A. Fuller et al., Repeat donor HLA-DR mismatches in renal transplantation: Is the increased failure rate caused by noncytotoxic HLA-DR alloantibodies?, TRANSPLANT, 68(4), 1999, pp. 589-591
Introduction. Data from the UCLA/UNOS and Collaborative Transplant Studies
Registries indicate that mismatched HLA-DR alloantigens expressed on a form
er donor renal allograft should not be repeated because of significantly po
orer long-term survival.
Methods. Retransplant candidates waiting for another renal allograft were s
creened for ELLA class II alloantibodies (aAb) using direct complement-depe
ndent cytotoxicity and several sensitive aAb binding assays.
Results. When screened by complement-dependent cytotoxicity, 46% of the pat
ients were aAb negative. In contrast, using aAb binding assays, 90% of the
patients had HLA-DR aAb specific for previous HLA-DR allograft mismatches.
Most important, no directly cytotoxic HLA-DR antibody was detected in 9 of
27 patients.
Conclusion. Our studies suggest that crossing the same HLA-DR mismatch in a
subsequent transplant may result in poorer survival due to underlying dono
r-specific HLA-DR aAb. If confirmed in a retrospective study of retransplan
t patients, B cell donor crossmatches using antiglobulin complement-depende
nt cytotoxicity or flow cytometry would appear essential if this barrier we
re to be crossed.