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Antibody titer How the Test is Performed:
Blood is drawn from a vein ( venipuncture ), usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood). A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding .
How to Prepare:
No special preparation is necessary for this test.
How it Feels:
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing .
Risks:
Risks associated with venipuncture are slight: - excessive bleeding
- fainting or feeling lightheaded
- hematoma (blood accumulating under the skin)
- infection (a slight risk any time the skin is broken)
- multiple punctures to locate veins
Why this Test is Performed:
The antibody level in the blood is a reflection of the body's past experience or exposure to an antigen , or something that the body does not recognize as self. Every living cell has different protein markers on its surface called antigens, and the body's immune system identifies those cells that are not part of its structure by those surface proteins .
Occasionally, the body makes an error and begins to recognize its own tissue as being non-self, or foreign. This leads to a mounting immune response against that tissue type, cell, or substance that is part of the body. The body uses antibodies to attack the foreign matter, or the self matter that it recognizes as self.
Levels of antibodies in the blood are measured with this test, and indicate that the body has come into contact with a particular antigen, or that the body's immune system has reverted, and recognizes it's own matter as foreign. This would be evident if there was a titer of antibodies against the bodies own tissue which is the case with some types of diabetes mellitus , SLE , and other autoimmune disorders .
Checking an antibody titer is also useful if your health care provider wants to check and see if you need a booster immunization, or if a recent administration caused a strong enough response from the immune system, bringing your antibody titer against that particular disease up to a preventative level.
Normal Values:
This depends of the antibody being tested. If your health care provider is testing for antibodies against your own tissue, then the normal value would be zero.
If your health care provider is testing to see if your immunization brought your antibody titer up to a preventative level, then that would be a given value determined by that immunization.
Abnormal Results:
If your health care provider is testing for antibodies against your own tissue, abnormal results would show a positive antibody titer. This means that your immune system is fighting its own tissue, cells, or substances.
If your health care provider is testing to see if your immunization brought your antibody titer up to a preventative level, an abnormal result would indicate that your body has not mounted an adequate response against the immunization, and you are not protected from the disease in its pure infectious form.
Cost:
Information not available.
Special Considerations:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
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