Immunoglobulins play a critical role in the body’s immune response. Quantitative immunoglobulin testing measures the total IgG, IgA and IgM and determines immune system status. Measuring the Total immunoglobulins may be used to monitor for a deficiency state or excess in one or more of the Immunoglobulin classes (IgG, IgA and IgM).
IgG- makes up the majority of immunoglobulins within the blood (approximately 70-80%). IgG antibodies are responsible for longer term defense against pathogens. IgG antibodies are usually secreted in the initial phase of an infection, rising after a few weeks, then they gradually decrease and stabilize. The body retains memory of IgG responses so the antibodies can be rapidly reproduced if the body is exposed to the same pathogen again. IgG deficiency may reflect an immunodeficiency state.
IgA – makes up approximately 15% of the total serum immunoglobulins. IgA is present in saliva, tears, respiratory and gastric secretions, and breast milk. IgA provides protection against infection in the mucus membranes of the body such as the respiratory tract and the gastrointestinal tract. When passed from mother to baby during breast-feeding, it helps protect the infant’s gastrointestinal tract. Generally, only a low level of IgA may be present in the body after 6 months of age, however IgA levels increase with age.
IgM- These are the antibodies that are first produced when the body encounters a new infection. They only offer short term protection, and then IgG takes over. IgM antibodies detected in a newborn may reflect that there was an infection during the pregnancy.
Common Conditions
- Immunoglobulin deficiency
- Recurrent Infections
- Frequent Respiratory Infections
- Chronic Diarrhoea or other Gastrointestinal issues
- Chronic Inflammation
- Disordered immunoglobulin production
- Monitoring for specific diseases/conditions
- Infants may be tested if the doctor suspects an infection during pregnancy
