title: De novo donor-specific human leukocyte antigen antibodies early after kidney transplantation.
abstract: BACKGROUND
  Our aim was to determine the incidence of de novo donor-specific human leukocyte antigen (HLA) antibody (dnDSA) during the first year after kidney transplantation and the impact of early dnDSA on acute rejection and protocol biopsy findings.
  
  
  METHODS
  We selected all patients who received a kidney transplant at our center between July 2010 and March 2012. Single antigen bead assay was performed at 1, 4 and 12 months after transplantation. Only DSAs with a mean fluorescence intensity (MFI) of greater 999 were included.
  
  
  RESULTS
  We included 245 kidney transplant recipients who did not have a DSA before transplantation. At 12 months, 8.2% of the patients developed dnDSA; 2.4% of them were to HLA class I and 6.5% to HLA class II. Of the 32 patients with a dnDSA at 1 or 4 months, only 8 (25%) persisted at 12 months. The risk of antibody-mediated rejection (AMR) was higher in the dnDSA group. For the dnDSA group with MFI of 3,000 or greater (compared with the group with MFI<3,000), the hazard ratio for AMR was 10.6 (95% confidence interval, 2.27-49.5). The cumulative incidence of AMR or mixed rejection at 1 year was 30% in the group with dnDSA MFI level of 3,000 or greater but only 4% for the group with dnDSA with MFI less than 3,000. On 1-year protocol biopsies, the dnDSA group showed more interstitial inflammation, tubulitis, and glomerulitis.
  
  
  CONCLUSIONS
  We conclude that dnDSA occurring during the first posttransplantation year may be transient, and the risk of AMR is higher in patients with a dnDSA MFI level that is greater than 3,000.
authors.affiliation: 1 Department of Medicine, Mayo Clinic, Phoenix, AZ. 2 Department of Pathology and Laboratory Medicine, Mayo Clinic, Phoenix, AZ. 3 Department of Surgery, Mayo Clinic, Phoenix, AZ. 4 Address correspondence to: Raymond L. Heilman, M.D., Department of Medicine, Mayo Clinic, 5777 East Mayo Blvd, Phoenix, AZ 85054.
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Heilman
authors.forename: Ala
authors.initials: A
authors.lastname: Nijim
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Desmarteau
authors.forename: Hasan
authors.initials: H
authors.lastname: Khamash
authors.forename: Marcelo Jorge
authors.initials: MJ
authors.lastname: Pando
authors.forename: Maxwell L
authors.initials: ML
authors.lastname: Smith
authors.forename: Harini A
authors.initials: HA
authors.lastname: Chakkera
authors.forename: Janna
authors.initials: J
authors.lastname: Huskey
authors.forename: Riccardo
authors.initials: R
authors.lastname: Valdez
authors.forename: Kunam Sudhakar
authors.initials: KS
authors.lastname: Reddy
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000276:immunology; D001706:Biopsy; D015331:Cohort Studies; D005260:Female; D006084:Graft Rejection / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D007676:Kidney Failure, Chronic / Q000276:immunology* / Q000601:surgery*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II