Graft histology characteristics in long-term survivors of pediatric liver transplantation

The factors that influence the long-term histological outcome of transplanted liver allografts in children are not yet fully understood, and the role of surveillance biopsies in patients with normal graft function remains controversial. The aims of this study were to describe the long-term graft histology of pediatric liver transplant recipients surviving at least 3 years and to analyze factors correlating with long-term histological outcome. Histological slides of 63 long-term liver transplant recipients were assessed for inflammation and fibrosis. The histological findings were correlated with clinical, biochemical, serological, and radiological findings. A significant proportion of biopsies from these patients showed some type of histological abnormalities, with fibrosis being observed in 61 (97%) patients. Duration of transplantation of >6 years and ≥grade 2 inflammation were significantly associated with advanced fibrosis. We could not identify any correlation between ≥stage 3 fibrosis and donor age, cold and warm ischemia time, history of de novo autoimmune hepatitis, hepatic artery thrombosis, chronic rejection, or alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase values. In conclusion, liver fibrosis appears to be a common finding in long-term pediatric liver transplant survivors. The cause of this fibrosis is uncertain, and normal alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase levels do not exclude the presence of significant fibrosis.