title: Rapid decreases in donor-specific cytotoxic T lymphocyte precursor frequencies and graft outcome after liver and lung transplantation.
abstract: BACKGROUND
  A decrease in donor-specific T cell precursor frequencies as seen late, one or more years, after transplantation is assumed to reflect transplantation tolerance, a condition important for long term acceptance of the allograft. However, such late decreases also occur in recipients that developed chronic transplant dysfunction questioning its relevance in transplantation tolerance. We investigated whether early, i.e., the first 6 months, decreases in donor-specific T cell precursor frequencies reflect transplantation tolerance and predict graft outcome after liver and lung transplantation.
  
  
  METHODS
  Donor and third party specific cytotoxic (CTLp) and helper T lymphocyte precursor (HTLp) frequencies were analyzed in pretransplant and 1 (or 2) and 6-month blood samples taken from liver and lung recipients and were correlated with graft outcome.
  
  
  RESULTS
  In liver allograft recipients with good graft function (n=7), mean donor-specific CTLp frequencies decreased as early as 1 month after transplantation and remained low thereafter. In contrast, mean CTLp frequencies did not decrease in liver allograft recipients with chronic transplant dysfunction (n=6). In lung allograft recipients, donor-specific CTLp frequencies remained relatively high and frequencies were not different between recipients without (n=6) or with (n=6) chronic transplant dysfunction. Donor-specific HTLp frequencies did not change significantly after liver or lung transplantation and did not differ between recipients without or with chronic transplant dysfunction.
  
  
  CONCLUSIONS
  An early decrease in donor-specific CTLp correlates with good graft outcome after liver transplantation. Such rapid decreases in alloreactivity do not occur after lung transplantation illustrating the unique capacity of liver allografts to induce transplantation tolerance.
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital Groningen, and Groningen University, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: de Haan
authors.forename: A P
authors.initials: AP
authors.lastname: van den Berg
authors.forename: W
authors.initials: W
authors.lastname: van der Bij
authors.forename: B G
authors.initials: BG
authors.lastname: Hepkema
authors.forename: E
authors.initials: E
authors.lastname: Bruin-van Dijk
authors.forename: I
authors.initials: I
authors.lastname: van der Gun
authors.forename: S P
authors.initials: SP
authors.lastname: Lems
authors.forename: M J
authors.initials: MJ
authors.lastname: Slooff
authors.forename: E B
authors.initials: EB
authors.lastname: Haagsma
authors.forename: L F
authors.initials: LF
authors.lastname: de Leij
authors.forename: J
authors.initials: J
authors.lastname: Prop
mesh_terms: D006801:Humans; D016031:Liver Transplantation / Q000473:pathology* / Q000502:physiology; D016040:Lung Transplantation / Q000473:pathology* / Q000502:physiology; D013234:Stem Cells / Q000166:cytology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology*; D016896:Treatment Outcome