HLA

One of a group of proteins found on the surface of white blood cells and other cells that play an important part in the body's immune response to foreign substances. These antigens vary from person to person, and HLA tests are done before organ transplantation to find out if tissues match between a donor and a recipient. Also called human leukocyte antigen and human lymphocyte antigen.

High Level Architecture

Abbreviation for human-leukocyte-antigen system. See: major histocompatibility antigens.