Reduced Hepatocellular Expression of Canalicular Transport Proteins in Infants with Neonatal Cholestasis and Congenital Hypopituitarism.

OBJECTIVE: To assess whether prolonged neonatal cholestasis, described in congenital hypopituitarism and septo-optic dysplasia (SOD), is associated with altered expression of selected canalicular ectoenzymes and canalicular transport proteins. STUDY DESIGN: Children with congenital hypopituitarism (n = 21), SOD (n = 18), and cholestasis seen in our center over 26 years were reviewed. Histopathologic findings in archival liver biopsy specimens were assessed (n = 10) and in those with low/normal levels of serum γ-glutamyltransferase (GGT) activity despite conjugated hyperbilirubinemia, expression of canalicular ectoenzymes and canalicular transport proteins was evaluated immunohistochemically. RESULTS: Patients presented at a median age of 8 weeks (range 3-20 weeks) with median total bilirubin 116 µmol/L (45-287 µmol/L), GGT 95 IU/L (25-707 UI/L), and serum cortisol 51 nmol/L (17-240 nmol/L). All but 3 had low free thyroxin (median 9.6 pmol/L [6.8-26.9]) with increased thyroid-stimulating hormone levels (median 5.95 mU/L [<0.1-9.24]). Liver histologic features included moderate-to-severe intralobular cholestasis with nonspecific hepatitis, giant-cell transformation of hepatocytes, and fibrosis. In all, immunohistochemical staining for canalicular ectoenzymes and canalicular transport proteins revealed a degree of reduced expression, associated with normal serum GGT values in 6 of the 10 patients, and another 6 nonbiopsied infants with cholestasis also had low/normal serum GGT activity. Sequencing of ABCB11 and ATP8B1 performed in 6 of the biopsied patients did not identify pathogenic mutations. Following replacement therapy, biochemical evidence of hepatobiliary injury resolved in all children within a median period of 6 months. CONCLUSION: Hepatobiliary involvement in congenital hypopituitarism associated with SOD has a good prognosis, but its etiology remains uncertain. Immunohistochemical expression of canalicular transport proteins was reduced in available liver samples.

Histopathology of 460 liver allografts removed at retransplantation: A shift in disease patterns over 27 years.

BACKGROUND AND AIM: Approximately 10%-19% of liver transplant recipients develop irreversible graft failure requiring retransplantation. We reviewed the histology of failed grafts removed at retransplantation in our center over 27 years. METHODS: Two hundred and seventy-six adults and 118 children underwent retransplantation from 1987 to 2014, receiving 321 and 139 liver grafts, respectively. We analyzed graft histology, recipient demographics, indications and time interval to retransplantation. We divided retransplantation in 3 eras: A (1987-1994), B (1995-2001), and C (2002-2014). RESULTS: A total of 3298 adult and 938 pediatric primary liver transplants were conducted in our center, and 8.4% of adults and 12.6% of children experienced retransplantation. Considering the changes throughout the eras, the proportion of chronic rejection declined, while that of unexplained chronic fibrosing hepatitis increased steadily, representing the main reason for retransplantation conducted >10 years after primary transplant in children, and second in adults in the most recent era. This chronic hepatitis of the graft might correspond to a slowly evolving form of rejection, possibly with a humoral component, associated with progressive graft fibrosis and eventually failure. CONCLUSIONS: We observed a shift in histopathology of failed liver grafts, with increasing relevance of chronic idiopathic hepatitis associated with progressive fibrosis and graft failure.

AST-to-platelet ratio index in non-invasive assessment of long-term graft fibrosis following pediatric liver transplantation.

Long-term graft fibrosis occurs in the majority of pediatric liver transplant recipients. Serial biopsies to monitor graft health are impractical and invasive. The APRI has been evaluated in pediatric liver disease, but not in the context of post-transplantation fibrosis. We aimed to investigate the validity of APRI as a predictor of long-term graft fibrosis in pediatric liver transplant recipients. This was a retrospective, observational study of a cohort of children who underwent liver transplantation at King's College Hospital between 1989 and 2003, with a relevant dataset available. Protocol liver biopsies were performed at 10-yr follow-up and fibrosis was graded using the Ishak scoring system, with S3-6 denoting "significant fibrosis." APRI was calculated concurrently with biopsy. A total of 39 asymptomatic patients (20 males; median age at transplant, 1.43 yr) underwent protocol liver biopsies at a median of 10.39 yr post-transplantation. APRI was associated with significant fibrosis (p = 0.012). AUROC for APRI as a predictor of significant fibrosis was 0.74 (p = 0.013). The optimal cutoff APRI value for significant fibrosis was 0.45 (sensitivity = 0.67; specificity = 0.79; PPV = 0.67; NPV = 0.79). APRI appears to be a useful non-invasive adjunct in the assessment of significant graft fibrosis in the long-term follow-up of pediatric liver transplant survivors.