Long-term graft survival is improved in cadaveric renal retransplantation by flow cytometric crossmatching

Background. Cadaveric renal retransplantation is associated with a higher risk of early graft failure than primary grafts. A large proportion of those graft losses is likely attributable to donor-directed HLA class I antibodies, detectable by flow cytometry crossmatching but not by conventional crossmatching techniques. Methods. Long-term graft survival in a group of 106 recipients of consecutive cadaveric renal regrafts between 1990 and 1997, in whom a negative flow T-cell IgG; crossmatch was required for transplantation, was compared with two other groups of cadaveric transplant recipients. The first group consisted of 174 cadaveric regrafts transplanted between 1985 and 1995 using only a negative anti-human globulin (AHG) T-cell IgG crossmatch. The second group was primary cadaveric transplants done concurrently with the flow group (1990 to 1997) using only the AHG T-cell IBG; crossmatch. Results. The long-term (7 year) graft survival rate of flow crossmatch-selected regraft recipients (68%; n=106) was significantly improved over that of regraft recipients who were selected for transplantation by only the AHG crossmatch technique (45%; n=174; log-rank=0.001; censored for patients dying with a functioning graft). Graft outcome for the flow crossmatched regraft recipients was not significantly different from that of primary cadaveric patients (72%; n=889; log-rank=0.2; censored for patients dying with a functioning graft). Finally, a positive B-cell IgG flow cytometric crossmatch had no influence on long-term regraft outcome. Conclusions. The use of the flow T-cell IgG; crossmatch as the exclusion criterion for cadaveric renal retransplantation yields an improved long-term graft outcome over that obtained when only the AHG crossmatch is used and has improved survival of regraft recipients to the level of our primary cadaveric renal transplant population.