Is there an optimal time to measure quantitative HCV RNA to predict non-response following interferon treatment for chronic HCV infection?

Ribavirin Contributes to Hepatitis C Virus Suppression by Augmenting pDC Activation and Type 1 IFN Production

Ribavirin is used as a component of combination therapies for the treatment of chronic hepatitis C virus (HCV) infection together with pegylated interferon and/or direct-acting antiviral drugs. Its mechanism of action, however, is not clear. Direct antiviral activity and immunomodulatory functions have been implicated. Plasmacytoid dendritic cells (pDCs) are the principal source of type 1 interferon during viral infection. The interaction of pDCs with HCV-infected hepatocytes is the subject of intense recent investigation, but the effect of ribavirin on pDC activation has not been evaluated. In this study we showed that ribavirin augments toll-like receptors 7 and 9-mediated IFNα/β expression from pDCs and up-regulated numerous interferon-stimulated genes. Using the H77S.3 HCV infection and replication system, we showed that ribavirin enhanced the ability of activated pDCs to inhibit HCV replication, correlated with elevated induction of IFNα. Our findings provide novel evidence that ribavirin contributes to HCV inhibition by augmenting pDCs-derived type 1 IFN production.

Rapid early innate control of hepatitis C virus during IFN-α treatment compromises adaptive CD4+ T-cell immunity

The ability to control HCV with IFN-α-based treatments provides an opportunity in humans to study how the rate of viral clearance in vivo impinges on the development of antiviral responses. Ex vivo (IFN-γ-producing) and cultured antiviral CD4⁺ T cells, serum cytokines, and viral loads were measured repeatedly in a cohort of chronically HCV-infected subjects (n = 33) receiving IFN-α. Rapid control of virus indicated by an increased calculated rate of virus clearance, occurred in those subjects demonstrating absent/minimal T-cell responses (p < 0.0006). Surprisingly, in subjects who demonstrated the most robust T-cell responses (and reduced serum IL-10), there was actually a reduced rate of early virus clearance. A subsequent analysis of NK-cell function in available subjects (n = 8) revealed an inverse correlation between pretreatment NK-cell expression of NKp46 and the potential to upregulate cytotoxic function on exposure to IFN-α (p < 0.004), as well as the subsequent measured rate of viral clearance (p = 0.045). Thus, the CD4⁺ T-cell response during IFN-α treatment appears to be shaped by the rate of innate virus suppression. These data suggest that individuals who respond most effectively to immune intervention may be most in need of subsequent vaccination to prevent reinfection.

Performance of two Real-Time RT-PCR assays for quantitation of hepatitis C virus RNA: evaluation on HCV genotypes 1-4

Accuracy for monitoring of the concentration of hepatitis C virus (HCV) RNA represents a major challenge throughout the management of patients with chronic hepatitis C. To investigate the genotype-independent efficiency and the accuracy of two real-time detection reverse transcription-polymerase chain reaction (RT-PCR) assays; the Cobas Ampliprep/Cobas TaqMan (CAP/CTM); and the Abbott RealTime HCV (ART), a total of 184 samples with different HCV subtypes were examined; 1b (n=58), 2a (n=39), 2b (n=26), 3a (n=20), and 4 (n=41). A robust linear correlation was observed between the two assays applied to genotypes 1b, 2a, 2b, and 3a [the correlation coefficient (R) ranged from 0.99 to 0.98], but not to genotype 4 specimens (R=0.78). A significant difference in measurements of HCV RNA using CAP/CTM and ART in serum samples with genotypes 1b and 4 was observed (0.72, -0.53 log IU/ml, P<0.0001, 0.01, respectively). A robust correlation was observed between the HCV core antigen and HCV RNA values by either of the HCV RNA quantitation assays applied to all genotypes with exception of genotype 4, for which R was higher with ART (R=0.95) than with CAP/CTM (R=0.80). The lower limit of detection of CAP/CTM and ART were 41.4 and 28.5 IU/ml using the WHO standards, respectively. In conclusion, two RT-PCR assays had a high efficiency and accuracy for quantitation of HCV RNA of genotypes 2a, 2b, and 3a, but the mean values of HCV RNA differed for genotype 1b and 4.

Comparison of antiviral activity of recombinant and natural interferons against crimean-congo hemorrhagic Fever virus

As a first line of defence against a virus infection, mammalian cells elicit an innate immune response, characterized by secretion of type I interferons (IFN) and up-regulation of interferon stimulated genes (ISGs). We have previously included Crimean Congo Hemorrhagic Fever Virus (CCHFV) in the list of type I IFN-sensitive viruses. In this in vitro study, we have compared the antiviral activity of two recombinant IFN-alpha preparations (Roferon A and Intron A) with a natural IFN-alpha produced in human leukocytes (Multiferon). Our results clearly demonstrate that these commercially available IFNs have significant antiviral activities against CCHFV. However, we could show that Multiferon inhibits viral replication more efficiently than the two recombinant IFN alpha preparations.

A model of patient choice with mid-therapy information

For many treatments, a patient's prognosis may be refined by conducting a mid-therapy assessment (MTA). When therapy lasts some time, an MTA predicts a patient's ultimate outcome based on early signs of response. The availability and timing of such assessments also serve as a mechanism by which policy makers can influence patients' treatment-initiation decisions. In this article, we examine how patients evaluate treatment options using MTAs of treatment effectiveness and discuss the policy implications of patient decision making in such contexts. To this end, we use indifference-curve analysis to characterize trade-offs between potential treatment success versus potential adverse effects in therapeutic situations where patients are encouraged to consider their own motivations for initiating treatment. Treatment initiation for chronic hepatitis C virus (HCV) infection is used for illustration, but the analysis can be easily adapted to a variety of clinical scenarios.Analysis shows that the existence of MTAs influences patients' initial treatment decisions by affecting the expectations of treatment success and adverse effects. Earlier MTAs have lower sensitivity and higher specificity, and the prior expectation of adverse effects is accordingly lower for two reasons. First, the lower chance for a false signal of treatment response and the higher chance for a false signal of no response make it more likely that the patient receives a signal leading to discontinuation. Second, if a signal to discontinue is received, fewer weeks of adverse effects have been endured before discontinuation occurs. Both factors make the expected burden of adverse effects lower when the MTA occurs earlier. Later MTAs have higher sensitivity and lower specificity, both of which serve to increase the probability of treatment completion, causing a higher prior likelihood of treatment success.These findings indicate that treatment demand may be increased by changing the timing of MTAs, depending on the information content of the alternative mid-therapy signals and the nature of patient preferences. In HCV infection and other diseases, clinical practice guidelines for conducting MTAs might be modified to better achieve public health or other policy objectives by studying the economics of patient choice.

Low-dose intermittent interferon-alpha therapy for HCV-related liver cirrhosis after curative treatment of hepatocellular carcinoma

AIM: To assess the efficacy of low-dose intermittent interferon (IFN) therapy in patients with hepatitis C virus (HCV)-related compensated cirrhosis who had received curative treatment for primary hepatocellular carcinoma (HCC).

METHODS: We performed a prospective case controlled study. Sixteen patients received 3 MIU of natural IFN-alpha intramuscularly 3 times weekly for at least 48 wk (IFN group). They were compared with 16 matched historical controls (non-IFN group).

RESULTS: The cumulative rate of first recurrence of HCC was not significantly different between the IFN group and the non-IFN group (0% vs 6.7% and 68.6% vs 80% at 1- and 3-year, P = 0.157, respectively). The cumulative rate of second recurrence was not also significantly different between the IFN group and the non-IFN group (0% vs 6.7% and 35.9% vs 67% at 1- and 3-year, P = 0.056, respectively). Although the difference in the Child-Pugh classification score between the groups at initial treatment of HCC was not significant, the score was significantly worse at the time of data analysis in the non-IFN group than IFN group (7.19 ± 1.42 vs 5.81 ± 0.75, P = 0.0008). The cumulative rate of deviation from objects of any treatment for recurrent HCC was also higher in the non-IFN group than IFN group (6.7% and 27% vs 0 and 0% at 1- and 3-year, P = 0.048, respectively).

CONCLUSION: Low-dose intermittent IFN-alpha therapy for patients with HCV-related compensated cirrhosis after curative HCC treatment was effective by making patients tolerant to medical or surgical treatment for recurrent HCC in the later period of observation.

Comparison of serum hepatitis C virus (HCV) RNA and core antigen levels in patients coinfected with human immunodeficiency virus and HCV and treated with interferon plus ribavirin

Trak-C (Ortho-Clinical Diagnostics) is an enzyme-linked immunosorbent assay-based method capable of quantifying hepatitis C virus (HCV) core antigen (CA) in serum and could be an alternative to molecular detection and quantification of HCV RNA. We have evaluated the Trak-C assay in comparison with an HCV RNA quantitative assay (Versant HCV v3.0; Bayer Diagnostics) in the follow-up of 348 treated, human immunodeficiency virus (HIV)/HCV-coinfected patients included in the ANRS HC02 RIBAVIC trial. ANRS HC02 RIBAVIC is a therapeutic, multicenter, randomized protocol comparing the efficacy of alpha interferon 2b (IFN-alpha2b) (3 million units three times a week)-ribavirin (800 mg/day) to that of pegylated IFN-alpha2b (1.5 mug/kg of body weight/week)-ribavirin (800 mg/day) during 48 weeks of treatment of HIV/HCV-coinfected patients naïve to HCV treatment. Patients were assessed for virological analysis at day 0 and weeks 4, 12, 24, 48, and 72. Correlation of HCV RNA and HCV CA at the initiation of treatment was excellent (r = 0.92). HCV RNA and CA kinetics were similar during follow-up of HCV treatment from day 0 to week 72 whatever the group of response and genotype. The positive and negative predictive values of response to the treatment at week 4 were 59 and 94%, respectively, for HCV RNA load reduction of >2 log and 54 and 94%, respectively, for HCV CA below the threshold value (4.18 log(10) pg/ml . 10(4)). Trak-C, a new assay able to quantify CA in HIV/HCV-coinfected patients, correlates well with quantitative HCV RNA assays and is cheaper and easier to perform than molecular technology. HCV CA could be a valuable alternative test for therapeutic follow-up of coinfected patients treated with IFN plus ribavirin in developing countries.

Prediction of sustained virological response in liver transplant recipients with recurrent hepatitis C virus following combination pegylated interferon alfa-2b and ribavirin therapy using tissue hepatitis C virus reverse transcriptase polymerase chain reaction testing

The optimal duration of therapy for pegylated interferon combined with ribavirin in recurrent Hepatitis C virus (HCV) following liver transplantation is not known. We wanted to determine if testing for HCV in liver tissue by reverse transcriptase polymerase chain reaction (RT-PCR) was superior in predicting sustained virological response (SVR) in comparison to standard HCV ribonucleic acid (RNA) detection in the serum. All recipients received combination pegylated alpha-2b interferon (1.5 mcg/kg) and ribavirin (200-600 mg/d) therapy for at least 48 weeks of therapy and were found to have nondetectable HCV RNA by PCR serum testing at the end of therapy. Sustained virological response (SVR) was defined as nondetectable serum HCV RNA at 6 months post treatment withdrawal. Ten liver transplant recipients were included in the study; mean time from transplantation was 29.2 months. All had nondetectable serum HCV RNA by RT-PCR. In hepatic tissue 7/10 patients HCV RNA was found to be positive by RT-PCR while 3/10 had nondetectable HCV RNA in their liver by RT-PCR. SVR was attained in all 3/10 that were hepatic tissue HCV PCR negative after 12 months of combination therapy. In conclusion, direct detection of HCV RNA by RT-PCR of liver tissue appears to more effectively predict SVR following pegylated interferon and ribavirin therapy than the conventional use of serum.

Early hepatitis C viral kinetics correlate with long-term outcome in patients receiving high dose induction followed by combination interferon and ribavirin therapy

BACKGROUND/AIMS

The majority of patients with genotype 1 do not respond to interferon (IFN) plus ribavirin. Limited data exist on the use of induction followed by combination therapy.

METHODS

In this prospective study of 28 patients infected with genotype 1, randomization involved either daily or twice daily high dose IFN for 6 weeks, followed by standard therapy of 3 million units three times a week in combination with ribavirin for an additional 42 weeks. Hepatitis C virus (HCV) RNA was quantitated before and frequently during treatment.

RESULTS

The best correlate of response was delta (the infected cell loss rate). Sixteen patients continued on the study because they had at least a 2 log drop in their HCV RNA levels by week 12; all but one were PCR negative for HCV RNA at 48 weeks, and 14 of these 16 patients continued to be PCR negative at 72 weeks. Both African-Americans in our trial failed to respond to therapy, and differences were evident during the induction phase.

CONCLUSIONS

This randomized study of induction IFN therapy followed by combination IFN plus ribavirin yielded the highest rate of sustained response (50%) reported to date in chronically HCV-infected patients with genotype 1. The predictive value of the infected cell loss rate needs to be evaluated prospectively in larger studies, particularly in patients receiving pegylated IFN.

Daily or three times per week interferon alpha-2b in combination with ribavirin or interferon alone for the treatment of patients with chronic hepatitis C not responding to previous interferon alone

BACKGROUND/AIMS

We compared the efficacy and safety of the combined therapy of daily interferon alpha-2b and ribavirin with those of interferon alpha-2b three times per week alone or in combination with ribavirin in non-responder patients with hepatitis C virus (HCV) infection.

METHODS

A total of 376 patients were randomly assigned to receive interferon alpha-2b (6 MU three times per week for 24 weeks followed by 3 MU three times per week for 24 weeks) alone (group A) or in combination with ribavirin for 48 weeks (group B), or daily interferon alpha-2b (3 MU per day for 24 weeks followed by 3 MU three times per week for 24 weeks) and ribavirin (group C).

RESULTS

After 24 weeks of therapy, HCV RNA was undetectable in 11.7, 24.0, and 37.8% for groups A, B, and C, respectively. Sustained virological response was more frequent in patients who received combination therapy with three times weekly interferon (20.9%) or daily interferon (26.0%) than in patients who received interferon alone (5.8%) (P<0.001). The predictive HCV parameters for sustained response were a low viral load on day 7 and a negative HCV RNA on week 12.

CONCLUSIONS

In conclusion, in non-responder patients with chronic hepatitis C, virological response with daily interferon and ribavirin, compared to interferon monotherapy, was significantly improved during treatment, although sustained virological response was similar for both combination therapies with ribavirin and three times a week or daily interferon.

Early detection of nonresponse to interferon plus ribavirin combination treatment of chronic hepatitis C

We have investigated the value of early hepatitis C virus (HCV) RNA decline (DeltaHCV RNA) to predict response to combination therapy in 66 chronic hepatitis C patients treated with IFN-alpha2b (3 MU thrice weekly) and ribavirin (800 mg daily) for 12 months [25 sustained responders (SR) and 41 nonresponders or relapsers (NR)]. Serum HCV RNA was retrospectively measured in samples obtained at baseline and 4, 8 and 12 weeks after treatment onset, using a commercially available quantitative RT-PCR assay. At 4 weeks, serum HCV RNA had decreased a mean of 2.6 +/- 0.8 logs among SR as compared with only 0.5 +/- 0.8 logs in NR (P < 0.001), and was already undetectable (< 600 IU/mL) in 12 (48%) of the SR but in none of the NR. At 8 weeks, HCV RNA was undetectable in 21 SR and in 2 NR and mean DeltaHCV RNA were 4.2 +/- 1.3 and 0.8 +/- 1.0 logs, respectively (P < 0.001). At week 12 all SR had undetectable HCV RNA as compared with only five NR (P < 0.001). Stepwise logistic regression analysis identified DeltaHCV RNA at 12 weeks as the strongest predictor of sustained response. Receiver operating characteristic (ROC) curves of DeltaHCV RNA for sustained response prediction identified sensitivity peaks with 100% negative predictive value corresponding to DeltaHCV RNA > 1 log at 4 weeks, > 2 logs at 8 weeks and > 3 logs at 12 weeks. Our results show that early changes in the HCV RNA level may reliably identify patients having no chance of a sustained virological response during the first 3 months of combination therapy, thus providing an excellent tool for optimizing antiviral treatment of chronic hepatitis C.

Hepatitis C advances in antiviral therapy: what is accepted treatment now?

The vast number of patients with hepatitis C represent a huge medical and economic burden. While 20-30% of these patients progress and develop advanced liver disease, the majority do not. Thus, it is crucial to identify patients suitable for treatment and those who may benefit most from therapy. Anti-viral therapy is recommended for those patients with chronic hepatitis C who also have elevated liver tests, detectable hepatitis C virus ribonucleic acid and significant inflammation and/or fibrosis on liver biopsy. Currently, the most effective initial therapy is the combination of interferon plus ribavirin. The sustained viral response rate (SVR) is 36-41% following a 24- or 48-week course of therapy. In general, patients with the genotype 1 infection should receive 48 weeks of therapy, and those with genotypes 2 or 3 infection only 24 weeks. Viral load estimations are problematic because of normal fluctuations (up to 0.5-10 log), assay variability and lack of a universally accepted standard; thus, viral load testing is not recommended routinely at present. The sustained viral response rate produces improvements in quality of life and liver histology (including reversal of bridging fibrosis and cirrhosis is some), and durable responses lasting 5-11 years in 95-97% of cases. While the optimal dose of ribavirin is currently unknown, available data suggest that higher doses increase efficacy (albeit with a greater degree of anemia). The dose of 800 mg/day may be the most appropriate lower dose for those patients who require dosage modification for anemia or other side-effects. Patients who have relapsed after interferon monotherapy can be successfully retreated with higher doses of interferon for 1 year or the combination of interferon and ribavarin for 24-48 weeks. Preliminary data suggest that patients with an unfavorable profile, including those with genotype 1 infection, should probably be retreated with interferon and ribavirin for 48 rather than 24 weeks. With our current best therapies, the majority of patients still do not achieve the benefits of a sustained response. Re-treatment with interferon and ribavirin may achieve a sustained response in approximately 10-25% of these patients. In the immediate future, once-weekly pegylated interferons will replace standard interferons. Initial data suggest that SVR achieved with these drugs in combination with ribavirin is increased to 54-61%, but dose modifications and side-effects are more frequent. They will thus provide an incremental benefit in terms of efficacy, particularly for genotype 1-infected patients.

Hepatitis C viral load does not predict disease outcome: going beyond numbers

The analysis of 58 patients with chronic hepatitis C without cirrhosis and treated with interferon-alpha demonstrated that hepatitis C viral (HCV) load does not correlate with the histological evolution of the disease (p = 0.6559 for architectural alterations and p = 0.6271 for the histological activity index). Therefore, the use of viral RNA quantification as an evolutive predictor or determinant of the severity of hepatitis C is incorrect and of relative value. A review of the literature provided fundamental and interdependent HCV (genotype, heterogeneity and mutants, specific proteins), host (sex, age, weight, etc) and treatment variables (dosage, time of treatment, type of interferon) within the broader context of viral kinetics, interferon-mediated immunological response (in addition to natural immunity against HCV) and the role of interferon as a modulator of fibrogenesis. Therefore, viral load implies much more than numbers and the correct interpretation of these data should consider a broader context depending on multiple factors that are more complex than the simple value obtained upon quantification.

Effective management of hepatitis C molecular testing improves test use without compromising patient management

CONTEXT

The availability of effective antiviral therapy for hepatitis C has increased the need for molecular detection and quantification of circulating hepatitis C viral particles. The limits of detection differ for the quantitative and qualitative reverse transcriptase polymerase chain reaction (RT-PCR) assays; furthermore, adequate patient assessment requires both detection of hepatitis C virus when it is present and quantitation of the viral load when possible. The combination of these factors promotes the simultaneous ordering of both tests with the possibility of generating redundant test information.

OBJECTIVE

To reduce the number of unnecessary hepatitis C tests performed.

METHODS

We established a reflexive testing protocol for quantitative and qualitative RT-PCR testing for hepatitis C.

RESULTS

During a 3(1/2)-month interval, 170 qualitative RT-PCR hepatitis C tests were eliminated (a 59.4% reduction in the number of these tests). This reduction was achieved without a clinically significant change in turnaround time or a compromise of patient care.

CONCLUSIONS

Establishing the quantitative and qualitative RT-PCR tests in-house and adopting the reflexive testing protocol was cost-effective and did not compromise patient management or care.

Predicting response to initial therapy with interferon plus ribavirin in chronic hepatitis C using serum HCV RNA results during therapy

In patients with chronic hepatitis C, 48 weeks of therapy with interferon (IFN) plus ribavirin results in a sustained virologic response of 40%. Preliminary analysis suggests that measuring HCV RNA at week 24, rather than week 12, might provide the best prediction of treatment response. To assess the clinical utility of serum HCV RNA determinations at different times during therapy as a predictor of a sustained virologic response we evaluated 912 treatment-naïve patients. Patients were randomized to receive IFN-alpha2b, 3 million units (MU) three times weekly (tiw), for 24 or 48 weeks with either ribavirin or placebo, and then followed for 24 weeks. Serum HCV RNA was measured at weeks 4 and 12 in patients treated for 24 weeks; at 4, 12, and 24 weeks during therapy in those treated for 48 weeks, and week 24 post-therapy in all patients. Sustained response was defined as loss of serum HCV RNA at week 24 follow-up. Other patients were considered virologic nonresponders. For patients receiving 48 weeks of combination therapy, detectable serum HCV RNA at week 24 predicted nonresponse (positive predictive value) in 99% of patients compared to 89% at week 12. In patients treated for 24 weeks, testing at week 12 was more predictive of nonresponse than testing at week 4 in the combination-therapy group but not in the monotherapy group. Hence, for combination therapy, testing for serum HCV RNA as a predictor of nonresponse is most accurate at week 24 of therapy; a positive test correctly identified 99% of nonresponders.

African Americans with genotype 1 treated with interferon for chronic hepatitis C have a lower end of treatment response than Caucasians

African Americans as a group have a higher incidence of chronic hepatitis C (CHC) than Caucasians but are often under-represented in clinical trials used to define response rates to interferon therapy. The aim of this study was to compare African Americans with Caucasians with respect to end-of-treatment response to interferon. This retrospective study had 61 African Americans and 49 Caucasians with CHC. All patients were treated for at least 12 weeks with interferon-alpha2b (Intron A) thrice weekly. End-of-treatment response was defined as three consecutive nondetectable HCV RNA measurements at least 1 month apart. Sustained response was defined as a negative serum HCV RNA 6 months after end of treatment. Of the 110 patients, 19 achieved an end-of-treatment response (17%) but only four achieved a sustained response (4/110=4%). Of the patients achieving a sustained response, one was genotype 1 (male Caucasian), three were genotype 2/3 with four patients having no follow-up information. The end-of-treatment response was 7% for patients with genotype 1 and 71% for genotype non-1 (P < 0.005 for genotype non-1). The end-of-treatment response was significantly higher in Caucasians (14/49=31%) compared with African Americans (5/61=8%; P < 0.05). A lower response rate in African Americans with genotype 1 in contrast to Caucasians was the primary reason for the difference in end-of-treatment response (1/45=2% vs. 5/33=15%, P < 0.05). Hence, interferon treatment resulted in a poor sustained response rate in the group of patients representative of the urban populations with the highest prevalence of hepatitis C. A genotype other than type 1 was the strongest predictor of end-of-treatment response in patients treated but over 86% of patients in this urban clinic were genotype 1. Caucasians were more likely to respond than African Americans, especially in patients with genotype 1.

Current and future therapies of hepatitis C

With recent advances in the treatment of chronic hepatitis C, patients with elevated aminotransferase levels, detectable HCV RNA in the serum, and chronic inflammation are candidates for therapy. The best initial therapy is interferon plus ribavirin, achieving a sustained response rate in 40% of patients. The duration of therapy should be based on HCV genotype (48 weeks for genotype 1; 24 weeks for other genotypes). Serum HCV RNA should be measured at week 24 to assess response and guide further therapy in patients with genotype 1 infection. Patients unsuitable for combination therapy can be treated with interferon monotherapy. Side effects, dose modification and discontinuation are generally more frequent with interferon plus ribavirin, but can be managed with close follow-up and careful monitoring. With rapid developments in treatment, new therapies will require careful prospective evaluation according to HCV genotype and viral-load characteristics. Recommendations for therapy will probably change every few years, and novel approaches may provide effective therapy for most patients with hepatitis C.

Factors predicting interferon treatment response in patients with chronic hepatitis c: late viral clearance does not preclude a sustained response

OBJECTIVES

Because of the suboptimal efficacy, cost, and adverse effects of interferon in chronic hepatitis C (HCV), predictors have been sought to detect patients with a good treatment response. Also, markers for determining a poor response early in the course of therapy, such as the lack of early viral clearance, have been proposed.

METHODS

Ninety-seven patients with chronic hepatitis C were enrolled to receive leukocyte alpha-interferon according to a stepped-care management protocol. The final virological treatment response was evaluated in 74 patients after a 6-month post-treatment follow-up. The relationship between pretreatment and during-treatment variables and the long-term response was assessed.

RESULTS

Non-1 viral genotype, higher pretreatment ALT levels, and lower gamma-glutamyl transferase (GGT)/ALT ratios and GGT as well as younger age were significantly associated with a sustained response; a trend was also detected for lower serum ferritin levels. Normalization of ALT by 3 months was also a significant predictor of a long-term response. Of the 27 patients carrying the HCV genotype 3a, seven (26%) were still HCV RNA positive at 6 months. Of these patients, however, five (19%) still achieved a sustained virological response after treatment for up to 12 months.

CONCLUSIONS

In contrast to some previous reports, our results suggest that a late viral clearance after 6 months of interferon monotherapy may not preclude a favorable long-term response after a 12-month treatment, especially in patients carrying a non-1 HCV genotype. A low pretreatment GGT/ALT ratio is a predictor of a good treatment response.

Efficacy of 5 MU of interferon in combination with ribavirin for naïve patients with chronic hepatitis C virus: a randomized controlled trial

BACKGROUND

In chronic hepatitis C the schedule of interferon (IFN), 3 MU thrice weekly (tiw) plus ribavirin (1000-1200 mg/daily) needs further evaluation, as IFN dosages >3 MU achieve better responses.

AIMS

To compare the efficacy of 5 MU tiw of IFN with (96 patients) or without ribavirin (96 patients) for 12 months in naïve patients, to evaluate the effect of baseline features on the response to therapy, and to determine a reliable point in time during treatment to predict non-response.

RESULTS

Sustained virologic response was 20.8% (95% CI 13-29) with IFN monotherapy and 54.2% (95% CI 44-64) with combination (P = 0.0001), the relapse rate 39.4% (95% CI 23-56) and 9% (95% CI 1-16) (P = 0.0007), and the combined rate of sustained biochemical and virologic response 22.7% (95% CI 14-31) and 60.5% (95% CI 50-71) (P = 0.0001), respectively. Patients given combination therapy were more likely to respond regardless of baseline features. Apart from genotype non-1, predictive factors for IFN monotherapy were ineffective in predicting response to combination therapy. Using logistic regression analysis, IFN-ribavirin was the strongest predictor of response (X2 = 21.3; P = 0.0001). Viral persistence at month 3 of therapy was a more accurate predictor than aminotransferase values for non-response to IFN monotherapy but not to combination therapy (positive predictive values of 98 and 82%, respectively).

CONCLUSION

In this study, 5 MU of IFN combined with a standard dose of ribavirin has yielded the highest rate of sustained response reported to date. Further dose finding studies are warranted.

Minimization of chronic plasma viremia in rhesus macaques immunized with synthetic HIV-1 Tat peptides and infected with a chimeric simian/human immunodeficiency virus (SHIV33)

HIV-1 Tat protein activates resting cells, rendering them permissive for viral replication. Replication of HIV-1 in vitro is enhanced by intercellular passage of Tat protein and inhibited by anti-Tat antibodies. Tat dependence of HIV-1 replication in vivo during acute, chronic asymptomatic and AIDS stages of infection was assessed by comparisons of plasma viremia in Tat-immunized or control monkeys challenged with SHIV(33) or SHIV(33A). Chronic plasma viremia became undetectable or minimized in Tat-immunized asymptomatic SHIV(33)-infected monkeys (p<0.008) while the high viral loads of acute infection or SHIV(33A)-induced simian AIDS were unaffected by Tat immunization. Active or passive immunotherapies targeting Tat provide potential approaches to controlling chronic HIV-1 viremia and preventing AIDS.

Adult beta-thalassemic patients with chronic hepatitis C: long-term efficacy of alpha-IFN treatment

Background: The purpose of this study was to assess the effectiveness of alpha-IFN in adult beta-thalassemic patients with chronic hepatitis C. After a long-term follow-up, we describe the special pattern of biochemical and virological response of thalassemics. Methods: Thirty-two anti-HCV-positive adult thalassemic patients (19 female and 13 male, mean age 23.4+/-5.5 years) with biopsy-proven chronic hepatitis were treated with IFN alpha2beta at a dose of 3 MU thrice weekly for 6-12 months. The patients were followed up until 45-62 months after the end of treatment. Results: A sustained response was obtained in eight patients (25%). Only two of the sustained responders (25%) normalized ALT during the first 3 months of treatment. Both early and late biochemical responders cleared HCV-RNA after 6 months of treatment. Eight patients (25%) responded with ALT normalization within 2 months of treatment but relapsed soon after stopping IFN. Sixteen patients (50%) did not respond to IFN. Conclusion: The response rate in multitransfused thalassemic patients with chronic hepatitis C treated with IFN is similar to that in non-thalassemics. The special feature of thalassemics is that early biochemical response does not predict a sustained response; on the contrary, patients who normalize ALT after 6 months of IFN treatment usually do not relapse.

Methodological issues in papers on IFN therapy: time for reappraisal

We conducted an analytical review of 194 full papers on interferon (IFN) therapy for chronic hepatitis C to evaluate current methodology (i.e. study design, criteria for evaluating the efficacy of therapy and predictors of response). Of the papers evaluated, 64 were randomized controlled trials (RCT), 40 were non-randomized controlled trials (NRCT) and 90 were observational studies (OS). The methodological analysis was focused mainly on clinical trials. The number of patients enrolled in RCT was higher compared with the number enrolled in NRCT. Uniform enrolment criteria were used in less than 50% of the trials. Only 20% of RCT and 2.5% of NRCT used criteria for defining sample size. The response rate was calculated on an intention-to-treat basis in 36 of the RCT and in 14 of the NRCT. The outcome of treatment and the criteria employed to define the response to treatment were found to be far from standardized. In 51.5% of the RCT and 42.5% of the NRCT, normalization of alanine aminotransferase (ALT) level at the end of follow-up was the only marker of response studied. Only 57.6% of the trials considered histological evidence as an important outcome. Among the clinical trials, 71.1% evaluated predictors of good response to IFN therapy. In 51% of the OS, ALT normalization by the end of follow-up was the only criterion for defining response. In conclusion, to ensure a high level of reliability in comparing or combining the results of different studies, some basic general requirements must be followed when planning trials on antiviral therapy.

Early predictors of response to treatment in patients with chronic hepatitis C

The term sustained response should be applied to patients with negative serum HCV-RNA and normal values of serum transaminases 6 months after interferon withdrawal. To investigate which factors identify sustained responders early during treatment we analysed 18 reports which used the definition sustained response. Eight reports, comprising 988 patients, have studied the value of early clearance of viraemia as a predictor of sustained response using multivariate analysis and all of them found that this was the strongest predictor of a sustained response. Determination of HCV-RNA 4 or 12 weeks after initiation of IFN therapy predicts treatment outcome more accurately than baseline viral load (the best pre-treatment predictor). ALT levels during the first 12 weeks of treatment have lower predictive value than early viral clearance. The sensitivity of a negative HCV-RNA test is similar at week 4 and at week 12 of therapy while the specificity and the accuracy is higher at week 4. The value of persistent viraemia for early prediction of no response is higher than 97%, with similar values at weeks 4 and 12. Persistence of HCV-RNA in serum at week 4 strongly indicates that the patient will not respond to treatment and in these cases interruption of treatment or other therapeutic options could be considered.

Overview of interferon therapy for chronic hepatitis C

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).

Interferon alfa-2b alone or in combination with ribavirin as initial treatment for chronic hepatitis C. Hepatitis Interventional Therapy Group

BACKGROUND

Only 15 to 20 percent of patients with chronic hepatitis C have a sustained virologic response to interferon therapy. We compared the efficacy and safety of recombinant interferon alfa-2b alone with those of a combination of interferon alfa-2b and ribavirin for the initial treatment of patients with chronic hepatitis C.

METHODS

We randomly assigned 912 patients with chronic hepatitis C to receive standard-dose interferon alfa-2b alone or in combination with ribavirin (1000 or 1200 mg orally per day, depending on body weight) for 24 or 48 weeks. Efficacy was assessed by measurements of serum hepatitis C virus (HCV) RNA and serum aminotransferases and by liver biopsy.

RESULTS

The rate of sustained virologic response (defined as an undetectable serum HCV RNA level 24 weeks after treatment was completed) was higher among patients who received combination therapy for either 24 weeks (70 of 228 patients, 31 percent) or 48 weeks (87 of 228 patients, 38 percent) than among patients who received interferon alone for either 24 weeks (13 of 231 patients, 6 percent) or 48 weeks (29 of 225 patients, 13 percent) (P<0.001 for the comparison of interferon alone with both 24 weeks and 48 weeks of combination treatment). Among patients with HCV genotype 1 infection, the best response occurred in those who were treated for 48 weeks with interferon and ribavirin. Histologic improvement was more common in patients who were treated with combination therapy for either 24 weeks (57 percent) or 48 weeks (61 percent) than in those who were treated with interferon alone for either 24 weeks (44 percent) or 48 weeks (41 percent). The drug doses had to be reduced and treatment discontinued more often in patients who were treated with combination therapy.

CONCLUSIONS

In patients with chronic hepatitis C, initial therapy with interferon and ribavirin was more effective than treatment with interferon alone.