Durability of serological remission in chronic hepatitis C treated with interferon-alpha-2B

Mutations in the NS5A gene are associated with response to interferon+ribavirin combination therapy in patients with chronic hepatitis C virus 3a infection

INTRODUCTION

The clinical correlation between hepatitis C virus (HCV) NS5A gene mutations and response to antiviral treatment in HCV-3a-infected patients is not as well known as that in HCV-1a-infected and HCV-1b-infected patients.

OBJECTIVES

This study attempted to determine mutations in the NS5A gene in isolates of HCV-3a obtained from infected Pakistani patients treated with interferon-α standard therapy and to determine its association with several host factors.

METHODS

A total of 71 consecutive chronically infected HCV patients [43 men and 28 women, mean age 38 years (range, 16-70 years)] without previous antiviral therapy, who fulfilled other criteria of the current study were enrolled for antiviral therapy.

RESULTS

Of the 71 patients enrolled, 53 completed the course of antiviral therapy. Among them, 23 (43.3%) patients showed an end-of-treatment response, 20 (41.4%) showed a sustained virological response, and three (5.6%) patients were HCV-RNA negative at the end of treatment but developed a relapse thereafter. Only seven (13.2%) patients were virologic nonresponders (NR). Probable transmission risk factors were previous major/minor surgery (20%), transfusion of blood or blood products (2%), dental surgery (10%), or sporadic (unknown; 60%). The estimated duration of infection varied from 6 months to 20 years. The correlation between the number of mutations and several factors was also studied. The first factor that was associated with the number of mutations in the NS5A gene was age older than 40 years, where the difference was statistically significant between viral sequences of patients showing an end-of-treatment response and NR (P<0.001). Further, the difference in the average number of mutations was statistically significant between patients showing sustained virological response and NR (P<0.005). The second and third factors that were found to be associated with number of mutations in the NS5A gene were sex and viral load, respectively.

CONCLUSION

Along with host factors such as age older than 40 years, female sex, and low baseline viral load, the less number of mutations in the NS5A gene of HCV-3a is associated with a positive outcome of treatment response in HCV patients receiving interferon plus ribavirin therapy.

Durability of sustained response shown in paediatric patients with chronic hepatitis C who were treated with interferon alfa-2b plus ribavirin

Long-term studies in adults indicate that sustained virologic response (SVR) after combination treatment for chronic hepatitis C (CHC) predicts long-term clearance. Although peginterferon plus ribavirin is now standard care for children with CHC, long-term follow-up studies are not yet available. This study evaluated durability of virologic response over 5 years in children previously treated with interferon alfa-2b plus ribavirin (IFN/R). Ninety-seven of 147 children with CHC, who were treated with IFN/R and completed the 6-month follow-up in two previous clinical trials, participated in this long-term follow-up study. All were assessed annually for up to 5 years; patients with SVR were assessed for durability of virologic response. Children with SVR (n = 56) and those with detectable hepatitis C virus (HCV) RNA 24-week post-treatment (n = 41) were followed for a median of 284 weeks. Overall, 70% (68/97) of patients completed the 5-year follow-up. One patient with genotype 1a CHC had SVR and relapsed at year 1 of follow-up with the same genotype. Kaplan-Meier estimate for sustained response at 5 years was 98% (95% CI: 95%, 100%). Six patients with low-positive HCV RNA levels (n = 4) or missing HCV RNA at the 24-week follow-up visit (n = 2) in the initial treatment studies had virologic response during this long-term follow-up study. Linear growth rate was impaired during treatment with rapid increases in the immediate 6 months post-treatment. Mean height percentile at the end of the 5-year follow-up was slightly less than the mean pretreatment height percentile. Five patients experienced serious adverse events; none related to study drug exposure. SVR after IFN/R predicts long-term clearance of HCV in paediatric patients; growth normalized in the majority of children during the long-term follow-up. Similar long-term results could be expected after peginterferon alfa-2b plus ribavirin treatment.

Long-term effectiveness and cost-effectiveness of antiviral treatment in hepatitis C

We systematically reviewed the evidence for long-term effectiveness and cost-effectiveness of antiviral treatment in patients with chronic hepatitis C. We performed a systematic literature search on the long-term effectiveness and cost-effectiveness of AVT in hepatitis C (1990-March 2007), and included health technology assessment (HTA) reports, systematic reviews, long-term clinical trials, economic studies conducted alongside clinical trials and decision-analytic modelling studies. All costs were converted to 2005euro. Antiviral therapy with peginterferon plus ribavirin in treatment-naïve patients with chronic hepatitis C was the most effective (3.6-4.7 life years gained [LYG]) treatment and was reasonably cost-effective (cost-saving to 84 700euro/quality adjusted life years [QALY]) when compared to interferon plus ribavirin. Some results also suggest cost-effectiveness (below 8400euro/(QALY) of re-treatment in nonresponders/relapsers. Results for patients with persistently normal alanine aminotransferase (ALT) levels or with special co-morbidities (e.g. HIV) or risk profiles were rare. We conclude that antiviral therapy may prolong life, improve long-term health-related quality-of-life and be reasonably cost-effective in treatment-naïve patients with chronic hepatitis C as well as in former relapsers/nonresponders. Further research is needed in patients with specific co-morbidities or risk profiles.

Benefit of sustained virological response to combination therapy on graft survival of liver transplanted patients with recurrent chronic hepatitis C

Recurrent hepatitis C infection is an important cause of progressive fibrosis, cirrhosis and graft loss after liver transplantation. Treatment for post-transplant recurrence results in sustained virological response (SVR) in up to 30% of cases. The aim of this study was to evaluate the impact of SVR on patients and graft survival. Thirty-four patients with an SVR to IFN-ribavirin were included. Forty-six nonresponders to the combination formed the control group. Follow-up data were recorded every 6 months and included HCV RNA, and the occurrence of clinical problems (cirrhosis, decompensation, hepatocellular carcinoma, death). A graft biopsy was performed every year. The mean follow-up duration was 52 months in responders and 57 months in nonresponders. Two patients died in each group of patients. Two patients with SVR developed late virological relapse. Fibrosis decreased in 38% of patients with SVR, remained stable in 44% and worsened in 18%. In contrast, fibrosis increased in the majority of nonresponder patients (74%, p<0.001). At the end of follow-up, no patient without cirrhosis at inclusion developed cirrhosis of the graft versus 9 among nonresponder patients (p=0.009). No difference in patient survival was observed in the two groups. In conclusion, this study shows that HCV eradication has a positive impact on graft survival.

Sustained viral response to interferon and ribavirin in liver transplant recipients with recurrent hepatitis C

Recurrent hepatitis C infection is an important cause of progressive fibrosis, cirrhosis, and graft loss following orthotopic liver transplantation. Treatment for posttransplant recurrence of hepatitis C with interferon-based therapy is difficult but results in loss of detectable virus in up to 30% of patients. However, the durability of viral clearance and the associated histologic response in this setting is unknown. The aim of this study was to determine whether viral loss in response to antiviral therapy is durable and associated with improvement in liver histology. All liver transplant recipients who received interferon-based treatment for recurrent hepatitis C virus (HCV) at the University of Florida from 1991 to 2002 were included in this study. Patients who lost detectable HCV after treatment with interferon alone or in combination with ribavirin were followed to assess the durability of viral response and its impact on liver histology. One hundred nineteen transplant recipients were treated with interferon or combination therapy. Twenty-nine (20 men, 9 women; mean age, 54 yrs [range, 42-74 yrs]) lost detectable HCV RNA and remained virus negative for at least 6 months after discontinuing therapy (sustained viral response[SVR]). The mean follow-up after discontinuing therapy was 24.7 months (range, 6-70 mos). Our study cohort included one patient with SVR following interferon monotherapy and 28 patients with SVR following combination therapy with interferon plus ribavirin. All patients remained HCV RNA negative (assessed by polymerase chain reaction or branched-DNA assay) during follow-up of up to 5 years. Liver histology assessed 2 years after treatment showed less inflammation compared with before treatment in 50% and showed no change in 38%. By 3 to 5 years post-treatment (n = 15 recipients), inflammation was reduced in 60% and remained unchanged in 33%. Fibrosis stage at 2 years improved by > or = 1 stage in 27 %, remained unchanged in 38 %, and worsened in 35% despite viral clearance. At 3 to 5 years, the fibrosis stage had improved in 67%, remained unchanged in 13%, and worsened in 20%. Both grade of inflammation and fibrosis stage improved by 3 to 5 years posttreatment compared with baseline histology (p < 0.05). In conclusion, loss of HCV after treatment of recurrent chronic hepatitis C with interferon and ribavirin is durable, and the durability of the SVR is associated with improvement in hepatic inflammation and regression of fibrosis.

Effect of interferon therapy on the natural history of hepatitis C virus-related cirrhosis and hepatocellular carcinoma

In patients with chronic hepatitis C who have a sustained virologic response to IFN therapy, there is a dramatic effect on the natural history of the disease, with ALT levels becoming normal, histologic activity improving or disappearing, and the progression of fibrosis slowing. A sustained virologic response 6 months after the end of treatment is predictive of a sustained remission 4 years later. From these results, a long-term survival benefit is expected from IFN treatment in patients with an intermediate or rapid rate of fibrosis. For patients with chronic hepatitis C who do not experience a sustained eradication of virus, there is evidence that IFN treatment significantly reduces the viral load and serum ALT level, improves histologic activity, and blocks fibrosis progression, in comparison with the natural history of this disease. Therefore, patients who still have a detectable level of HCV RNA should no longer be considered nonresponders to IFN therapy. Although the number of randomized trials is [figure: see text] small, cumulative data suggest that IFN therapy can reduce the incidence of and the mortality from hepatocellular carcinoma in patients with cirrhosis.