title: CPRA for allocation of kidneys in the US: More candidates ≥98% CPRA, lower positive crossmatch rates and improved transplant rates for sensitized patients.
abstract: In 2009 calculated panel reactive antibody (CPRA) replaced PRA as the metric for HLA sensitization in the US kidney allocation system. During the next four years, registrants with at least one unacceptable antigen increased (34-40%) and registrants with ≥98% PRA/CPRA increased from 7% to 9% of the waitlist. These changes were accompanied by a reduction in kidney offers refused for positive crossmatch: 14,137 (1.7%) in 2009 and 3,310 in 2013 (0.4%). Registrants with ≥98% PRA/CPRA had highest rates of refusal but also showed substantial improvement (20% in 2009 vs 8% in 2013). For registrants with ≥98% PRA/CPRA, 45% of accepted offers in 2009 were not transplanted into the intended recipient compared to 11% in 2013. Transplant rates remained low for these patients (∼50/1000 active patient-years), but rates improved for patients with 80-97% PRA/CPRA (223/1000 active patient-years in 2009 vs 354/1000 in 2013). In 2013, 40% regraft candidates had CPRA ≥98% compared to 4% of primary graft candidates. More females than males were ≥98% CPRA (14% vs 7%) and more females had CPRA above 0 (50% vs 28%). In the CPRA era, listing of unacceptable antigens increased, positive crossmatches were diminished and transplant rates for sensitized patients improved.
authors.affiliation: Children's Hospital Los Angeles and University of Southern California, Los Angeles, CA, United States. Electronic address: lbaxterlowe@chla.usc.edu.
authors.forename: Lee Ann
authors.initials: LA
authors.lastname: Baxter-Lowe
authors.affiliation: United Network for Organ Sharing, Richmond, VA, United States.
authors.forename: Anna
authors.initials: A
authors.lastname: Kucheryavaya
authors.affiliation: Stanford University, Palo Alto, CA, United States.
authors.forename: Dolly
authors.initials: D
authors.lastname: Tyan
authors.affiliation: Cedars-Sinai and University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Nancy
authors.initials: N
authors.lastname: Reinsmoen
mesh_terms: D001788:Blood Grouping and Crossmatching; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007114:Immunization; D007518:Isoantibodies / Q000378:metabolism*; D016030:Kidney Transplantation; D008297:Male; D012737:Sex Factors; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D066027:Transplant Recipients; D014481:United States
chemical_list: D006680:HLA Antigens; D007518:Isoantibodies
keywords: CPRA; Crossmatch; HLA antibodies; Kidney transplant; Sensitization