Liver enzyme values in injection drug users with chronic hepatitis C.

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.
Aims: 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.
Patients: 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.