title: A non-invasive algorithm accurately predicts advanced fibrosis in hepatitis C: a comparison using histology with internal-external validation.
abstract: OBJECTIVE
  Biochemical tests and ultrasonography (US) are useful in the non-invasive assessment of liver fibrosis in patients with chronic hepatitis C (CH-C); however histology remains the reference standard. This multicenter, cross-sectional cohort study evaluated the accuracy of APRI (AST-to-platelet-ratio-index) and liver surface ultrasound nodularity (LSN), singularly and sequentially combined in an algorithm, in diagnosing advanced fibrosis (i.e. METAVIR F3,F4), to derive a prediction rule to confirm or exclude F3,F4.
  
  
  METHODS
  Four hundred and thirty consecutive CH-C patients with elevated ALT, grouped into a first cohort (training set), and an internal and an external validation cohort, were studied. APRI and LSN were compared to liver biopsy and sequentially combined in order to obtain a predictive rule for advanced fibrosis METAVIR F3,F4.
  
  
  RESULTS
  LSN was negative and APRI < or = 1 in 185/430 patients, whereas LSN was positive and APRI>2 in 46/430 cases, with a 94% diagnostic accuracy for presence/absence of F3, F4, respectively. In a further 60/430 patients, F3,F4 was detected with an accuracy of 83%. In the remaining cases no classification was possible.
  
  
  CONCLUSIONS
  An algorithm based on APRI and LSN confirms or excludes F3,F4 in 54% of CH-C patients with elevated ALT and suggests a highly probable diagnosis in a further one-sixth of patients, thus rendering liver biopsy unnecessary in these patients.
authors.affiliation: Second Division of Gastroenterology, Fondazione IRCCS Policlinico, Mangiagalli e Regina Elena, University of Milan, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Paggi
authors.forename: Agostino
authors.initials: A
authors.lastname: Colli
authors.forename: Mirella
authors.initials: M
authors.lastname: Fraquelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Viganò
authors.forename: Paolo
authors.initials: P
authors.lastname: Del Poggio
authors.forename: Corinna
authors.initials: C
authors.lastname: Facciotto
authors.forename: Massimo
authors.initials: M
authors.lastname: Colombo
authors.forename: Guido
authors.initials: G
authors.lastname: Ronchi
authors.forename: Dario
authors.initials: D
authors.lastname: Conte
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001219:Aspartate Aminotransferases / Q000097:blood; D001792:Blood Platelets / Q000473:pathology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006526:Hepatitis C / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008103:Liver Cirrhosis / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography
chemical_list: D001219:Aspartate Aminotransferases