Panel reactive antibody

Panel Reactive Antibody (PRA) is an immunological laboratory test routinely performed on the blood of people awaiting organ transplantation. The PRA score is expressed as a percentage between 0% and 99%. It represents the proportion of the population to which the person being tested will react via pre-existing antibodies. These antibodies target the Human Leukocyte Antigen (HLA), a protein found on most cells of the body. Each population will have a different demographic of HLA antigens, and so the PRA test will differ from country to country.