PRETRANSPLANT PANEL REACTIVE-ANTIBODY SCREENS - ARE THEY TRULY A MARKER FOR POOR OUTCOME AFTER CARDIAC TRANSPLANTATION

Background The effect of pretransplant sensitization on out come after cardiac transplant has been controversial. Sensitization, defined as a positive panel-reactive antibody (PRA) screen in patients awaiting t ransplant, represents circulating antibodies to a random panel of dono r lymphocytes (usually T lymphocytes). The significance of pretranspla nt circulating antibodies to B lymphocytes has not been reported, and many centers disregard its use. Methods and Results We retrospectively reviewed the pretransplant PRA screens for 311 patients who underwent cardiac transplant at our institution. The PRA screen was performed b y use of the lymphocytotoxic technique treated with dithiothreitol to remove IgM autoantibodies. Patients with PRA greater than or equal to 11% against T or B lymphocytes had significantly lower 3-year survival (T lymphocytes, 39%; B lymphocytes, 56%) than those patients with PRA =0% and PRA=1% to 10% (T lymphocytes, 76% and 78%; B lymphocytes, 78% and 74%, respectively) (P<.001). For this high-risk group, the rejecti on episode tended to occur earlier than in those patients with PRA=0% and PRA=1% to 10% (T lymphocytes, 2.3 versus 4.0 and 3.8 months; B lym phocytes, 2.1 versus 4.1 and 3.4 months, respectively), and there were more clinically severe rejections that required OKT3 therapy. Conclus ions Cardiac transplant patients with pretransplant T- and/or B-lympho cyte PRA greater than or equal to 11% despite negative donor-specific crossmatch at the time of transplant appear to have earlier and more s evere rejection with significantly lower survival after transplant sur gery. Modification of immunosuppression in these high-risk patients ma y be warranted.