Late allograft fibrosis in pediatric liver transplant recipients: Assessed by histology and transient elastography

Late allograft fibrosis in LT recipients can cause graft dysfunction and may result in re-transplantation. TE is a non-invasive tool for the assessment of liver fibrosis. We aimed to evaluate the prevalence of allograft fibrosis in pediatric LT recipients, identify factors associated with allograft fibrosis, and determine the diagnostic value of TE, compared to histology. All children who underwent LT for ≥3 years were included. TE was performed for LSM in all patients. LSM of ≥7.5 kPa was considered as abnormal and suggestive of allograft fibrosis. Percutaneous liver biopsy was performed when patients had abnormal LSM and/or abnormal LFTs. Histological fibrosis was diagnosed when METAVIR score ≥F1 or LAF scores ≥1. TE was performed in 43 patients and 14 (32.5%) had abnormal LSM suggestive of allograft fibrosis. Histological fibrosis was identified in 10 of the 15 patients (66.7%) who underwent percutaneous liver biopsy and associated findings included chronic active HBV infection (n = 3), and late acute rejection (n = 3). Multivariate analysis showed that graft age was significantly associated with allograft fibrosis (OR = 1.22, 95% CI: 1.05-1.41, P = 0.01). In conclusion, late allograft fibrosis is common in children undergoing LT for ≥3 years and associated with graft age. HBV infection and late acute rejection are common associated findings. Abnormal TE and/or LFTs may guide physicians to consider liver biopsy for the detection of late allograft fibrosis in LT children.