title: Pretransplant donor-specific HLA antibodies detected by single antigen bead flow cytometry: risk factors and outcomes after kidney transplantation.
abstract: BACKGROUND
  The clinical significance of pretransplant donor-specific antibodies (pre-Tx DSAs) detected by single antigen bead flow cytometry (SAB-FC) remains unclear. Our aim was to investigate the impact that pre-Tx DSAs detected by SAB-FC have on the early and late clinical outcomes.
  
  
  METHODS
  We retrospectively tested stored frozen pre-Tx sera from 222 deceased-donor kidney transplants performed between November 1997 and November 2006. All patients had a negative complement-dependent cytotoxicity (CDC) cross-match with the donor. Median follow up was 5.1 years.
  
  
  RESULTS
  Twenty-two (10%) patients had pre-Tx HLA antibodies detected by CDC. Pre-Tx HLA antibodies were detected using SAB-FC in the sera of 46 (20.7%) patients; 36 (16.2%) of them presented pre-Tx DSAs, 18 had class I antibodies, 9 class II, and 9 patients presented both classes. Mean pre-Tx DSA class I/II was 2360/1972 (MFI) mean fluorescence index in non CDC-sensitized patients. Pre-Tx DSAs were associated with female sex, retransplants, and pretransplant transfusions. Patients with Pre-Tx DSAs more than 1000 MFI and negative CDC screening presented a higher percentage of delayed graft function (61.1% versus 38.9%), more episodes of acute vascular rejection (33.3% versus 13.7%), and chronic rejection as the cause of allograft failure (22.2% versus 9.7%) compared with non-pre-Tx DSAs patients. Five-year allograft survival was significantly worse in patients with pre-Tx DSA (68.5% versus 82%, P = .006) and in patients with pre-Tx DSA class II more than 1000 MFI (43% versus 82%, P = .009). We didn't find differences in patient survival.
  
  
  CONCLUSIONS
  Pre-Tx DSAs detected by SAB-FC were more frequent in female recipients, and they were associated with acute vascular and chronic rejection and a poorer graft outcome.
authors.affiliation: Nephrology and Haemodialysis Department, Dr Peset Universitary Hospital, Gaspar Aguilar Valencia, Spain. jkanter@senefro.org
authors.forename: J
authors.initials: J
authors.lastname: Kanter Berga
authors.forename: A
authors.initials: A
authors.lastname: Sancho Calabuig
authors.forename: E
authors.initials: E
authors.lastname: Gavela Martinez
authors.forename: N
authors.initials: N
authors.lastname: Puig Alcaraz
authors.forename: S
authors.initials: S
authors.lastname: Beltran Catalan
authors.forename: A
authors.initials: A
authors.lastname: Avila Bernabeu
authors.forename: J
authors.initials: J
authors.lastname: Crespo Albiach
authors.forename: J A
authors.initials: JA
authors.lastname: Montoro
authors.forename: L M
authors.initials: LM
authors.lastname: Pallardo Mateu
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D005434:Flow Cytometry; D006084:Graft Rejection / Q000276:immunology; D006085:Graft Survival; D006680:HLA Antigens / Q000097:blood*; D006648:Histocompatibility; D006650:Histocompatibility Testing / Q000379:methods*; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D053208:Kaplan-Meier Estimate; D016030:Kidney Transplantation / Q000009:adverse effects / Q000276:immunology* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D006680:HLA Antigens; D007518:Isoantibodies