title: A virtual crossmatch protocol significantly increases access of highly sensitized patients to deceased donor kidney transplantation.
abstract: BACKGROUND
  Patients with preexisting antihuman leukocyte antigen (HLA) antibodies (sensitized patients) are more likely to have a positive crossmatch with possible donors and have a lower likelihood of receiving a renal transplant with longer wait times. A virtual crossmatch protocol using solid-phase technology to determine the specificity of anti-HLA antibodies may improve the probability of identifying a crossmatch-negative compatible donor and increase access of sensitized patients to kidney transplantation.
  
  
  METHODS
  A virtual crossmatch protocol was implemented on October 1, 2006 with solid-phase HLA antibody characterization for all sensitized patients on the waiting list. Transplant rates for the period from October 2006 to June 2008 were compared with Scientific Registry of Transplant Recipients (SRTR) data from 2006 to determine national transplant rates for sensitized patients.
  
  
  RESULTS
  SRTR data for 2006 showed that nationally 590 of 10,659 transplants (5.5%) were in-patients with panel reactive antibody (PRA) more than or equal to 80%. During 2006 to 2008, after initiation of the virtual crossmatch protocol, we performed 122 deceased donor kidney transplants, of which 15 (12.3%) sensitized patients (PRA>or=80%) received transplants (P=0.004 compared with SRTR national data), with 9 (7.4%) patients having a PRA more than 90%. The virtual crossmatch protocol was predictive of a negative-final crossmatch and eliminated the use of preliminary cross-matching with attendant cost savings of more than $100,000.
  
  
  CONCLUSIONS
  Initiation of a virtual crossmatch protocol using solid-phase histocompatibility techniques significantly increased access of sensitized patients to kidney transplantation and was more cost effective. Usage of a virtual crossmatch may facilitate greater sharing of kidneys to improve access to transplantation for sensitized recipients.
authors.affiliation: Texas Transplant Institute, Methodist Specialty and Transplant Hospital, San Antonio, TX 78229, USA. adam.bingaman@mhshealth.com
authors.forename: Adam W
authors.initials: AW
authors.lastname: Bingaman
authors.forename: Cathi L
authors.initials: CL
authors.lastname: Murphey
authors.forename: Juan
authors.initials: J
authors.lastname: Palma-Vargas
authors.forename: Francis
authors.initials: F
authors.lastname: Wright
mesh_terms: D002102:Cadaver; D006085:Graft Survival / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology*; D006681:HLA-D Antigens / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006650:Histocompatibility Testing / Q000379:methods*; D007114:Immunization; D007518:Isoantibodies / Q000276:immunology; D016030:Kidney Transplantation / Q000276:immunology*; D012189:Retrospective Studies; D014019:Tissue Donors; D023001:Transplantation Tolerance; D014184:Transplantation, Homologous / Q000276:immunology; D014584:User-Computer Interface
chemical_list: D006680:HLA Antigens; D006681:HLA-D Antigens; D015395:Histocompatibility Antigens Class I; D007518:Isoantibodies