title: Allocating Deceased Donor Kidneys to Candidates with High Panel-Reactive Antibodies.
abstract: OBJECTIVE
  In December of 2014, the Organ Procurement and Transplant Network implemented a new Kidney Allocation System (KAS) for deceased donor transplant, with increased priority for highly sensitized candidates (calculated panel-reactive antibody [cPRA] >99%). We used a modified version of the new KAS to address issues of access and equity for these candidates.
  
  
  METHODS
  In a simulation, 10,988 deceased donor kidneys transplanted into waitlisted recipients in 2010 were instead allocated to candidates with cPRA≥80% (n=18,004). Each candidate's unacceptable donor HLA antigens had been entered into the allocation system by the transplant center. In simulated match runs, kidneys were allocated sequentially to adult ABO identical or permissible candidates with cPRA 100%, 99%, 98%, etc. to 80%. Allocations were restricted to donor/recipient pairs with negative virtual crossmatches.
  
  
  RESULTS
  The simulation indicated that 2111 of 10,988 kidneys (19.2%) would have been allocated to patients with cPRA 100% versus 74 of 10,988 (0.7%) that were actually transplanted. Of cPRA 100% candidates, 74% were predicted to be compatible with an average of six deceased donors; the remaining 26% seemed to be incompatible with every deceased donor organ that entered the system. Of kidneys actually allocated to cPRA 100% candidates in 2010, 66% (49 of 74) were six-antigen HLA matched/zero-antigen mismatched (HLA-A, -B, and -DR) with their recipients versus only 11% (237 of 2111) in the simulation. The simulation predicted that 10,356 of 14,433 (72%) candidates with cPRA 90%-100% could be allocated an organ compared with 7.3% who actually underwent transplant.
  
  
  CONCLUSIONS
  Data in this simulation are consistent with early results of the new KAS; specifically, nearly 20% of deceased donor kidneys were (virtually) compatible with cPRA 100% candidates. Although most of these candidates were predicted to be compatible with multiple donors, approximately one-quarter are unlikely to receive a single offer.
authors.affiliation: Department of Pathology, Emory University Hospital, Atlanta, Georgia;
authors.forename: Howard M
authors.initials: HM
authors.lastname: Gebel
authors.affiliation: Scientific Registry of Transplant Recipients, Minneapolis Medical Research Foundation, Minneapolis, Minnesota; Department of Medicine, Hennepin County Medical Center, Minneapolis, Minnesota;
authors.forename: Bertram L
authors.initials: BL
authors.lastname: Kasiske
authors.affiliation: Scientific Registry of Transplant Recipients, Minneapolis Medical Research Foundation, Minneapolis, Minnesota;
authors.forename: Sally K
authors.initials: SK
authors.lastname: Gustafson
authors.affiliation: Scientific Registry of Transplant Recipients, Minneapolis Medical Research Foundation, Minneapolis, Minnesota;
authors.forename: Joshua
authors.initials: J
authors.lastname: Pyke
authors.affiliation: Scientific Registry of Transplant Recipients, Minneapolis Medical Research Foundation, Minneapolis, Minnesota;
authors.forename: Eugene
authors.initials: E
authors.lastname: Shteyn
authors.affiliation: Scientific Registry of Transplant Recipients, Minneapolis Medical Research Foundation, Minneapolis, Minnesota; Department of Medicine, Hennepin County Medical Center, Minneapolis, Minnesota; Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota; isran001@umn.edu.
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Israni
authors.affiliation: Department of Pathology, Emory University Hospital, Atlanta, Georgia;
authors.forename: Robert A
authors.initials: RA
authors.lastname: Bray
authors.affiliation: Scientific Registry of Transplant Recipients, Minneapolis Medical Research Foundation, Minneapolis, Minnesota; Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota;
authors.forename: Jon J
authors.initials: JJ
authors.lastname: Snyder
authors.affiliation: Departments of Medicine and Surgery, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and.
authors.forename: John J
authors.initials: JJ
authors.lastname: Friedewald
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Dorry L
authors.initials: DL
authors.lastname: Segev
mesh_terms: D015415:Biomarkers / Q000097:blood; D003198:Computer Simulation; D046148:Donor Selection; D006680:HLA Antigens / Q000276:immunology*; D006297:Health Services Accessibility; D006648:Histocompatibility; D006650:Histocompatibility Testing; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D016030:Kidney Transplantation / Q000379:methods*; D011237:Predictive Value of Tests; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D014019:Tissue Donors / Q000600:supply & distribution*; D009927:Tissue and Organ Procurement; D014481:United States; D014850:Waiting Lists
chemical_list: D015415:Biomarkers; D006680:HLA Antigens; D007518:Isoantibodies
keywords: HLA antigens; adult; humans; kidney; kidney transplantation; tissue donors; transplant outcomes; transplantation
references.citation: N Engl J Med. 2011 Jul 28;365(4):318-26
references.pmid: 21793744
references.citation: Curr Opin Organ Transplant. 2011 Aug;16(4):439-43
references.pmid: 21666478
references.citation: Am J Transplant. 2012 Dec;12(12):3191-212
references.pmid: 23157207
references.citation: Transplant Rev (Orlando). 2013 Apr;27(2):50-6
references.pmid: 23481320
references.citation: Curr Opin Nephrol Hypertens. 2013 Nov;22(6):681-8
references.pmid: 24076558
references.citation: Am J Transplant. 2014 Jul;14(7):1592-8
references.pmid: 24934640
references.citation: J Am Soc Nephrol. 2014 Aug;25(8):1842-8
references.pmid: 24833128
references.citation: Am J Transplant. 2014 Sep;14(9):1964-75
references.pmid: 25088978
references.citation: Am J Transplant. 2014 Dec;14(12):2917
references.pmid: 25274464
references.citation: Am J Transplant. 2015 Jan;15(1):284-5
references.pmid: 25403877
references.citation: Am J Transplant. 2015 Jan;15(1):101-18
references.pmid: 25534446
references.citation: Am J Transplant. 2015 Sep;15(9):2465-9
references.pmid: 26137963
references.citation: Clin Transpl. 2011;:1-16
references.pmid: 22755397
references.citation: Hum Immunol. 2002 May;63(5):339-52
references.pmid: 11975978
references.citation: Transplantation. 2003 Mar 27;75(6):889-97
references.pmid: 12660520
references.citation: Science. 1988 Sep 30;241(4874):1815-7
references.pmid: 3051377
references.citation: Transpl Int. 1988 Jul;1(2):53-7
references.pmid: 3076380
references.citation: Clin Transplant. 1999 Aug;13(4):287-95
references.pmid: 10485368
references.citation: Hum Immunol. 2006 Jun;67(6):419-23
references.pmid: 16728263
references.citation: Am J Transplant. 2006 Oct;6(10):2307-15
references.pmid: 16939516
references.citation: N Engl J Med. 2008 Jul 17;359(3):242-51
references.pmid: 18635429
references.citation: Transplantation. 2009 Aug 27;88(4):447-52
references.pmid: 19696624
references.citation: Am J Transplant. 2010 Jan;10(1):26-9
references.pmid: 19958328
references.citation: Nat Rev Nephrol. 2010 May;6(5):297-306
references.pmid: 20234355
references.citation: Curr Opin Nephrol Hypertens. 2010 Nov;19(6):598-602
references.pmid: 20720491
references.citation: Am J Transplant. 2011 Apr;11(4):719-24
references.pmid: 21114658
references.citation: Curr Opin Organ Transplant. 2011 Aug;16(4):404-9
references.pmid: 21666476