title: Liver enzyme values in injection drug users with chronic hepatitis C.
abstract: BACKGROUND
  Liver enzymes fluctuate in chronic hepatitis C virus infection. However, the range that can be attributed to the course of hepatitis C virus (versus an intercurrent cause of hepatitis) is unknown.
  
  
  OBJECTIVE
  To characterise the range of liver enzyme values as a function of the upper limit of normal (ULN) of the assay among persons chronically infected with hepatitis C virus.
  
  
  METHODS
  One thousand and fifty-nine hepatitis C virus chronically infected individuals with > or =5 semi-annual evaluations.
  
  
  METHODS
  Alanine aminotransferase and aspartate aminotransferase levels were prospectively obtained. Potential causes of elevations were examined using serologic testing.
  
  
  RESULTS
  Among 1059 individuals, 11,463 enzyme measurements were obtained over 6.5 years, of which 63.5% were <1.25x ULN, 26.5% were 1.25-2.5x ULN, 8.3% were 2.5-5x ULN, and 1.6% were 5-10x ULN; only 0.2% were >10x ULN. Elevations >10x ULN were transient, the alanine aminotransferase/aspartate aminotransferase ratio tended to be different at the time of the elevation compared to before and after and 24% were associated with acute viral hepatitis. On the other hand, subjects with elevations 5-10x ULN tended to have elevated levels throughout follow-up and only 8% were associated with acute viral hepatitis.
  
  
  CONCLUSIONS
  Liver enzymes fluctuate up to 5x ULN in most hepatitis C virus-infected persons; clinicians should seek alternate explanations for those with higher alanine aminotransferase or aspartate aminotransferase levels, especially among hepatitis C virus-infected persons with greater than 10-fold elevations.
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, MD, USA. shmehta@jhsph.edu
authors.forename: S H
authors.initials: SH
authors.lastname: Mehta
authors.forename: D
authors.initials: D
authors.lastname: Netski
authors.forename: M S
authors.initials: MS
authors.lastname: Sulkowski
authors.forename: S A
authors.initials: SA
authors.lastname: Strathdee
authors.forename: D
authors.initials: D
authors.lastname: Vlahov
authors.forename: D L
authors.initials: DL
authors.lastname: Thomas
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D043384:Glutamyl Aminopeptidase / Q000097:blood / Q000378:metabolism; D006521:Hepatitis, Chronic / Q000150:complications / Q000201:enzymology*; D006801:Humans; D008099:Liver / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000201:enzymology*; D005723:gamma-Glutamyltransferase / Q000097:blood / Q000378:metabolism
chemical_list: D005723:gamma-Glutamyltransferase; D000410:Alanine Transaminase; D043384:Glutamyl Aminopeptidase