To understand serologic tests and why they’re useful, it’s helpful to know a little about the immune system and why we get sick. Antigens are substances that provoke a response from the immune system. They are most often too small to see with the naked eye. They can enter the human body through the mouth, through broken skin, or through the nasal passages. Antigens that commonly affect people include the following:
bacteria
fungi
viruses
parasites
The immune system defends against antigens by producing antibodies. These antibodies are particles that attach to the antigens and deactivate them. When your doctor tests your blood, they can identify the type of antibodies and antigens that are in your blood sample and identify the type of infection you have.
Sometimes the body mistakes its own healthy tissue for outside invaders and produces unnecessary antibodies. This is known as an autoimmune disorder. Serologic testing can detect these antibodies to help your doctor diagnose an autoimmune disorder.
