title: Histopathological causes of late liver allograft dysfunction: analysis at a single institution.
abstract: BACKGROUND
  We summarize our experience in the pathological diagnosis of late complications of liver transplantation (LT) to better understand the causes of late allograft dysfunction in a population mostly composed of patients with hepatitis B virus (HBV) infection.
  
  
  METHODS
  We reviewed 361 post-transplant liver biopsies from 174 patients who underwent LT and first presented with liver function abnormalities 3 months post-procedure. The underlying diseases included HBV-associated liver disease (77%), toxic or alcoholic liver disease (10.3%), hepatitis C virus (HCV)-associated liver disease (8.6%), primary biliary cirrhosis (1.2%), primary sclerosing cholangitis (1.2%), and metabolic disease (1.7%).
  
  
  RESULTS
  The three most common late complications were acute rejection (32.5%), recurrent disease (19.1%), and biliary complication (17.1%). Patients who underwent LT for HBV infection or for drug- or alcohol-related liver disease had a lower incidence of recurring disease than those who underwent transplantation for HCV infection. During post-transplantation months 3-12, acute rejection was the most common cause of allograft dysfunction and recurring disease was the leading cause for allograft dysfunction (p=0.039). The two primary causes of late allograft dysfunction have overlapping histological features, although acute rejection more frequently showed bile duct damage and vascular endothelialitis than recurring HBV infection, and recurring HBV infection had more frequent lobular activity and piecemeal necrosis.
  
  
  CONCLUSIONS
  The causes of late liver allograft dysfunction are closely associated with the original liver diseases and the period after LT. Careful attention is required for differential diagnosis between acute rejection and recurrent HBV.
authors.affiliation: Department of Pathology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Eun
authors.initials: E
authors.lastname: Shin
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Eunsil
authors.initials: E
authors.lastname: Yu
keywords: Biopsy; Complication; Liver transplantation