CPT® Code 86831

Antibody to human leukocyte antigens (HLA), solid phase assays (eg, microspheres or beads, ELISA, Flow cytometry); antibody identification by qualitative panel using complete HLA phenotypes, HLA Class II

The human leukocyte antigen (HLA) system is a critical component of the major histocompatibility complex (MHC), which plays a vital role in the immune system by facilitating self-recognition. This means that the MHC helps the body identify its own cells and tissues, distinguishing them from foreign substances, such as microorganisms and non-self cells. The HLA system is divided into two main classes: Class I and Class II. The testing associated with CPT® Code 86831 specifically focuses on HLA Class II phenotypes. These tests are essential for identifying the presence and characteristics of HLA alloantibodies, which are antibodies that the immune system produces against HLA antigens from another individual, often in the context of organ transplantation. By utilizing complete HLA phenotypes, the tests can predict the risk of an immunological response to organ transplants. The methodology for these tests typically involves solid phase assays, such as enzyme-linked immunosorbent assay (ELISA), which utilize fluorescent beads coated with HLA molecules. These beads can be analyzed using flow cytometry or Luminex instrumentation to detect the presence of antibodies. CPT® Code 86831 is specifically used when a complete panel of Class II HLA phenotypes is employed to identify antibodies against approximately 40 antigens using a bead array of 30 or more beads.