Fibrosis progression in chronic hepatitis C: morphometric image analysis in the HALT-C trial

Abstract

Computer-assisted morphometry can provide precise measurement of hepatic fibrosis on a continuous scale. Previous morphometric studies of large cohorts of patients with treatment refractory chronic hepatitis C have shown a mean increase in fibrosis of 30% to 58% in 1 year. The aim of the present study was to quantify fibrosis progression in biopsy specimens obtained over 1.5 to 5 years from three groups of patients with baseline bridging fibrosis or cirrhosis (Ishak stages 3-6) enrolled in the Hepatitis C Antiviral Long-term Treatment Against Cirrhosis Trial. The main group of 346 lead-in nonresponders (viremic after 24 weeks of peginterferon-ribavirin therapy) had a mean fibrosis increase of 61% over pretreatment baseline after 2 years and 80% after 4 years. In contrast, the 78 breakthrough/relapse patients (undetectable serum hepatitis C virus RNA after 24 weeks of peginterferon-ribavirin and receiving antiviral therapy for 48 weeks) showed a mean increase in fibrosis of 48% when biopsied 36 months from pretreatment baseline but no further increase at 60 months. Finally, the 111 express patients with baseline biopsies following unsuccessful peginterferon-ribavirin outside the trial had significantly more baseline fibrosis than the others but an increase of only 21% after 21 months and a slight decrease at 45 months. Maintenance therapy with low-dose peginterferon had no effect on fibrosis changes in any of the groups.

Conclusion: Morphometry demonstrated complex, nonlinear changes in fibrosis over time in this heterogeneous cohort of patients with interferon-refractory chronic hepatitis C.

Figure 1

Design of the HALT-C Trial, showing the source of the three cohorts of patients used in morphometric analyses of fibrosis. Lead-in nonresponder patients (blue line) were those who remained viremic the lead-in phase of Peginterferon/ribavirin for 6 months and were then randomized to maintenance peginterferon or the untreated control group. They had baseline liver biopsies before the lead-in phase and approximately 24 and 48 months later. Breakthrough/relapse patients (green line) developed undetectable HCV RNA during the lead-in phase of peginterferon/ribavirin and completed 12 months of therapy and 6 months of follow-up. Those who became viremic while still receiving therapy (breakthrough) or during follow-up (relapse) were randomized to maintenance or untreated control groups. They had baseline biopsies before the lead-in phase and approximately 36 and 60 months later. Express patients (red line) received the equivalent of the lead-in phase outside the trial but remained viremic. Most had baseline biopsies immediately before randomization to maintenance peginterferon or the control group. Subsequent biopsies were at 18 and 42 months after randomization.

Figure 2

Distribution of Ishak fibrosis stages at each biopsy among 535 patients used for morphometric analyses, showing an increasing proportion of patients with stage 6 cirrhosis (p<0.0001). Panels show the three randomization strata with lead-in nonresponders (n=346) in upper left, breakthrough/relapse (n=78) in upper right, express (n=111) in lower left and the total cohort (n=535) in lower right. There were no significant differences among the three strata at baseline. All three strata showed a significant increase in cirrhosis, but there were significantly fewer breakthrough/relapse patients with advanced stages at biopsy 2 (p=0.01) and biopsy 3 (p=0.004) than in the other two strata.

Figure 3

Distribution of measurements of collagen content at each Ishak fibrosis stage for the 1269 liver biopsies in the study. The boxes show the median, 25^th and 75^th percentiles, whereas the lines 2.5 and 97.5 percentiles (outliers not shown). The Spearman correlation coefficient is 0.57 (p<0.0001).

Figure 4

Mean collagen content (± SEM) for the 535 patients in the study by treatment group, showing no difference between long-term interferon and untreated controls at any of the three time points.

Figure 5

Mean collagen content (± SEM) at different time points for the 535 patients in the study by randomization strata. The median interval between baseline biopsy and biopsy 2 was 36.8 months for the breakthrough/relapse patients, 25.3 months for the end of lead-in patients and 21.4 months for the express patients. Mean collagen in biopsy 2 was significantly greater than in the baseline biopsy for lead-in nonresponders (p<0.0001) breakthrough/relapse patients (p=0.0029), but biopsy 3 was not statistically significantly greater than biopsy 2 for either group. Express patients had significantly more collagen in the baseline biopsy than lead-in and breakthrough/relapse patients (p<0.0001), but the differences between baseline biopsy, biopsy 2 and biopsy 3 for express patients were not statistically significant.

Figure 6

Mean collagen content (± SEM) at different time points showing significantly more fibrosis at each time (baseline p=0.0137, biopsy 2 p=0.0030, biopsy 3 p=0.0031) in the 42 patients who had clinical outcomes than in the 493 patients who did not have an outcome.

Figure 7

Mean collagen content (± SEM) for the 535 patients in the study by baseline collagen levels (approximately one-third of patients in each group). The group with high (>.055 units) baseline collagen tended to have less in subsequent biopsies, while those with medium or low collagen increased.