Short-term versus sustained response to interferon therapy: effect on histology

Quantitative analysis of liver fibrosis and stellate cell changes in patients with chronic hepatitis C after interferon therapy

OBJECTIVE

The proliferation and differentiation of stellate (Ito, or fat-storing) cells into myofibroblast-like cells is responsible for the development of liver fibrosis. Using computer image analysis, we evaluated the changes of alpha smooth muscle actin-positive stellate cells and liver fibrosis after interferon-alpha or -beta (IFN-alpha, beta) therapy in patients with chronic hepatitis C.

METHODS

Patients with chronic hepatitis C were treated with IFN-alpha or -beta and were divided into three groups on the basis of clinical criteria; a complete responder group (CR, 18 of 51), a partial responder group (PR, 17 to 51), and a nonresponder group (NR, 16 of 51). Liver fibrosis was assessed from specimens stained with Sirius red and was quantitated by computer image analysis. We also evaluated alpha-smooth muscle actin expression in the liver before and after IFN therapy by a semiquantitative scoring method (the alpha-smooth muscle actin index).

RESULTS

Before IFN therapy, a large number of stellate cells expressing a-smooth muscle actin were present in the liver biopsy specimens. There was a significant correlation (r = 0.699, p < 0.05) between the change in the percent area of fibrosis and the alpha-smooth muscle actin index before and after IFN therapy in all groups. The complete responder group also showed a significant reduction of a-smooth muscle actin-expressing cells that was correlated with the reduction of serum ALT (r = 0.686, p < 0.05).

CONCLUSION

These results suggest a-smooth muscle actin-expressing cells are responsible for liver fibrosis, and the elimination of factors stimulating matrix synthesis (e.g., hepatitis virus) may decrease liver fibrosis.

Influence of pretreatment lesions on histologic response to interferon therapy in chronic hepatitis C

We have assessed the predictive value of the grade of pretreatment liver lesions on histologic response to interferon therapy in patients with chronic hepatitis C. In 93 patients with chronic hepatitis C virus (HCV) infection who showed an initial response to interferon therapy, HCV RNA load and serum aminotransferase levels together with grade of liver histologic lesions were assessed at baseline and 6 months after treatment cessation. Regression of portal and periportal necroinflammation was observed only in sustained responders (normalization of aminotransferase levels and HCV RNA clearance). Neither short-term response nor the absence of virus was associated with significant histologic changes in the liver biopsies. Logistic regression analysis showed that pretreatment histologic lesion was an independent predictive factor of biologic response in the histologic regression of lesions 6 months after cessation of interferon treatment. In conclusion, a dense inflammatory necrotic activity is a positive predictor of histologic response in interferon-treated patients with HCV.

Randomised, double-blind, placebo-controlled trial of interferon alpha-2b with and without ribavirin for chronic hepatitis C. The Swedish Study Group

BACKGROUND

Pilot studies suggested that more patients with chronic hepatitis C virus (HCV) infection had a sustained virological response when treated with the combination of interferon alpha-2b and ribavirin than with interferon alpha-2b alone. We investigated the biochemical and virological responses and safety of treatment with interferon alpha-2b and ribavirin compared with interferon alpha-2b alone.

METHODS

In this double-blind trial 100 patients were randomly assigned to treatment with interferon alpha-2b (3 MU three times a week) in combination with ribavirin (1000 or 1200 mg per day) or placebo for 24 weeks and then followed up for a further 24 weeks. A further follow-up was done 1 year after active treatment stopped. The primary endpoint was the sustained virological response, defined as no detectable HCV RNA by PCR at both week 24 and week 48. Retrospectively, the baseline HCV-RNA load was analysed as a predictor of a sustained virological response. Data were analysed by intention to treat.

FINDINGS

18 (36%) of the 50 patients in the interferon alpha-2b and ribavirin group had a sustained virological response compared with nine (18%) of the 50 patients in the interferon alpha-2b and placebo group (p = 0.047). At the 1 year follow-up the proportion of patients with a virological response was greater in the interferon alpha-2b and ribavirin group than the interferon alpha-2b and placebo group (42 vs 20%, p = 0.03), respectively. More patients with baseline HCV-RNA concentrations greater than 3 x 10(6) genome equivalents (Eq) per mL had a sustained response with interferon alpha-2b and ribavirin than with interferon alpha-2b and placebo (12/29 vs 1/26, p = 0.009), whereas the sustained response did not differ between the two treatment groups for HCV-RNA amounts less than 3 x 10(6) Eq per mL (6/21 vs 8/24, p = 0.67), respectively.

INTERPRETATION

More patients with chronic hepatitis C have a sustained virological response with interferon alpha-2b and ribavirin than with only interferon alpha-2b treatment. We suggest that patients with high HCV-RNA loads should be treated with interferon alpha-2b and ribavirin.