Predicting the therapeutic response in patients with chronic hepatitis C: the role of viral kinetic studies

Interferon-γ-inducible protein-10 in chronic hepatitis C: Correlations with insulin resistance, histological features & sustained virological response

BACKGROUND & OBJECTIVES

One of the multiple factors contributing to virological response in chronic hepatitis C (CHC) is interferon-gamma-inducible protein-10 (IP-10). Its level reflects the status of interferon-stimulated genes, which in turn is associated with virological response to antiviral therapy. The aim of this study was to evaluate the role of serum IP-10 levels on sustained virological response (SVR) and the association of this parameter with insulin resistance (IR) and liver histology.

METHODS

Two hundred and three consecutive biopsy proven CHC patients were included in the study. Serum levels of IP-10 were determined using ELISA method. IR was evaluated by homeostasis model assessment-IR (HOMA-IR). Histological features were assessed invasively by liver biopsy and noninvasively using FibroTest, ActiTest and SteatoTest. Predictive factors for SVR and their interrelations were assessed.

RESULTS

A cut-off value for IP-10 of 392 pg/ml was obtained to discriminate between responders and non-responders. SVR was obtained in 107 patients (52.70%). Area under the receiver operating characteristic curve for SVR was 0.875 with a sensitivity of 91.6 per cent, specificity 74.7 per cent, positive predictive value 80.3 per cent and negative predictive value 88.7 per cent. Higher values of IP-10 were associated with increasing stages of fibrosis (P<0.01) and higher grades of inflammation (P=0.02, P=0.07) assessed morphologically and noninvasively through FibroTest and ActiTest. Significant steatosis and IR were also associated with increased levels of IP-10 (P=0.01 and P=0.02). In multivariate analysis, IP-10 levels and fibrosis stages were independently associated with SVR.

INTERPRETATION & CONCLUSIONS

Our findings showed that the assessment of serum IP-10 level could be a predictive factor for SVR and it was associated with fibrosis, necroinflammatory activity, significant steatosis and IR in patients with chronic HCV infection.

Viability of pegIFNα-RBV for CHC in the direct acting antiviral era: a practical algorithm between efficacy and cost containment

The classical pegylated interferon α (peg-IFNα) and ribavirin (RBV) treatment of chronic hepatitis C (CHC) is progressively being replaced by new direct acting antivirals, whose costs remain a major barrier to widespread use. Using baseline data and viral kinetics, we developed a predictive algorithm to allocate to DAA patients who are not going to respond to peg-IFNα/RBV. This prospective study evaluated 205 CHC patients treated with peg-IFNα/RBV. HCVRNA kinetics during the initial 3 days of therapy and baseline variables including age, genotype, fibrosis and ALTs were used to construct a prediction rule in terms of sustained virological response (SVR). One hundred and twenty-one patients achieved an SVR (59%). Variables independently associated with SVR were HCVRNA, ALT, glycaemia, viral genotype, and fibrosis. The decline of viremia from baseline to 48/72 h was significantly different in SVR compared to non-SVR patients (2.2 vs. 0.65 log10 IU/mL; p < 0.001), and was influenced by viral genotype, levels of ALT, stage of fibrosis and IL28B polymorphism. In genotype 1, HCVRNA decline <0.8 logs had a negative predictive value of 90%, and in genotype 2, HCVRNA decline >1.2 logs had a positive predictive value of 92%. A combination of HCVRNA kinetics and a score based on pre-treatment parameters was highly accurate in predicting SVR in most patients. Outcome of peg-IFNα/RBV treatment may be predicted combining evaluation of baseline variables and HCVRNA kinetics. This allows to individualize treatment, reserving newer and more expensive DAAs to CHC patients who are in most need of them.

Modeling a dynamic bi-layer contact network of injection drug users and the spread of blood-borne infections

Injection drug users (IDUs) are at high risk of acquiring and spreading various blood-borne infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and a number of sexually transmitted infections. These infections can spread among IDUs via risky sexual and needle-sharing contacts. To accurately model the spread of such contagions among IDUs, we build a bi-layer network that captures both types of risky contacts. We present methodology for inferring important model parameters, such as those governing network structure and dynamics, from readily available data sources (e.g., epidemiological surveys). Such a model can be used to evaluate the efficacy of various programs that aim to combat drug addiction and contain blood-borne diseases among IDUs. The model is especially useful for evaluating interventions that exploit the structure of the contact network. To illustrate, we instantiate a network model with data collected by a needle and syringe program in Chicago. We model sexual and needle-sharing contacts and the consequent spread of HIV and HCV. We use the model to evaluate the potential effects of a peer education (PE) program under different targeting strategies. We show that a targeted PE program would avert significantly more HIV and HCV infections than an untargeted program, highlighting the importance of reaching individuals who are centrally located in contact networks when instituting prevention programs.

Homozygosity for HLA group 2 alleles predicts treatment failure with interferon-α and ribavirin in chronic hepatitis C virus genotype 1 infection

Host genetic factors influence treatment responses to antiviral therapy in chronic hepatitis C virus (HCV) infection. We retrospectively investigated associations between host genetic markers and treatment-induced virologic responses to dual therapy with interferon-α and ribavirin in chronically infected HCV genotype 1 (g1)- and genotype 3 (g3)-infected individuals. A total of 171 patients (89 HCV g1 and 82 HCV g3 infected) were investigated for genetic markers influencing treatment-induced sustained virologic response (SVR). Overall, SVR was observed for 46/89 (52%) HCV g1- and 57/82 (70%) HCV g3-infected patients. Of the 4 interleukin 28B (IL28B) single-nucleotide polymorphisms (SNPs), rs12979860 was the host genetic marker most significantly associated with failure to achieve an SVR in HCV g1-infected individuals [P=3.83×10(-4); odds ratio (OR)=5.61; confidence interval (CI)=2.07-15.18] and gave a positive predictive value for treatment failure of 81.3% for minor homozygotes (TT). Using additive (P=3.54×10(-4)) and dominant models (P=3.83×10(-4)), a dosage effect of the T allele was observed, with the dominance term not significant for this SNP. Logistic regression showed an association between HLA-C1/C1 and rapid virologic response in HCV g1 infections with an OR relative to the heterozygote of 10.0 (95% CI: 1.6-62.5, P=0.014). HLA-C2 homozygosity was a significant predictor of nonresponse to treatment in HCV g1-infected individuals (P=0.023).

Treatment of chronic hepatitis C genotype 1 early responders with 36 week pegylated interferon and ribavirin therapy

INTRODUCTION

Standard treatment for patients with chronic hepatitis C genotype 1 (CHC G-1) infection includes pegylated interferon plus ribavirin (PEG-RBV) for 48 weeks. Shorter treatment regimen would be more acceptable due to lower cost and fewer side-effects. We aimed to compare the efficacy of 36 week PEG-RBV therapy with standard 48 week therapy in CHC G-1 patients who achieve complete early virological response (cEVR).

MATERIAL AND METHODS

Consecutive treatment-naïve patients with CHC G-1 were treated with pegylated interferon a2b (1.5 μg/kg/week) or α2a (180 μg/week) and weight based ribavirin. Patients who achieved cEVR at 12 weeks [undetectable HCV RNA irrespective of RVR (rapid virological response)] were randomized into- group A (48 weeks therapy) and group B (36 weeks therapy). Primary end-point was achievement of sustained virological response (SVR) at 24 weeks of follow up.

RESULTS

Out of the total 166 patients started on treatment, 112 (69.3%) achieved cEVR, and were randomized into group A (n = 59) and group B (n = 53). Fifty-five (93.2%) patients in group A and 50 (94.3%) in group B completed therapy. The overall SVR rate in group A was 79.6% (47/59) and group B was 84.9% (45/53) (p = 0.622). SVR rates in the two groups were comparable in all patient sub-groups according to factors like viral load (≤ or > 400,000 IU/mL), RVR (achieved/not achieved), age (≤ or > 40 years), body mass index (≤ or > 27) and cirrhosis (present/absent).

CONCLUSION

In CHC G-1 patients who achieve cEVR, 36 weeks PEG-RBV therapy is as effective as standard 48 weeks therapy, irrespective of other host or virological factors.

Relationship of interferon-γ-inducible protein-10 kDa with viral response in patients with various heterogeneities of hepatitis C virus genotype-4

INTRODUCTION

The role of serum interferon-γ-inducible protein-10 kDa (IP-10) level in the treatment of chronic hepatitis C genotype-4 (HCV-4) and its various subtypes remains unknown. We aimed to study the impact of pretreatment IP-10 levels on the sustained viral response (SVR) in HCV-4 patients (n=64) undergoing peginterferon α-2a/ribavirin therapy.

PATIENTS AND METHODS

Pretreatment IP-10 levels and HCV-4 subtypes (4a=48.4%, 4d=39%, others=12.5%) were measured and correlated with treatment responses. Variables significantly associated with SVR on univariate analysis were included in a multivariate logistic regression model.

RESULTS

Patients with SVR had lower pretreatment IP-10 levels (462.4±282.7 vs. 840.1±490.6 pg/ml; P=0.002), but the levels were not significantly different in those with a rapid (P=0.245) or an early viral response (P=0.221). IP-10 levels were similar across all subtypes. The pretreatment level was significantly lower in subtype 4d patients with SVR (465.9±349.1) compared with non-SVR patients (904.9±532.1; P<0.001), but not when compared with genotype 4a patients (564.7±288.9 vs. 658.6±374.9, respectively; P=0.330). IP-10 levels [odds ratio (OR), 0.998; 95% confidence interval (CI): 0.996-0.999; P=0.006], low viremia (OR, 8.852; 95% CI: 1.244-63.03; P=0.029), and early viral response (OR, 4.162; 95% CI: 1.023-16.94; P=0.046) were independent predictors of SVR. Receiver operating characteristic curve analysis identified a threshold IP-10 level of 359 pg/ml (area under receiver operating characteristic curve, 0.737; sensitivity, 81.8%; specificity, 45.2; positive predictive value, 43.9%; negative predictive value, 82.6%) for SVR.

CONCLUSION

Pretreatment serum IP-10 level is a predictor for SVR in HCV-4-infected patients. The baseline IP-10 level is significantly lower in responders among HCV genotype-4d patients as compared with 4a patients.

Cost effectiveness of screening strategies for early identification of HIV and HCV infection in injection drug users

OBJECTIVE

To estimate the cost, effectiveness, and cost effectiveness of HIV and HCV screening of injection drug users (IDUs) in opioid replacement therapy (ORT).

DESIGN

Dynamic compartmental model of HIV and HCV in a population of IDUs and non-IDUs for a representative U.S. urban center with 2.5 million adults (age 15-59).

METHODS

We considered strategies of screening individuals in ORT for HIV, HCV, or both infections by antibody or antibody and viral RNA testing. We evaluated one-time and repeat screening at intervals from annually to once every 3 months. We calculated the number of HIV and HCV infections, quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs).

RESULTS

Adding HIV and HCV viral RNA testing to antibody testing averts 14.8-30.3 HIV and 3.7-7.7 HCV infections in a screened population of 26,100 IDUs entering ORT over 20 years, depending on screening frequency. Screening for HIV antibodies every 6 months costs $30,700/QALY gained. Screening for HIV antibodies and viral RNA every 6 months has an ICER of $65,900/QALY gained. Strategies including HCV testing have ICERs exceeding $100,000/QALY gained unless awareness of HCV-infection status results in a substantial reduction in needle-sharing behavior.

DISCUSSION

Although annual screening for antibodies to HIV and HCV is modestly cost effective compared to no screening, more frequent screening for HIV provides additional benefit at less cost. Screening individuals in ORT every 3-6 months for HIV infection using both antibody and viral RNA technologies and initiating ART for acute HIV infection appears cost effective.

Very early prediction of response to HCV treatment with PEG-IFN-alfa-2a and ribavirin in HIV/HCV-coinfected patients

The objective of this study was to find very early viral kinetic markers to predict nonresponse to hepatitis C virus (HCV) therapy in a group of human immunodeficiency virus (HIV)/HCV-coinfected patients. Twenty-six patients (15 HCV genotype-1 and 11 genotype-3) were treated with a 48-week regimen of peginterferon-alfa-2a (PEG-IFN) (180 μg/week) and weight-based ribavirin (11 mg/kg/day). Samples were collected at baseline; 4, 8, 12, 18, 24, 30, 36 and 42 h; days 2, 3, 4, 7, 8, 15, 22, 29, 43 and 57 then weekly and monthly. Five patients discontinued treatment. Seven patients (27%) achieved a sustained virological response (SVR). Nadir HCV RNA levels were observed 1.6 ± 0.3 days after initiation of therapy, followed by a 0.3- to 12.9-fold viral rebound until the administration of the second dose of PEG-IFN, which were not associated with SVR or HCV genotype. A viral decline <1.19 log for genotype-1 and <0.97 log for genotype-3, 2 days after starting therapy, had a negative predictive value (NPV) of 100% for SVR. The day 2 virological response had a similar positive predictive value for SVR as a rapid virological response at week 4. In addition, a second-phase viral decline slope (i.e., measured from day 2 to 29) <0.3 log/week had a NPV = 100% for SVR. We conclude that first-phase viral decline at day 2 and second-phase viral decline slope (<0.3 log/week) are excellent predictors of nonresponse. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of nonresponse in patients with HCV and HIV.

Controlled release recombinant human interferon-α2b for treating patients with chronic hepatitis C genotype 1: a phase 2a clinical trial

Better convenience and tolerability and sustained therapeutic concentrations might improve interferon (IFN) treatment for chronic hepatitis C virus (HCV) infection. In an open-label, randomized study, controlled release free (chemically unmodified) recombinant human IFN-α(2b) in poly(ether-ester) microspheres (CR-rhIFN-α(2b)), was injected at doses of 160, 320, 480 or 640 μg every 2 weeks for 12 weeks with concomitant weight-based oral ribavirin in 32 treatment-naïve patients with chronic HCV genotype 1. Treatment was well tolerated, with 31 patients (97%) successfully completing the study. Full doses of CR-rhIFN-α(2b) were administered on 96% of scheduled occasions. Flu-like symptoms were generally mild and brief. Injection site reactions developed in 13 patients (41%), and neutropenia occurred in six of eight patients receiving 640 μg. In the 320, 480 and 640 μg groups, 62-75% of patients achieved a ≥2 log(10) HCV RNA reduction by 4 weeks and 88-100% by 12 weeks. For those groups, the pooled median time to ≥2 log(10) reduction was 11 days (95% confidence interval, 7-35 days). In those groups, viral reduction below the limit of detection was accomplished in 25% of patients by 4 weeks and in 62% by 12 weeks. The 160-μg dose was less potent. After CR-rhIFN-α(2b) injection, stable plateau levels of serum IFN-α(2b) were generally reached within 72 h. Treatment-emergent neutralizing antibodies to IFN-α(2b) were observed in one patient. No antibodies to host plant proteins were detected. CR-rhIFN-α(2b) with ribavirin cotherapy was well tolerated and displayed potent early antiviral activity in patients with chronic HCV genotype 1.

T-cell responses at baseline and during therapy with peginterferon-alpha and ribavirin are not associated with outcome in chronic hepatitis C infected patients

BACKGROUND

Since the association between hepatitis C virus (HCV)-specific T-cell responses both pre-treatment and during interferon-alpha based therapy and viral clearance is unresolved, a combined analysis of distinctive T-cell characteristics (proliferation and interferon-gamma production) is important to clarify this issue.

METHODS

Peripheral blood mononuclear cells (PBMC) collected in 22 chronic HCV infected patients at pre-treatment and at week 4 during pegIFN-alpha/ribavirin therapy, were stimulated with overlapping peptide pools in a [3H]-thymidine assay, an interferon-gamma-ELISA, and a sensitive 12-day T-cell expansion assay.

RESULTS

Compared to the [3H]-thymidine proliferation and interferon-gamma secretion assays, the 12-day T-cell expansion assay was more sensitive in detecting T-cell responses. No significant association was demonstrated between pre-treatment HCV-specific CD4+ or CD8+ T-cell responses and either a sustained virological response (SVR) or a rapid virological response (RVR). However, a skewing of individual responses towards the non-structural antigens was observed. During pegIFN-alpha/ribavirin therapy, HCV-specific CD4+ and CD8+ T-cells declined similarly in both SVR/RVR and non-SVR/non-RVR patients.

CONCLUSION

No correlation was found between the magnitude of pre-treatment HCV-specific T-cell responses and the outcome of pegIFN-alpha/ribavirin therapy in terms of SVR and RVR. Moreover, the magnitude of HCV-specific T-cell responses declined in all patients early during treatment.

Prediction of nonSVR to therapy with pegylated interferon-alpha2a and ribavirin in chronic hepatitis C genotype 1 patients after 4, 8 and 12 weeks of treatment

In patients with chronic hepatitis C genotype 1, the current algorithm for treatment discontinuation is based on no early virological response (<2 log decline in hepatitis C virus (HCV)-RNA) at 12 weeks. It is important to determine whether prediction of nonsustained virological response (NR) before 12 weeks can be robustly obtained by statistical methods. We used longitudinal discriminant analysis (LDA) to build and cross-validate models including baseline patient characteristics and measurements of serum HCV-RNA in the first 4, 8 or 12 weeks of treatment. The performance of each model was evaluated by the partial AUC (PA) index, exploring the accuracy of prediction in the range of high negative predictive values. Models were compared by computing 95% confidence intervals for the difference in PA indices. NR was best predicted before week 12 by a single HCV-RNA measurement at week 8 taken together with gender, BMI and age (W8 model, PA index = 0.857). This model was not inferior to models that included a measurement at week 12 (PA index = 0.831). The best model obtained with LDA within the first 4 weeks, which included measurements at days 4, 8 and at week 4, was found to be inferior to the week 8 model (PA index = 0.796). These results indicate that lack of sustained viral response is best predicted after 8 weeks of treatment and that waiting until 12 weeks does not improve the prediction.

Factors associated with rapid and early virologic response to peginterferon alfa-2a/ribavirin treatment in HCV genotype 1 patients representative of the general chronic hepatitis C population

Rapid virologic response (RVR) and complete early virologic response (cEVR) are associated with sustained virologic response to hepatitis C virus (HCV) therapy. We retrospectively examined baseline and on-treatment factors associated with RVR (HCV RNA undetectable at week 4) and cEVR (HCV RNA undetectable at week 12, regardless of week 4 response). The analysis comprised 1550 HCV genotype-1 patients from five clinical trials, including three enriched with difficult-to-treat populations, randomized to peginterferon alfa-2a 180 microg/week plus ribavirin 1000-1200 mg/day. Overall, 15.6% achieved RVR and 54.0% achieved cEVR. Baseline factors predictive of RVR were serum HCV RNA <or= 400,000 IU/mL (OR: 7.34; P < 0.0001), alanine aminotransferase >3 x ULN (OR: 2.01; P < 0.0001), non-cirrhotic status (OR: 1.92; P = 0.0087), age <or= 40 years (OR: 1.56; P = 0.0085), white non-Latino ethnicity (OR: 1.41; P = 0.0666) and individual study (P < 0.0001). These factors plus body mass index <or= 27 kg/m(2) were predictive of cEVR. After adjusting for these factors, mean on-treatment ribavirin dose >13 mg/kg/day was predictive of RVR (OR: 1.69; P = 0.005) and cEVR (OR: 1.24; P = 0.09), whereas peginterferon alfa-2a dose reduction was not. Greater decreases in haematologic parameters were observed in patients who achieved cEVR compared with patients who did not. In conclusion, several baseline and on-treatment factors were associated with RVR and cEVR to peginterferon alfa-2a plus ribavirin in difficult-to-treat HCV genotype-1 patients, providing important prognostic information on the antiviral response in a patient cohort that is reflective of the general chronic hepatitis C population.

Effect of killer immunoglobulin-like receptors in the response to combined treatment in patients with chronic hepatitis C virus infection

Killer immunoglobulin-like receptors (KIRs) are related to the activation and inhibition of NK cells and may play an important role in the innate response against infection with viruses such as hepatitis C virus (HCV). We examined whether the different combinations of KIRs with their HLA class I ligands influenced the response to combined treatment (pegylated alpha interferon and ribavirin) of patients infected by HCV. A total of 186 consecutive patients diagnosed with chronic HCV infection were analyzed. Seventy-seven patients exhibited HCV RNA levels at 6 months posttreatment and were called nonresponders (NR), while 109 cleared viral RNA and were named sustained viral responders (SVR). Patients were typed for HLA-B, HLA-Cw, KIR genes, and HCV genotype. In our study, the frequency of the KIR2DL2 allele was significantly increased in NR (P < 0.001; odds ratio [OR] = 1.95), as was the frequency of the KIR2DL2/KIR2DL2 genotype (P < 0.005; OR = 2.52). In contrast, the frequencies of the KIR2DL3 genotype (P < 0.001) and KIR2DL3/KIR2DL3 genotype (P < 0.05; OR = 0.54) were significantly increased in the SVR. Different combinations of KIR2DL2 and KIR2DL3 alleles with their ligands were analyzed. The frequency of the KIR2DL2/KIR2DL2-HLA-C1C2 genotype was significantly increased in the NR (P < 0.01; OR = 3.15). Additionally, we found a higher frequency of the KIR2DL3/KIR2DL3-HLA-C1C1 genotype in the SVR group (P < 0.05; OR = 0.33). These results were not affected by the HCV genotype. In conclusion, patients who carried the KIR2DL2/KIR2DL2-HLA-C1C2 genotype were less prone to respond to treatment. However, the KIR2DL3/KIR2DL3-HLA-C1C1 genotype clearly correlated with a satisfactory response to treatment, defined by the clearance of HCV RNA.

Plasma HCV-RNA decline in the first 48 h identifies hepatitis C virus mono-infected but not HCV/HIV-coinfected patients with an undetectable HCV viral load at week 4 of peginterferon-alfa-2a/ribavirin therapy

During peginterferon-alfa-2a/ribavirin therapy, plasma hepatitis C virus (HCV)-RNA decreases with a rapid first phase and a slower second phase. We compared the viral load decrease and slope in the first 48 h in patients with a rapid viral response (RVR, i.e. HCV-RNA < 50 IU/mL at week 4) with patients not achieving an RVR. From 23 HCV-infected (14 mono-infected and nine HCV/HIV-coinfected) genotype 1 or 4 positive peginterferon-alfa-2a/ribavirin-treated patients, plasma HCV-RNA was determined at baseline, 48 h, weeks 1, 2, 4, 8, 12, 48 and 72. The HCV viral load decrease (Delta0-48), the slope (lambda(1)) and the efficiency factor (epsilon) were determined in the first 48 h after the start of therapy. Five (36%) HCV mono-infected patients and three (33%) HIV/HCV-coinfected patients achieved an RVR whereas six (43%) HCV mono-infected patients and five (56%) HIV/HCV-coinfected patients reached a sustained viral response (SVR). In contrast to HIV/HCV-coinfected patients, five HCV mono-infected patients with an RVR showed both a larger Delta0-48 and steeper lambda(1) (-1.77log(10) IU/mL +/- 0.66 and -2.04/day +/- 0.76) compared to nine non-RVR patients (-0.66log(10) IU/mL +/- 0.39; P = 0.019 and -0.76/day +/- 0.41; P = 0.019). When divided by SVR, a greater Delta0-48 and steeper lambda(1) were also seen in both HCV mono-infected and HIV/HCV-coinfected patients. Thus, in the first 48 h after the start of therapy, HCV mono-infected patients with an RVR have a larger viral load decrease, steeper viral slope and a higher efficiency factor as compared with non-RVR patients.

Hepatitis C viral kinetics during treatment with peg IFN-alpha-2b in HIV/HCV coinfected patients as a function of baseline CD4+ T-cell counts

BACKGROUND

HIV/hepatitis C virus (HCV) coinfected patients are known to have lower sustained viral response (SVR) rates than HCV monoinfected patients. However, the role of CD4+ T-cell counts on viral kinetics and outcome is not fully understood.

METHODS

HCV RNA kinetics (bDNA v3, lower limit of detection [LD] = 615 IU/mL) was analyzed in 32 HIV/HCV coinfected persons treated with Pegylated-interferon-alpha2b (1.5 microg/kg weekly) and ribavirin (1-1.2 g daily) for 48 weeks and compared with results obtained from 12 HCV monoinfected patients treated with the same regimen.

RESULTS

Baseline CD4+ T-cell counts > or =450 cells/mm3 were significantly (P < 0.002) associated with SVR in coinfected genotype 1 patients. First phase decline was significantly lower among patients with low as compared with high CD4 counts (P < 0.03) and among coinfected compared with monoinfected patients (P < 0.002). Second phase decline slope showed a similar trend for coinfected patients.

CONCLUSIONS

Low baseline CD4+ T-cell count is associated with slower HCV viral kinetics and worse response to treatment among HIV coinfected patients, suggesting HCV treatment response depends on immune status. HCV genotype 1 coinfected patients have slower first phase viral kinetics than HCV monoinfected patients. First phase viral decline (>1.0 log) and second phase viral decline slope (>0.3 log/wk) are excellent predictors of SVR for coinfected patients.

Clinical trial: low plasma cholesterol and oxidative stress predict rapid virological response to standard therapy with peginterferon and ribavirin in HCV patients

BACKGROUND

Rapid virological response (RVR) is the best predictor of sustained response to standard HCV treatment.

AIM

To evaluate predictive factors of RVR.

METHODS

Sixty-five patients (mean age 52.6 +/- 13.8; 37 genotype-1, and 28 genotypes-2/3) were consecutively treated with pegIFN-alpha 2a or 2b once weekly plus daily ribavirin based on body weight for 24 or 48 weeks, according to genotype. RVR was defined as undetectable HCV-RNA at week 4.

RESULTS

Twenty-seven percent of patients achieved RVR in genotypes 1 and 60.7% in genotypes 2/3 (P < 0.01). Rapid responders had higher mean serum baseline total and LDL-cholesterol levels (P < 0.01). RVR was 20.0% in the bottom tertile of total cholesterol and 63.6% in the top tertile (P < 0.01). HCV-RNA levels at week 4 were positively correlated with baseline serum insulin (P < 0.01), HOMA-IR (P < 0.01), body mass index (P < 0.05) and number of components of metabolic syndrome (P < 0.01) and negatively correlated with cholesterol levels (P < 0.05). At multivariate analysis, age, LDL-cholesterol, HCV genotype and serum 8-iso-PGF 2 alpha, a marker of oxidative stress, were independent predictors of RVR.

CONCLUSIONS

Our prospective study supports a role of low serum total and LDL-cholesterol and of oxidative stress as positive independent predictive factors of poor RVR in HCV patients.

Factors associated with rapid and early virologic response to peginterferon alfa-2a/ribavirin treatment in HCV genotype 1 patients representative of the general chronic hepatitis C population

Rapid virologic response (RVR) and complete early virologic response (cEVR) are associated with sustained virologic response to hepatitis C virus (HCV) therapy. We retrospectively examined baseline and on-treatment factors associated with RVR (HCV RNA undetectable at week 4) and cEVR (HCV RNA undetectable at week 12, regardless of week 4 response). The analysis comprised 1550 HCV genotype-1 patients from five clinical trials, including three enriched with difficult-to-treat populations, randomized to peginterferon alfa-2a 180 microg/week plus ribavirin 1000-1200 mg/day. Overall, 15.6% achieved RVR and 54.0% achieved cEVR. Baseline factors predictive of RVR were serum HCV RNA <or= 400,000 IU/mL (OR: 7.34; P < 0.0001), alanine aminotransferase >3 x ULN (OR: 2.01; P < 0.0001), non-cirrhotic status (OR: 1.92; P = 0.0087), age <or= 40 years (OR: 1.56; P = 0.0085), white non-Latino ethnicity (OR: 1.41; P = 0.0666) and individual study (P < 0.0001). These factors plus body mass index <or= 27 kg/m(2) were predictive of cEVR. After adjusting for these factors, mean on-treatment ribavirin dose >13 mg/kg/day was predictive of RVR (OR: 1.69; P = 0.005) and cEVR (OR: 1.24; P = 0.09), whereas peginterferon alfa-2a dose reduction was not. Greater decreases in haematologic parameters were observed in patients who achieved cEVR compared with patients who did not. In conclusion, several baseline and on-treatment factors were associated with RVR and cEVR to peginterferon alfa-2a plus ribavirin in difficult-to-treat HCV genotype-1 patients, providing important prognostic information on the antiviral response in a patient cohort that is reflective of the general chronic hepatitis C population.

A liver slice culture-based ex vivo assay to predict the outcome of antiviral therapy for chronic hepatitis C

A liver slice culture-based, ex vivo drug suppression assay was developed as a pre-therapeutic predictor for the outcome of antiviral therapy. To investigate its clinical application, 106 consecutive patients with chronic hepatitis C virus (HCV) infection were evaluated. Ex vivo drug suppression assay was performed before administrating a standard course of peginterferon plus ribavirin combination therapy. Stepwise logistic regression model was used to estimate sustained virological response (SVR) on the presence of various clinicopathological parameters. Suppression of HCV replication in the ex vivo assay was present in 32 patients, 29 (90.6%) of whom achieved SVR. Stepwise logistic regression analysis indicated that the presence of interferon suppression effect in the ex vivo assay (odds ratio [OR], 5.552; 95% confidence interval [CI], 1.114-27.673; P = 0.036), genotype 1 (OR; 0.045, 95% CI, 0.008-0.259; P = 0.001), HCV-RNA level (OR, 0.739; 95% CI, 0.617-0.885; P = 0.001), the presence of fatty metamorphosis (OR, 0.205; 95% CI, 0.053-0.793; P = 0.022), and albumin (OR, 9.687; 95% CI, 2.237-41.940; P = 0.002) were independent determinants of SVR. Categorical analysis revealed that 17 of 17 (100%) patients with genotype non-1 and positive ex vivo suppression test achieved SVR, while 20 of 40 (50%) with genotype 1 and negative ex vivo suppression test achieved SVR. In conclusion, the ex vivo drug suppression assay may serve as an independent pre-therapeutic predictor for the SVR in interferon-based antiviral therapy.

Early gene expression profiles of patients with chronic hepatitis C treated with pegylated interferon-alfa and ribavirin

Responsiveness to hepatitis C virus (HCV) therapy depends on viral and host factors. Our aim was to assess sustained virologic response (SVR)-associated early gene expression in patients with HCV receiving pegylated interferon-alpha2a (PEG-IFN-alpha2a) or PEG-IFN-alpha2b and ribavirin with the duration based on genotypes. Blood samples were collected into PAXgene tubes prior to treatment as well as 1, 7, 28, and 56 days after treatment. From the peripheral blood cells, total RNA was extracted, quantified, and used for one-step reverse transcription polymerase chain reaction to profile 154 messenger RNAs. Expression levels of messenger RNAs were normalized with six "housekeeping" genes and a reference RNA. Multiple regression and stepwise selection were performed to assess differences in gene expression at different time points, and predictive performance was evaluated for each model. A total of 68 patients were enrolled in the study and treated with combination therapy. The results of gene expression showed that SVR could be predicted by the gene expression of signal transducer and activator of transcription-6 (STAT-6) and suppressor of cytokine signaling-1 in the pretreatment samples. After 24 hours, SVR was predicted by the expression of interferon-dependent genes, and this dependence continued to be prominent throughout the treatment.

CONCLUSION

Early gene expression during anti-HCV therapy may elucidate important molecular pathways that may be influencing the probability of achieving virologic response.

Characteristics and treatment outcomes among HIV-infected individuals in the Australian Trial in Acute Hepatitis C

BACKGROUND

The Australian Trial in Acute Hepatitis C (ATAHC) is a National Institutes of Health-funded prospective cohort study of the natural history and efficacy of treatment in individuals with recently acquired hepatitis C. Enrollment is open to both human immunodeficiency virus (HIV)-infected and -uninfected individuals. The aim of this article was to evaluate characteristics and virological outcomes among HIV-infected individuals enrolled in ATAHC.

METHODS

Eligibility criteria included the first positive result of testing for anti-hepatitis C virus (HCV) antibody within 6 months and either clinical hepatitis diagnosed within the past 12 months or documented anti-HCV seroconversion within the past 24 months.

RESULTS

Of the initial 103 patients enrolled, 27 (26%) were HIV infected. HIV-infected patients were more likely to be older, to have HCV genotype 1 infection and high levels of HCV RNA at baseline than were HCV-monoinfected patients. Sexual acquisition accounted for the majority (56%) of HCV infections among HIV-infected patients, compared with only 8% of HCV-monoinfected patients. The median duration from estimated HCV infection to treatment was 30 weeks. Treatment with 24 weeks of pegylated interferon and ribavirin resulted in rates of undetectability of HCV RNA of 95%, 90%, and 80% at weeks 12, 24, and 48, respectively. Undetectability at week 4 was achieved in 44% of patients and yielded positive and negative predictive values for sustained virological response of 100% and 33%, respectively.

CONCLUSIONS

Significant differences were demonstrated between HIV-infected and HIV-uninfected individuals enrolled in ATAHC. Treatment responses among HIV-infected individuals with both acute and early chronic infection are encouraging and support regular HCV screening of high-risk individuals and early treatment for recently acquired HCV infection.

Predictors of sustained virological response to a 48-week course of pegylated interferon alfa-2a and ribavirin in patients infected with hepatitis C virus genotype 4

BACKGROUND AND OBJECTIVES

Knowledge of the predictors of sustained viral response (SVR) to pegylated interferon (PEG-INF) alfa-2a and ribavirin (RBV) therapy in patients with hepatitis C genotype-4 (HCV-4) is crucial for selecting patients who would benefit most from therapy. We assessed the predictors of SVR to this combination therapy in Saudi patients with chronic HCV-4 infection.

PATIENTS AND METHODS

This retrospective study included 148 patients with HCV-4 infection who underwent clinical, biochemical and virological assessments before treatment and at 12, 24, 48 and 72 weeks post-treatment.

RESULTS

Of the 148 patients, 90 (60.8%) were males. Mean (SD) for age was 48.5 (12.7) years and BMI was 27.9 (7.5) kg/m(2). Seventy-nine of 148 (60.1%) patients were treatment naïve and 110 (74.3%) underwent pre-treatment liver biopsy. Eighteen (12.2%) patients did not complete therapy because of side effects or they were lost to follow up. Early virological response was achieved in 84 of 91 (92.3%) patients. In the 130 (87.8%) patients who completed therapy, 34 (26.2%) were non-responders and 96 (63.8%) achieved end-of-treatment virological response (ETVR). SVR and virological relapse (24 weeks after ETVR) occurred in 66/130 (50.7%) and 30/130 (31.2%) patients, respectively. Compared to relapsers, sustained responders were significantly younger (P=.005), non-diabetic (P=.005), had higher serum albumin (P=.028), lower alpha-fetoprotein level (P=.026), lower aspartate aminotransferase (AST) (P=.04) levels, and were treatment-naïve (P=.008). In a multivariate regression analysis, the independent predictors of SVR were younger age (P=.016), lower serum AST (P=.012), and being treatment naïve (P=.021).

CONCLUSION

Approximately half of HCV-4 patients who complete the course of combination therapy achieve an SVR, especially if they are young, treatment naA ve and have lower AST levels.

Early and sustained virological response in non-responders with chronic hepatitis C: a randomized open-label study of pegylated interferon-alpha-2a versus pegylated interferon-alpha-2b

OBJECTIVES

The purpose of this randomized open-label study was to assess the efficacy of treatment with pegylated interferon-alpha-2a versus pegylated interferon-alpha-2b, both plus ribavirin, in inducing early and sustained virological response (EVR and SVR) in chronic hepatitis C non-responders.

PATIENTS AND METHODS

A total of 108 patients with chronic hepatitis C who were non-responders to previous combined therapy (standard interferon-alpha plus ribavirin for > or = 3 months) were enrolled and equally randomized into two groups in this intention-to-treat analysis. The patients exhibited similar baseline features. One group received subcutaneous pegylated interferon-alpha-2a 180 microg once weekly, while the other was treated with subcutaneous pegylated interferon-alpha-2b 1.5 microg/kg once weekly. Ribavirin 15 mg/kg/day was included in both protocols. Treatment duration for EVR was 12 weeks. Patients who demonstrated non-detectable hepatitis C virus (HCV) RNA or a > or = 2 log(10) reduction in viral load at week 12 continued therapy up to 48 weeks, with assessments every 3 months during a follow-up of 24 weeks.

RESULTS

All patients in both groups completed the EVR study, then seven patients receiving pegylated interferon-alpha-2a and seven patients receiving pegylated interferon-alpha2b discontinued treatment as a result of severe adverse effects. After 12 weeks of treatment, viral load reduction was >2 log(10) with both pegylated interferon-alpha-2a (-2.53) and pegylated interferon-alpha-2b (-2.48) with no significant difference. At the end of week 48, HCV RNA was undetectable in 14 of 54 patients (25.9%) receiving pegylated interferon-alpha-2a and in 15 of 54 patients (27.7%) receiving pegylated interferon-alpha-2b. When terminating follow-up, an SVR was observed in 11 of 54 patients (20.4%) who received pegylated interferon-alpha-2a and 10 of 54 patients (18.4%) receiving pegylated interferon-alpha-2b. The incidence and severity of adverse events was similar in both groups.

CONCLUSIONS

Our results seem to show that in chronic hepatitis C patients who are non-responsive to previous therapy, EVR to the two pegylated interferons did not significantly differ with a similar therapeutic efficacy defined as SVR.

Viral kinetic of HCV genotype-4 during pegylated interferon alpha 2a: ribavirin therapy

Kinetics of hepatitis C virus (HCV) during pegylated interferon (PEG-IFN) and early monitoring of viral decline were recently described to predict treatment outcomes and in turn reduce the course of treatment, adverse effects and cost. However, there is limited (if any) information on the viral dynamics of HCV-4. Our aim is to follow the HCV-RNA kinetics during PEG-IFN alpha 2a and ribavirin therapy and the best time for predicting sustained viral response (SVR) in genotype-4 patients. Serum HCV-RNA levels before initial dosing (baseline level) and at 24 h, week 1, week 4, week 12, week 24, week 48 and week 72 were assessed in 84 HCV genotype-4 patients treated weekly by PEG-IFN alpha 2a and daily ribavirin. At the end of treatment, out of the 84 treated patients, 19 (22.6%) were non-responders while 65 (77%) showed end-of-treatment response (ETR). However, 8 patients relapsed (9.5%), thus the SVR was observed in 57 patients (67.9%). Younger patients were more likely to attain SVR, where the odds of SVR increased by a factor of 0.94 for each year increase in age (95% CI: 0.90-0.99, P = 0.019). Although a significant negative correlation between stage of fibrosis and rate of viral decline at weeks 1 and 4 (P < 0.005 and 0.001, respectively) was seen, neither fibrosis stage (χ(2) = 3.4882, P > 0.1) nor grade of inflammation (χ(2) = 0.0057, P > 0.1) significantly predicted response to treatment. Non-responders had no or only a limited decline at week 1 and week 4, whereas sustained virological responders had a significant decline at both week 1 and week 4. Area under the (receiver operating characteristic) curve (AUC) revealed that week 12 is better than any other time point in predicting the SVR (AUC = 0.97; 95% CI: 0.94-1.01), (sensitivity 98.3%; 95% CI: 90.7-99.9), (specificity 88.5%; 95% CI: 71.0-96.0), positive predictive value of 94.9% and negative predictive value of 95.8%. A drop of more than 1.17 log viral load at week 1 and viral clearance or decline >3 log were considered as the earliest predictors of SVR. In genotype-4 patients, while failure to achieve an EVR at week 12 predicts non-response, an RVR at week 1 and week 4 98% guaranteed SVR. These findings further re-enforce the value of week 12 in the course of IFN treatment. Genotype-4 patients who show significant viral clearance (>1.17 log viral load) by the first week of treatment and viral clearance >3 log by week 4 are expected to show SVR and should therefore be assigned to a shorter drug regimen lasting for 24 weeks. Those unfortunate cases who do not achieve viral clearance by week 1 or week 4 should not be deprived from the treatment but rather given more time till week 12 before being classified as non-responders.

Peginterferon alpha-2a and ribavirin versus peginterferon alpha-2a monotherapy in early virological responders and peginterferon alpha-2a and ribavirin versus peginterferon alpha-2a, ribavirin and amantadine triple therapy in early virological nonresponders: the SMIEC II trial in naïve patients with chronic hepatitis C

OBJECTIVE

The objective of this study was to compare the efficacy of anti-hepatitis C virus (anti-HCV) treatment schedules on the basis of an early virological response (EVR), defined as undetectable serum HCV-RNA (<50 IU/ml) after a 12-week induction course of peginterferon alpha-2a (PEG-IFN) 180 mcg/week.

METHODS

A total of 210 interferon-naïve patients (69% male; median age, 42 years) with histologically proven chronic hepatitis C infection (genotype 1: 62%) received PEG-IFN 180 mcg/week for 12 weeks. Patients with EVR (58%) were randomized to continue PEG-IFN monotherapy (n=64) or to add ribavirin (RBV), 800 mg/day (n=57), for 36 additional weeks. Patients without EVR (42%) were randomized to add RBV (n=42), or RBV plus amantadine, 200 mg/day (n=47), for 36 additional weeks. Sustained virological response (SVR, undetectable HCV-RNA 24 weeks after treatment completion) was compared among treatment groups.

RESULTS

Patients with EVR: SVR rate was 60.3% in the PEG-IFN group versus 67.2% in the PEG-IFN+RBV group (NS). In genotypes 2/3, SVR rates were 66.7 versus 73.1% (NS); in genotypes 1/4, SVR rates were 51.6 versus 61.3%, respectively (NS). Patients without EVR: SVR was 16.7% in the PEG-IFN+RBV group versus 31.9% in the triple therapy group (P=0.07). In patients with genotypes 1/4, SVR rates were 9.4 versus 29.7% (P=0.041).

CONCLUSION

In genotypes 1/4 patients without EVR, triple therapy results in higher SVR rates than standard dual therapy. This study confirms that addition of amantadine is beneficial in early-recognized 'difficult-to-treat' patients.

Gene-gene and gene-environment interactions in interferon therapy for chronic hepatitis C

INTRODUCTION

In studies of pharmacogenomics, it is essential to address gene-gene and gene-environment interactions to describe complex traits involving pharmacokinetic and pharmacodynamic mechanisms. In this work, our goal is to detect gene-gene and gene-environment interactions resulting from an analysis of chronic hepatitis C patients' clinical factors including SNPs, viral genotype, viral load, age and gender.

MATERIALS & METHODS

We collected blood samples from 523 chronic hepatitis C patients who had received interferon and ribavirin combination therapy. Based on the treatment strategy for chronic hepatitis C patients, we focused our search for candidate genes involved in pathways related to interferon signaling and immunomodulation. To investigate gene-gene and gene-environment interactions, we implemented an artificial neural network-based method for identifying significant interactions between clinical factors with the fivefold crossvalidation method and permutation tests. The artificial neural network model was trained by an algorithm with an adaptive momentum and learning rate.

RESULTS

A total of 20 SNPs were selected from six candidate genes including adenosine deaminase-RNA-specific (ADAR), caspase 5 (CASP5), interferon consensus sequence binding protein 1 (ICSBP1), interferon-induced protein 44 (IFI44), phosphoinositide-3-kinase catalytic gamma polypeptide (PIK3CG), and transporter 2 ATP-binding cassette subfamily B (TAP2) genes. By applying our artificial neural network-based approach, IFI44 was found in the significant two-locus, three-locus and four-locus gene-gene effect models, as well as in the significant two-factor and three-factor gene-environment effect models. Furthermore, viral genotype remained in the best two-factor, three-factor and four-factor gene-environment models. These results support the hypothesis that IFI44 and viral genotype may play a role in the pharmacogenomics of interferon treatment. In addition, our approach identified a panel of ten clinical factors that may be more significant than the others for further study.

CONCLUSION

We demonstrated that our artificial neural network-based approach is a promising method to assess the gene-gene and gene-environment interactions for interferon and ribavirin combination treatment in chronic hepatitis C patients by using clinical factors such as SNPs, viral genotype, viral load, age and gender.

The use of different Peg-interferon alpha-2b regimens plus ribavirin in HCV-1b-infected patients after rapid virological response does not affect the achievement of sustained virological response

In patients with chronic hepatitis C, rapid virological response (RVR) at week 4 of treatment seems to be strongly associated with a high probability of achieving a sustained virological response (SVR). The aim of this study was to investigate the outcome of different pegylated interferon-alpha2b (Peg-IFN-alpha2b) dosages plus ribavirin (RBV) in patients with RVR. Forty-five naïve patients chronically infected with hepatitis C virus (HCV)-1b started Peg-IFN-alpha2b (1.5 microg/kg/week) in combination with weight-based RBV doses (800-1200 mg/day). Thirty-one patients (68.9%) attained RVR at week 4 of therapy, while four further patients showed negative HCV-RNA values for the first time at week 12 and were considered early virological responders (EVR). The 31 RVR patients were randomized to receive either RBV plus 1.5 microg/kg/week (17 pts) or 1.0 microg/kg/week (14 pts) of Peg-IFN-alpha2b for the remaining 44 weeks. The two groups were matched for age, sex, baseline alanine aminotransferase levels, viral load and fibrosis score. After 6 months of post-treatment follow-up, the prevalence of SVR was 94.1% (16/17) among RVR patients treated with 1.5 microg/kg/week and 92.8% (13/14) in RVR patients treated with 1.0 microg/kg/week (P = not significant). A high-baseline viral load (P = 0.01) and bridging fibrosis/cirrhosis (P = 0.02) negatively influenced the likelihood of achieving RVR. On the contrary, the ability of RVR patients to achieve SVR did not correlate with these baseline characteristics in either of the treatment group. Finally, the SVR rate among EVR patients who responded after more than 4 weeks of treatment was significantly lower than among RVR patients (1/4 = 25%vs 29/31 = 93.5%; P = 0.0058), because of a high prevalence of post-treatment relapse among patients with EVR.

Sustained virologic response to peginterferon alpha-2a and ribavirin in 335 patients with chronic hepatitis C: a tertiary care center experience

BACKGROUND/AIM

This retrospective study assessed the efficacy, safety, and the predictors of sustained viral response (SVR) to a 48-week-course of peginterferon alpha-2a (Pegasys) and ribavirin combination therapy in 335 consecutive Saudi patients with chronic hepatitis C virus (HCV) infection.

MATERIALS AND METHODS

Clinical, biochemical, and virological parameters were collected at time 0 (pretreatment) and at 12, 24, 48, and 72 weeks posttreatment. The mean +/- SD age was 49.1 +/- 13.0 years; 229 (68.4%) were males, mean +/- SD body mass index was 27.8 +/- 7.4, 85 (25.4%) were diabetic, 25 (7.5%) had renal impairment, 136 (40.6%) had previously received interferon +/- ribavirin therapy, and 247 (73.7%) underwent pretreatment liver biopsy. Patients with genotypes 1, 2 or 3, 4 and mixed genotype were 60 (22.15%), 30 (11.0%), 148 (54.4%), and 34 (12.5%), respectively.

RESULTS

Early viral response (>or=2-log10 HCV-RNA decline 12 weeks posttreatment) was achieved in 253 (75.3%). Patients who completed 48 weeks of treatment were 292 (87.1%); of these, 121 (75.6%) achieved ETVR, 161 (55.1%) continued to have SVR and 60 (20.5%) had a viral relapse following end-of-treatment response, that is 48.1 and 17.9% of all patients (n = 335), respectively. Nonresponders (NR) were 71 (24.3%) patients and 43 (12.8%) were unable to complete treatment (due to side effects or loss to follow up). Compared to the relapsers, patients with SVR were significantly younger (P = 0.000), nondiabetics (P = 0.015), had higher serum albumin (P = 0.007), had less pretreatment inflammatory grade (P = 0.011), infected with genotypes 2 or 3 (P = 0.014), and treatment-naïve patients (P = 0.001). However, in stepwise multivariate logistic regression analysis, only treatment naiveté and low pretreatment inflammatory score were the independent predictors of SVR (P = 0.005 and P = 0.018, respectively).

CONCLUSION

Combination therapy, if tolerated and completed, is effective in treating chronic HCV patients, especially those with no previous interferon therapy and lower pretreatment inflammatory grade.

Retreatment of chronic hepatitis C in previous non-responders and relapsers

Therapy for chronic hepatitis C has improved dramatically over the past 20 years. Unfortunately, approximately 50% of those treated do not have a durable response to therapy. Non-responders and relapsers after previous interferon-based therapy are particularly challenging with regard to clinical management. This article provides a general overview of the treatment of hepatitis C and reviews present data regarding management of patients with chronic hepatitis C who are non-responders or relapsers after previous treatment. The review ends with the authors' opinion regarding present management of non-responders and relapsers and future emerging therapies.

Early virologic response after peginterferon alpha-2a plus ribavirin or peginterferon alpha-2b plus ribavirin treatment in patients with chronic hepatitis C

Patients infected with hepatitis C virus (HCV) genotype 1 and with serum HCV RNA concentrations over 800 000 IU/mL have relatively low rates of virologic response to pegylated interferons. The 2 forms of pegylated interferon have different pharmacokinetic profiles, and pilot studies comparing them have yielded varying results. We compared the virologic response to 12 weeks of treatment with peginterferon alpha-2a plus ribavirin vs peginterferon alpha-2b plus ribavirin in 380 patients who were infected with HCV genotype 1 and had high viral loads. We observed no between-group differences in viral load reduction over time and no differences in the percentage of patients treated with peginterferon alpha-2a or peginterferon alpha-2b plus ribavirin who achieved early virologic response (EVR), defined as >/=2-log reduction in HCV RNA concentration or undetectable HCV RNA at 12 weeks (66%vs 63%). Serum levels of interferon were more frequently below the level of quantitation in patients treated with peginterferon alpha-2b plus ribavirin (58-68%) than in those treated with peginterferon alpha-2a plus ribavirin (1-2%). Patients treated with peginterferon alpha-2b plus ribavirin had higher rates of discontinuation for safety reasons (6%vs 1%). In conclusion, a substantial percentage of patients infected with HCV genotype 1 and high viral load can achieve EVR when treated with peginterferon and ribavirin. The 2 pegylated interferons showed comparable anti-HCV activity during the first 12 weeks of treatment when combined with the same doses of ribavirin (1000-1200 mg/day), but discontinuations for safety reasons were higher in the patients treated with peginterferon alpha-2b plus ribavirin.

Controversies in and challenges to our understanding of hepatitis C

Discovered in 1989, the hepatitis C virus (HCV) continues to cause significant morbidity and mortality world-wide despite a huge research commitment to defining and understanding the virus and the disease it causes. This paper discusses a number of areas where progress in the management of the HCV have not kept pace with the scientific understanding of the HCV. It is suggested that in the fields of HCV prevention and providing access to treatment, practice falls short of what could be achieved. The role of alcohol in the pathogenesis of HCV liver injury is discussed. Discrimination against those with HCV infection and particularly those in prison settings fails to match good clinical practice. The complicated processes of sharing information between specialty groups is also discussed in an attempt to optimise knowledge dissemination in this field.

Involvement of dendritic cell frequency and function in virological relapse in pegylated interferon-alpha and ribavirin therapy for chronic hepatitis C patients

A combination of pegylated interferon alpha (PEG-IFNalpha) and ribavirin has been used widely. Enhancement of immune response against hepatitis C virus (HCV) is known to be involved in the efficacy of the combination therapy. The aim of the study was to elucidate whether the frequency or function of immunocompetent blood cells is related to the outcome of the therapy. Twenty-five chronic hepatitis C patients with high viral load of HCV genotype 1 who underwent 48 weeks of PEG-IFNalpha2b and ribavirin therapy were examined. During the treatment, frequencies of dendritic cell subsets, helper T cell subsets, and NK cells were phenotypically determined. In some patients, the ability of dendritic cells to stimulate allogeneic CD4(+)T cells was examined at the end and after the therapy. Among the 25 patients, 11 showed a sustained virological response, 11 a transient response, and 3 no response. In comparison with sustained virological responders, non-sustained virological responders showed impaired dendritic cell function at the end and after the treatment. The transient responders showed a decline of plasmacytoid dendritic cell frequency from Weeks 1-12 and impaired dendritic cell function as well. Even in patients who attained negative serum HCV RNA at Week 12, the transient responders showed a significant decrease of plasmacytoid dendritic cell frequency and impaired dendritic cell function. In conclusion, in PEG-IFNalpha and ribavirin combination therapy for chronic hepatitis C patients, the early-phase plasmacytoid dendritic cell frequency and/or end-of-treatment dendritic cell function are related to the virological outcome of the therapy.

Predictive value of rapid virological response and early virological response on sustained virological response in HCV patients treated with pegylated interferon alpha-2a and ribavirin

BACKGROUND AND AIM

The therapeutic effect of pegylated interferon (peg-IFN)-alpha-2a combination with ribavirin on patients with chronic hepatitis C virus (HCV) infection is dependent on the rapidity of the virological response. The aim of this study was to investigate the predictive value of rapid virological response (RVR) and early virological response (EVR) on sustained virological response (SVR) in HCV patients treated with peg-IFN-alpha-2a and ribavirin.

METHODS

The HCV genotypes of 105 patients with chronic hepatitis C were detected by enzyme-immunoassay. Patients received subcutaneous 180 microg peg-IFN-alpha-2a once weekly plus daily ribavirin. Patients with genotype 1 were treated for 48 weeks and patients with genotype 2 or 3 were treated for 24 weeks. HCV RNA was assessed by qualitative PCR at pretreatment, at weeks 4 and 12 during treatment, and at week 24 of follow-up. Virological response rates at different weeks were investigated, with RVR defined as serum HCV RNA undetectable after 4 weeks and EVR defined as HCV RNA either undetectable or decrease by >or=2 log(10) after 12 weeks. The effects of virological response rates at different weeks on SVR were analyzed.

RESULTS

Of the 105 patients, 44 (41.9%) were genotype 1, 46 (43.8%) were genotype 2, and 15 (14.3%) were genotype 3. RVR rates (19.5%) of patients with genotype 1 were significantly lower than those (60.7%) of genotype 2 or 3 (chi(2) = 16.836, P = 0.000); and EVR rates (73.2%) of patients with genotype 1 were significantly lower than those (96.7%) of genotype 2 or 3 (chi(2) = 12.220, P = 0.000). The SVR rates (86.7%) of patients who had achieved RVR were significantly higher than those (43.9%) of patients who had not achieved RVR (chi(2) = 19.713, P = 0.000). The positive predictive value of RVR in all patients was higher than that of EVR, but there was no significant difference between RVR and EVR. The negative predictive value of RVR in all patients or with genotype 1 was significantly lower than that of EVR. In univariate analysis, HCV RNA level (P = 0.014), genotype (P = 0.001), RVR (P = 0.000) and EVR (P = 0.000) were associated with effect of treatment. However, in stepwise regression analysis, the independent factors associated with effect of antiviral therapy were RVR (OR = 6.501, P = 0.001), EVR (OR = 2.776, P = 0.003) and genotype (OR = 3.061, P = 0.024).

CONCLUSIONS

The RVR and EVR rates of patients with genotype 1 were significantly lower than those of patients with genotype 2 or 3. RVR had a similar predictive value as EVR on SVR. Genotype, HCV RNA level, RVR and EVR were associated with SVR. Genotype, RVR and EVR were independent factors for predicting the effect of antiviral therapy.

The Magnitude of Week 4 HCV RNA Decay on Pegylated Interferon/Ribavirin Accurately Predicts Virological Failure in Patients with Genotype 1

Background

Current stopping rules during pegylated interferon (peg-IFN)/ribavirin (RBV) treatment rely on week 12 HCV RNA response, but earlier identification of non-responders offers clinical and economic advantages. Aims and

Methods

To evaluate, among 129 HCV-genotype-1-infected, treatment-naive patients receiving peg-IFN/RBV, the feasibility of predicting treatment failure using receiver operating characteristics (ROC) curves after measuring week 4 HCV RNA decreases, and to assess baseline predictors of not achieving sustained virological response (SVR).

Results

Peg-IFN-α2b was used in 84.5% of patients. Fifty-three (41%) reached SVR. The best cutoff value of HCV RNA decrease at week 4 to predict non-SVR corresponded to 1 log10 IU/ml: sensitivity and negative predictive value: 100%; specificity: 64%; positive predictive value: 66%; ROC curve area: 0·91 (95% confidence interval [CI]: 0·86–0·96). By applying this threshold, treatment could have been discontinued at week 4 in 64% of virological non-responders (49/76). By univariate analysis, baseline HCV RNA >800,000 IU/ml ( P=0.029), older age ( P=0.011), and higher aspartate aminotransferase (AST) levels ( P=0.005) or AST/alanine aminotransferase ratio values ( P=0.04) were associated with failure. After multivariate analysis, only baseline HCV RNA >800,000 IU/ml (odds ratio [OR]: 2.12; 95% CI: 1.005–4.488; P=0.048) and higher AST levels (OR: 1.01; 95% CI: 1.003–1.024; P=0.011) remained statistically significant.

Conclusions

The lack of ≥1 log10 IU/ml decrease in baseline HCV RNA at week 4 was 100% predictive of treatment failure, independently associated with HCV RNA >800,000 IU/ml and higher AST levels.

Predictive Value of Early Virologic Response in HIV/Hepatitis C Virus-Coinfected Patients Treated With an Interferon-Based Regimen Plus Ribavirin

BACKGROUND

As a result of adverse events, a moderate rate of virologic response, and high costs associated with hepatitis C virus (HCV) therapy, finding early markers of sustained treatment response is a clinical priority. In the HCV-monoinfected population, a reduction >or=2 log in plasma HCV RNA at week 12 of therapy (early virologic response [EVR]) predicts a sustained virologic response (SVR). Few data are available in HIV/HCV-coinfected patients, however.

METHODS

A subanalysis of data from HIV/HCV-coinfected patients treated with pegylated interferon-alpha-2b (PEG, 100-150 mug/wk) or interferon-alpha-2b (IFN, 3 MIU 3 times per week) plus ribavirin (RBV, 800-1200 mg/d) was conducted in a randomized single-center clinical trial. The duration of treatment was 48 weeks (only 24 weeks for HCV genotype 2 or 3 with a baseline HCV RNA level <800,000 IU/mL).

RESULTS

Ninety-five patients were randomized (43 assigned to IFN + RBV and 52 assigned to PEG + RBV). Eighty patients completed at least 12 weeks on therapy and were included in the EVR analysis. Thirty-five (43%) of them attained an SVR (56% and 30% of patients treated with PEG and IFN, respectively; P = 0.026). An EVR occurred in 55 (69%; 80% of PEG + RBV group and 56% of IFN + RBV group). Overall, 35 of 55 patients with an EVR were sustained responders, yielding a positive predictive value of 64% (70% in PEG + RBV arm and 55% in IFN + RBV arm). None of the patients who demonstrated an HCV RNA decline of <2 logs at week 12 reached an SVR (negative predictive value of 100%).

CONCLUSION

Our results confirm the utility of an EVR to predict the chance of the lack of an SVR in HIV/HCV-coinfected patients, particularly those treated with PEG.

Pegylated interferon and ribavirin in re-treatment of responder-relapser HCV patients

BACKGROUND

The re-treatment of patients who relapse after a course of standard interferon and ribavirin with pegylated interferon alfa-2b plus ribavirin is an open issue.

AIMS

To evaluate efficacy and safety of treatment with pegylated interferon alfa-2b plus ribavirin and the role of early HCV-RNA assessment as a predictor of sustained response.

PATIENTS

Between May 2001 and December 2002, 242 consecutive patients with chronic hepatitis C were enrolled in an open, regional, multicentre study. Seventy-eight of them were responder-relapsers to a previous course of combination therapy.

METHODS

Patients were treated with pegylated interferon alfa-2b (1 microg/kg/week) plus ribavirin (800-1200 mg daily). Qualitative HCV-RNA was performed at week 2. Genotypes 1-4 were treated for 48 weeks, while genotypes 2 and 3 were treated for 24 weeks.

RESULTS

We obtained an overall sustained virological response rate of 41.0% (78.6% for patients with genotypes 2-3).

CONCLUSION

This treatment schedule prove to be safe and effective in relapsers with genotype non-1 while genotype 1-4 patients had a low rate of sustained virological response. Qualitative virological assessment after 2 weeks may identify patients who are more likely to reach sustained virological response, but it is not a valid tool for a stopping rule approach.

Differences in viral kinetics between genotypes 1 and 3 of hepatitis C virus and between cirrhotic and non-cirrhotic patients during antiviral therapy

AIM: To evaluate the impact of hepatitis C virus (HCV) infection with genotype 1 or 3 and the presence or absence of liver cirrhosis (LC) in the early viral kinetics response to treatment.

METHODS: Naive patients (n = 46) treated with interferon-α (IFN-α) and ribavirin and followed up with frequent early HCV-RNA determinations were analysed. Patients were infected with genotype 1 (n = 28, 7 with LC) or 3 (n = 18, 5 with LC).

RESULTS: The first phase decline was larger in genotype 3 patients than in genotype 1 patients (1.72 vs 0.95 log IU/mL, P < 0.001). The second phase slope decline was also larger in genotype 3 patients than in genotype 1 patients (0.87 vs 0.15 log/wk, P < 0.001). Differences were found in both cirrhotic and non-cirrhotic patients. Genotype 1 cirrhotic patients had a slower 2^nd phase slope than non-cirrhotic patients (0.06 vs 0.18 log/wk, P < 0.02). None of genotype 1 cirrhotic patients had a 1^st phase decline larger than 1 log (non-cirrhotic patients: 55%, P < 0.02). A similar trend toward a slower 2^nd phase slope was observed in genotype 3 cirrhotic patients but the 1^st phase slope decline was not different. Sustained viral response was higher in genotype 3 patients than in genotype 1 patients (72% vs 14%, P < 0.001) and in genotype 1 non-cirrhotic patients than in genotype 1 cirrhotic patients (19% vs 0%). A second phase decline slower than 0.3 log/wk was predictive of non-response in all groups.

CONCLUSION: Genotype 3 has faster early viral decline than genotype 1. Cirrhosis correlates with a slower 2^nd phase decline and possibly with a lower 1^st phase slope decline in genotype 1 patients.

An artificial neural network approach to the drug efficacy of interferon treatments

INTRODUCTION

Interferon taken alone or in combination with ribavirin can be used for the treatment of persons with chronic hepatitis C. It is highly desirable, both clinically and economically, to establish tools to distinguish responders from nonresponders and to predict possible outcomes of the treatments. In this work, our goal is to develop a prediction model resulting from the analysis of chronic hepatitis C patients' single nucleotide polymorphisms, viral genotype, viral load, age and gender, to predict the responsiveness of interferon combination treatment.

MATERIALS AND METHODS

We collected blood samples from 523 chronic hepatitis C patients that had received interferon and ribavirin combination therapy. Based on the current treatment strategy for chronic hepatitis C patients, we focused our search for candidate genes involved in pathways related to interferon signaling and immunomodulation. With artificial neural network algorithms, we then developed pattern recognition methodologies to achieve predictions among the patients. The artificial neural network model was trained by an algorithm with an adaptive momentum and learning rate.

RESULTS

There were seven single nucleotide polymorphisms selected from six candidate genes including adenosine deaminase-RNA-specific, caspase 5, interferon consensus sequence binding protein 1, interferon-induced protein 44, phosphoinositide-3-kinase catalytic gamma polypeptide and transporter 2 ATP-binding cassette subfamily B genes. We further applied the artificial neural network algorithms with these seven single nucleotide polymorphisms, viral genotype, viral load, age and gender information to build tools for predicting the responsiveness of interferon. Based on the fivefold cross-validation method to evaluate the performance, the model achieved a high success rate of prediction.

CONCLUSION

We demonstrated that a trained artificial neural network model is a promising method for providing the inference from factors such as single nucleotide polymorphisms, viral genotype, viral load, age and gender to the responsiveness of interferon.

IP-10 predicts viral response and therapeutic outcome in difficult-to-treat patients with HCV genotype 1 infection

Plasma from 173 patients with HCV genotype 1 infection was analyzed for IP-10 levels prior to treatment with pegylated interferon-alpha-2a and ribavirin. Significantly lower IP-10 levels were observed in patients achieving a rapid viral response (RVR) (P < .0001), even in those with body mass index (BMI) > or = 25 kg/m2 (P = .004) and with baseline viral load > or = 2 million IU/mL (P = .001). Similarly, significantly lower IP-10 levels were observed in patients obtaining a sustained viral response (SVR) (P = .0002), including those having higher BMI (P < .05), higher viral load (P = .0005), and both higher BMI and viral load (P < .03). In multivariate logistic regression analyses, a low IP-10 value was independently predictive of both RVR and SVR. A baseline cutoff IP-10 value of 600 pg/mL yielded a negative predictive value (NPV) of 79% (19/24) for all genotype 1-infected patients, which was comparable with that observed using a reduction in HCV-RNA by at least 2 logs after 12 weeks of therapy (NPV 86%; 19/22); by combining the two, 30 of 38 patients (NPV 79%) potentially could have been spared unnecessary therapy. In patients having both higher BMI and viral load, cut-off levels of 150 and 600 pg/mL yielded a positive predictive value (PPV) of 71% and NPV of 100%, respectively. In conclusion, pretreatment IP-10 levels predict RVR and SVR in patients infected with HCV genotype 1, even in those with higher BMI and viral load. A substantial proportion of the latter patients may achieve SVR in spite of unfavorable baseline characteristics if their pretreatment IP-10 level is low. Thus, pretreatment IP-10 analysis may prove helpful in decision-making regarding pharmaceutical intervention.

Outcome of Chronic Hepatitis C Patients who Required Early Termination of Pegylated Interferon-α plus Ribavirin Combination Therapy

Background

Pegylated interferon/ribavirin (peg-IFN/RBV) combination therapy is effective for chronic hepatitis C (CHC) but frequently causes adverse events, leading to early termination. Little is known about the outcome of CHC patients who required early termination.

Methods

Of 617 treatment-naive CHC patients prescribed a 24-week protocol of peg-IFN/RBV, 29 (4.7%) patients who terminated treatment early at <20 weeks were recruited to evaluate the rate of and the factors associated with sustained virological response (SVR), defined as seronegativity of hepatitis C virus (HCV) RNA throughout the 24-week off-treatment follow-up period.

Results

The reasons for early termination were flu-like symptoms/signs ( n=9, 31.0%), irritability ( n=1, 3.4%), severe urticaria ( n=1, 3.4%), insomnia ( n=2, 6.9%), pulmonary tuberculosis ( n=1, 3.4%), suicide idea ( n=2, 6.9%), poor response ( n=2, 6.9%), depression ( n=2, 6.9%), unwilling to continue ( n=1, 3.4%), mortality ( n=1, 3.4%), gastrointestinal upset ( n=1, 3.4%), pancytopenia complicated with cellulitis ( n=1, 3.4%), anaemia ( n=3, 10.3%), overseas work ( n=1, 3.4%) and an unknown cause ( n=1, 3.4%). Five (17.2%) patients achieved an SVR, comprising none of 16 HCV genotype-1 and five of the 13 (38.5%) genotype-2 patients ( P=0.001). All sustained responders were HCV RNA seronegative at week 4 of treatment. The SVR rate among HCV-2 patients was 0% (0/1), 0% (0/2), 25% (1/4), 33% (1/3) and 100% (3/3) in those who received peg-IFN/RBV for 1–3, 4–7, 8–11, 12–15 and 16–19 weeks, respectively ( P=0.019, χ2 with linear trend).

Conclusions

Based on this limited study, we observed that an SVR might be achieved in patients who required early termination of a 24-week regimen of peg-IFN/RBV, especially for HCV-2 patients with HCV RNA seronegativity at week 4.

Sensitivity to antiviral therapy may change after liver transplantation in patients with chronic hepatitis C virus infection

In hepatitis C virus (HCV)-infected patients, it is generally assumed that the pattern of response to antiviral therapy remains unaltered after liver transplantation (LT). However, changes in the circulating HCV quasispecies and in the gene expression profiles of the graft might influence response to treatment after LT. We evaluated 22 HCV-infected patients who received antiviral treatment while awaiting LT and in whom HCV infection recurred. Eleven of these patients underwent a new antiviral treatment course. Our study analyses the early virological response to both treatment courses to assess the influence of the changes in HCV on the response to therapy. Patients were considered early virological responders (EVR) if viral load declined > or = 2 log10 during the first 12 weeks of therapy. The remaining individuals were considered nonresponders (NR). HCV sequences from hypervariable region 1 and nonstructural 5A (NS5A) region before both treatment regimens were compared. Of 11 patients, 8 (73%) showed identical early response to both courses of therapy (group A: five EVR-EVR, three NR-NR). Interestingly, the response changed in three patients (27%) (group B): two NR became EVR after transplantation, whereas one EVR became NR. Fixation of mutations within the NS5A occurred preferentially in group B (100%) compared with group A (37%)(P = 0.12). However, the number of fixed mutations was not significantly different between groups, suggesting that the changes in sensitivity to therapy after LT are not exclusively dependent on variations in HCV strains. In conclusion, in HCV-infected patients undergoing LT, the pattern of response to antiviral treatment may change after transplantation, and this possibility needs to be incorporated in clinical practice.

Albumin-interferon-α in the treatment of chronic hepatitis C

Despite advances in treating chronic hepatitis C, newer treatments are required. Albumin fusion technology allows the enhanced pharmacokinetic properties of albumin to be combined with the pharmacodynamic properties of other agents. Albumin-interferon-α has an extended half-life that supports bimonthly or monthly dosing and may provide superior steady-state exposure to interferon. Preclinical studies show that albumin-interferon has better antiviral activity and pharmacokinetics than either standard or pegylated interferons. Phase I–II and Phase IIa studies that have explored a wide dose range (from 10 to 1200 μg) in interferon-experienced and -naïve patients have shown the drug to be safe and well tolerated, with no dose-limiting adverse events. Its half-life is 6–7 days and it is detectable 4 weeks after a single dose. The longer term safety and efficacy of albumin-interferon and ribavirin is being evaluated in both interferon-naïve patients and nonresponders to previous standard and pegylated interferon therapy.

Duration of peginterferon therapy in acute hepatitis C: a randomized trial

Spontaneous resolution of acute hepatitis C virus infection cannot be predicted, and chronic evolution of the disease occurs in a majority of cases. To assess the efficacy and safety of peginterferon alpha-2b administered for 8, 12, or 24 weeks in patients with acute hepatitis C virus infection a total of 161 patients were identified with acute hepatitis C virus infection. Of these, 30 patients refused treatment but were retained in the study as a nonrandomized comparison group. Of the 131 patients who consented to treatment, 29 patients spontaneously resolved, leaving 102 patients randomly assigned to peginterferon alpha-2b (1.5 microg/kg) for 8 weeks (group A; n=34), 12 weeks (group B; n=34), and 24 weeks (group C; n=34). The primary end point was sustained virologic response. An intent-to-treat analysis was used for efficacy and safety end points. Sustained virologic response was achieved in 23/34 (67.6%), 28/34 (82.4%), and 31/34 (91.2%) of patients in groups A, B, and C, respectively; all had undetectable hepatitis C virus RNA 48 weeks after the end of therapy. Treatment for 8 or 12 weeks was effective in genotypes 2, 3, and 4, whereas genotype 1 required 24 weeks of therapy. The 8- and 12-week regimens were associated with fewer adverse events compared with the 24-week regimen. In conclusion, peginterferon alpha-2b effectively induces high sustained virologic response rates in patients with acute hepatitis C virus infection, thus preventing development of chronic hepatitis C. Duration of treatment should be further optimized based on genotype and rapid virologic response at week 4.

Treatment of chronic HCV infection in special populations

The mainstay of treatment of chronic hepatitis C is pegylated interferon combined with ribavirin and more than 50% of naïve patients will have viral cure with either 6 months (genotypes 2 and 3) or 12 months (genotypes 1,4, and 6) with the initial treatment. However, populations have been defined that respond less well to routine treatment including African Americans, immune suppressed populations, obese patients and cirrhotic patients. These types of patients are enriched in groups of patients who are non-responders to treatment. This article discusses viral kinetics that may impact treatment response, strategies to maximize treatment effectiveness in these populations and the treatment of non-responders in general. Early viral kinetics can be used to define response or non-response and these results can be used to modify subsequent treatment length and dose.