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.
An antibody titer test is used to determine if you’ve had previous infections and whether or not you need certain immunizations. This test can be used to determine the following:
- if you need a booster shot
- whether you recently had or currently have an infection
- whether your immune system has a strong response to your own tissues, possibly indicating an autoimmune disorder
- whether an immunization triggers a strong enough response against the disease it’s meant to protect you against
It’s essential that you tell your doctor about any prescription or nonprescription medications, dietary supplements, and vitamins you’re currently taking before a medical test is performed.
In general, no special preparation is needed for this test. However, research has shown people receiving chemotherapy have a decrease in antibody levels, so let your doctor know if you’ve recently undergone or are currently undergoing chemotherapy.
The antibody titer is a blood test. A phlebotomist, a person specially trained to draw blood, ties a band above the site where the blood will be taken. They next clean and sterilize the site with antiseptic before inserting a small needle directly into a vein.
Most people feel sharp pain at the initial puncture, which quickly fades as the blood is drawn. Once the blood is collected, the phlebotomist removes the needle, and you will be asked to apply pressure to the puncture site with a cotton ball or gauze. A bandage is placed on the site, and you are then free to leave.
This test is a low-risk procedure. However, slight risks can include:
- feeling faint at the sight of blood
- dizziness or vertigo
- soreness or redness at the puncture site
- hematoma (bruising)
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 current or past infections, such as:
- meningitis, which is inflammation of the membranes that cover your brain and spinal cord
- diphtheria, a bacterial infection
- infection from helicobacter pylori bacteria