Short and long-term effects of interferon on serum markers of hepatitis C virus replication

Antiviral treatment responses in patients with chronic hepatitis C virus infection evaluated by a third generation anti-hepatitis C virus assay

Antibodies to hepatitis C virus (HCV) may decrease or disappear after viral clearance in treated or spontaneously resolved infection. We evaluated the usefulness of serial antibody assays in predicting the antiviral treatment responses. One hundred and four chronic hepatitis C patients who received 24 weeks of interferon and ribavirin combination therapy were assayed with a third generation enzyme immunoassay anti-HCV. The mean titre of anti-HCV decreased by more than 50% (from 89.5 +/- 10.8 to 43.6 +/- 17.5) at 48 weeks post-treatment in patients with a sustained virological response, while in nonsustained virological responders and nonresponders, the titres remained over 85% of the pretreatment level at 48 weeks post-treatment. There was a divergence of anti-HCV titres between sustained and nonsustained virological responders during 6-9 months. By using the ratio of 9-month to 6-month titres as an index and receiver operator characteristic curve analysis with the cut-off point set at 90%, we could differentiate sustained virological responders from nonsustained virological responders with a sensitivity and specificity of 91.7% and 90.9%, respectively, 3 months after treatment. The titre of this third generation anti-HCV decreased progressively in sustained virological responders and this assay may be used to monitor and predict antiviral treatment responses.

Immunohistochemical analysis of hepatic interferon alpha-beta receptor level: relationship between receptor expression and response to interferon therapy in patients with chronic hepatitis C

BACKGROUND/AIMS

This study aimed to determine the expression level of interferon alpha/beta (IFN-alpha/beta) receptor in the liver immunohistochemically and evaluate its usefulness in predicting the outcome to IFN therapy in patients with chronic hepatitis C.

METHODS

The level of IFN-alpha/beta receptor expression was determined in immunoperoxidase-stained pretreatment sections of 55 chronic hepatitis C patients later treated with IFN. We used liver biopsy specimens and mouse monoclonal anti-human IFN-alpha/beta receptor antibody. Quantitative analysis of immunostaining was performed by image analysis software. The level of IFN-alpha/beta receptor was expressed as Unit (U). Sustained responders were patients who showed persistent disappearance of serum HCV-RNA during the 6-month period after treatment, while non-responders showed persistence of viremia after therapy.

RESULTS

Positive immunostaining was observed in the cytoplasm of hepatocytes. The mean expression level of hepatic IFN-alpha/beta receptor in sustained responders (2.65+/-1.11 U, n = 15) was significantly (p<0.001) higher than in non-responders (1.61+/-1.05 U, n = 40). A significant decrease in IFN-alpha/beta receptor expression level was observed in patients with advanced liver fibrosis. In patients with low level viremia (pretreatment serum HCV-RNA <1 Meq/ml, n = 18), the level of IFN-alpha/beta receptor in sustained responders (2.89+/-1.12 U, n = 11) was significantly (p<0.01) higher than in non-responders (0.93+/-0.33 U, n = 7).

CONCLUSIONS

Our results suggest that measurement of the level of hepatic IFN-alpha/beta receptor in patients with chronic hepatitis C might be useful for predicting the response to IFN therapy. Resistance to IFN therapy in patients with chronic hepatitis C might be due to low levels of hepatic IFN-alpha/beta receptor.

Chronic hepatitis C and interferon alpha: conventional and cumulative meta-analyses of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the clinical usefulness of surrogate markers of the interferon effect (i.e., alanine aminotransferase levels and serum HCV-RNA status) as predictors of long term response, and to identify the optimal schedule of treatment for patients with chronic hepatitis C by means of meta-analysis.

METHODS

Pertinent randomized clinical trials and prospective studies were selected using MEDLINE (1986-1996), a reference list from published articles or reviews. Twenty-six prospective studies reporting data on surrogate markers of interferon response were selected. Thirty-nine trials comparing interferon alpha to no treatment and 25 trials comparing different schedules of interferon were reviewed. Conventional meta-analysis according to the DerSimonian and Laird method was used for the pooling of results.

RESULTS

The pooled probability of late relapse among sustained responders with negative serum HCV-RNA 6 months after treatment was very low (8.7%; 95% confidence interval 5.8-11.6%). The overall risk difference between treated and control groups was 16.63% (95% confidence interval 11.95-21.31%) for sustained aminotransferase normalization. Therapy with higher interferon dose compared with standard dose significantly improves the rate of sustained response (pooled risk difference 10.56%, 95% CI 5.47-15.65%). Cumulative meta-analyses suggest that a clear dose-response relationship exists across a wide range of interferon dosages. The multivariate meta-regression model confirms that the total interferon dose is an independent predictor of sustained response and that it seems more important than the length of treatment.

CONCLUSIONS

Testing for serum HCV-RNA, 6 months after interferon therapy in sustained biochemical responders, is useful for predicting long term response. The current standard total interferon dose of 234 mega-units is suboptimal. Further trials that directly compare different schedules of treatment are needed.

The effect of interferon on the liver in chronic hepatitis C: a quantitative evaluation of histology by meta-analysis

BACKGROUND/AIMS

Several randomized clinical trials of interferon in chronic hepatitis C have examined the histological changes in paired biopsy specimens. We have attempted a quantitative evaluation by meta-analysis.

METHODS

Randomized Clinical Trials found by MEDLINE search were included if: a) they compared different IFN regimens with non-active treatment or with each other, b) they obtained biopsies before starting and at the time of stopping IFN in a sizable proportion of the treated and control patients, and c) they assessed the biopsy-specimens semi-quantitatively according to Scheuer's numerical scoring system or Knodell's Histological Activity Index, with quantitation of fibrosis and of lobular, portal and periportal necroinflammation.

RESULTS

Seventeen trials were identified, in which 1223 adult patients had been studied. All trials homogeneously pointed towards a favorable interferon effect. The pooled data show a statistically significant histological improvement in treated patients as compared with controls for each of the four Histological Activity Index components and for the total Histological Activity Index score (overall improvement was -0.82 in favor of interferon, p<0.0001, 95% Confidence Interval -1.25 to -0.40). In the ten trials reporting histological changes separately in biochemical responders (primary and sustained responders) and non-responders, histological improvement was confined to the subset of biochemical responders. No change or very little change occurred in non-responders.

CONCLUSIONS

Interferon treatment in chronic hepatitis C significantly improves liver histology. The effect of interferon is closely related to biochemical response. Studies assessing histological outcome 1 year or more after interferon treatment in long-term responders and comparatively in non-responders or relapsers would be important to confirm the regression of the necroinflammatory process in the former, as suggested by the normal serum alanine aminotransferase levels.

Quantitative analysis of interferon alpha/beta receptor mRNA in the liver of patients with chronic hepatitis C: correlation with serum hepatitis C virus-RNA levels and response to treatment with interferon

We analysed the expression of interferon (IFN) alpha/beta receptor mRNA in the liver of patients with chronic hepatitis C and examined the relationship between the expression of this receptor gene and the level of hepatitis C virus (HCV)-RNA as well as the response to 16 weeks of 6 x 10(6) units IFN. The mean level of IFN alpha/beta receptor mRNA in patients with chronic HCV infection (expressed as delta cycle; 10.8 +/- 1.9 (mean +/- SD); n = 39) was significantly higher than that of control subjects (9.4 +/- 0.5; n = 6; P < 0.01). There was a significant negative correlation between the level of IFN alpha/beta receptor mRNA and serum HCV-RNA in 39 patients with chronic hepatitis C (R = -0.546; P < 0.01). The mean level of IFN alpha/beta receptor mRNA in six patients who showed a complete response to IFN therapy (12.3 +/- 1.6) was higher than that of 15 patients who failed to respond to therapy (10.1 +/- 1.5; P < 0.01). Our results are consistent with the suggestion that the anti-viral activity of IFN depends on the level of the IFN alpha/beta receptor on hepatocytes in patients with chronic hepatitis C.

Treatment with ribavirin+alpha interferon in HCV chronic active hepatitis non-responders to interferon alone: preliminary results

Alpha interferon (IFN-alpha) represents the best therapy for HCV active chronic hepatitis, but only 25% of treated patients achieve a complete recovery. Several attempts have been made to increase this percentage. The objective of our study is to verify whether the combination ribavirin (R)+ IFN-alpha can lead to positive results in non-responders to treatment with IFN-alpha alone. The preliminary results for 5 subjects, all non-responders to IFN, treated with R+ IFN for 60 days and then IFN alone for 4 months more show that during the R+IFN treatment, 2 subjects presented a reduction in transaminase; a month after the suspension of R, ALT returned to pre-treatment values. The results are preliminary but we can say that this combination in the proposed doses and times in these subjects, cannot be considered adequate to modify the natural course of this disease.

Clinical usefulness of an assay for hepatitis C virus core in the diagnosis of non-A, non-B hepatitis and monitoring of the response to interferon therapy

The clinical utility of a new JCC-2 enzyme-linked immunosorbent assay kit that detects and quantitates anti-hepatitis C virus (anti-HCV) core antibodies (anti-HCc) was investigated. Serum samples were obtained from 102 patients with various non-A, non-B liver diseases, including 19 cases of chronic hepatitis type C who had been treated with interferon (IFN). The results of the anti-JCC-2 assay were significantly correlated with serum HCV-RNA positivity. Patients who were HCV-RNA positive exhibited a high rate of positivity for anti-JCC-2 (72.2% in acute hepatitis, > 90% in chronic liver diseases). The geometric mean of the anti-JCC-2 titre was not significantly different among different stages of chronic liver disease (among CPH, CAH and LC). The anti-JCC-2 titre decreased gradually in cases that became HCV-RNA negative after IFN therapy. If HCV-RNA positivity recurred, the anti-JCC-2 titre increased, indicating that serial measurements of the anti-JCC-2 titre are useful for monitoring the antiviral effect of IFN treatment. These results suggest that quantification of anti-HCc by the anti-JCC-2 assay is superior to the semi-quantification of circulating HCV-RNA provided by monitoring of IFN therapy. Monitoring of HCV-RNA status using reverse transcription-nested polymerase chain reaction (RT-nested PCR) is possible, but it is technically demanding and too expensive for routine clinical use.

Changes in antibody titers to hepatitis C virus following interferon therapy for chronic infection

The use of quantitative assays for hepatitis C virus specific antibodies (anti-HCV) as a prognostic marker was evaluated in 31 patients with chronic hepatitis C treated with interferon (IFN). Changes in titers of serum HCV-RNA and anti-HCV antibodies; anti-C11 (anti-core), anti-C100 (anti-NS3), and anti-C7 (anti-NS3) were investigated. Recombinant IFN-alpha 2a was administered and the patients were followed for more than 1 year. The patients were classified into three groups according to their responses to IFN: 11 sustained responders with continuous normalizations of serum alanine aminotransferase (ALT) levels; 14 transient responders with transient decreases in ALT; and six nonresponders who had no changes in ALT levels. Ten of 11 sustained responders had a continuous decrease in anti-C11 titers after completion of treatment, decreasing to less than half of pretreatment titers. No patients in the other two groups had a continuous decrease in anti-C11 titers. Although sustained responders had decreases in anti-C100 and anti-C7 titers after IFN therapy, these titers also decreased in some patients in the other two groups. HCV-RNA was not detected in the sera of 10 of 11 sustained responders following IFN therapy. In contrast, while 9 of 10 transient and non-responders had a decrease or disappearance of HCV-RNA at the completion of therapy, they had increased levels thereafter. These results indicate that anti-HCV-core (anti-C11) titers most closely reflect the status of HCV replication. A quantitative assay for anti-HCV-core antibody can be used as a predictive marker of remission in IFN-treated patients with chronic hepatitis C.