Most Hepatitis C virus infections are acquired by injection drug use.
Dr Lucy Wilson and colleagues from the USA assessed prospective data on the progression of liver fibrosis.
Baseline liver biopsies were obtained from 1996 to 1998 on a random sample of 210 out of 1667 Hepatitis C virus-positive injection drug users.
Subjects were followed biannually, with a second biopsy offered to those eligible.
Among 119 prospectively followed injection drug users, 96% were African American, and 97% were Hepatitis C virus genotype 1a/b.
A further 27% were HIV-infected, with a median age of 42 years.
Paired biopsies were scored from 0 to 6.
The research team defined significant fibrosis was as score 3 or greater.
Progression of fibrosis was defined as an increase 2 or more units or clinical evidence of end-stage liver disease.
|The predictive value for alanine aminotransferase specificities was 73%|
The team's predictive values of blood markers include FibroSURE, aspartate aminotransferase-to-platelet-ratio index and alanine aminotransferase.
The researchers assessed the detection of contemporaneous and future liver fibrosis.
The team noted that 91% did not have significant liver fibrosis at first biopsy.
The researchers' predictive value for detecting insignificant fibrosis at first biopsy was greater than 95% for FibroSURE.
The predictive value for aminotransferase-to-platelet-ratio index, and alanine aminotransferase specificities were 73%.
After 4 years median follow-up, 21% had progression of fibrosis.
The researchers observed that this was significantly associated with serum level of Hepatitis C virus RNA and alanine aminotransferase.
No serological test had a predictive value greater than 40% for contemporaneous or future significant fibrosis.
Initial biopsy result had only a 30% value for predicting future significant fibrosis.
Dr Wilson's team concluded, “Significant liver fibrosis and progression were detected in some, but not most, injection drug users in this cohort.”
“In this setting with low fibrosis prevalence, FibroSURE, alanine aminotransferase, and aminotransferase-to-platelet-ratio index tests predict insignificant fibrosis.”
“However, further work is needed to find noninvasive markers of significant liver fibrosis.”