Immunoglobulins (antibodies) are special proteins that are secreted by cells of the immune system to protect against foreign agents (microorganisms, toxins).

Depending on the function performed, there are 5 types of antibodies: A, D, E, G, M. IgG is the most numerous group of all antibodies (80% of the total), which shows the importance of this immunoglobulin. IgG protects the body from almost all foreign agents (antigens), including bacteria, fungi, viruses, toxins... Immunoglobulin G penetrates through the placenta into the fetal body and becomes an important factor in the defense of the newborn child, whose immune system is not yet able to fight all kinds of infection on its own.

The mechanisms of action of G antibodies are quite diverse. They not only neutralize antigens, but also contribute to the destruction of complex "pests" by cells of the immune system. Another feature of IgG is the ability to "memorize" the microorganism, and with repeated contact much faster to cope with the disease.

The presence of specific IgG in the blood (for example, to chlamydia) indicates a chronic form of the disease - in this case, chlamydia.