Permanent response to alpha-interferon therapy in chronic hepatitis C is preceded by rapid clearance of HCV-RNA from serum

A randomised controlled trial of losartan as an anti-fibrotic agent in non-alcoholic steatohepatitis

Introduction

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease worldwide. Experimental and small clinical trials have demonstrated that angiotensin II blockers (ARB) may be anti-fibrotic in the liver. The aim of this randomised controlled trial was to assess whether treatment with Losartan for 96 weeks slowed, halted or reversed the progression of fibrosis in patients with non-alcoholic steatohepatitis (NASH).

Methods

Double-blind randomised-controlled trial of Losartan 50 mg once a day versus placebo for 96 weeks in patients with histological evidence of NASH. The primary outcome for the study was change in histological fibrosis stage from pre-treatment to end-of-treatment.

Results

The study planned to recruit 214 patients. However, recruitment was slower than expected, and after 45 patients were randomised (median age 55; 56% male; 60% diabetic; median fibrosis stage 2), enrolment was suspended. Thirty-two patients (15 losartan and 17 placebo) completed follow up period: one patient (6.7%) treated with losartan and 4 patients (23.5%) in the placebo group were “responders” (lower fibrosis stage at follow up compared with baseline). The major reason for slow recruitment was that 39% of potentially eligible patients were already taking an ARB or angiotensin converting enzyme inhibitor (ACEI), and 15% were taking other prohibited medications.

Conclusions

Due to the widespread use of ACEI and ARB in patients with NASH this trial failed to recruit sufficient patients to determine whether losartan has anti-fibrotic effects in the liver.

Trial registration

ISRCTN 57849521

Basic PK/PD principles of drug effects in circular/proliferative systems for disease modelling

Disease progression modelling can provide information about the time course and outcome of pharmacological intervention on the disease. The basic PK/PD principles of proliferative and circular systems within the context of modelling disease progression and the effect of treatment thereupon are illustrated with the goal to better understand/predict eventual clinical outcome. Circular/proliferative systems can be very complex. To facilitate the understanding of how a dosing regimen can be defined in such systems we have shown the derivation of a system parameter named the Reproduction Minimum Inhibitory Concentration (RMIC) which represents the critical concentration at which the system switches from growth to extinction. The RMIC depends on two parameters (RMIC = (R₀ − 1) × IC₅₀): the basic reproductive ratio (R₀) a fundamental parameter of the circular/proliferative system that represents the number of offspring produced by one replicating species during its lifespan, and the IC₅₀, the potency of the drug to inhibit the proliferation of the system. The RMIC is constant for a given system and a given drug and represents the lowest concentration that needs to be achieved for eradication of the system. When exposure is higher than the RMIC, success can be expected in the long term. Time varying inhibition of replicating species proliferation is a natural consequence of the time varying inhibitor drug concentrations and when combined with the dynamics of the circular/proliferative system makes it difficult to predict the eventual outcome. Time varying inhibition of proliferative/circular systems can be handled by calculating the equivalent effective constant concentration (ECC), the constant plasma concentration that would give rise to the average inhibition at steady state. When ECC is higher than the RMIC, eradication of the system can be expected. In addition, it is shown that scenarios that have the same steady state ECC whatever the dose, dosage schedule or PK parameters have also the same average R₀ in the presence of the inhibitor (i.e. R_0-INH) and therefore lead to the same outcome. This allows predicting equivalent active doses and dosing schedules in circular and proliferative systems when the IC₅₀ and pharmacokinetic characteristics of the drugs are known. The results from the simulations performed demonstrate that, for a given system (defined by its RMIC), treatment success depends mainly on the pharmacokinetic characteristics of the drug and the dosing schedule.

2'-,5'-Oligoadenylate synthetase response ratio predicting virological response to PEG-interferon-α2b plus ribavirin therapy in patients with chronic hepatitis C

OBJECTIVE

Although all the mechanisms of elimination of hepatitis C virus (HCV) by Interferon (IFN) have not been fully elucidated, the 2'-5'-oligoadenylate (2-5A) system is one of the mechanisms of the antiviral effect of IFN. Consequently, the measurement of 2'-5'-oligoadenylate synthetase (2-5AS) activity could be useful for the evaluation of IFN treatment. This retrospective study was aimed at assessing whether 2-5AS activity functions as a clinical marker of virological response to PEG-interferon-alpha2b (PEG-IFN) plus ribavirin therapy of chronic hepatitis C.

METHODS

The 32 patients included in this study had high viral loads of serum HCV-RNA of genotype 1b with chronic hepatitis C. All the patients received a regimen of PEG-IFN plus ribavirin for 48 weeks, and were then divided into two groups: one group (effective group) with undetectable serum HCV-RNA levels at 24 weeks (n = 22) of therapy, the other group (ineffective group) with persistent presence of HCV-RNA in serum at 24 weeks (n = 10). The 2-5AS activity in serum was measured 2, 8 and 12 weeks before initial administration.

RESULTS

The 2-5AS response ratio (measured value/measured value of baseline 2-5AS) at 2, 8 and 12 weeks after the administration in the effective group was significantly higher than that in the ineffective group.

CONCLUSIONS

These results suggest that the ratio of 2-5AS is closely related to the antiviral effect, and that the measurement of 2-5AS response ratio may be a useful clinical parameter of virological response to PEG-IFN plus ribavirin therapy of chronic hepatitis C.

Peginterferon-alfa2a plus ribavirin for 48 versus 72 weeks in patients with detectable hepatitis C virus RNA at week 4 of treatment

BACKGROUND & AIMS

Patients with chronic hepatitis C who do not respond rapidly to therapy have a low chance of developing a sustained virologic response (SVR) when treated for 48 weeks. This study investigated whether treatment for 72 weeks increases the rate of SVR in patients with detectable hepatitis C virus (HCV)-RNA levels at week 4 of treatment.

METHODS

A total of 510 treatment-naive patients were treated with peginterferon-alfa2a (180 microg/wk) plus ribavirin (800 mg/day). Patients with detectable HCV-RNA levels at week 4 (n = 326) were randomized to complete 48 (group A, n = 165) or 72 weeks (group B, n = 161) of treatment. Patients with undetectable HCV-RNA levels at week 4 (n = 184) were allocated into group C (n = 148) or group D (n = 36), according to HCV genotype and baseline viremia, and treated for 24 or 48 weeks, respectively. All patients were followed-up for 24 weeks after the end of treatment.

RESULTS

The end-of-treatment response rate (61%) was similar in groups A and B, but the SVR rate was higher in group B (45% vs 32% in A; P = .01). In genotype 1-infected patients randomized to group A (n = 149) or B (n = 142), SVR rates were 28% and 44%, respectively (P = .003). The incidence of adverse events was similar in all groups. Treatment discontinuation was more frequent in group B (36%) than in group A (18%) (P = .0004). SVR rates in groups C and D were 79% and 64%, respectively.

CONCLUSIONS

Extension of treatment with peginterferon-alfa2a plus ribavirin from 48 to 72 weeks significantly increases the rate of SVR in patients with detectable viremia at week 4 of treatment.

Development and validation of two models for early prediction of response to therapy in genotype 1 chronic hepatitis C

Early prediction of response to therapy in genotype 1 chronic hepatitis C is difficult. Two predictive models, a pretreatment scoring model (PreT-SM) and a fourth week of therapy scoring model (4w-SM) were constructed in a cohort of 104 patients from a single center (estimation cohort) and validated in a cohort of 141 patients from four independent centers (validation cohort). Individual scores were calculated using variables independently associated with sustained virological response (SVR). Baseline viral load, aspartate aminotransferase/alanine aminotransferase ratio, serum cholesterol, and a numerical score for noninvasive estimation of liver fibrosis were included in the PreT-SM; HCV RNA clearance and PreT-SM scores were included in the 4w-SM. Receiver operating characteristic analysis revealed the area under the curve in the estimation cohort and in the validation cohort to be, respectively, 0.856 and 0.847 for the PreT-SM and 0.908 and 0.907 for the 4w-SM. Low scores were associated with SVR, high scores with non-SVR. The best cutoff scores from the PreT-SM (7 and 9.70) identified, respectively, 36% of patients with SVR and 41% of those with non-SVR from the validation cohort, with high accuracy (> or =90% positive predictive value [PPV] and specificity). Similarly, cutoff scores of 3.20 and 5.60 from the 4w-SM identified, respectively, 71% of patients with SVR and 53% of those with non-SVR from the same cohort with high accuracy (PPV and specificity >92%). In conclusion, these models predicted response to therapy before or after 4 weeks of treatment in approximately 60% of genotype 1 patients and may be valuable for the management of this condition.

Prediction of Efficacy of Interferon Treatment of Chronic Hepatitis C and Occurrence of HCC after Interferon Treatment by a New Classification

One hundred and twenty-one chronic hepatitis C patients were administered interferon (IFN) and divided into two groups: 31 complete responders (CR) with prolonged HCV-RNA negative 1 year after treatment and 90 non-complete responders (non-CR), including partial responders (PR) with transiently negative HCV-RNA and non-responders (NR) with continuously positive HCV-RNA. Liver biopsy specimens were classified into four grades and stages according to the degree of severity and the extent of fibrosis, respectively. No correlation was observed between the rate of IFN efficacy and grading. By staging, however, a difference in the efficacy of IFN was observed between F1 or F2 and F3 (0.05 < p < 0.1 and 0.01 < p < 0.025, respectively). Of the CR, 0% (0/5) were at F0 and 27.9% (24/86) at F1, 42.9% (6/14) at F2, and 6.3% (1/16) at F3. Another group of 118 chronic hepatitis patients (31 CR, 41 PR and 46 NR) followed up for over 2 years after IFN treatment were analyzed. By staging, 7 cases were at F0, 76 at F1, 18 at F2, and 17 at F3. HCC occurred in 1 of the 31 CR cases (representing an annual incidence rate of 1.21%), in 4 of the 41 PR cases (4.08%), and in 4 of the 46 NR cases (3.55%). HCC did not occur in any of the 7 cases at F0 (representing an annual incidence rate of 0%); it occurred in 2 of the 76 cases at F1 (1.01%), in 1 of the 18 cases at F2 (2.28%), and in 6 of the 17 cases at F3 (16.57%). These results suggest that the new classification would be conducive to roughly predicting the efficacy of IFN treatment and the occurrence of HCC after IFN treatment.

Interleukin 6 and 12, Alanine Aminotransferase Activity, and HCV Viral Load in Children with Chronic Hepatitis C Treated with Interferon and Ribavirin

The response to viral infections is mediated through the co-operation of cellular and humoral mechanisms. The aim of this study was to seek the correlation between IL-6 and IL-12 level, HCV viral load, ALT activity during the 48-week treatment with interferon-alpha-2b (IFN-alpha-2b) combined with ribavirin in children with diagnosed CHC and to search their influence on positive response to treatment. The group of 27 children with CHC was enrolled into this study. The children were treated with interferon-alpha and ribavirin in the course of 48-week therapy. The results show that both ALT activity and the viral load at the time of implementation of treatment with IFN-alpha and ribavirin is an important prognostic tool when treating children. It has been shown that the levels of IL-6 do not bear any significant prognostic importance to the implemented therapy, yet the increase of IL-12 levels in the 24th week of the treatment may be of prognostic value and may point out the possible elimination of HCV-RNA.

To interfere and to anti-interfere: the interplay between hepatitis C virus and interferon

As popular strategies used by numerous viruses, interception of interferon (IFN) signaling and inhibition of IFN-induced antiviral functions allow viruses to evade the host immune response and set up successful infections. Hepatitis C virus (HCV), the leading cause of chronic liver disease worldwide and a major public health hazard, causes persistent infection in the majority of infected individuals. IFN-based therapies, currently the only ones available for HCV infection, have been unable to eliminate viral infection in the majority of patients, and many studies suggest that HCV possesses mechanisms to antagonize the IFN-induced antiviral response. Multiple viral, host, and IFN-associated factors have been implicated in the interplay between HCV and IFN. Two viral proteins, NS5A and E2, became the focus of much attention and extensive study because of their abilities to inhibit IFN-induced, double-stranded RNA-activated protein kinase (PKR), a major mediator of the IFN-induced biologic response, and to perturb the IFN signaling pathway. In this review, we discuss the significance of the interferon sensitivity determining region (ISDR) within NS5A, which has been the subject of intense debates. In addition, we discuss the potential mechanisms by which NS5A interferes with IFN signaling and the current working models. Further understanding of the molecular mechanisms underlying the interaction between HCV and IFN will likely facilitate improvement of current IFN-based therapies and development of novel treatments for the HCV pandemic. Future HCV research will benefit from both the development of efficient, convenient model systems for viral propagation, and the utilization of high throughput, genomic-scale approaches.

High sustained response to daily dosing of interferon with ribavirin in chronic hepatitis C patients naïve to therapy

BACKGROUND

: Viral kinetics suggests that daily administration of alpha-interferon (IFN) will clear hepatitis C virus (HCV) RNA earlier and more frequently compared with standard t.i.w. To reduce the likelihood of viral replication, mutation and subsequent development of resistance, daily dosing with IFN may be appropriate. To determine the safety and efficacy of daily IFN with ribavirin in chronic HCV infection we performed a prospective study.

METHODS

: Thirty-five naïve adult HCV-positive patients (25 male/10 female) were treated with IFN-alpha2b; 5 MU daily for 2 weeks followed by 3 MU daily for 22 weeks and ribavirin 800-1200 mg/day depending on weight. Liver biopsy, performed in 25 patients, showed mild to moderate activity in 19 patients (76%) and severe activity in six patients (24%). Two patients showed staged IV fibrosis. Serotyping was performed in 29 patients by an enzyme immunoassay-based Murex assay. Type 3 was the predominant serotype, present in 14 cases. Hepatitis C virus RNA was measured by the Chiron bDNA assay.

RESULTS

: Mean baseline HCV-RNA level was 14.2 +/- 18.7 MEq/mL (median 6.09; range 0.2-92.5), which became undetectable in all but three patients at week 4. Normalization of alanine aminotransferase (ALT) at week 4 was seen in 27 patients. Three patients withdrew due to non-compliance. Thirty-two patients completed 24 weeks of therapy as per the protocol. At the end of treatment, the HCV-RNA level was negative in 29 of 32 patients (90.6%) and ALT was normal in 31 of 32 patients (97%). Sustained viral response at 6 months follow up was seen in 28 of 32 patients (88%). The ALT level was normal in 28 of 32 patients (88%).

CONCLUSION

: Daily administration of IFN with ribavirin is well tolerated in the majority of patients. There is rapid elimination of virus with normalization of ALT and a significantly high sustained viral response.

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 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.

Influence of the genetic heterogeneity of the ISDR and PePHD regions of hepatitis C virus on the response to interferon therapy in chronic hepatitis C

Two genomic regions of hepatitis C virus (HCV), the interferon sensitivity-determining region (ISDR) of the non-structural 5A gene (NS5A) and the protein kinase-RNA activated (PKR)-eukariotic transcription factor (eIF2-alpha) phosphorylation homology domain (PePHD) of the structural E2 gene, interact in vitro with the interferon-inducible cellular PKR protein kinase. Mutations within these regions might, therefore, influence the response to interferon therapy. Viral load at baseline and sequence heterogeneity of HCV in NS5A and E2 regions was studied in 74 HCV-1b and in 12 HCV-3a infected patients with chronic hepatitis C who were treated with interferon. As previously reported by us, in a smaller series of patients in which the ISDR region was analyzed [Saiz et al. (1998) Journal Infectious Diseases 177:839-847], in the present study a low viral load and a high number of amino acid mutations within the ISDR, but not within the PePHD region, were significantly associated with long-term response to interferon among HCV-1b infected patients. No relationship between these viral features and response to therapy was disclosed in patients infected with HCV-3a.

[Why are not all patients with chronic liver disease associated with hepatitis C virus treated?]

AIMS

To analyze the prevalence of patients with chronic liver disease associated with hepatitis C virus (HCV) not undergoing antiviral treatment and the reasons for which this treatment was not indicated.

PATIENTS AND METHODS

718 patients with HCV infection referred for therapeutic evaluation between January 1990 and January 1998. Demographic, clinical, biological and histological variables were prospectively analyzed. The patients were divided into two groups: treated and untreated.

RESULTS

393 patients were treated and in 325 patients antiviral treatment was not considered to be indicated. The most frequent reasons for not starting therapy were advanced age, the presence of decompensated cirrhosis and the patients' refusal to undergo antiviral treatment.

CONCLUSIONS

A broad subgroup of patients with chronic liver disease associated with HCV do not receive antiviral treatment. This is related with: a) patients' advanced age at diagnosis, b) diagnosis at the advanced stages of the disease, and c) patients' refusal to undergo such treatment after being informed of its potential risks and benefits.

Early addition of ribavirin to interferon in chronic hepatitis C not responsive to interferon monotherapy

BACKGROUND/AIM

Persistence of HCV-RNA in serum early in treatment is a strong predictor of failure of alpha-interferon therapy for chronic hepatitis C. Therefore, we compared the efficacy of ribavirin addition to alpha-interferon with a doubling of the dosage of alpha-interferon in case of lack of early virological response to alpha-interferon therapy.

METHODS

Sixty patients were administered interferon alpha2b at the dosage of 3 million units 3 times a week. After the first 4 weeks of therapy, serum HCV-RNA was evaluated. The patients with negative HCV-RNA test received the same treatment for a further 11 months, while those with detectable HCV-RNA were randomized to receive either the same dosage of alpha-interferon plus ribavirin (1000 mg/day) or double dosage of alpha-interferon (6 million units tiw) for 11 months. We considered sustained response to be the maintenance of normal alanine aminotransferase and negativity at HCV-RNA testing until the end of a 6-month post-treatment follow-up.

RESULTS

After the first 4 weeks of treatment, 12 (20%) patients showed virological response and 48 patients (80%) remained positive on HCV-RNA testing. Sustained response was observed in 5/12 (42%) patients with early virological response, in 10/24 (42%) patients without early virological response who were administered ribavirin and alpha-interferon, and in only 1/24 (4%) patients who were administered the double dosage of alpha-interferon (p=0.006).

CONCLUSIONS

This study shows the efficacy of the addition of ribavirin to alpha-interferon and the lack of efficacy of doubling the dosage of alpha-interferon in patients without clearance of hepatitis C virus early on in treatment.

Different turnover rate of hepatitis C virus clearance by different treatment regimen using interferon-beta

BACKGROUND/AIM

Since patients with high viral load and HCV subtype 1b are known to respond poorly to interferon (IFN) therapy, the viral dynamics of HCV RNA after initiation of interferon therapy were examined in the present study with respect to two different administration regimens, once vs. twice a day.

METHODS

Twenty-two patients with chronic hepatitis C confirmed by liver biopsy and with >1 Meq/ml of HCV RNA and HCV subtype 1b were randomly assigned to two different IFN administration regimens (6 million units of IFN once a day or 3 million units of IFN twice a day), and the serum HCV RNA level was serially measured.

RESULTS

Graphs of HCV RNA levels vs. treatment time showed an initial rapid fall, followed by a slower clearance phase. Fitting the data to a model for HCV decay proposed by Neumann et al. showed that the treatment efficacy was significantly higher with twice daily administration. Negativity for HCV RNA measured by Amplicor assay in the twice-a-day administration group was 18%, 73% and >89% at 1, 2 and 3 weeks, respectively, in contrast to 0%, 0%, and 18%, respectively, with once-a-day administration. However, a significant reduction of platelet count and albumin level, a marked increase in serum aspartate aminotransferase/alanine aminotransferase, and a high incidence of renal toxicity (proteinuria) were found in patients receiving IFN twice a day in comparison with those receiving it once a day.

CONCLUSION

The twice-a-day administration of IFN accelerated the clearance of HCV RNA from serum, leading to a more efficient virological response for patients with chronic hepatitis C, but with a high rate of renal toxicity.

Pre-treatment with prednisolone does not improve the efficacy of subsequent alpha interferon therapy in chronic hepatitis C

BACKGROUND/AIMS

Alpha interferon administration is quite disappointing as a single therapy in chronic hepatitis C. A brief course of corticosteroid therapy might increase the effectiveness of subsequent alpha interferon administration, but data on this issue are controversial.

METHODS

One hundred and fifty-six consecutive patients with chronic hepatitis C were randomly assigned to be treated blind with tapering doses of oral prednisolone or placebo for 4 weeks. Two weeks after cessation of therapy, patients received alpha interferon (3 MU t.i.w.) for 48 weeks and were followed for 24 additional weeks. Response was defined by the presence of normal alanine aminotransferase (ALT) and negative HCV-RNA in serum.

RESULTS

ALT activity decreased during prednisolone administration and rebounded upon withdrawal in 38% of the patients treated with this drug. Significant changes in serum bilirubin were not observed. HCV-RNA serum concentration tended to increase during prednisolone administration and to decrease upon withdrawal. ALT and HCV-RNA did not change during administration of placebo. At the end of interferon administration, 33% of patients treated with prednisolone and 25% of those treated with placebo presented biochemical and virological response. At the end of post-treatment follow-up, response was maintained in 12% and 13% of patients treated with prednisolone or placebo respectively. Response was not related to ALT or HCV-RNA changes observed during the pre-interferon phase of the study. No adverse events related to prednisolone administration were observed.

CONCLUSIONS

Prednisolone administration and withdrawal induced a rebound in ALT activity and a decrease in HCV-RNA serum concentration in about one third of the patients with chronic hepatitis C. However, these changes did not enhance the effectiveness of subsequent alpha interferon therapy.

Utility of early testing for HCV viremia as predictive factor of sustained response during interferon or interferon plus ribavirin treatment

BACKGROUND/AIM

To evaluate the utility of early testing for hepatitis C viremia as a predictor of treatment outcome during interferon or combination therapy.

METHODS

We studied 184 patients with chronic hepatitis C who received interferon and were monitored for HCV RNA. Sixty-two patients received interferon alone for 12 months and 122 patients, who were still HCV RNA positive at 2 months, received an additional 12-month course of interferon and ribavirin combination therapy.

RESULTS

Using this strategy, sustained response occurred in a total of 34 patients (18.5%). Independent variables associated with sustained response were HCV genotype (p=0.06), viral load < or = 5.1 logs/ml (p= 0.005) and negative HCV RNA at 1 month (p<0.0001) in the interferon group, and female sex (p=0.04), genotype (p=0.03), viral load < or = 5.5 logs/ml (p=0.01), normal ALT (p=0.001) and decline in viral load > or = 1.2 logs/ml after 2 months of interferon monotherapy (p<0.001) and negative viremia at 5 months of ribavirin onset (p<0.0001) in the combination therapy group. Persistence of viremia at 1 month of interferon monotherapy and at 5 months of combination therapy were the strongest predictors of non-response (negative predictive value of 100% and 99%, respectively).

CONCLUSIONS

Qualitative assessment of HCV RNA during treatment is the strongest predictor of sustained response during interferon or combination therapy for chronic hepatitis C.

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.

Predictors of the efficacy of interferon therapy for patients with chronic hepatitis C before and during therapy: how does this modify the treatment course?

Antiviral therapy for hepatitis C virus (HCV) infection should be based on the natural history of HCV infection; there is a sequential, but slow, progression from chronic hepatitis to cirrhosis, leading to death from either liver failure or hepatocellular carcinoma (HCC). The risk of HCC development increases in association with the advance of fibrosis, and antiviral therapy can reduce this risk. More than 30 indices have been proposed as 'predictors' of favourable response to IFN therapy: host factors (age, gender, duration of HCV-infection, alcohol intake, hepatic iron stores, platelet count, histological staging of the liver disease), viral factors (HCV RNA levels in serum, HCV subtype, diversity of the hypervariable region, mutation of non-structure 5A gene), and IFN factors (dose, duration of treatment, type, treatment regimens i.e. every day vs three times a week, escalating dose regimen). Before starting IFN therapy, HCV subtype and pretreatment HCV RNA load, as well as the fibrotic stage of the liver, should be determined. The response to IFN therapy should be monitored by the HCV RNA status in serum during therapy, and the treatment regimen modified, or discontinued as required. A sustained virological response should be checked at more than 3 months after the completion of therapy. Even though the risk of HCC is markedly reduced in sustained responders, it is possible to develop HCC several years after completion of IFN therapy.

Prediction of relapse or sustained response in biochemical responders by serum hepatitis C virus RNA monitoring during interferon therapy

Normalization of serum aminotransferase levels is achieved in approximately 50% of chronic hepatitis C patients treated with interferon (IFN); however, in about one-half of these patients the hepatitis relapses after therapy. In this study we investigated the efficacy of serum hepatitis C virus (HCV) RNA monitoring during IFN therapy to predict the outcome of a biochemical end-of-treatment (ETR) response. Eighty patients with chronic hepatitis C received leucocyte (natural) IFN-alpha (13 patients) or recombinant IFN-alpha2a (67 patients). Antiviral therapy was given for 12 months to 43 (53.7%) responders and this group was analysed further. During follow-up, 15 relapsed and 28 showed a sustained response (median follow-up 50 months, range 39-67 months). Viraemia was monitored at baseline, and at months 1, 3, 6, 9 and 12 of treatment, by nested polymerase chain reaction (PCR) (sensitivity 10-100 copies ml-1). A combination of positive nested PCR and HCV RNA values at the 3rd and 6th months of treatment was 100% predictive of relapse (sensitivity, 66.6%; specificity, 100%). A combination of negative nested PCR and HCV RNA values at the 1st and 3rd months of treatment was 100% predictive of sustained response (sensitivity, 39.3%; specificity, 100%). In conclusion, serum HCV RNA monitoring is an appropriate and reliable tool for predicting early outcome of the biochemical ETR response after IFN discontinuation. This could be useful in the modulation of therapeutic management of chronic hepatitis C.

The role of HBV DNA quantitative PCR in monitoring the response to interferon treatment in chronic hepatitis B virus infection

BACKGROUND/AIMS

To investigate whether the measurement of HBV DNA by quantitative polymerase chain reaction (PCR) is helpful in monitoring response to interferon treatment in chronic hepatitis B virus infection, we have determined sequentially serum levels of HBV DNA during and up to 18 months after treatment, in 10 patients with a sustained response (all anti-HBe positive, five also HBsAg negative and anti-HBs positive) and, as controls, in 12 non-responders.

METHODS

Serum HBV DNA was measured by standard hybrisation assay (Genostics, Abbott) and by quantitative PCR (Amplicor HBV Monitor test, Roche Diagnostic Systems).

RESULTS

A clear difference in HBV viral load between responders and non-responders was observed from the fourth week of treatment and was maintained throughout the study period. At the last follow up 16-26 (median 21) months after starting treatment, all the 10 responders were HBV DNA negative by hybridisation. By PCR, however, five (one anti-HBs and four anti-HBe positive) were still HBV DNA positive. In addition, one anti-HBs positive patient HBV DNA negative by PCR at last follow up, had fluctuating levels of HBV DNA by PCR during the observation period, only intermittently falling below the threshold of the assay.

CONCLUSIONS

The measurement of HBV DNA by quantitative PCR provides early prediction of response to interferon, allowing prompt modification of treatment. With this technique, HBV DNA is detected in a high proportion of sustained responders, suggesting that HBV may never be completely eliminated by interferon treatment, even after anti-HBs seroconversion.

Should patients with early loss of serum HCV-RNA during alpha interferon therapy for chronic hepatitis C be treated for 6 or 12 months?

BACKGROUND/AIMS

Retrospective studies have suggested that early loss of serum HCV-RNA predicts sustained response to alpha-interferon treatment in chronic hepatitis C, but the optimal duration of therapy after loss of HCV-RNA is not known. The aims of this study were: a) to prospectively evaluate the effectiveness of HCV-RNA testing after 1 month of alpha-interferon treatment in the prediction of sustained response, and b) to compare the efficacy of 6 and 12 months of therapy in patients with a negative serum HCV-RNA test after the first month of treatment.

METHODS

One hundred and thirty patients were administered interferon alpha-2b at doses related to body weight (< or > or = 60 kg) and to HCV genotype: 5 or 8 MU tiw for type 1, and 3 or 5 MU tiw for genotypes non-1. Serum HCV-RNA testing was performed using in-house nested RT-PCR at month 1, at the end of treatment and 6 months afterwards. We considered sustained response to be the maintenance of normal alanine aminotransferase and negativity at serum HCV-RNA testing until the end of follow-up.

RESULTS

Sustained response was observed in 2/72 (2.8%) patients with detectable HCV-RNA after the initial month of therapy, in 8/30 (26.7%) patients with early loss of HCV-RNA treated for 6 months and in 20/28 (71.4%) patients treated for 12 months (p<0.01).

CONCLUSIONS

Serum HCV-RNA detectability after the first month is strongly associated with a very poor chance of sustained response, and these cases should be offered other treatments. Patients with early loss of HCV-RNA should complete a 12-month treatment, which appeared more effective than a 6-month treatment.

Viral and host factors in the prediction of response to interferon-alpha therapy in chronic hepatitis C after long-term follow-up

Acute infection with hepatitis C virus (HCV) develops into a chronic hepatitis in about 50-70% of patients. Treatment of these patients with interferon-alpha (IFN-alpha) results in a sustained long-term response in only 15-20% but causes numerous unwanted side-effects in a higher percentage of patients. The aim of our study was to define host or viral parameters that would allow identification of responders and non-responders to IFN-alpha prior to the onset of treatment. We studied a group of 87 patients suffering from chronic hepatitis C who were treated with IFN-alpha. After long-term follow-up, 18 patients (21%) showed a sustained response to IFN-alpha therapy (normalization of serum transaminases and loss of viral RNA from serum) for up to 7 years after therapy had ceased. By univariate and multivariate analyses, no host factors were found to be predictive of response to therapy. Neither the degree of inflammation or fibrosis in liver biopsy samples obtained before treatment nor immunogenetic factors (major histocompatibility complex II haplotype and tumour necrosis factor-alpha promoter polymorphism) were associated with response to therapy. In contrast, viral parameters showed a strong association with response to therapy. HCV genotype 3 was found significantly more frequently in responders (P = 0.034), and mean HCV RNA concentration was lower in responders (3.1 x 10(4)) than in non-responders (2.5 x 10(5)) (P = 0.01). By multivariate analysis, both HCV genotype and HCV RNA concentration were independent predictors of response to therapy. However, exact prediction of response to treatment for an individual patient was not possible on the basis of pretreatment viral RNA concentration or viral genotype. The best association with response to therapy was found to be clearance of HCV RNA from serum 3 months after the start of treatment (32 of 34 partial and sustained responders vs 0 of 53 non-responders; P = 0.001). In conclusion, determination of pretreatment viral factors, but not host factors, was significantly correlated with treatment response but did not give an accurate prediction for patients, whereas clearance of HCV RNA from serum after 3 months of therapy was predictive of response to therapy.

Early hepatitis C virus-RNA responses predict interferon treatment outcomes in chronic hepatitis C. The Consensus Interferon Study Group

In previous studies employing interferons (IFNs) in the treatment of chronic hepatitis C, there have been few reliable predictors of sustained responses. We retrospectively evaluated the predictive value of hepatitis C virus (HCV)-RNA measurements in the first few months during consensus interferon (CIFN) treatment using a sensitive reverse-transcriptase polymerase chain reaction assay to determine sustained responses. Data from two large treatment trials, one of IFN-naive patients and one of retreated relapsers and nonresponders, were used, including serum samples at 2-week intervals in the naive study and 8-week intervals in the retreatment study. Patients received initial CIFN (9 microgram) treatment for 6 months and were assessed 6 months after treatment. There were 28 sustained viral responders of 232 CIFN-treated patients. Of the sustained responders, 48% had already cleared HCV RNA from serum (<100 copies/mL) by week 2, 78% by week 4, 81% by week 6, and 96% by week 12. Patients with early HCV-RNA clearance were more likely to have sustained responses than those who responded later. Early clearance of HCV from serum was also associated with greater likelihood of a sustained response to 48 weeks of retreatment with 15 microgram CIFN. Ninety-five percent of the sustained responders were HCV-RNA-negative by week 8 of retreatment. Early assessment of HCV RNA may help in the prediction of sustained responses to IFN and allow the value of continued treatment to be determined early in the course of IFN therapy.

Importance of pretreatment viral load and monitoring of serum hepatitis C virus RNA in predicting responses to interferon-alpha2a treatment of chronic hepatitis C. Hanshin Chronic Hepatitis C Study Group

The aim of this study was to determine what factors correlate with a favorable response to interferon-alpha2a (IFN-alpha2a) treatment in chronic hepatitis C. Fifty patients with chronic hepatitis C who received a 26-week treatment with IFN-alpha2a (474 million units in total) were assessed for pretreatment parameters and biochemical and virologic events during the treatment. According to biochemical and virologic responses to the treatment, 16 patients (32%) were categorized as sustained complete responders (SR), 13 (26%) as initial complete responders (IR), and 21 (42%) as nonresponders (NR). By multivariate analysis, a low viremia level was the only independent predictor of SR among pretreatment parameters (p = 0.0088). The percentage of patients showing hepatitis C virus RNA negativity at 2 and 12 weeks of treatment was significantly higher in SR (94% and 100%, respectively) or IR (69% and 92%, respectively) than in NR (14% and 33%, respectively) (p = 0.001). In contrast, the normalization of serum alanine aminotransferase levels at both time points failed to differentiate among SR, IR, and NR. These results indicate that monitoring of serum hepatitis C virus RNA at an appropriate time during treatment in addition to determination of pretreatment viral load is important in predicting responses to IFN-alpha2a treatment.