, monitor treatment responses, or evaluate immune responses in certain conditions.

Why You Might Need This Test

A healthcare provider may recommend this test if you have symptoms of a weakened immune system, such as frequent infections, recurrent illnesses, or if you’re being treated for an immune-related condition. It can also be part of a broader evaluation for conditions like HIV, autoimmune diseases, or congenital immune disorders.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate the serum (the liquid part without clots). This serum is tested for IgG levels or presence.

Test Results and Interpretation

Results are typically reported as qualitative (positive/negative) or quantitative (levels of IgG). A qualitative test tells if IgG is present, while a quantitative test provides a specific measurement. Interpretation depends on clinical context, such as your medical history and symptoms.