title: The Association Between Broad Antigen HLA Mismatches, Eplet HLA Mismatches and Acute Rejection After Kidney Transplantation.
abstract: BACKGROUND
  Epitope matching, which evaluates mismatched amino acids within antigen-antibody interaction sites (eplets), may better predict acute rejection than broad antigen matching alone. We aimed to determine the association between eplet mismatches and acute rejection in kidney transplant recipients.
  
  
  METHODS
  The association between eplet mismatches, broad antigen mismatches and acute rejection was assessed using adjusted Cox proportional hazard regression. Model discrimination for acute rejection was evaluated using the area under receiver operating characteristic curves.
  
  
  RESULTS
  Of the 3,499 kidney transplant recipients from 2006 to 2011, the average (SD) number of broad antigen and eplet mismatches were 3.4 (1.7) and 22.8 (12.2), respectively. Compared with 0 to 2 eplet mismatches, the adjusted hazard ratio (HR) for acute rejection among those with 20 or greater eplet mismatches was 2.16 (95% confidence interval [CI], 1.33-3.52;P= 0.001). The adjusted area under the curve for broad antigen mismatches was 0.58 (95% CI, 0.56-0.61), similar to that for eplet mismatches (HR, 0.59; 95% CI, 0.56-0.61;P= 0.365). In recipients who were considered as low immunological risk (0-2 broad antigen HLA-ABDR mismatch), those with 20 or greater eplet mismatches experienced an increased risk of rejection compared to those with less than 20 mismatches (adjusted HR, 1.85; 95% CI, 1.11-3.08;P= 0.019).
  
  
  CONCLUSIONS
  Increasing number of eplet mismatches is associated with acute rejection in kidney transplant recipients. Consideration of eplet HLA mismatches may improve risk stratification for acute rejection in a selected group of kidney transplant candidates.
authors.affiliation: School of Medicine and Pharmacology, The University of Western Australia, Crawley, Australia.
authors.forename: Hung Thanh
authors.initials: HT
authors.lastname: Do Nguyen
authors.affiliation: Sydney School of Public Health, The University of Sydney, Sydney, Australia.; Centre for Kidney Research, The Children's Hospital at Westmead.
authors.forename: Germaine
authors.initials: G
authors.lastname: Wong
authors.affiliation: Sydney School of Public Health, The University of Sydney, Sydney, Australia.; Centre for Transplant and Renal Research, Westmead Hospital, Westmead, Australia.
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: Chapman
authors.affiliation: ANZDATA Registry, Adelaide, Australia.; Nephrology and Transplantation Services, The Queen Elizabeth Hospital, Adelaide, Australia.; Discipline of Medicine, The University of Adelaide, Adelaide, Australia.; Discipline of Public Health, The University of Adelaide, Adelaide, Australia.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: McDonald
authors.affiliation: Nephrology and Transplantation Services, The Queen Elizabeth Hospital, Adelaide, Australia.; Discipline of Medicine, The University of Adelaide, Adelaide, Australia.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Coates
authors.affiliation: Australian RedCross Blood Service, Sydney, Australia.
authors.forename: Narelle
authors.initials: N
authors.lastname: Watson
authors.affiliation: ANZDATA Registry, Adelaide, Australia.; Nephrology and Transplantation Services, The Queen Elizabeth Hospital, Adelaide, Australia.; Discipline of Medicine, The University of Adelaide, Adelaide, Australia.
authors.forename: Graeme R
authors.initials: GR
authors.lastname: Russ
authors.affiliation: Department of Clinical Immunology, Fiona Stanley Hospital, Perth, Australia.; School of Pathology and Laboratory Medicine, The University of Western Australia, Crawley, Australia.
authors.forename: Lloyd
authors.initials: L
authors.lastname: D'Orsogna
authors.affiliation: School of Medicine and Pharmacology, The University of Western Australia, Crawley, Australia.; Department of Renal Medicine, Sir Charles Gairdner Hospital, Nedlands, Australia.
authors.forename: Wai Hon
authors.initials: WH
authors.lastname: Lim