title: Renal allograft outcome in recipients of positive-crossmatch combined liver-kidney transplantation.
abstract: BACKGROUND
  Successful kidney transplantation despite positive crossmatch (+CXM) before transplantation is well recognized in combined liver-kidney transplant (CLKT) recipients. This is probably due to immunologic protection of the renal allograft (RA) conferred by the liver allograft. However, occurrences of antibody-mediated rejection and poor long-term RA outcome is also documented with +CXM CLKT recipients, suggesting that such immunologic protection may not be universal.
  
  
  METHODS
  A total of 1,401 CLKT recipients with known status of pre-transplantation CXM were identified from the United Network for Organ Sharing registry from January 1, 1986, to December 31, 2006. Univariate analysis for significant differences in clinical variables and Kaplan-Meier estimate for patient and graft survivals were performed. The results were compared between positive and negative CXM groups.
  
  
  RESULTS
  Pre-transplantation +CXM was seen in 17.3% (242/1401) of CLKT recipients studied. The demographic and clinical characteristics were similar between the groups, except for higher panel reactive antibody level and CXM positivity in female recipients. Outcome analysis showed higher RA rejection (19.3% vs 10.8%; P = .026) and increased hospital length of stay (37.3 ± 46.0 vs 28.8 ± 33.2 days; P = .028) in the +CXM group. RA survivals at 1, 3, and 5 years were 8%, 7%, and 6% lower in the +CXM group. The patient and liver allograft survivals were not different between the groups.
  
  
  CONCLUSIONS
  In CLKT recipients with pre-transplantation +CXM, the immunologic protection of RA conferred by the liver allograft is less robust than previously perceived and may lead to higher rejection rate and poor RA outcome. This can be mitigated with routine pre-transplantation CXM.
authors.affiliation: Division of Nephrology and Transplantation, William-Beaumont Hospital, Royal Oak, Michigan. Electronic address: ravi.parasuraman@beaumont.edu.
authors.forename: R K
authors.initials: RK
authors.lastname: Parasuraman
authors.forename: K K
authors.initials: KK
authors.lastname: Venkat
authors.forename: M
authors.initials: M
authors.lastname: Abouljoud
authors.forename: D
authors.initials: D
authors.lastname: Samarapungavan
authors.forename: L
authors.initials: L
authors.lastname: Rocher
authors.forename: A J
authors.initials: AJ
authors.lastname: Koffron
mesh_terms: D005260:Female; D006084:Graft Rejection; D006085:Graft Survival; D006650:Histocompatibility Testing; D006801:Humans; D016030:Kidney Transplantation; D016031:Liver Transplantation; D008297:Male; D012042:Registries; D014184:Transplantation, Homologous; D016896:Treatment Outcome