title: Relevance of posttransplant flow cytometric T- and B-cell crossmatches in tacrolimus-treated renal transplant patients.
abstract: BACKGROUND
  De novo development of anti-human leukocyte antigen (HLA) antibodies after transplantation is associated with increased rejection and decreased graft survival. In this study, the effect of posttransplant HLA antibodies on clinical outcome was evaluated in patients treated with tacrolimus by means of flow cytometric crossmatches (FCXm).
  
  
  METHODS
  T- and B-cell FCXm were performed retrospectively on posttransplant sera of patients who received a graft between 1997 and 1999. Ninety-four kidney-only recipients were tested and all FCXm positive sera were investigated for the presence of HLA class I and II antibodies by Flow panel reactive antibodies.
  
  
  RESULTS
  From 94 patients with a negative pretransplant complement-dependent cytotoxicity crossmatch, seven (7%) showed a positive pretransplant FCXm. After transplantation the FCXm became positive in five patients (6%). The predictive value of a positive FCXm after transplantation, and the log-transformed relative change in fluorescence ratio between pretransplant and posttransplant serum, were not significant to rejection within six months, nor to graft survival censored for death.
  
  
  CONCLUSIONS
  The presence of HLA antibodies before rejection or graft failure could only be shown in a minority of patients; most antibodies were detected after graft failure, especially after transplantectomy. Monitoring through antibody testing after transplantation on the basis of our results has no added value with tacrolimus-based immunosuppression.
authors.affiliation: Tissue Typing Laboratory, University Hospital Maastricht, the Netherlands.
authors.forename: Jo I V
authors.initials: JI
authors.lastname: Lenaers
authors.forename: Maarten H L
authors.initials: MH
authors.lastname: Christiaans
authors.forename: Christina E M
authors.initials: CE
authors.lastname: Voorter
authors.forename: Hans P
authors.initials: HP
authors.lastname: van Hooff
authors.forename: Ella M
authors.initials: EM
authors.lastname: van den Berg-Loonen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006084:Graft Rejection / Q000175:diagnosis* / Q000188:drug therapy; D006085:Graft Survival; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing / Q000379:methods*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013601:T-Lymphocytes / Q000276:immunology; D016559:Tacrolimus / Q000627:therapeutic use
chemical_list: D000906:Antibodies; D006680:HLA Antigens; D007166:Immunosuppressive Agents; D016559:Tacrolimus