title: Organ-specific differences in achieving tolerance.
abstract: OBJECTIVE
  When it comes to tolerance induction, kidney allografts behave differently from heart allografts that behave differently from lung allografts. Here, we examine how and why different organ allografts respond differently to the same tolerance induction protocol.
  
  
  RESULTS
  Allograft tolerance has been achieved in experimental and clinical kidney transplantation. Inducing tolerance in experimental recipients of heart and lung allografts has, however, proven to be more challenging. New protocols being developed in nonhuman primates based on mixed chimerism and cotransplantation of tolerogenic organs may provide mechanistic insights to help overcome these challenges.
  
  
  CONCLUSIONS
  Tolerance induction protocols that are successful in patients transplanted with 'tolerance-prone' organs such as kidneys and livers will most likely not succeed in recipients of 'tolerance-resistant' organs such as hearts and lungs. Separate clinical trials using more robust tolerance protocols will be required to achieve tolerance in heart and lung recipients.
authors.affiliation: aCenter for Transplantation Science, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts bDivision of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Missouri cDivision of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Maria Lucia L
authors.initials: ML
authors.lastname: Madariaga
authors.forename: Daniel
authors.initials: D
authors.lastname: Kreisel
authors.forename: Joren C
authors.initials: JC
authors.lastname: Madsen
mesh_terms: D000818:Animals; D046528:Chimerism; D006801:Humans; D007108:Immune Tolerance; D016030:Kidney Transplantation; D009928:Organ Specificity; D014184:Transplantation, Homologous