title: Casting a smaller net into a bigger donor pool: A single center's experience with the new kidney allocation system.
abstract: The new kidney allocation system (KAS) provides additional allocation points for candidates with broad HLA sensitization in an effort to increase transplant rates for this underserved population. Following the implementation of KAS, our center lowered the HLA antibody threshold for listing unacceptable antigens from a cytotoxicity crossmatch level to a flow cytometric crossmatch level increasing Calculated Panel Reactive Antibody (CPRA) values and allocation points, yet restricting acceptable donor HLA phenotypes. As a result, many sensitized candidates were transitioned from 50% to 98% CPRA categories into the 99% CPRA regional share and 100% CPRA national share categories. Exposure to these larger donor pools significantly increased transplantation with compatible donors for 100% CPRA candidates, but regional sharing was not sufficient to increase transplantation rates for our 99% CPRA candidates. Competition within the 100% CPRA cohort identified inequities for 99.99-100.0% CPRA candidates and highlighted the continued need for desensitization therapies to reduce immunological barriers and provide transplant opportunities for the most highly sensitized candidates.
authors.affiliation: Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Houp
authors.affiliation: Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Karl P
authors.initials: KP
authors.lastname: Schillinger
authors.affiliation: Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Eckstein
authors.affiliation: Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Renato M
authors.initials: RM
authors.lastname: Vega
authors.affiliation: Department of Surgery, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Niraj M
authors.initials: NM
authors.lastname: Desai
authors.affiliation: Department of Surgery, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Bonnie E
authors.initials: BE
authors.lastname: Lonze
authors.affiliation: Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA. Electronic address: ajackson@jhmi.edu.
authors.forename: Annette M
authors.initials: AM
authors.lastname: Jackson
mesh_terms: D015331:Cohort Studies; D033161:Government Regulation; D006680:HLA Antigens / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D007114:Immunization; D007518:Isoantibodies / Q000378:metabolism; D016030:Kidney Transplantation; D012189:Retrospective Studies; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D066027:Transplant Recipients; D016896:Treatment Outcome; D014481:United States
chemical_list: D006680:HLA Antigens; D007518:Isoantibodies
keywords: Calculated Panel Reactive Antibody (CPRA); HLA sensitization; Kidney allocation system (KAS); Kidney transplantation; Unacceptable antigens