title: Stability of liver fibrosis among HCV-infected injection drug users.
abstract: BACKGROUND
  There are few published data characterizing patterns of liver stiffness measurements (LSMs) among HCV-infected persons and their potential impact on clinical decisions (for example, deferring treatment and hepatocellular carcinoma surveillance).
  
  
  METHODS
  A total of 591 HCV-infected injection drug users in a community-based cohort had four LSMs. We used semi-parametric latent class growth modelling to identify patterns, which then became a gold standard against which we characterized validity of information from the initial measurements.
  
  
  RESULTS
  Median age was 49, 68% were male, 92% African-American and 33% HIV-coinfected. The median LSM at visit 1 was 6.7 kPa (IQR 5.3-8.8). Over a median 1.75 years, LSM measures were stable; median change between visits was 0 kPa (IQR -1.4-1.7). Only 3% had evidence of fibrosis progression. Other groups included stable patterns of no fibrosis (59%), moderate fibrosis (21%), severe fibrosis (7%) and cirrhosis (9%). Individuals with fibrosis progression were more likely to be HIV-infected than those with stable low fibrosis (P<0.001). The diagnostic accuracy of the first LSM for identification of need for cancer surveillance (cirrhosis ≥12.3 kPa) was high (positive predictive value =97%). Although no single low LSM had high negative predictive value for significant fibrosis (metavir <2), individuals with two or more low results rarely had progression.
  
  
  CONCLUSIONS
  These data underscore the stability of liver fibrosis in a cohort of predominantly African-American HCV-infected persons over 1.75 years, support using LSMs to monitor untreated persons at risk for progression and assess need for hepatocellular carcinoma surveillance.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. shmehta@jhsph.edu
authors.forename: Shruti H
authors.initials: SH
authors.lastname: Mehta
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Kirk
authors.forename: Jacquie
authors.initials: J
authors.lastname: Astemborski
authors.forename: Mark S
authors.initials: MS
authors.lastname: Sulkowski
authors.forename: Nezam H
authors.initials: NH
authors.lastname: Afdhal
authors.forename: David L
authors.initials: DL
authors.lastname: Thomas
mesh_terms: D000328:Adult; D015331:Cohort Studies; D060085:Coinfection; D018450:Disease Progression; D055030:Drug Users; D054459:Elasticity Imaging Techniques; D005260:Female; D015658:HIV Infections / Q000276:immunology; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000276:immunology; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis