Search

Background: Nitazoxanide, licensed in the US for treatment of Cryptosporidium parvum and Giardia lamblia, inhibits hepatitis C virus replication in replicon systems., Aim: To evaluate the safety and efficacy of nitazoxanide monotherapy for the treatment of chronic hepatitis C., Methods: This multicentre, randomized, double-blind, placebo-controlled study randomized 50 adult patients with chronic hepatitis C genotype 4 at three centres in Egypt to nitazoxanide 500 mg tablet or placebo twice daily for 24 weeks. Patients were followed up every 4 weeks during treatment and for 24 weeks after therapy., Results: Seven of 23 patients (30.4%) in the nitazoxanide group achieved undetectable serum HCV RNA compared to 0 of 24 in the placebo group during therapy (P = 0.004). Each of the seven responders had baseline HCV RNA levels < or =400 000 IU/mL. Six of the seven virological responders were followed up for 24 weeks after the end of treatment, and four patients (17.4% of 23 treated) had a sustained virological response. Adverse events were similar in the nitazoxanide and placebo groups., Conclusion: Nitazoxanide monotherapy is safe and effective in achieving sustained virological response in a modest number of patients with chronic hepatitis C genotype 4, particularly in patients with low baseline serum HCV RNA levels.

The diagnosis of chronic hepatitis B virus (HBV) infection is made using a combination of serological, virological, biochemical, and histological markers. The natural history of HBV infection can be divided into 3 phases: immune tolerant, immune active with chronic hepatitis B, and inactive carrier; patients in the immune active phase are candidates for antiviral therapy. The primary goal of therapy for chronic hepatitis B is suppression of viral replication, which has been shown to reduce hepatic necroinflammation and retard progression of hepatic fibrosis. Long-term suppression of serum HBV DNA is likely to reduce progression to cirrhosis and hepatic decompensation and may also decrease the risk of hepatocellular carcinoma. Current antiviral therapy for chronic hepatitis B includes interferon alpha, lamivudine and adefovir, with recent studies demonstrating good safety and efficacy of peginterferon and other nucleoside analogues that will soon become additional treatment options. In patients with HBeAg-positive chronic hepatitis B, antiviral treatment is indicated when the serum HBV DNA level is = or >10(5) copies/mL and the alanine aminotransferase (ALT) level is elevated, particularly greater than 2 times the upper limits of normal. For HBeAg-negative patients, the threshold for initiation of therapy is a HBV DNA level = or >10(4) in association with an elevated ALT level. The presence of at least moderate necroinflammation and the presence of fibrosis on liver biopsy, which is optional and not mandatory before therapy, may be useful in supporting the decision to initiate therapy. While undergoing therapy, patients require monitoring every 3 to 6 months to ensure compliance and to test for the development of resistance if an oral agent is used. Issues that remain controversial or need to be studied further are the necessity of a baseline liver biopsy, the HBV DNA and ALT thresholds for initiation of therapy, the optimal duration of antiviral therapy, selection of one agent over another, and the role of combination therapy.

Background: Screening for hepatocellular carcinoma in cirrhotic patients using abdominal ultrasonography and alpha-foetoprotein levels is widely practiced., Aim: To evaluate its cost-effectiveness using a Markov decision model., Methods: Several screening strategies with abdominal ultrasonography or computerized tomography and serum alpha-foetoprotein at 6-12-month intervals in 40-year-old patients with chronic hepatitis C and compensated cirrhosis were simulated from a societal perspective, resulting in discounted costs per quality-adjusted life-year saved. Extensive sensitivity analysis was performed., Results: For the least efficacious strategy, annual alpha-foetoprotein/ultrasonography, the incremental cost-effectiveness ratio (vs. no screening) was $23 043/quality-adjusted life-year. Biannual alpha-foetoprotein/annual ultrasonography, the most commonly used strategy in the United States, was more efficacious, with a cost-effectiveness ratio of $33 083/quality-adjusted life-year vs. annual alpha-foetoprotein/ultrasonography. The most efficacious strategy, biannual alpha-foetoprotein/ultrasonography, resulted in a cost-effectiveness ratio of $73 789/quality-adjusted life-year vs. biannual alpha-foetoprotein/annual ultrasonography. Biannual alpha-foetoprotein/annual computerized tomography screening resulted in a cost-effectiveness ratio of $51 750/quality-adjusted life-year vs. biannual alpha-foetoprotein/annual ultrasonography screening., Conclusions: Screening for hepatocellular carcinoma is as cost-effective as other accepted screening protocols. Of the strategies evaluated, biannual alpha-foetoprotein/annual ultrasonography gives the most quality-adjusted life-year gain while still maintaining a cost-effectiveness ratio <$50 000/quality-adjusted life-year. Biannual alpha-foetoprotein/annual computerized tomography screening may be cost-effective.

Background: Randomized controlled trials over the last decade have demonstrated incremental improvement in the treatment efficacy of chronic hepatitis C with combination interferon and ribavirin therapy when compared with interferon monotherapy., Aim: To perform a systematic review of clinical trials directly comparing interferon formulations to test the hypothesis that a true difference in terms of efficacy exists between standard interferon (with and without ribavirin) and peginterferon (with and without ribavirin)., Methods: A search of the on-line bibliographic databases MEDLINE and PUBMED was performed independently by two authors to identify all relevant articles. In addition, the reference sections of all relevant articles were manually searched to identify any missed articles. Quality was assessed using the Jadad scale, which is an accepted scale specific for randomized controlled trials. A priori, it was decided to include only articles with a Jadad score of three or higher in the final analysis. Data were abstracted on to pre-determined abstraction sheets. The inclusion of articles, the data abstracted and the methodological score differences were adjudicated by consensus with agreement of the authors performing the search., Results: Seven citations of randomized controlled trials, comparing at least two different interferon formulations and evaluating the sustained virological response as a primary end-point, were identified. These relevant articles were abstracted, and five of the seven were found to have a Jadad score of three or higher and comprised the final set of citations reviewed. The studies consistently demonstrated that peginterferon monotherapy was superior to standard interferon, even in patients with advanced fibrosis. With regard to combination interferon therapy, only two high-quality articles compared peginterferon plus ribavirin with standard interferon plus ribavirin. Both studies demonstrated that the overall sustained virological response was statistically better with peginterferon plus ribavirin., Conclusions: On the basis of this systematic review, peginterferon-based regimens are superior to standard interferon-based regimens for the treatment of chronic hepatitis C.

Advances in immunosuppressive therapy, operative techniques, and perioperative management have resulted in long-term patient survival rates approaching 90% following liver transplantation for chronic viral hepatitis. The increasing number of referrals for liver transplantation reflects the impact of chronic HCV infection as a cause of end-stage liver disease. Unlike hepatitis B, there is still no effective treatment in preventing recurrent hepatitis C after liver transplantation. The spectrum of allograft injury related to universal HCV infection recurrence ranges from no evidence of histologic injury to mild inflammation to severe disease with allograft failure in small proportion of patients. Various factors may explain these differing outcomes, including degree of pretransplantation viremia, HLA compatibility, presence of more pathogenic HCV genotypes, integrity of cellular immune response, and type of immunosuppression. Fortunately, patient survival does not seem to be affected short-term; the long-term outcome of liver transplantation for chronic hepatitis C is unclear but is likely to be decreased. Combination therapy with interferon plus ribavirin seems to be a promising treatment strategy for posttransplantation recurrent hepatitis C, and the use of pegylated interferon plus ribavirin may improve these results. Patients with moderate to severe allograft hepatitis are appropriate candidates for combination antiviral therapy. Histopathologically documented recurrent hepatitis C in liver transplant recipients is associated with impaired quality of life, inferior physical condition, and a higher incidence of depression compared with patients who did not have HCV and in those without HCV recurrence. In conclusion, it is possible that the continued improvements in antiviral therapy against HCV infection may ultimately decrease the number of patients needing liver transplantation. Suitable candidates with chronic HCV infection thus warrant treatment with pegylated interferon plus ribavirin combination therapy in the hope of decreasing disease progression. Recent studies, which require confirmation, suggest that nonresponders to standard antiviral therapy may benefit from maintenance therapy. The donor pool for patients with chronic hepatitis C and decompensated cirrhosis can be improved by using HCV-positive donors and by increasing utilization of newer surgical techniques, including adult-to-adult living-donor liver transplantation and split-liver transplantation.

Prior studies seeking evidence of viral replication in peripheral lymphocytes of hepatitis C virus (HCV)-infected patients have yielded conflicting results. This study sought to quantitatively determine whether a permissive HCV cell interaction could be detected in leukocytes from infected patients. Peripheral leukocytes from chronically infected patients were purified and were tested for HCV RNA. The results show that virus load is highest in B cells. Other subsets of peripheral leukocytes consistently had very low levels of viral RNA or were negative. Negative-strand HCV was found only in hepatocytes. To determine whether HCV replication could be induced by activation, B cells from HCV-infected patients were stimulated in vitro. No HCV replicating in peripheral leukocytes was detected by a highly sensitive assay. If HCV replication occurs in the leukocyte subsets analyzed here, it is at extremely low levels or occurs under alternate physiological conditions.

Dendritic cells (DCs) are important for the initiation of immune responses to foreign antigens. Their antigen uptake and presentation capacities enable them to prime and activate T cells. Immature DCs capture antigens; however, they must be activated to mature before serving as efficient antigen-presenting cells. The antigen-presenting capacity of DCs can be diminished during viral infection and as a consequence of tumor formation. Chronic infection with hepatitis C virus (HCV) has been shown to affect the allostimulatory function of DCs. In this study, it is demonstrated that monocyte-derived DCs from patients with chronic HCV infection do not respond to maturation stimuli. Instead, they maintain their immature phenotype, reflected by the pattern of cell surface markers and by their continued capacity to uptake antigen. Moreover, their allostimulatory abilities are impaired compared with those of mature DCs derived from healthy donors. To investigate a possible correlation between viral clearance and this DC maturation defect, patients with resolved HCV infection after a course of antiviral therapy were studied. Results demonstrate that DCs from patients who cleared HCV behaved like DCs from healthy donors: in response to maturation stimuli, they decrease antigen uptake, up-regulate expression of appropriate surface markers, and are potent stimulators of allogeneic T cells. (Blood. 2001;97:3171-3176)

For chronic hepatitis B, treatment with a 4-month course of interferon alfa-2b can achieve hepatitis B e antigen seroconversion, normalization of aminotransferase levels, reduced hepatic inflammation, and possibly reduced progression to cirrhosis and improvement in survival in 20%-30% of patients. Similar results can be achieved with a 12-month course of lamivudine, with response rates increasing to 40%-65% after 3 years of therapy. Interferon can also be used in early cirrhotic patients, and lamivudine can be used in advanced cirrhotics and immunosuppressed patients. Combination interferon and lamivudine therapy does not confer additional benefits. For chronic hepatitis C, the combination of interferon alfa-2b and ribavirin is the treatment of choice, offering superior sustained response rates (40%) compared with interferon alone (15%). Therapy should be administered for 12 months to patients with genotype 1 virus but for only 6 months to patients with genotypes 2 and 3. Patients experiencing relapse after 6 months of interferon monotherapy can be re-treated with interferon and ribavirin or high-dose interferon, with 45%-56% sustained response rates. However, relatively few patients who are prior nonresponders to interferon monotherapy will have sustained response to further interferon-based treatments, including combination therapy with ribavirin. Successful therapy not only leads to the eradication of viral RNA but also may delay progression to cirrhosis and hepatocellular carcinoma. Interferon combined with polyethylene glycol (PEG), shows promise as an improved formulation of interferon with yet higher sustained response rates.

Objective: The effect of baseline viral concentration on response was assessed as part of a multicenter phase 3 trial evaluating the safety and efficacy of CIFN therapy for chronic HCV infection., Methods: Patients (n = 472) received either CIFN 9 microg or IFN alpha-2b 3 MU subcutaneously t.i.w. for 24 wk, followed by 24 wk of observation., Results: Efficacy was assessed by the percentage of patients who achieved normal ALT values or undetectable HCV RNA values (using RT-PCR with a sensitivity of 100 copies/ml). There was a clear relationship between baseline viral concentration and either ALT or HCV RNA response; patients with lower titer HCV RNA had better response rates. End-of-treatment HCV RNA responses were better for patients with low viral concentrations treated with CIFN (51%) than for patients treated with IFN a-2b (31%) (p = 0.03). ALT responses in patients with low viral concentrations were 60% for CIFN-treated patients and 27% for IFN alpha-2b-treated patients (p < 0.01) at the end of treatment. Patients with high titer HCV RNA were more likely to have a sustained HCV RNA response after treatment with CIFN 9 microg, compared with those treated with IFN alpha-2b (7% vs 0%, p = 0.03)., Conclusions: Both genotype and baseline viral concentration were independent factors that affected response to interferon.

We assessed differences in the pattern of HCV RNA decrease for HCV genotypes 1, 2, and 3 during interferon treatment to determine if the lower response rates observed among genotype 1 patients were related to a slower decrease in HCV clearance. Serum HCV RNA values of 472 chronic hepatitis C patients treated with either consensus interferon (CIFN) or interferon alfa-2b (IFN alfa-2b) were evaluated. Neither virological sustained responders nor relapsers differed in the pattern of serum HCV RNA decrease based on genotype. Virological sustained responders infected with genotype 1 cleared HCV RNA as rapidly as sustained responders who were infected with genotype 2 or 3. Relapsers had a slower rate of serum HCV RNA decrease than did virological sustained responders. Nonresponders differed in the pattern of serum HCV RNA decrease based on genotype: HCV genotype 3 patients had the greatest decrease in serum HCV RNA; genotype 2 patients had an intermediate decrease; and genotype 1 patients had the least serum HCV RNA decrease. HCV genotype 1 patients treated with CIFN had a greater decrease in serum HCV RNA during therapy than did patients treated with IFN alfa-2b. However, there was no difference in the magnitude of serum HCV RNA decrease between the two interferon treatments for patients infected with genotype 2 or 3. In summary, both genotype and ultimate response to treatment are determinants of the pattern and rate of serum HCV RNA change during interferon therapy of chronic hepatitis C.

Hepatitis C virus (HCV) genotyping has been shown to predict response to interferon, but is expensive. HCV serotyping is less expensive and simpler, and may be similarly useful. Using data from a large, randomized trial comparing consensus interferon (CIFN) and interferon alfa-2b (IFN alfa-2b) in patients with chronic HCV, we evaluated response rates based on HCV serotypes versus genotypes. Patients included in this analysis received subcutaneous injection of 9 microg CIFN (n = 232) or 3 MU IFN alfa-2b (n = 240) three times weekly for 24 weeks followed by 24 weeks of observation. Serum HCV RNA concentrations were measured regularly during treatment and at the end of both the treatment and post-treatment periods. Response to interferon was similar for HCV antibody types and their corresponding genotypes. The end-of-treatment HCV RNA rate of response (defined as undetectable serum on two consecutive assessments) was 29% for serotype 1 versus 24% for genotype 1 after CIFN; and 14% versus 15%, respectively, after IFN alfa-2b. Independently of treatment, patients infected with serotype or genotype 2 or 3 had a better therapeutic response than those infected with serotype or genotype 1. Similar results were obtained based on HCV antibody typing and genotyping, suggesting the potential of the former for predicting response to interferon.

The future therapy for chronic hepatitis C will probably include measures to decrease hepatocellular injury along with multidrug combinations, including inhibitors of the hepatitis C viral protease, helicase, or polymerase to reduce serum levels or eradicate HCV RNA. The results of recently concluded trials of IFN-alpha 2b plus ribavirin combination therapy have shown a twofold improvement in the biochemical and virologic response rates and superiority by other measures of efficacy with an acceptable safety profile. In view of these results, new guidelines for the management of chronic HCV infection are appropriate (Fig. 1).

The National Institutes of Health Consensus Development Conference on the management of hepatitis C, which took place in March 1997 and was published in September 1997, established guidelines for the diagnosis and management of chronic hepatitis C. The recommended treatment of chronic hepatitis C virus (HCV) infection is interferon alpha (or equivalent) 3 MIU three times per week for 12 months, in patients showing response to therapy after 3 months. Patients with the greatest risk for progression to cirrhosis (i.e. persistently elevated alanine aminotransferase levels, detectable serum HCV-RNA and liver biopsy showing portal or bridging fibrosis and at least moderate inflammation and necrosis) are recommended as candidates for therapy. The indication for therapy is less obvious in patients with milder histological changes, compensated cirrhosis and age less than 18 years or older than 60 years. Treatment is not indicated for patients with persistently normal aminotransferases or decompensated cirrhosis. This review outlines the background studies that led to the recommendations of the National Institutes of Health for the treatment of chronic hepatitis C and reviews newer evolving treatment strategies over the past year. In particular, the results of studies exploring treatment options for relapsers and non-responders to prior interferon therapy and the reported results to date on the safety and efficacy of combination therapy with interferon plus ribavirin are highlighted. Although aggressive suppression of HCV-RNA with induction therapy (daily and/or higher doses) or long-acting pegylated interferon preparations may improve the current results of therapy, few data are yet available. Finally, the treatment of chronic hepatitis C with protease inhibitors holds promise but has yet to reach the stage of clinical trials.

We have investigated the relationship between serum alanine aminotransferase (ALT) and hepatitis C virus (HCV) RNA in the assessment of responses to interferon (IFN) therapy in chronic HCV infection. Data from 704 patients with HCV infection who were randomized to receive consensus IFN-alpha (CIFN) 3 micrograms (n = 232 patients) or 9 micrograms (n = 232 patients), or IFN-alpha 2b 3 million units (MU) (n = 240 patients), were used for these analyses. All patients were treated three times weekly. Hepatitis C viral RNA (HCV RNA) was determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) with a lower limit of detection of 100 copies ml-1. Of patients with normal serum ALT concentrations, 53% (120/225) had undetectable HCV RNA at the end-of-treatment period and 47% (51/109) had undetectable HCV RNA at the end of the post-treatment observation period. In contrast, of the patients with undetectable HCV RNA, 75% (120/161) and 84% (51/61) had normal serum ALT activities at the end-of-treatment and post-treatment observations periods, respectively. The majority of patients with undetectable HCV RNA had normal ALT values. In contrast, only half of the patients with normal ALT values were negative for HCV. End-of-treatment HCV RNA response also better predicted sustained virological response than did end-of-treatment ALT response.

A multicenter, open-label, phase 3 study was conducted in 337 patients with chronic hepatitis C virus (HCV) infection who had either not responded to previous interferon therapy or had relapsed after discontinuation of therapy with either consensus interferon (9 microg) or interferon alpha-2b (3 million U) three times a week for 24 weeks. Patients were randomized to receive a higher dose of consensus interferon (15 microg) administered subcutaneously three times a week for 24 or 48 weeks and then were observed for an additional 24 weeks. Patients who had relapsed after prior interferon therapy were more likely to have a sustained alanine aminotransferase response and HCV RNA response (as measured by reverse transcription-polymerase chain reaction with a sensitivity of < 100 copies/mL) than were patients who had not responded to prior interferon therapy. For relapsers, the sustained HCV RNA response rate was 58% (48 weeks) and 28% (24 weeks). The sustained alanine aminotransferase response for relapsers was 52% (48 weeks) and 39% (24 weeks). The sustained HCV RNA response rate among prior nonresponders was 13% (48 weeks) and 5% (24 weeks), and the sustained alanine aminotransferase response rate for nonresponders was 17% (48 weeks) and 12% (24 weeks). The administration of 15 microg of consensus interferon was well tolerated and was not associated with an increase in the incidence of side effects. These data demonstrate that re-treatment with 15 microg of consensus interferon is safe and effective therapy for patients with chronic hepatitis C who have either not responded to previous interferon therapy or relapsed after discontinuation of interferon therapy.