title: Impact of human leukocyte antigen mismatching on outcomes of liver transplantation: a meta-analysis.
abstract: OBJECTIVE
  To assess the effect of human leukocyte antigen (HLA) mismatching on liver graft outcome and acute rejection from a meta-analysis of available cohort studies.
  
  
  METHODS
  Articles in PubMed/MEDLINE, EMBASE and the Cochrane database from January 1970 to June 2009, including non-English literature identified in these databases, were searched. Only studies comparing HLA or sub-phenotype matching with mismatching were extracted. The percentage of graft survival was extracted by "Engauge Digitizer" from survival curves if the raw data were not displayed. A meta-analysis was performed when at least 3 studies provided data.
  
  
  RESULTS
  Sixteen studies met the inclusion criteria. A lower number of HLA mismatches (0-2 vs 3-6) did reduce the incidence of acute rejection (relative risk: 0.77, P = 0.03). The degree of HLA mismatching (0-2 vs 3-6) had no significant effect on 1-year [hazard ratio (HR): 1.04, P = 0.68] and 5-year (HR: 1.09, P = 0.38) graft survival. In sub-phenotype analysis, the degree of HLA-A, B and DR mismatching (0 vs 1-2) had no significant effect on 1-year and 5-year graft survival, either. The HRs and P-values were 0.95, 0.71 (HLA-A, 1-year); 1.06, 0.60 (HLA-A, 5-year); 0.77, 0.16 (HLA-B, 1-year); 1.07, 0.56 (HLA-DR, 1-year); 1.18, 0.23 (HLA-DR, 5-year), respectively.
  
  
  CONCLUSIONS
  The results of this systematic review imply that good HLA compatibility can reduce the incidence of acute rejection in spite of having no influence on graft outcomes. To obtain a short recovery time and minimize rejection post transplantation, HLA matching studies should be considered before the operation.
authors.affiliation: Department of Hepatobiliary Surgery and Liver Transplantation Centre, Children's Hospital of Chongqing Medical University, 136, Zhongshan 2nd Road, Yuzhong District, Chongqing 400014, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Lan
authors.forename: Ming-Man
authors.initials: MM
authors.lastname: Zhang
authors.forename: Cong-Lun
authors.initials: CL
authors.lastname: Pu
authors.forename: Chun-Bao
authors.initials: CB
authors.lastname: Guo
authors.forename: Quan
authors.initials: Q
authors.lastname: Kang
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Li
authors.forename: Xiao-Ke
authors.initials: XK
authors.lastname: Dai
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Deng
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xiong
authors.forename: Zhi-Mei
authors.initials: ZM
authors.lastname: Ren
mesh_terms: D016208:Databases, Factual; D000939:Epitopes; D006084:Graft Rejection / Q000276:immunology*; D006085:Graft Survival / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D016031:Liver Transplantation / Q000009:adverse effects / Q000276:immunology; D016896:Treatment Outcome
chemical_list: D000939:Epitopes; D006680:HLA Antigens