title: Predicting operational tolerance in pediatric living-donor liver transplantation by absence of HLA antibodies.
abstract: BACKGROUND
  The role of anti-human leukocyte antigen (HLA) antibodies in operational tolerance (OT) after pediatric living-donor liver transplantation (LDLT) remains inconclusive. We investigated whether the presence of HLA antibodies impeded the development of OT.
  
  
  METHODS
  We retrospectively examined the prevalence of anti-HLA antibodies in pediatric LDLT recipients before transplantation and at 3 weeks after transplantation and analyzed the significance of those antibodies in relation to later OT. Forty pediatric LDLTs were performed between April 1996 and December 2000 and followed up through July 2011, with sera available for measurement of HLA antibodies. Seventeen patients achieved OT (mean follow-up, 4571.9±544.7 days) and 23 patients did not achieve OT (mean follow-up, 4532.0±425.4 days). Protocol liver biopsy was done for 14 OT patients and 16 non-OT patients. Their sera were tested for anti-HLA class I and II antibodies using the LABScreen single antigen beads test, in which a 1000 mean fluorescence value was considered positive.
  
  
  RESULTS
  The prevalence of antibodies after transplantation in non-OT patients was higher than in OT patients (95.2% vs. 73.3%; P<0.001). The highest mean fluorescence intensity of antibodies was significantly higher in non-OT patients than in OT patients. The prevalence of HLA-B, HLA-C, HLA-DQ, and HLA-DR antibodies was significantly higher in non-OT patients than in OT patients. The highest mean fluorescence intensity of HLA-A, HLA-B, and HLA-DQ observed in non-OT patients was significantly higher than those in OT patients.
  
  
  CONCLUSIONS
  In our study, posttransplantation HLA antibodies were associated with the future absence of OT. A prospective study with more patients is necessary to confirm the predictive value of HLA antibodies for OT.
authors.affiliation: Department of Ubiquitous Health Informatics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. kwaki-tky@umin.ac.jp
authors.forename: Kayo
authors.initials: K
authors.lastname: Waki
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Koichi
authors.initials: K
authors.lastname: Mizuta
authors.forename: Michiko
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Miyuki
authors.initials: M
authors.lastname: Ozawa
authors.forename: Masaru
authors.initials: M
authors.lastname: Hirata
authors.forename: Masumi
authors.initials: M
authors.lastname: Nozawa
authors.forename: Junichi
authors.initials: J
authors.lastname: Kaneko
authors.forename: Koki
authors.initials: K
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Paul I
authors.initials: PI
authors.lastname: Terasaki
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kokudo
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006085:Graft Survival; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007223:Infant; D007518:Isoantibodies / Q000097:blood*; D016031:Liver Transplantation; D019520:Living Donors; D008297:Male; D012189:Retrospective Studies
chemical_list: D006680:HLA Antigens; D007518:Isoantibodies