Influence of pretransplant panel-reactive antibody on outcomes in 8,160 heart transplant recipients in recent era

Background. Panel-reactive antibody (PRA) screening to detect HLA antibodies is an important part of evaluation for potential heart transplant recipients. We sought to determine how different levels of PRA affect outcomes in heart transplantation. Methods. A retrospective cohort study of using data reported to the United Network for Organ Sharing /Organ Procurement and Transplantation Network (UNOS/OPTN) registry from January 1, 2000, to December 31, 2004, was performed. The association between PRA at transplant and primary end points, allograft and patient survival, as well as a secondary end point, rejection within 1 year, was analyzed. Results. Pretransplant PRA was reported for 8,160 (79.4%) of the 10,279 first heart transplant recipients during the study period. Panel-reactive antibody was 0% in 6,481 (79.4%) patients (group 1), 1% to 10% in 930 (11.4%) patients (group 2), 11% to 25% in 309 (3.8%) patients (group 3), and greater than 25% in 440 (5.4%) patients (group 4). Actuarial survival was significantly different among the four groups by Kaplan-Meier method (p < 0.001). Furthermore, using PRA cutoffs of 0%, 10%, or 25%, the group with lower PRA had significantly better patient and allograft survival. Cox proportional hazard modeling revealed increasing PRA as a significant predictor of mortality (p < 0.001). However, when each group (2, 3, and 4) was compared with group 1 (PRA 0%), only group 4 (PRA > 25%) had worse survival on multivariate analysis. Patients with PRA greater than 25% confirmed by the flow cytometric technique had the worst overall survival. Rejection rate within 1 year after transplantation also significantly increased with increasing PRA. Propensity-matched patients demonstrated similar results. Conclusions. This large series of patients from the United Network for Organ Sharing database has demonstrated that elevated PRA remains a significant risk factor in a recent cohort of heart transplant recipients. Patients with PRA greater than 25% are at a particularly high risk.