Background: A pretransplant lymphocyte crossmatch (XM) test is usually considered mandatory but may delay deceased donor renal transplantation. We report on the safety and clinical efficacy of omitting the XM when it is predicted to be negative based on sensitization history and human leukocyte antigen-specific antibody screening.
Methods: From 1998 to 2008, 606 deceased donor kidney transplants were performed at our center and the prospective donor-recipient XM omitted in 257 (42%). In all cases, a negative XM was confirmed retrospectively. Four hundred fourteen (68%) kidneys were donated after brain death (DBD) and 192 (32%) after cardiac death (DCD). The effect of this policy on cold ischemia time (CIT), delayed graft function (DGF), and transplant survival was assessed.
Results: Mean CIT was 16.7 hr with a prospective XM and 14.3 hr when it was omitted (P<0.001). The beneficial effect of omitting the XM on DGF was only apparent in recipients of DBD kidneys, where the DGF rate was 28% with a prospective XM and 18% without a prospective XM (P=0.03). The corresponding DGF rate in recipients of DCD kidneys was 52% with a prospective XM and 54% without a prospective XM. Logistic regression analysis, after adjustment for variables that influenced DGF, showed that the odds on suffering DGF were lower when the pretransplant XM test was omitted (P=0.04). Neither acute rejection rate nor long-term graft survival was influenced by omission of the XM.
Conclusion: Rigorous recording of potential allosensitizing events and comprehensive antibody screening allows the XM to be safely omitted in selected patients and this helps limit CIT and may reduce DGF.