Histology Utility in Liver Graft Surveillance: What About Normal Liver Tests?

Introduction: In liver transplantation, late graft dysfunction can have several causes, particularly rejection, infection, vascular, biliary complications, and others, usually suspected by abnormal liver tests. However, normal liver tests do not confirm a normal graft and liver biopsy could identify unexpected features with repercussions in immunosuppressive therapy. The aim of this study was to determinate the histological abnormalities in patients 10 years after liver allograft transplantation with sustainably normal liver tests and evaluate the changes in immunosuppressive therapy triggered by histological data.

Material and methods: A retrospective analysis of liver allograft recipients was performed in an adult liver transplantation center with graft histological characterization 10 years after transplantation. Patients with abnormal liver tests and retransplantation were excluded.

Results: We evaluated 39 patients with repeatedly normal liver tests. Familial amyloid polyneuropathy (n = 27) was the mainly indication for liver transplantation. Allograft histological dysfunction was observed in 13 (21.7%) patients. In 3 patients we observed chronic hepatitis, signs of cellular rejection in another 3 patients, and histological features suggesting autoimmune hepatitis in 7 patients. The diagnosis of de novo autoimmune hepatitis was proposed according to contemporaneous positive autoantibodies. Changes in immunosuppressive treatment were proposed in 7 patients.

Conclusion: Allograft histological dysfunctions 10 years after liver transplantation were observed in 21.7% of patients despite normal liver tests. Although the histological features led to alterations of immunosuppressive therapy in half of the cases, the absence of enzymatic tests changes makes monitoring a challenging process.