The antibody titer is a test that detects the presence and measures the amount of antibodies within a person’s blood. The amount and diversity of antibodies correlates to the strength of the body’s immune response.
The immune system produces antibodies to mark invading microorganisms for destruction or to neutralize them before they can cause an infection. Invading microorganisms are known as pathogens. Pathogens have markers on them known as antigens, which antibodies find and bind to.
The binding of antigens to antibodies sparks the immune response. This is a complex interaction of immune tissues and cells that work to defend against invading organisms and fight infection. A second part of the immune response against infection is the presence of memory cells. Memory cells have previously encountered a specific antigen and formed a response against it. They are long-living and optimize the immune system’s ability to fight recurrent and persistent infections.
Vaccines are small amounts of microbes or antigens administered to stimulate the immune system to produce memory cells against a specific disease. Memory cells are so effective that a person’s immune system may fight off an infection before any symptoms can occur. The body is left susceptible to infection when the immune system can no longer produce antibodies or its antibodies stop functioning.
Sometimes the immune system becomes confused and loses the ability to determine which cells are foreign invaders and which belong to healthy tissues. A condition in which the body attacks itself is known as autoimmunity. Autoimmunity is responsible for autoimmune diseases.
An antibody titer is prescribed to investigate problems regarding:
- frequent bacterial or viral infections
- low levels of white blood cells
- liver disease
- flu-like symptoms
- suspected viral disease
- suspected autoimmune disorder
- suspected parasite infection
- to determine if a repeat vaccination or booster is needed
It is essential that you tell your doctor about any prescription or non-prescription medications, dietary supplements, and vitamins you are currently taking before a medical test is performed.
Antibiotics (such as amoxicillin and penicillin) and immune system-suppressing medications can affect your test results. Studies have shown patients receiving chemotherapy have a decrease in antibody levels, so let your doctor know if you have recently undergone or are currently undergoing chemotherapy.
The antibody titer is a blood test. A phlebotomist, a person specially trained to draw blood, will tie a band above the site where the blood will be taken. He or she will clean and sterilize the site with antiseptic before a small needle is inserted directly into the vein.
Most people feel sharp pain at the initial puncture, which quickly fades as the blood is drawn. Once the blood is collected, the needle will be removed and you will be asked to apply pressure to the puncture site with a cotton ball or gauze. A bandage will be placed on the site and you will be free to leave.
This test is a low-risk procedure. However, slight risks can include:
Abnormal test results may indicate immune disorders such as:
- hyper-IgE syndrome
- antiphospholipid antibody syndrome (aPL)
- X-linked hyper IgM syndrome
Abnormal results may also indicate other illnesses, such as:
All your results should be discussed with your doctor. Further testing may include:
- quantitative measure of serum Ig levels
- peripheral blood smear
- complete blood count (CBC)