Pathology of liver transplantation

SummaryLiver transplantation has been increasingly used over the past four decades as an effective treatment for end-stage liver disease. Although the demand exceeds the supply of cadaveric organs, the donor pool has expanded with the increasing use of split-liver grafts, non-heart-beating donor livers and living-related donors. Histopathologists play a role in the pre-transplant and post-transplant period; their input is crucial in both identifying and monitoring post-transplant complications. The degree of acute cellular rejection is best assessed histologically, and biopsy interpretation informs changes to the immunosuppressive regimen. Chronic rejection is characterised by progressive ductopenia; a number of lesions have been identified that predict the likelihood of progression to chronic rejection. Other post-transplant complications readily assessed on liver core biopsies include vascular and biliary complications, infectious, recurrent and de novo disease. De novo hepatitis with ‘autoimmune’ features is described as is idiopathic chronic hepatitis, but the relationship of these lesions to alloimmune pathways remains uncertain. Although liver transplantation is generally performed in specialist centres, an increasing number of histopathologists working in non-specialist units are being exposed to post-transplant biopsies and need to be aware of the spectrum of changes that can occur.