A titer is a measurement of the amount or concentration of a substance in a solution. It usually refers to the amount of antibodies found in a person's blood.
Information
Blood titer measurements can help determine medical treatment. Antibody titers show if a person is immune to diseases such as measles, chickenpox, or hepatitis. They can also help measure harmful antibodies related to lupus or other autoimmune diseases.
A titer measurement is expressed as a ratio, such as 1:40.
References
Aoyagi K, Ashihara Y, Kasahara Y. Immunoassays and immunochemistry. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 45.
Review Date:
11/1/2023
Reviewed By:
Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
