Author/Authors :
Graff, Ralph J. Saint Louis University - School of Medicine, Center for Outcomes Research - Histocompatibility and Immunology Laboratory, USA , Graff, Ralph J. Dartmouth Hitchcock Medical Center, USA , Xiao, Huiling Saint Louis University - School of Medicine, Center for Outcomes Research, USA , Duffy, Brian Saint Louis University - School of Medicine - Histocompatibility and Immunology Laboratory, USA , Schnitzler, Mark A. Saint Louis University - School of Medicine, Center for Outcomes Research, USA , Axelrod, David Dartmouth Hitchcock Medical Center, USA , Lentine, Krista L. Saint Louis University - School of Medicine, Center for Outcomes Research - Department of Surgery, Division of Abdominal Organ Transplantation, USA
Abstract :
We analyzed clinical factors and graft survival associated with complement-dependent microcytotoxicity (CDC) crossmatch (XM) positive (+) kidney transplants in 1995 to 2009 United Network of Sharing (UNOS) registry data. CDCXM negative (-) transplants were selected from centers and years in which at least one CDCXM+ transplant was performed at a given center in a given year. CDCXM+ and CDCXM- results were compared with bivariate and multivariate survival analysis. Our observations are as follows: (1) The risk of graft loss with CDCXM+ vs. CDCXM- results was markedly lower than the risk observed historically,e.g.,living donor (LD)-CDCXM+ absolute all-cause graft survival reductions were 0.7% at 24 hours (P=0.007),2.9% at one year (P 0.0001),3.7% at five years (P 0.0001); deceased donor (DD)-CDCXM+ absolute graft survival reductions were 0.7% at 24 hours (P=0.02),3.5% at one year (P 0.0001),2.7% at five years (P=0.0009). On covariate adjustment,the only significant association of CDCXM+ vs. CDCXM- results was with one-year graft loss risk: LD aHR 1.44 (95% CI 1.05-1.96),DD aHR 1.33 (CI 1.10-1.61). (2) CDCXM+ transplantation was more commonly performed among groups disadvantaged with respect to transplant access,including sensitized,previously transplanted women and black recipients. (3) In CDCXM+ recipients,there was a high percentage of flow cytometry (FC) XM- and autoXM+ results. After removing these groups,outcomes with CDCXM+ results were relatively good. (4) CDCXM+/FCXM+ vs. CDCXM-/FCXM- graft loss risk was observed only in LD recipients transplanted at centers performing fewer than 10 such transplants during the study period: 11.0% reduction (P 0.0001) and aHR of 2.86 (CI 1.18-6.94) at one year; 14.7% reduction (P 0.0001) and aHR of 1.77 (CI 0.88-3.58) at five years. Although using CDCXM+ as a contraindication to transplantation has been associated with virtual elimination of hyperacute rejection,the negative effect of a CDCXM+ in contemporary practice is relatively small,questioning the value of the CDCXM as a standalone test.
