title: H-Y as a minor histocompatibility antigen in kidney transplantation: a retrospective cohort study.
abstract: BACKGROUND
  In haematopoietic stem-cell transplantation, male recipients of female grafts have an increased risk of graft-versus-host disease and female recipients have both an increased risk of rejection of male grafts and of specific T-cell and antibody reactivity against H-Y encoded gene products. By contrast, in kidney transplantation, the role of H-Y as a minor histocompatibility antigen has been disputed. We aimed to investigate whether an immunological H-Y effect occurs in kidney transplantation.
  
  
  METHODS
  We did a retrospective cohort study between 1985 and 2004 in 195 516 recipients of allografts from deceased donors. We used multivariate statistical methods to compare graft survival and death-censored graft survival rates for female and male donor kidneys in female and male recipients at 1 and 10 years.
  
  
  RESULTS
  Graft loss was more common with kidneys from female donors than with those from male donors (p<0.001) after both 1 and 10 years. Female recipients had a lower rate of graft failure between the end of the first year and the end of the tenth year (p<0.001). Compared with all other combinations of sex, transplantation of male donor kidneys into female recipients was associated with an increased risk of graft failure during the first year (hazard ratio [HR] 1.08, 95% CI 1.03-1.14, p=0.003; death censored HR 1.11, 1.04-1.19, p=0.003) and between 2 and 10 years (HR 1.06, 1.01-1.10, p=0.008; death censored HR 1.10, 1.05-1.16, p<0.001).
  
  
  CONCLUSIONS
  H-Y minor histocompatibility affects human kidney transplantation.
authors.affiliation: Department of Haematology, University Hospital Basel, Switzerland. hematology@uhbs.ch
authors.forename: Alois
authors.initials: A
authors.lastname: Gratwohl
authors.forename: Bernd
authors.initials: B
authors.lastname: Döhler
authors.forename: Martin
authors.initials: M
authors.lastname: Stern
authors.forename: Gerhard
authors.initials: G
authors.lastname: Opelz
mesh_terms: D000328:Adult; D000818:Animals; D015331:Cohort Studies; D005260:Female; D006085:Graft Survival / Q000276:immunology*; D006182:H-Y Antigen / Q000276:immunology*; D006801:Humans; D016030:Kidney Transplantation / Q000276:immunology* / Q000706:statistics & numerical data; D008297:Male; D051379:Mice; D015337:Multicenter Studies as Topic; D012189:Retrospective Studies; D012737:Sex Factors; D015996:Survival Rate
chemical_list: D006182:H-Y Antigen