Flow cytometry crossmatching as a predictor of acute rejection in sensitized recipients of cadaveric renal transplants

Flow cytometry crossmatching (FCXM) was developed as a more sensitive assay than the standard complement-dependent cytotoxicity crossmatch (CDCXM) for the detection of anti-donor antibodies, that mediate hyperacute rejection and graft loss in the early post-transplant period in renal transplant reci pients. The role of FCXM in predicting long-term clinical outcome in renal allograft recipients is unclear. This study examines the role of FCXM in pr edicting lone-term clinical outcome in highly sensitized recipients of cada veric renal transplants. All patients (n = 100) with peak panel reactive an tibody (PRA) levels > 30%, who received cadaveric renal transplants between 1/1/'90 and 12/31/'95 at our institution, were divided into FCXM + and FCX M - groups. The incidence of acute rejection was determined for each group during the first yr after transplant. Graft survival rates at 1, 2, and 3 y r, and creatinine levels were also compared between groups. FCXM + patients experienced a higher incidence of acute rejection during the first yr afte r transplant (69 vs. 45%), and a higher percentage of FCXM + patients had m ore than one episode of acute rejection during the first yr after transplan t (34 vs. 8%) when compared to FCXM - patients. There was no statistically significant difference in 1-, 2-, or 3-yr graft survival between FCXM + and FCXM - patients (76 vs. 83, 62 vs. 80, 62 vs. 72%, respectively). These re sults suggest that sensitized FCXM + cadaveric renal transplant recipients have a higher incidence of acute rejection episodes in the first yr after t ransplant. Given the association of multiple rejection episodes with poor l ong-term allograft survival, FCXM may be a useful predictor of long-term cl inical outcome in this sub-group of renal transplant recipients.