title: HLA and MICA: targets of antibody-mediated rejection in heart transplantation.
abstract: BACKGROUND
  The goal of this study was to determine whether antidonor antibodies directed against human leukocyte antigen (HLA) or endothelial cells (ECs) expressed antigens, including major histocompatibility complex class I chain-related antigens A (MICA) are associated with the diagnosis of antibody-mediated rejection (AMR) in heart transplant recipients.
  
  
  METHODS
  We studied posttransplant antidonor HLA antibodies in 168 heart allograft recipients transplanted from October 2001 to December 2005. Among them, there were 37 AMR+ patients and 131 age- and sex- matched AMR- controls. Sera were collected at the time of protocol biopsies and tested for the presence of HLA antibodies. Seventy-two of the 168 patients were genotyped for donor and recipient MICA alleles and were tested for the presence of anti-MICA antibodies. Thirty-one patients who never developed antibodies to HLA or MICA were further tested for anti-EC antibodies.
  
  
  CONCLUSIONS
  Of 37 AMR+ patients, 22 (60%) developed donor-specific antibodies (DSA) to HLA compared with 6 of 131(4%) AMR- patients (P<0.0001). Of the remaining 15 AMR+ patients, 5 had anti-HLA antibodies that were not donor specific and 10 did not show any HLA antibodies. In the subgroup of 72 patients, all 19 AMR+ patients had clearly demonstrable antibodies reactive with donor HLA, MICA or with nondonor-derived ECs, with 30% of them showed antibodies directed to non-HLA antigens. The incidence of transplant coronary artery disease was significantly higher in patients who had DSA to HLA and MICA compared with patients without DSA.
authors.affiliation: Department of Pathology and Laboratory Medicine, UCLA Immunogenetics Center, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA. jpzhang@mednet.ucla.edu
authors.forename: Qiuheng
authors.initials: Q
authors.lastname: Zhang
authors.forename: J Michael
authors.initials: JM
authors.lastname: Cecka
authors.forename: David W
authors.initials: DW
authors.lastname: Gjertson
authors.forename: Ping
authors.initials: P
authors.lastname: Ge
authors.forename: Marlene L
authors.initials: ML
authors.lastname: Rose
authors.forename: Jignesh K
authors.initials: JK
authors.lastname: Patel
authors.forename: Abbas
authors.initials: A
authors.lastname: Ardehali
authors.forename: Jon A
authors.initials: JA
authors.lastname: Kobashigawa
authors.forename: Michael C
authors.initials: MC
authors.lastname: Fishbein
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Reed
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D016022:Case-Control Studies; D002478:Cells, Cultured; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000276:immunology*; D042783:Endothelial Cells / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006084:Graft Rejection / Q000175:diagnosis / Q000276:immunology*; D006085:Graft Survival; D006680:HLA Antigens / Q000276:immunology*; D016027:Heart Transplantation / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012698:Serologic Tests; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D007518:Isoantibodies; C099187:MHC class I-related chain A