CPT® Code 86403

Particle agglutination tests are laboratory procedures used to assess the presence of specific antibodies in a patient's blood, which can indicate infection status. These tests are particularly useful for identifying infections caused by various pathogens, including viruses and bacteria. For instance, they can help diagnose measles virus infection, streptococcal infections, or syphilis caused by Treponema pallidum. The CPT® Code 86403 is specifically designated for reporting each individual antibody that is screened during this testing process. When a screening result is positive, indicating the presence of antibodies, the subsequent titer levels for each antibody are reported using CPT® Code 86406. The testing process involves obtaining a blood sample through a procedure known as venipuncture, which is separately reportable. The serum or plasma obtained from the blood sample is then analyzed using various methodologies, including semiquantitative hemagglutination, fluorescent enzyme assays, and light flow cytometry, to determine the presence and levels of antibodies.