title: Levels of alanine aminotransferase confound use of transient elastography to diagnose fibrosis in patients with chronic hepatitis C virus infection.
abstract: OBJECTIVE
  Hepatic elastography (HE) is a noninvasive technique that measures liver stiffness and is used to diagnose hepatic fibrosis. It can help patients who are thought to have early-stage disease avoid a staging liver biopsy, but only when confounding variables that increase liver stiffness are excluded. Chronic inflammation from hepatitis C virus (HCV) infection is not considered to be one of these variables.
  
  
  METHODS
  We identified 684 patients with HCV and METAVIR fibrosis scores of 0-2 from a prospective, multi-institutional study of liver stiffness in 2880 patients with chronic liver disease. Patients were 49.6 ± 9.0 years old, 64.3% were male, and they had an average body mass index of 26.7 ± 4.1 kg/m(2).
  
  
  RESULTS
  In a multivariate analysis, inflammation (based on histologic analysis) and level of alanine aminotransferase (ALT) were associated with liver stiffness. The chances of a patient having a level of stiffness that indicates cirrhosis increased with grade of inflammation and level of ALT. By using a conservative 14.5-kPa cutoff for the diagnosis of cirrhosis, grade 3 inflammation had an odds ratio of 9.10 (95% confidence interval, 2.49-33.4). Likewise, levels of ALT greater than 80 and 120 IU/L had odds ratios of 3.84 (95% confidence interval, 2.10-7.00) and 4.10 (95% confidence interval, 2.18-7.69), respectively. The effect of the level of ALT persisted when analysis was restricted to patients with fibrosis scores of F0 to F1.
  
  
  CONCLUSIONS
  In patients with HCV infection and early-stage fibrosis, increased levels of ALT correlate with liver stiffness among patients in the lowest strata of fibrosis (METAVIR scores 0-2). Patients without fibrosis but high levels of ALT could have liver stiffness within the range for cirrhosis. Inflammation should be considered a confounding variable in analysis of liver stiffness.
authors.affiliation: The Liver Center, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Elliot B
authors.initials: EB
authors.lastname: Tapper
authors.forename: Eric B
authors.initials: EB
authors.lastname: Cohen
authors.forename: Keyur
authors.initials: K
authors.lastname: Patel
authors.forename: Bruce
authors.initials: B
authors.lastname: Bacon
authors.forename: Stuart
authors.initials: S
authors.lastname: Gordon
authors.forename: Eric
authors.initials: E
authors.lastname: Lawitz
authors.forename: David
authors.initials: D
authors.lastname: Nelson
authors.forename: Imad A
authors.initials: IA
authors.lastname: Nasser
authors.forename: Tracy
authors.initials: T
authors.lastname: Challies
authors.forename: Nezam
authors.initials: N
authors.lastname: Afdhal
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood*; D054459:Elasticity Imaging Techniques / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000473:pathology*; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D000410:Alanine Transaminase