What Is an Antibody Titer?

An antibody titer is a method of determining the presence and strength of antibodies in the blood. A doctor removes a small amount of blood from a patient, which is then analyzed externally for the presence or absence of antibodies. Depending on the results, an antibody titer may be indicative of an internal infection or autoimmune disease.

Significance

• An antibody titer is a test used to detect the level of antibodies in the blood. Because the body utilizes antibodies in the disruption and elimination of disease, any past exposure to foreign substances (known as antigens) will directly affect the level of antibodies in the blood.

Diagnosis

• An antibody titer is an important step in the diagnosis of bodily immunities. It is performed much like a typical blood test. First, a small portion of the skin is cleaned with rubbing alcohol or antiseptic. A doctor then inserts a needle into a vein in the arm, typically in the underside of the elbow or back of the hand, and removes a small portion of blood for diagnosis. The blood is then analyzed in an external biopsy for traces and levels of antibodies.

Benefits

• The benefit of an antibody titer lies in its ability to determine the strength and function of antibodies in the blood. An antibody titer may reveal the presence of an autoimmune disease such as systemic lupus erythematosus (SLE). Such autoimmune diseases cause antibodies to malfunction, leading them to attack healthy tissues and internal organs. This may result in serious illness or death over time. An antibody titer may also indicate the need for a booster immunization in an individual who is susceptible to a certain pathogen. An antibody titer can regulate the response from an immunization and determine whether it is strong enough to repel a certain disease.

Results

• An antibody titer will result in an antibody count of zero if there are no antibodies currently present in the blood. This is good if an antibody titer was administered to check for an autoimmune response. It is detrimental if the antibody titer was administered to check for the body's ability to fight infection or infectious agents.

Warning

• An overall low level of antibodies in the blood may indicate an immune deficiency. Immune deficiencies are dangerous complications that should be addressed immediately. A doctor may schedule additional testing or treatment if a patient exhibits an abnormally low level of antibodies.

  Risks associated with an antibody titer are slight and include fainting, lightheadedness, an accumulation of blood under the skin (hematoma) or minor infection.