Health Library

Antibody titer blood test

Titer - antibodies; Serum antibodies

Antibody titer is a lab test that measures the level of antibodies in a blood sample.

Images

I Would Like to Learn About:

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is necessary for this test.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Why the Test is Performed

The antibody level (titer) in the blood tells your health care provider whether or not you have been exposed to an antigen, or something that the body thinks is foreign. The body uses antibodies to attack and remove foreign substances.

In some situations, your provider may check your antibody titer to see if you had an infection in the past (for example, chickenpox or measles) or to decide which vaccines you need.

The antibody titer is also used to determine:

• The strength of an immune response to the body's own tissue in diseases such as systemic lupus erythematosus (SLE) and other autoimmune disorders
• If you need a booster vaccine
• Whether a vaccine you had before helped your immune system protect you against the specific disease
• If you have had a recent or past infection, such as mononucleosis or viral hepatitis

Normal Results

Normal values depend on the antibody being tested.

If the test is being done to look for antibodies against your own body tissues, the normal value would be zero or negative. In some cases, a normal level is below a specific number.

If the test is being done to see if a vaccine fully protects you against a disease, the normal result depends on the specific value for that immunization.

Antibody tests can help check for certain infections. A negative test may mean that a specific infection is not present, but because antibodies take time to develop (usually 1-2 weeks), it may not be definitive.

Normal value ranges may vary slightly among different labs. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results depend on which antibodies are being measured.

Abnormal results may be due to:

• Autoimmune disease
• Bacterial infections
• Failure of a vaccine to fully protect you against a certain disease
• Immune deficiency
• Viral infections

Risks

There is little risk involved with having your blood taken. Veins vary in size from one person 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.

Risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Related Information

References

Kroger AT, Orenstein WA, Krow-Lucal E, Wodi AP. Immunization for specific infections. In: Blaser MJ, Cohen JI, Holland SM, et al, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 10th ed. Philadelphia, PA: Elsevier; 2026:chap 322.

McPherson RA, Riley RS, Massey HD. Laboratory evaluation of immunoglobulin function and humoral immunity. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 47.

Nadeau KC. Approach to the patient with allergic or immunologic disease. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 230.

Review Date: 1/20/2026  

Reviewed By: Deborah Pedersen, MD, MS, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics. This site complies with the HONcode standard for trustworthy health information: verify here.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language.

© 1997- 2026 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

All content on this site including text, images, graphics, audio, video, data, metadata, and compilations is protected by copyright and other intellectual property laws. You may view the content for personal, noncommercial use. Any other use requires prior written consent from Ebix. You may not copy, reproduce, distribute, transmit, display, publish, reverse-engineer, adapt, modify, store beyond ordinary browser caching, index, mine, scrape, or create derivative works from this content. You may not use automated tools to access or extract content, including to create embeddings, vectors, datasets, or indexes for retrieval systems. Use of any content for training, fine-tuning, calibrating, testing, evaluating, or improving AI systems of any kind is prohibited without express written consent. This includes large language models, machine learning models, neural networks, generative systems, retrieval-augmented systems, and any software that ingests content to produce outputs. Any unauthorized use of the content including AI-related use is a violation of our rights and may result in legal action, damages, and statutory penalties to the fullest extent permitted by law. Ebix reserves the right to enforce its rights through legal, technological, and contractual measures.