panel-reactive antibody
(PRA) 1. the pre-existing anti-HLA antibody in the serum of a potential allograft recipient that reacts with specific antigen in a panel of leukocytes (see antibody screening, under screening). A higher percentage of PRA indicates a higher risk of a positive crossmatch. 2. the percentage of such antibody in the recipient's serum.
Medical dictionary.
2011.