title: Comparison of acoustic radiation force impulse/serum noninvasive markers for fibrosis prediction in liver transplant.
abstract: OBJECTIVE
  Fibrosis, related to several causes, can be diagnosed in children and adolescents' liver grafts that are >1 year old. At present, liver biopsy is the gold standard for assessing liver damage in the posttransplant setting. We aimed to evaluate the accuracy of noninvasive biomarkers of fibrosis, namely, acoustic radiation force impulse (ARFI), aspartate-to-platelet ratio index, and aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio index, either alone or in combination, for predicting fibrosis in pediatric patients submitted to liver transplantation.
  
  
  METHODS
  We prospectively assessed liver fibrosis in 30 children/adolescents with liver transplant through biopsy (liver transplant follow-up during 12 months). ARFI with Virtual Touch Software (Acuson 2000) was performed, and blood samples were taken to determine liver function and platelet count. Two groups were analyzed according to the histopathologic stage of fibrosis, namely, none/mild (F0-F1) versus significant fibrosis (F2-4).
  
  
  RESULTS
  The mean age of the 30 patients was 11 years (3-18 years), with a mean posttransplant period of assessment of 6.5 years. Twenty-four patients (80%) presented stage F0-F1 fibrosis and 6 patients (20%) presented stage F2-4. The area under the curve using receiver operating characteristic analysis for ARFI, aspartate-to-platelet ratio index, and AST/ALT ratio index for significant fibrosis was 0.76 (P = 0.052), 0.74 (P = 0.066), and 0.69 (P = 0.162), respectively. Through multivariate logistic regression analysis, the only independent predictor of significant fibrosis was ARFI (odds ratio 10.7, 95% confidence interval 1.2-95.7; P = 0.045). The combination of ARFI and AST/ALT ratio index presented a good diagnostic accuracy of fibrosis (area under the curve of 0.83; P = 0.013).
  
  
  CONCLUSIONS
  ARFI may serve as a potential method for assessing significant fibrosis in pediatric patients with liver transplant, particularly in combination with AST/ALT ratio index.
authors.affiliation: *Medical Imaging Department †Hepatology Department, Pediatric Hospital of Coimbra ‡Pathology Department §Laboratory of Biostatistics and Medical Informatics, University Hospitals of Coimbra, Coimbra, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Pinto
authors.forename: Hugo
authors.initials: H
authors.lastname: Matos
authors.forename: Susana
authors.initials: S
authors.lastname: Nobre
authors.forename: Maria A
authors.initials: MA
authors.lastname: Cipriano
authors.forename: Margarida
authors.initials: M
authors.lastname: Marques
authors.forename: João M S
authors.initials: JM
authors.lastname: Pereira
authors.forename: Isabel
authors.initials: I
authors.lastname: Gonçalves
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Noruegas
mesh_terms: D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood*; D019540:Area Under Curve; D001219:Aspartate Aminotransferases / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver / Q000201:enzymology / Q000473:pathology; D008103:Liver Cirrhosis / Q000097:blood / Q000473:pathology; D016031:Liver Transplantation; D016015:Logistic Models; D008297:Male; D010976:Platelet Count; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase