Predictive factors of early and sustained responses to peginterferon plus ribavirin combination therapy in Japanese patients infected with hepatitis C virus genotype 1b: amino acid substitutions in the core region and low-density lipoprotein cholesterol levels

Toward the establishment of a prediction system for the personalized treatment of chronic hepatitis C

BACKGROUND

Although several direct-acting antivirals (DAAs) are now available, the therapy regimen for chronic hepatitis C will continue to include pegylated interferon and ribavirin for the foreseeable future. Despite their improved rate of sustained virological response (SVR), DAAs pose increased risks of side effects and selection for antiviral resistance. Not all patients require DAA to achieve SVR, whereas others are unlikely to respond even to triple therapy. Therefore, a personalized approach to candidate selection is necessary.

METHODS

In this retrospective study, data from 640 Japanese patients who were treated for chronic hepatitis C genotype 1, 2, or 3 with pegylated interferon plus ribavirin combination therapy was compiled to identify robust pretreatment predictive factors for SVR.

RESULTS

A logistic regression model for personalized therapy was developed based on age, viral genotype, initial viral load, aspartate aminotransferase/alanine aminotransferase ratio, α-fetoprotein levels, and IL28B single-nucleotide polymorphism genotype. The area under the receiver-operating characteristic curve (AUC) was 0.85. The mean AUC following 10 rounds of 10-fold cross validation was 0.82, with a true positive rate of 78.2%.

CONCLUSIONS

A personalized approach to therapy may better inform treatment decisions and reduce incidence of side effects and antiviral resistance.

Genotype rs8099917 near the IL28B gene and amino acid substitution at position 70 in the core region of the hepatitis C virus are determinants of serum apolipoprotein B-100 concentration in chronic hepatitis C

The life cycle of the hepatitis C virus (HCV) is closely related to host lipoprotein metabolism. Serum levels of lipid are associated with the response to pegylated interferon plus ribavirin (PEG-IFN/RBV) therapy, while single nucleotide polymorphisms (SNPs) around the human interleukin 28B (IL28B) gene locus and amino acid substitutions in the core region of the HCV have been reported to affect the efficacy of PEG-IFN/RBV therapy in chronic hepatitis with HCV genotype 1b infection. The aim of this study was to elucidate the relationship between serum lipid and factors that are able to predict the efficacy of PEG-IFN/RB therapy, with specific focus on apolipoprotein B-100 (apoB-100) in 148 subjects with chronic HCV G1b infection. Our results demonstrated that both the aa 70 substitution in the core region of the HCV and the rs8099917 SNP located proximal to the IL28B were independent factors in determining serum apoB-100 and low-density lipoprotein (LDL) cholesterol levels. A significant association was noted between higher levels of apoB-100 (P = 1.1 × 10(-3)) and LDL cholesterol (P = 0.02) and the subjects having Arg70. A significant association was also observed between subjects carrying the rs8099917 TT responder genotype and higher levels of apoB-100 (P = 6.4 × 10(-3)) and LDL cholesterol (P = 4.2 × 10(-3)). Our results suggest that apoB-100 and LDL cholesterol are markers of impaired cellular lipoprotein pathways and/or host endogenous interferon response to HCV in chronic HCV infection. In particular, serum apoB-100 concentration might be an informative marker for judging changes in HCV-associated intracellular lipoprotein metabolism in patients carrying the rs8099917 responder genotype.

A multicenter study to clarify the optimal HCV-RNA negative period during combined therapy with pegylated interferon plus ribavirin in patients with chronic hepatitis caused by HCV genotype 2

OBJECTIVE

A multicenter open trial was performed to clarify the optimal duration of combined pegylated interferon (Peg-IFN) plus ribavirin therapy in patients with chronic hepatitis caused by HCV genotype 2.

METHODS

A total of 100 patients seen between 2005 and 2007 received the combination therapy for 4 to 52 weeks. The cutoff value of the HCV-RNA-negative (titers under 1.7 Log IU/mL) period during the therapy to predict sustained virological response (SVR) was determined by ROC curve and multivariate logistic regression analyses. The result was validated in 48 patients between 2008 and 2009.

RESULTS

SVR was achieved in 78 patients. Serum HCV-RNA titers decreased to less than 1.7 Log IU/mL at 4 weeks of the therapy in 60 patients. The SVR rate in these patients was 85%, which was significantly higher than that of remaining 40 patients with a SVR rate of 68%. An HCV-RNA-negative period of ≥17 weeks was selected as the cutoff value, which showed a significant odds ratio of 4.77 for SVR. Among the 35 patients who showed a decrease of the serum HCV-RNA of less than 1.7 Log IU/mL between 8 and 16 weeks of therapy, the SVR rate was significantly higher in 16 patients with a serum HCV-RNA-negative period of ≥17 weeks (94%) than in 19 patients in whom the period was less than 17 weeks (63%). Similar results were obtained in the subsequent validation study.

CONCLUSION

Prolonged combined Peg-IFN plus ribavirin therapy, with an HCV-RNA-negative period of ≥17 weeks, yielded good therapeutic outcomes in patients with chronic HCV genotype 2 hepatitis.

Controversies in surveillance and early diagnosis of hepatocellular carcinoma

The surveillance of hepatocellular carcinoma (HCC) is an established approach to detect early cancers in patients with defined risks. However, there are still varied controversies and issues to be addressed regarding the optimal surveillance methods and interval. Moreover, there are discrepancies in the opinion or practice of HCC surveillance between Eastern and Western countries. The Western strategy of ultrasound without a biomarker such as α-fetoprotein reflects the cost-effective utilization of limited resources. On the contrary, combined measurements of biomarkers in Eastern countries are based on the assumption that increased detection of early cancers could result in an overall survival benefit. To address this complicated issue, a prospective study comparing different surveillance tests might be required. More importantly, discovery of a novel biomarker with higher performance would be an alternative.

Sequences in the interferon sensitivity-determining region and core region of hepatitis C virus impact pretreatment prediction of response to PEG-interferon plus ribavirin: data mining analysis

The aim of the present study was to clarify the significance of viral factors for pretreatment prediction of sustained virological response to pegylated-interferon (PEG-IFN) plus ribavirin (RBV) therapy for chronic hepatitis C using data mining analysis. Substitutions in the IFN sensitivity-determining region (ISDR) and at position 70 of the HCV core region (Core70) were determined in 505 patients with genotype 1b chronic hepatitis C treated with PEG-IFN plus RBV. Data mining analysis was used to build a predictive model of sustained virological response in patients selected randomly (n = 304). The reproducibility of the model was validated in the remaining 201 patients. Substitutions in ISDR (odds ratio = 9.92, P < 0.0001) and Core70 (odds ratio = 1.92, P = 0.01) predicted sustained virological response independent of other covariates. The decision-tree model revealed that the rate of sustained virological response was highest (83%) in patients with two or more substitutions in ISDR. The overall rate of sustained virological response was 44% in patients with a low number of substitutions in ISDR (0-1) but was 83% in selected subgroups of younger patients (<60 years), wild-type sequence at Core70, and higher level of low-density lipoprotein cholesterol (LDL-C) (≥ 120 mg/dl). Reproducibility of the model was validated (r(2) = 0.94, P < 0.001). In conclusion, substitutions in ISDR and Core70 of HCV are significant predictors of response to PEG-IFN plus RBV therapy. A decision-tree model that includes these viral factors as predictors could identify patients with a high probability of sustained virological response.

[Current options for predicting therapeutic response in chronically infected patients with hepatitis C virus genotype 1]

Only about 50% of patients chronically infected with hepatitis C virus genotype 1 achieve a successful response to standard treatment with pegylated interferon-alfa and ribavirin. Moreover, the recently approved protease inhibitors will have to be administered together with these drugs. Consequently, predicting response to standard treatment, ideally before starting it, remains an important challenge. Although several baseline predictors of treatment failure have been described, including clinical and virological factors, none of them is able to provide reliable predictions at the individual level. In addition, the development of multivariate models combining several predictive factors has not yet yielded predictions with the requisite reliability for use in clinical practice. Therefore, further research is needed to improve predictive models and to describe new factors that would enable us to predict treatment outcome with greater reliability and reproducibility. The development of candidate selection algorithms that help clinicians to identify which patients could benefit from the new therapies on the basis of their chances of responding to standard therapy is of major interest for both patient well-being and healthcare expense. This review attempts to provide a view of the current options for predicting the response to pegylated interferon-alfa plus ribavirin therapy in patients chronically infected with hepatitis C virus genotype 1.

Suppressor of cytokine signal 3 and IL28 genetic variation predict the viral response to peginterferon and ribavirin

AIM

  The aim of this study was to investigate the relationship among the expression of suppressor of cytokine signaling 3 (SOCS 3) in the liver, the SNPs in the IL28B locus, and the outcome of interferon therapy.

METHODS

  Prior to interferon treatment, we immunostained 67 liver specimens from chronic hepatitis C (CHC) patients who were receiving peginterferon alpha-2b/ribavirin therapy for suppressor of cytokine signaling 3 (SOCS3), and compared the expression of SOCS3, IL28 polymorphisms and other clinical factors between the patients and compared their eventual outcomes.

RESULTS

  Significant differences between the low SOCS3 group and high SOCS3 group were found in age, as well as in the platelet, transaminase, gamma-glutamyl transpeptidase levels. The incidence of high SOCS3 was not significantly different between subjects with the TT genotype and the TG genotype (TT : TG = 71%:29%, P = 0.250). In a multivariate analysis, age (≥65 years old) (odds ratio 0.221 [0.120-0.966], P = 0.045), IL28B gene (genotype TT) (odds ratio 5.422 [1.254-23.617], P = 0.024) and SOCS3 (high) (odds ratio 0.308 [0.104-0.948], P = 0.040) were significant predictors of the interferon response. In patients with the TT genotype, those with low SOCS3 immunostaining showed a high sustained virological response (69%), while the sustained virological rate was low (27%) in the patients with high SOCS3 immunostaining.

CONCLUSIONS

  Using a combination of the SOCS3 immunostained area in the liver and the expression of IL28B single nucleotide polymorphisms might be a useful predictor of hepatitis C virus clearance by interferon therapy.

Host genetics

PURPOSE OF REVIEW

To update the information on genetic markers influencing the outcome of hepatitis C virus (HCV) infection.

RECENT FINDINGS

Single-nucleotide polymorphisms (SNPs) in the region of the IL28B gene on chromosome 19, coding for the interferon (IFN)-λ3, are involved in HCV spontaneous and treatment-induced clearance, and may have an influence on liver fibrosis and inflammation in chronic carriers. The rs12979860 SNP has been recommended as single diagnostic genotype. IL28B variations are strongly associated with response to pegylated-IFN plus ribavirin (Peg-IFN/RBV) in patients with chronic infection by HCV genotype 1 or 4. Thus, the rs12979860 CC genotype is associated with a two-fold increase in the sustained virological response (SVR) rate in this setting. SVR is less influenced by IL28B variants in HCV genotype 2 or 3 carriers. The rs12979860 CC genotype frequencies vary among diverse genetic ancestor groups, explaining partly the differences in SVR among them. The underlying mechanisms are unclear, but it may involve the expression of IFN-stimulated genes in the liver. Inosine triphosphatase genotype is predictive of RBV-induced anemia, but its clinical usefulness is less straightforward than that of IL28B SNPs.

SUMMARY

IL28B genotyping can aid in Peg-IFN/RBV clinical decision-making, and it may be useful in the selection of candidates for triple therapy with Peg-IFN/RBV plus direct-acting antiviral drugs.

IL28B alleles exert an additive dose effect when applied to HCV-HIV coinfected persons undergoing peginterferon and ribavirin therapy

BACKGROUND

Genetic studies have demonstrated a strong association between single nucleotide polymorphisms (SNPs) at IL28B and response to treatment with peginterferon (PEG) and ribavirin (RBV) in HCV monoinfected persons. We sought to test these associations in a prospective PEG / weight based ribavirin (WBR) treatment trial (ACTG A5178) (National Institution of Health registration number NCT00078403) in persons with HCV-HIV coinfection, and to develop a prediction score.

METHODS

We selected subjects enrolled in A5178 who completed at least the first 12 weeks of the trial and had DNA available, and genotyped three SNPs at IL28B (rs12979860, rs12980275, rs8099917). We used multivariate logistic regression analysis to evaluate the association between IL28B SNPs and HCV treatment outcomes and to develop the prediction score.

RESULTS

231 HCV/HIV coinfected subjects were included. We observed a strong association between IL28B genotype and response to therapy among those with genotypes 1 or 4 (odds ratio for complete early virologic responses (cEVR) and sustained virologic response (SVR) was 2.98 [1.7-5.3] and 3.4 [1.7-6.9], respectively, for each additional copy of the C allele of rs12979860). Differences in frequency of the responder allele explained some of the discrepancy in HCV treatment outcomes between blacks and whites. A simple pretreatment prediction score that incorporates the IL28B genotype and baseline HCV viral load has a 93% negative predictive value (NPV) for SVR.

CONCLUSIONS

IL28B SNPs have an additive allele dose effect in predicting HCV treatment outcomes in HCV/HIV coinfected persons and can be incorporated into a simple pretreatment prediction score that could minimize the risk of exposure to PEG/RBV therapy for persons with unfavorable scores.

Genetic heterogeneity of hepatitis C virus in association with antiviral therapy determined by ultra-deep sequencing

Background and Aims

The hepatitis C virus (HCV) invariably shows wide heterogeneity in infected patients, referred to as a quasispecies population. Massive amounts of genetic information due to the abundance of HCV variants could be an obstacle to evaluate the viral genetic heterogeneity in detail.

Methods

Using a newly developed massive-parallel ultra-deep sequencing technique, we investigated the viral genetic heterogeneity in 27 chronic hepatitis C patients receiving peg-interferon (IFN) α2b plus ribavirin therapy.

Results

Ultra-deep sequencing determined a total of more than 10 million nucleotides of the HCV genome, corresponding to a mean of more than 1000 clones in each specimen, and unveiled extremely high genetic heterogeneity in the genotype 1b HCV population. There was no significant difference in the level of viral complexity between immediate virologic responders and non-responders at baseline (p = 0.39). Immediate virologic responders (n = 8) showed a significant reduction in the genetic complexity spanning all the viral genetic regions at the early phase of IFN administration (p = 0.037). In contrast, non-virologic responders (n = 8) showed no significant changes in the level of viral quasispecies (p = 0.12), indicating that very few viral clones are sensitive to IFN treatment. We also demonstrated that clones resistant to direct-acting antivirals for HCV, such as viral protease and polymerase inhibitors, preexist with various abundances in all 27 treatment-naïve patients, suggesting the risk of the development of drug resistance against these agents.

Conclusion

Use of the ultra-deep sequencing technology revealed massive genetic heterogeneity of HCV, which has important implications regarding the treatment response and outcome of antiviral therapy.

Sequence heterogeneity of NS5A and core proteins of hepatitis C virus and virological responses to pegylated-interferon/ribavirin combination therapy

Both host and viral factors have been implicated in influencing the response to pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy for hepatitis C virus (HCV) infection. Among the viral factors, sequence heterogeneity within NS5A and core regions has been proposed. This study aimed to clarify the relationship between virological responses to PEG-IFN/RBV therapy and sequence heterogeneity within NS5A, including the IFN/RBV resistance-determining region (IRRDR), the interferon sensitivity-determining region (ISDR) and the core region. Pretreatment sequences of NS5A and the core regions were analyzed in 57 HCV-1b-infected patients who were to be treated with PEG-IFN/RBV. Of 40 patients infected with HCV having an IRRDR with four or more mutations (IRRDR ≥ 4), 28 (70%) patients achieved a sustained virological response (SVR). On the other hand, only 4 (24%) of 17 patients infected with HCV having an IRRDR with three or fewer mutations (IRRDR ≤ 3) achieved a SVR (P = 0.001). Similarly, 22 (71%) of 31 patients infected with HCV and having an ISDR with one or more mutations (ISDR ≥ 1) achieved a SVR while 10 (38%) of 26 patients infected with HCV and having an ISDR without any mutations (ISDR = 0) achieved a SVR (P = 0.014). As for the core region, there was significant correlation between a single mutation at position 70 (Gln(70) ) and non-SVR (P = 0.02). Notably, Gln(70) was more prominently associated with the null response (P = 0.0007). In conclusion, sequence heterogeneity within the IRRDR and ISDR, and a single point mutation at position 70 of the core region of HCV-1b are likely to be correlated with virological responses to PEG-IFN/RBV therapy.

Impact of genetic polymorphisms near the IL28B gene and amino acid substitutions in the hepatitis C virus core region on interferon sensitivity/resistance in patients with chronic hepatitis C

It has been reported that genetic polymorphisms near the IL28B gene or amino acid substitutions in hepatitis C virus (HCV) core protein are associated with the clinical outcome of peginterferon (PEG-IFN) and ribavirin combination therapy. The impact of these factors on the pure sensitivity/resistance to interferon was evaluated. Changes in the HCV RNA levels 24, 48, 72, and 120 hr after administering a single dose of standard interferon (IFN) were measured in 156 HCV-infected patients. The changes were compared based on the genetic polymorphisms near the IL28B gene or amino acid substitutions in the HCV core region. Among patients with HCV genotype 1b, there were differences in the reduction and subsequent increase in HCV RNA levels after administering IFN based on rs8099917 genetic polymorphisms. Amino acid substitutions at residue 70 were associated with differences in the changes in HCV RNA levels only in patients with TG/GG genotype. Multivariate analyses showed that genetic polymorphisms near the IL28B gene was the sole independent factor that was associated with the reduction in HCV RNA levels after administering IFN and the final response to the combination therapy. Among patients infected with HCV genotype 2a or 2b, there were no differences in the changes in HCV RNA levels based on the genetic polymorphisms near the IL28B gene. In HCV genotype 1b, genetic variations near the IL28B gene affected the sensitivity/resistance to IFN strongly. Genetic polymorphisms near the IL28B gene did not affect the sensitivity/resistance to IFN in HCV genotype 2.

Disadvantages of peginterferon and ribavirin treatment in older patients with chronic hepatitis C: an analysis using the propensity score

PURPOSE

Peginterferon (PEG-IFN) and ribavirin (RBV) combination treatment for patients with chronic hepatitis C (CHC), infected by genotype-1 hepatitis C virus with high viral loads, results in a sustained viral response (SVR) in ~50%. However, a trend of decreasing SVR in the older patients has been reported. In the present study, we verified this trend of treatment efficacy in older patients using the propensity score (PS).

METHODS

We conducted a survey of 327 patients with CHC (genotype 1 and high viral loads) who were treated with PEG-IFN and RBV for 48 weeks. The SVR rate was compared between patients =60 and <60 years of age. Because backgrounds of these patients differed considerably, we verified this efficacy between the older (n = 102) and younger (n = 102) patients matched for gender, body weight, platelets (PLT), and red blood cell (RBC) counts using PS.

RESULTS

The total SVR rate was 42.9% (161/327); this rate decreased with increasing age and was lower in the older patients (≥60 years: 41.5%, <60 years: 54.3%, P = 0.0245). Moreover, younger age was a significant factor for SVR. After correction by PS, the SVR in older patients remained significantly lower (≥60 years: 43.1%, <60 years: 57.8%, P = 0.0497). In addition, RBC counts and hemoglobin (Hgb) concentrations, as well as RBV adherence in the older patients, decreased with this treatment, although there were no significant differences in pretreatment RBC and Hgb levels.

CONCLUSIONS

The analysis using PS indicated that RBV adherence in the older patients decreased even if they did not have lower pretreatment RBC and Hgb levels.

Impact of viral amino acid substitutions and host interleukin-28b polymorphism on replication and susceptibility to interferon of hepatitis C virus

Amino acid (aa) substitutions of core 70 and 91 and in the NS5A (nonstructural protein 5A) interferon sensitivity determining region (ISDR) as well as genetic polymorphisms in the host interleukin-28B (IL28B) locus affect the outcome of interferon (IFN)-based therapies for patients with chronic hepatitis C. The combination of these factors and the quasispecies nature of the virus complicate understanding of the underlying mechanism. Using infectious hepatitis C virus (HCV) genotype 1b clone HCV-KT9, we introduced substitutions at both core aa70 (Arg to Gln) and aa91 (Leu to Met). We also introduced four and nine ISDR aa substitutions into core mutant HCV-KT9. Using human hepatocyte chimeric mice with different IL28B genotypes, we examined the infectivity, replication ability, and susceptibility to IFN of these clones. Although aa substitutions in the ISDR significantly impaired infectivity and replication ability of the virus, core aa70 and 91 substitutions did not. The effect of IFN treatment was similar in core wild-type and mutant viruses. Interestingly, virus titer was significantly higher in mice with the favorable IL28B allele (rs8099917 TT and rs12979860 CC) in the transplanted hepatocytes than in mice with hepatocytes from rs8099917 TG and rs12979860 TT donors (P < 0.001). However, the effect of IFN was significantly greater, and intrahepatic expression levels of IFN-stimulated genes were significantly higher in mice with the favorable IL28B allele.

CONCLUSION

Our data suggest that HCV replication levels and response to IFN are affected by human hepatocyte IL28B single-nucleotide polymorphism genotype and mutations in the ISDR. The mechanism underlying the clinically observed association of wild-type core protein in eradication-favorable host cells should be investigated further.

Antiviral combination therapy with peginterferon and ribavirin does not induce a therapeutically resistant mutation in the HCV core region regardless of genetic polymorphism near the IL28B gene

An association has been reported between genetic polymorphism near IL28B gene and the prevalence of mutation of hepatitis C virus (HCV) core region residue 70, both of which have been associated with a lack of virologic response to antiviral combination therapy with peginterferon (PEG-IFN) and ribavirin. This study investigated whether PEG-IFN/ribavirin combination therapy induces amino acid (AA) mutation at residue 70 of HCV and whether genetic polymorphism near IL28B gene affects it. AA substitutions at residue 70 of the HCV core region were measured and compared before and after combination therapy in 65 non-responders and 88 relapsers to the combination therapy. In three patients in whom both wild-type AA (arginine) and mutant-type AA (glutamine or histidine) were detected at residue 70 before treatment, only mutant-type AA was identified after treatment. In two patients who had wild-type AA solely before treatment, both wild-type and mutant-type AAs were identified at residue 70 after treatment. In five patients, in whom the AA had changed at residue 70 between before and after treatment, four patients carried the TT genotype at a polymorphic locus (rs8099917) near the IL28B gene and one carried the TG/GG genotype. No difference was found in the prevalence of this change of AA at residue 70 between the TT and the TG/GG genotype. Antiviral combination therapy with PEG-IFN and ribavirin does not appear to induce mutation of HCV core region residue 70 regardless of genetic polymorphism near the IL28B gene in Japanese patients infected with HCV genotype 1b.

Inverse association of IL28B genotype and liver mRNA expression of genes promoting or suppressing antiviral state

High intrahepatic expression levels of interferon stimulated genes (ISGs) in chronic hepatitis C patients are associated with poor response to interferon plus ribavirin combination therapy. Expression levels of 16 genes (OAS1, PKR, MxA, ISG15, RIG-I, TLR8, IRF7, IRF9, NFKBIA, IL28A/IL28B, IL29, IL28RA, IL10RB, IFNAR2, and STAT1) that promote antiviral state and 4 genes (SOCS1, SOCS3, Zc3h12a, and A20) that suppress antiviral state were analyzed using real-time PCR assays in 133 liver biopsy samples from patients infected with genotypes 1 or 2. Expression levels of genes promoting antiviral state were positively correlated with each other but were not correlated with those that suppress antiviral state. Expression levels of some ISGs were inversely associated with common polymorphisms within the IL28B locus. Genes promoting antiviral state were expressed lower (e.g., ISG15, P = 1.42E-12 and MxA, P = 6.40E-11) in individuals with the protective rs12979860 CC genotype, and genes suppressing antiviral state were expressed higher (A20, P = 0.00107 and Zc3h12a, P = 0.00129, respectively), although some ISGs were not significant after the Bonferroni correction. The expression levels of both an antiviral (MxA) and a suppressor (SOCS1) ISG were independent predictors for non-response. These results suggest that rs12979860 genotype may be associated with response to combination therapy through an inverse relationship between antiviral and suppressor ISGs in the liver.

Characterization of naturally occurring protease inhibitor-resistance mutations in genotype 1b hepatitis C virus patients

BACKGROUND AND AIMS

Protease inhibitor (PI)-resistant hepatitis C virus (HCV) variants may be present in substantial numbers in PI-untreated patients according to recent reports. However, influence of these viruses in the clinical course of chronic hepatitis C has not been well characterized.

METHODS

The dominant HCV nonstructural 3 (NS3) amino acid sequences were determined in 261 HCV genotype 1b-infected Japanese patients before pegylated interferon plus ribavirin (PEG-IFN/RBV) therapy, and investigated the patients' clinical characteristics as well as treatment responses including sustained virological response (SVR) rate. HCV-NS3 sequences were also determined in 39 non-SVR patients after completion of the therapy.

RESULTS

Four single mutations (T54S, Q80K, I153V, and D168E) known to confer PI resistance were found in 35 of 261 patients (13.4%), and double mutations (I153V plus T54S/D168E) were found in 6 patients (2.3%). Responses to PEG-IFN/RBV therapy did not differ between patients with and without PI-resistance mutations (mutation group, SVR 48%; wild-type group, SVR 40%; P = 0.38). On the other hand, two mutations appeared in two non-SVR patients after PEG-IFN/RBV therapy (I153V and E168D, 5.1%).

CONCLUSIONS

PI-resistance-associated NS3 mutations exist in a substantial proportion of untreated HCV-1b-infected patients. The impact of these mutations in the treatment of PIs is unclear, but clinicians should pay attention to avoid further development of PI resistance.

Redefining baseline demographics: the role of genetic testing in hepatitis C virus infection

The current standard of care for hepatitis C virus (HCV) infection is pegylated interferon and ribavirin. Unfortunately, treatment cures at best only 40% to 50% of patients infected with genotype 1 HCV, the most common HCV genotype in Western countries. Treatment is also expensive and is often poorly tolerated. Therefore, the identification of patients most likely to benefit from treatment is clinically important. Genome-wide association studies have recently identified genetic variants, most notably IL28B and ITPA, which will enhance the ability of clinicians to personalize antiviral therapy for HCV infection.

Cholesterol and chronic hepatitis C virus infection

Cholesterol is an essential molecule for the life cycle of the hepatitis C virus (HCV). This review focuses on the roles of cholesterol in HCV infection and introduces HCV events related to cholesterol metabolism and applications for cholesterol metabolism as a therapeutic target. HCV appears to alter host lipid metabolism into its preferable state, which is clinically recognized as steatosis and hypocholesterolemia. While hepatic fatty acid and triglyceride syntheses are upregulated in chronic hepatitis C patients, no direct evidence of increased hepatic de novo cholesterol biosynthesis has been obtained. Impaired VLDL secretion from hepatocytes is suggested to increase intracellular cholesterol concentrations, which may lead to hypocholesterolemia. Clinically, lower serum cholesterol levels are associated with lower rates of sustained virological responses (SVR) to pegylated-interferon plus ribavirin therapy, but the reason remains unclear. Clinical trials targeting HMG-CoA reductase, the rate-limiting enzyme in the cholesterol biosynthetic pathway, are being conducted using statins. Anti-HCV actions by statins appear to be caused by the inhibition of geranylgeranyl pyrophosphate synthesis rather than their cholesterol lowering effects. Other compounds that block various steps of cholesterol metabolic pathways have also been studied to develop new strategies for the complete eradication of this virus.

Sustained virological response of patients with hepatitis C virus genotype 2 depends on pegylated interferon compliance

AIM

  Patients infected with hepatitis C virus (HCV) genotype 2 are more sensitive to interferon (IFN) therapy than those infected with genotype 1, but 10-20% of patients do not achieve a sustained viral response (SVR) to combination therapy with pegylated (PEG) IFN and ribavirin (RBV). This study examines the prognostic factors associated with SVR in patients infected with HCV genotype 2 treated with PEG IFN and RBV.

METHODS

  We treated 149 patients with chronic hepatitis C caused by HCV genotype 2. The patients received s.c. PEG IFN-α-2b (1.5 µg/kg) and a weekly weight-adjusted dose of RBV (600, 800 and 1000 mg per <60, 60-80 and >80 kg, respectively) for 24 weeks and then prognostic factors associated with the SVR were examined.

RESULTS

  Among the 149 patients, 138 completed the combination therapy and a sustained viral response was achieved in 71.8% of them. Univariate analysis showed that age, as well as mean RBV and PEG IFN doses were factors affecting the SVR (P = 0.012, =0.021, =0.014). Multivariate analysis identified age and mean PEG IFN dose (P = 0.021, =0.018, respectively) as factors involved in the SVR, but not mean RBV dose.

CONCLUSION

  The SVR of patients infected with HCV genotype 2 depended on the dosage of PEG IFN, but not of RBV. Selecting sufficient doses of PEG IFN for combination with RBV is critical for treating such patients.

Low-density lipoprotein receptor genotyping enhances the predictive value of IL28B genotype in HIV/hepatitis C virus-coinfected patients

OBJECTIVE

The aims of this study were to appraise the predictive value of variations in a single-nucleotide polymorphism (SNP) in the low-density lipoprotein receptor (LDLR) gene for sustained virological response (SVR) to pegylated interferon (Peg-IFN) and ribavirin (RBV), as well as to analyze the relationship between LDLR genotype and other predictors of SVR, particularly IL28B genotype, in patients coinfected with HIV and hepatitis C virus (HCV).

METHODS

One hundred and eighty-four HIV/HCV-coinfected, treatment-naive patients with chronic HCV infection, who received Peg-IFN and RBV, were included. Variations in the SNP rs14158 and rs12979860 were tested by Taqman PCR assay.

RESULTS

Twenty-eight (38%) patients with rs14158 TT/TC and 61 (55%) with CC (P = 0.028) achieved SVR. The rates of SVR in patients with rs14158 TT/TC and with CC harboring HCV 1-4 were 20 and 41% (P = 0.020), respectively, and, in those with HCV genotype 2-3, 75 and 84% (P = 0.513), respectively. Patients with rs14158 CC showed less commonly plasma HCV-RNA load at least 600000 IU/ml (57 vs. 71%, P = 0.047) and lower likelihood of relapse (13 vs. 30%, P = 0.023). In patients with HCV genotype 1-4, the rates of SVR according to the combination of IL28B/LDLR genotypes were: CC/CC = 69%; CC/non-CC: 30%; non-CC/CC: 25%; non-CC/non-CC: 14% (P < 0.001).

CONCLUSION

Variations in rs14158 are associated with SVR to Peg-IFN and RBV in HIV/HCV-coinfected patients harboring HCV genotype 1-4. LDLR and IL28B genotypes seem to have a synergistic effect on SVR. The combined use of LDLR and IL28B genotypes in routine clinical practice could enhance the predictive value of IL28B genotype alone.

Amino acid substitution in HCV core/NS5A region and genetic variation near IL28B gene affect treatment efficacy to interferon plus ribavirin combination therapy

OBJECTIVE

To evaluate predictive factors of treatment efficacy to interferon (IFN)/ribavirin in patients infected with HCV genotype 1b (HCV-1b).

METHODS

This study investigated pretreatment predictors, including viral- (aa substitutions in core aa 70/91 and NS5A-ISDR/IRRDR) and host-related factors (genetic variation near IL28B gene), to 48-week IFN/ribavirin in 490 Japanese adults infected with HCV-1b.

RESULTS

The proportion of patients who showed end-of-treatment response (ETR), sustained virological response (SVR), and SVR after ETR was 76, 54, and 76%, respectively. There was a significant positive correlation between the number of aa substitutions in ISDR and those in IRRDR. Concerning the substitution of core aa 91, the number of aa substitutions in ISDR/IRRDR of patients with Leu91 was significantly higher than that of patients with Met91. Furthermore, levels of viremia were influenced by aa substitutions in core aa 91 and ISDR/IRRDR. By multivariate analysis, rs8099917 genotype was an important predictor of ETR and SVR. With regard to viral factors, core aa 70/91 was an important predictor of ETR, and SVR after ETR. ISDR was an important predictor of SVR, and SVR after ETR.

CONCLUSION

aa substitution in core/NS5A region and genetic variation near IL28B were important predictors of treatment efficacy to IFN/ribavirin.

Antiviral effects of peginterferon alpha-2b and ribavirin following 24-week monotherapy of telaprevir in Japanese hepatitis C patients

BACKGROUND/AIMS

Anemia is commonly observed as a side effect in a treatment with protease inhibitors combined with peginterferon alpha and ribavirin for hepatitis C virus infection. This study assessed the safety, tolerability, viral kinetics, and selection of variants in telaprevir monotherapy for 24 weeks, and outcomes of the off-study treatment with peginterferon alpha-2b and ribavirin among Japanese female patients at a median age of 54 years who were difficult to treat with the standard therapy (peginterferon alpha-2b and ribavirin) alone in Japan.

METHODS

Four treatment-naïve patients with chronic hepatitis C virus subtype 1b infection received telaprevir (750 mg every 8 h) alone for 24 weeks. All patients then started the off-study treatment with peginterferon alpha-2b and ribavirin. Safety, tolerability, hepatitis C virus RNA levels, and emergence of telaprevir-resistant variants were monitored.

RESULTS

During the 24 weeks of telaprevir monotherapy, there was no discontinuation due to adverse events, but 2 patients stopped the intake at weeks 6 and 15 because of viral breakthrough. Emergence of telaprevir-resistant variants was observed in 3 patients who showed viral breakthrough. These variants were eliminated by the off-study treatment, and sustained virological response was achieved in all patients.

CONCLUSIONS

Anemia was manageable by carefully adjusting the ribavirin dosage in the standard therapy that followed telaprevir monotherapy. This sequential regimen seems to be safer and more tolerable than the triple combination of telaprevir, peginterferon alpha, and ribavirin, especially among elderly females with low baseline hemoglobin.

Impact of ribavirin dose reduction on the efficacy of pegylated interferon plus ribavirin combination therapy for elderly patients infected with genotype 1b and high viral loads

AIM

  To examine the impact of ribavirin dose reduction on the efficacy of pegylated interferon (PEG IFN) plus ribavirin combination therapy for elderly patients infected with genotype 1b and high viral loads.

METHODS

  A total of 72 patients, over 65 years old, were recruited for this study. Patients were divided into groups receiving either 600-800 mg of ribavirin according to bodyweight (Group 1, n = 36) or 400 mg of ribavirin (Group 2, n = 36) plus 1.5 µg/kg (range: 1.3-2.0 µg/kg) of PEG IFN-α-2b for 48 weeks.

RESULTS

  Total ribavirin doses were administrated at 9.80 ± 2.39 mg/kg per day (3.29 ± 0.80 g/kg) for Group 1 and 5.87 ± 1.82 mg/kg per day (1.97 ± 0.61 g/kg) for Group 2 (P < 0.001). According to the total clearance (CL/F) of ribavirin, 34 of 36 patients in Group 1 received over-doses of ribavirin. In contrast, numbers of those receiving equivalent doses of ribavirin were two of 36 patients in Group 1 and 36 of 36 patients in Group 2, respectively (P < 0.001). End-of-treatment response (ETR) rates were observed in 23 of 36 patients (63.9%) in the standard ribavirin dose protocol and in 23 of 36 patients (63.9%) in the reduction ribavirin dose protocol (NS). Sustained virological response (SVR) rates were observed in 11 of 36 patients (30.6%) in the standard ribavirin dose protocol, and in 13 of 36 patients (36.1%) in the reduced ribavirin dose protocol (NS).

CONCLUSION

  Reduction of ribavirin doses for elderly patients did not affect the outcome for the 48-week combination therapy.

IL28B but not ITPA polymorphism is predictive of response to pegylated interferon, ribavirin, and telaprevir triple therapy in patients with genotype 1 hepatitis C

BACKGROUND

Pegylated interferon, ribavirin, and telaprevir triple therapy is a new strategy expected to eradicate the hepatitis C virus (HCV) even in patients infected with difficult-to-treat genotype 1 strains, although adverse effects, such as anemia and rash, are frequent.

METHODS

We assessed efficacy and predictive factors for sustained virological response (SVR) for triple therapy in 94 Japanese patients with HCV genotype 1. We included recently identified predictive factors, such as IL28B and ITPA polymorphism, and substitutions in the HCV core and NS5A proteins.

RESULTS

Patients treated with triple therapy achieved comparatively high SVR rates (73%), especially among treatment-naive patients (80%). Of note, however, patients who experienced relapse during prior pegylated interferon plus ribavirin combination therapy were highly likely to achieve SVR while receiving triple therapy (93%); conversely, prior nonresponders were much less likely to respond to triple therapy (32%). In addition to prior treatment response, IL28B SNP genotype and rapid viral response were significant independent predictors for SVR. Patients with the anemia-susceptible ITPA SNP rs1127354 genotype typically required ribavirin dose reduction earlier than did patients with other genotypes.

CONCLUSIONS

Analysis of predictive factors identified IL28B SNP, rapid viral response, and transient response to previous therapy as significant independent predictors of SVR after triple therapy.

IL28 variation affects expression of interferon stimulated genes and peg-interferon and ribavirin therapy

BACKGROUND & AIMS

Common genetic variation within the IL28 locus has been found to influence the effect of peg-interferon and ribavirin combination therapy against chronic hepatitis C virus (HCV) infection. Expression of IL28 in peripheral blood cells has been reported to be higher in patients with IL28 SNP genotypes associated with favorable response.

METHODS

We analyzed 52 liver and 114 blood samples obtained from patients with HCV genotype 1b. We used reverse transcription-real time polymerase chain reaction to analyze expression levels of IL28 and several interferon stimulated genes (ISGs), including MxA, double stranded RNA dependent protein kinase (PKR), 2'-5' oligo-nucleotide synthetase (OAS1), ISG15, and SOCS1.

RESULTS

Interestingly, expression of IL28 was significantly lower in patients with the response-favorable rs8099917 TT genotype compared to those with TG or GG genotypes (p<0.005). In hepatic cells, expression of MxA, PKR, OAS1, and ISG15 were also significantly lower in rs8099917 TT patients (p<0.001, p=0.005, p=0.001, p<0.001, respectively), whereas in peripheral blood mononuclear cells ISG expression levels did not differ significantly. Among patients treated with peg-interferon plus ribavirin therapy, liver mRNA levels of IL28, MxA, PKR, OAS1, and ISG15 were significantly or marginally lower in responders who became negative for HCV RNA (p=0.001, 0.004, 0.014, 0.051, and 0.015, respectively).

CONCLUSIONS

Expression levels of ISGs are differentially regulated in the liver and peripheral blood. The mechanism underlying the expression levels of IL28 and ISGs and the correlation with the effect of the therapy should be further investigated.

Common genetic polymorphism of ITPA gene affects ribavirin-induced anemia and effect of peg-interferon plus ribavirin therapy

An association between a single nucleotide polymorphism (SNP) in the inosine triphosphate pyrophosphatase (ITPA) gene and reduction of hemoglobin during peg-interferon plus ribavirin combination therapy for patients with chronic hepatitis C virus (HCV) infection has been reported. However, the effect of the SNP on outcome of therapy has not been fully elucidated. Factors associated with anemia during combination therapy, including rs1127354 genotype, were analyzed in 1,002 treated patients. The effect of the SNP on outcome of therapy was analyzed in a subset of 830 patients with genotype 1. A rapid initial decrease in hemoglobin levels was observed in patients with rs1127354 genotype CC compared with a slow decrease in non-CC patients. Cumulative reduction of ribavirin was significantly more frequent in genotype CC patients than non-CC patients (odds ratio 1.928, P = 8.6 × 10(-8) ). The frequency of patients who received at least the recommended 80% of scheduled ribavirin was significantly lower among genotype CC patients, especially among those who had pretreatment hemoglobin levels between 13.5 and 15 g/dl (P < 0.03), and the sustained viral response rate was significantly lower in this group of patients. Independent predictive factors for sustained virological response included a SNP in the IL28B locus (rs809991), age, fibrosis, ITPA SNP rs1127354 as well as pretreatment hemoglobin levels. Our data suggests that measures to prevent anemia should be considered for patients who have pretreatment hemoglobin levels less than 13.5 g/dl or who have rs1127354 genotype CC and pretreatment hemoglobin levels between 13.5 and 15 g/dl.

Prediction of response to peginterferon-alfa-2b plus ribavirin therapy in Japanese patients infected with hepatitis C virus genotype 1b

Variation at the IL-28B locus was recently reported to be a significant predictive factor of viral response to pegylated-interferon plus ribavirin combination therapy against chronic hepatitis C. Predictive factors for the effect of therapy, including IL-28B polymorphism rs8099917 and viral and clinical factors were investigated. A total of 288 patients were enrolled who were chronically infected with hepatitis C virus (HCV) genotype 1b and treated with combination therapy. Among them, 87 patients completed 48 weeks of therapy without dose reduction or discontinuation. In multivariate regression analysis, the rs8099917 TT genotype was the only independent factor significantly associated with sustained viral response (P = 0.016, OR 61.5), whereas substitutions at amino acid 70 (aa 70) of the HCV core protein (P = 0.038, OR 5.9) and non-TT genotypes (P = 0.002, OR 17.2) were associated with nonvirological response. Both factors were also associated with viral dynamics during the initial stage of the therapy. Correlation analysis revealed that rs8099917 genotype was correlated with γ-glutamyl transpeptidase, hyaluronic acid, and HCV core aa 70. In conclusion, host (IL-28B polymorphism) and viral (aa 70) factors independently affect response to combination therapy.

Dysregulation of IFN system can lead to poor response to pegylated interferon and ribavirin therapy in chronic hepatitis C

BACKGROUND

Despite being expensive, the standard combination of pegylated interferon (Peg-IFN)-α and ribavirin used to treat chronic hepatitis C (CH) results in a moderate clearance rate and a plethora of side effects. This makes it necessary to predict patient outcome so as to improve the accuracy of treatment. Although the antiviral mechanism of genetically altered IL28B is unknown, IL28B polymorphism is considered a good predictor of IFN combination treatment outcome.

METHODOLOGY

Using microarray, we quantified the expression profile of 237 IFN related genes in 87 CH liver biopsy specimens to clarify the relationship between IFN pathway and viral elimination, and to predict patients' clinical outcome. In 72 out of 87 patients we also analyzed IL28B polymorphism (rs8099917).

PRINCIPAL FINDINGS

Five IFN related-genes (IFI27, IFI 44, ISG15, MX1, and OAS1) had expression levels significantly higher in nonresponders (NR) than in normal liver (NL) and sustained virological responders (SVR); this high expression was also frequently seen in cases with the minor (TG or GG) IL28B genotype. The expression pattern of 31 IFN related-genes also differed significantly between NR and NL. We predicted drug response in NR with 86.1% accuracy by diagonal linear discriminant analysis (DLDA).

CONCLUSION

IFN system dysregulation before treatment was associated with poor IFN therapy response. Determining IFN related-gene expression pattern based on patients' response to combination therapy, allowed us to predict drug response with high accuracy. This method can be applied to establishing novel antiviral therapies and strategies for patients using a more individual approach.

Impact of amino acid substitutions in hepatitis C virus genotype 1b core region on liver steatosis and glucose tolerance in non-cirrhotic patients without overt diabetes

BACKGROUND AND AIM

The hepatitis C virus (HCV) core protein induces hepatic steatosis and glucose intolerance in transgenic mice. The aim of this study was to clarify the impact of mutations in the HCV core region on hepatic steatosis and glucose tolerance in patients with chronic hepatitis C.

METHODS

Seventy-four Japanese patients (27 men, 47 women; mean age, 61.9 years) infected with HCV 1b with high viral load (>5 log IU/ml), without cirrhosis and overt diabetes, were enrolled. Substitutions in amino acids 70 and 91 of the HCV genotype 1b core region, the percentage of hepatic steatosis by liver histology, and glucose tolerance evaluated by the oral glucose tolerance test were investigated in all patients.

RESULTS

Steatosis was observed in 40 patients (54%). Transaminase activities, γ-glutamyl-transpeptidase, serum ferritin levels, homeostasis model assessment of insulin resistance index, and substitutions of amino acid 70 were significantly associated with the presence of steatosis, upon univariate analysis. Glucose intolerance was more prevalent in patients with steatosis (63%) than in those without steatosis (32%, P = 0.012). Multivariate analysis showed that substitution of amino acid 70 (odds ratio: 4.924; 95% confidence interval: 1.442-16.815; P = 0.014) and glucose intolerance (odds ratio: 3.369; 95% confidence interval: 1.076-10.544; P = 0.040) were independent factors related to liver steatosis. Levels of plasma glucose and serum insulin after glucose load were similar between patients with and without substitutions of amino acids 70 and 91.

CONCLUSIONS

Amino acid substitutions in the HCV genotype 1b core region are associated with hepatic steatosis in patients with chronic hepatitis C, independent of glucose intolerance.

IL-28B predicts response to chronic hepatitis C therapy--fine-mapping and replication study in Asian populations

Type I interferon (IFN) is used for the treatment of chronic hepatitis C virus (HCV) infection. Despite advances in antiviral therapy, a large proportion of patients remain infected following current therapies. Through a genome-wide scan, we found two variants (rs8099917 and rs12979860) in the IL-28B locus that affect the outcome of PEG-IFN and ribavirin combination therapy, consistent with recent studies (P = 6.52×10(-8); odds ratio 2.46 and P = 8.63×10(-8), odds ratio 2.40, respectively). Significant associations were also observed in the case of IFN monotherapy for HCV genotypes 1b and 2a. With rs8099917, HCV genotype 1b patients had a significantly lower frequency of the favourable genotype (86.6 %) compared with healthy controls (91.7 %), and HCV genotype 2a patients had an intermediate frequency (89.9 %). Similar results were found for rs12979860. Fine-mapping analysis revealed that rs8099917 had the strongest association with treatment outcome and 14 others, including four novel single nucleotide polymorphisms, had comparable associations. Haplotype analysis revealed that none of the haplotypes showed stronger association than any single marker. Early non-responders who could not achieve 2 log viral decline during the first 12 weeks of treatment had higher odds ratios for these two variants. The favourable allele of rs8099917 is also associated with initial viral decline at 2 and 4 weeks following the start of therapy. Multivariate analysis of PEG-IFN and ribavirin-treated patients showed that rs8099917 genotype, viral load, fibrosis and age were significant predictors of response to therapy. Common variation at the IL-28B locus is predictive of various IFN-based therapies for HCV independent of regimen or HCV genotype.

Open-label, ascending dose, prospective cohort study evaluating the antiviral efficacy of Rosuvastatin therapy in serum and lipid fractions in patients with chronic hepatitis C

HMG CoA reductase inhibition suppresses in vitro HCV replication through depletion of cellular sterol proteins such as geranylgeraniol. Our aims were to prospectively evaluate the changes in serum and lipid fraction HCV RNA with Rosuvastatin in non-responder (NR) patients with CHC. A total of 11 patients with CHC genotype-1 received Rosuvastatin at 20 mg qd (weeks 0-4), 40 mg qd (weeks 5-12), with 4 week follow up. Lipid fractions were separated by a sucrose density gradient ultracentrifugation, HCV RNA determined at wks 0, 2, 4, 8, 12, 16 in serum, and in selected very low- (VLDF) to high-density (HDF) lipid fractions. A reduction in LDL and total cholesterol (TC) was not accompanied by significant decline in HCV RNA. At baseline, there was an inverse correlation between HDL and HCV RNA (ρ = -0.45, P = 0.036). At 20 mg, there was correlation between change (Δ) in TG and Δ HCV RNA (ρ = 0.75, P = 0.007), Δ ALT and Δ TC (ρ = -0.64, P = 0.03) and Δ LDL (ρ = -0.67, P = 0.02). At 40 mg, Δ TG maintained a positive correlation with Δ HCV RNA (ρ = 0.65, P = 0.03). There was a group difference for HCV RNA in relation to lipid fractions (P = 0.04) but not study time intervals (P = 0.17); mean log HCV RNA was greater in VLDF compared to HDF (5.81 ± 0.59 vs 5.06 ± 0.67, P = 0.0002) with no other differences to study time intervals (P = 0.099). Short-term Rosuvastatin monotherapy is not associated with significant changes in serum or lipid fraction HCV RNA in NR patients. HCV co-localizes with the lowest density lipid fractions in serum.

Analysis of interferon signaling by infectious hepatitis C virus clones with substitutions of core amino acids 70 and 91

Substitution of amino acids 70 and 91 in the hepatitis C virus (HCV) core region is a significant predictor of poor responses to peginterferon-plus-ribavirin therapy, while their molecular mechanisms remain unclear. Here we investigated these differences in the response to alpha interferon (IFN) by using HCV cell culture with R70Q, R70H, and L91M substitutions. IFN treatment of cells transfected or infected with the wild type or the mutant HCV clones showed that the R70Q, R70H, and L91M core mutants were significantly more resistant than the wild type. Among HCV-transfected cells, intracellular HCV RNA levels were significantly higher for the core mutants than for the wild type, while HCV RNA in culture supernatant was significantly lower for these mutants than for the wild type. IFN-induced phosphorylation of STAT1 and STAT2 and expression of the interferon-inducible genes were significantly lower for the core mutants than for the wild type, suggesting cellular unresponsiveness to IFN. The expression level of an interferon signal attenuator, SOCS3, was significantly higher for the R70Q, R70H, and L91M mutants than for the wild type. Interleukin 6 (IL-6), which upregulates SOCS3, was significantly higher for the R70Q, R70H, and L91M mutants than for the wild type, suggesting interferon resistance, possibly through IL-6-induced, SOCS3-mediated suppression of interferon signaling. Expression levels of endoplasmic reticulum (ER) stress proteins were significantly higher in cells transfected with a core mutant than in those transfected with the wild type. In conclusion, HCV R70 and L91 core mutants were resistant to interferon in vitro, and the resistance may be induced by IL-6-induced upregulation of SOCS3. Those mechanisms may explain clinical interferon resistance of HCV core mutants.

Factors predictive of sustained virological response following 72 weeks of combination therapy for genotype 1b hepatitis C

BACKGROUND

Treatment of genotype 1b chronic hepatitis C virus (HCV) infection has been improved by extending peg-interferon plus ribavirin combination therapy to 72 weeks, but predictive factors are needed to identify those patients who are likely to respond to long-term therapy.

METHODS

We analyzed amino acid (aa) substitutions in the core protein and the interferon sensitivity determining region (ISDR) of nonstructural protein (NS) 5A in 840 genotype 1b chronic hepatitis C patients with high viral load. We used logistic regression and classification and regression tree (CART) analysis to identify predictive factors for sustained virological response (SVR) for patients undergoing 72 weeks of treatment.

RESULTS

When patients were separately analyzed by treatment duration using multivariate logistic regression, several factors, including sex, age, viral load, and core aa70 and ISDR substitutions (P = 0.0003, P = 0.02, P = 0.01, P = 0.0001, and P = 0.0004, respectively) were significant predictive factors for SVR with 48 weeks of treatment, whereas age, previous interferon treatment history, and ISDR substitutions (P = 0.03, P = 0.01, and P = 0.02, respectively) were the only significant predictive factors with 72 weeks of treatment. Using CART analysis, a decision tree was generated that identified age, cholesterol, sex, treatment length, and aa70 and ISDR substitutions as the most important predictive factors. The CART model had a sensitivity of 69.2% and specificity of 60%, with a positive predictive value of 68.4%.

CONCLUSIONS

Complementary statistical and data mining approaches were used to identify a subgroup of patients likely to benefit from 72 weeks of therapy.

Mutations in the core and NS5A region of hepatitis C virus genotype 1b and correlation with response to pegylated-interferon-alpha 2b and ribavirin combination therapy

Mutations in two regions of hepatitis C virus (HCV) have been implicated in influencing response to interferon (IFN) therapy. Substitutions in the NS5A region of HCV have been associated with response to IFN therapy, and this region has been known as the IFN sensitivity-determining region (ISDR). The mutations in the core region of HCV have also been reported to predict IFN response. The aim of this study was to investigate whether amino acid substitutions in the core region and ISDR among patients with HCV genotype 1b affect the response to IFN therapy. A total of 213 patients who completed IFN treatment were randomly selected. All patients received pegylated-IFN-alpha 2b once each week, plus oral ribavirin daily for 48 weeks. Of the 213 patients, 117 (54.9%) showed early virologic response (EVR), with HCV-negativity, at 12 weeks. Factors related to EVR on multivariate analysis were non-Gln70 and Leu91 in the core region, and ISDR mutant-type. One hundred and two (47.9%) showed a sustained virologic response (SVR). SVR occurred more frequently in patients without Gln70 (55.4%) than in those with Gln70 (21.3%) (P < 0.0001). SVR was achieved in 43.6% of patients with wild-type ISDR and 62.5% of patients with mutant-type (P = 0.0227). Of the 34 patients who simultaneously had non-Gln70 and mutant-type ISDR, 26 (76.5%) achieved SVR. Factors related to SVR on multivariate analysis were non-Gln70 and ISDR mutant-type. In conclusion, amino acid substitutions in the core region and ISDR were useful for predicting the response to IFN in patients with HCV genotype 1b.

Pre-treatment prediction of response to pegylated-interferon plus ribavirin for chronic hepatitis C using genetic polymorphism in IL28B and viral factors

BACKGROUND & AIMS

Pegylated interferon and ribavirin (PEG-IFN/RBV) therapy for chronic hepatitis C virus (HCV) genotype 1 infection is effective in 50% of patients. Recent studies revealed an association between the IL28B genotype and treatment response. We aimed to develop a model for the pre-treatment prediction of response using host and viral factors.

METHODS

Data were collected from 496 patients with HCV genotype 1 treated with PEG-IFN/RBV at five hospitals and universities in Japan. IL28B genotype and mutations in the core and IFN sensitivity determining region (ISDR) of HCV were analyzed to predict response to therapy. The decision model was generated by data mining analysis.

RESULTS

The IL28B polymorphism correlated with early virological response and predicted null virological response (NVR) (odds ratio=20.83, p<0.0001) and sustained virological response (SVR) (odds ratio=7.41, p<0.0001) independent of other covariates. Mutations in the ISDR predicted relapse and SVR independent of IL28B. The decision model revealed that patients with the minor IL28B allele and low platelet counts had the highest NVR (84%) and lowest SVR (7%), whereas those with the major IL28B allele and mutations in the ISDR or high platelet counts had the lowest NVR (0-17%) and highest SVR (61-90%). The model had high reproducibility and predicted SVR with 78% specificity and 70% sensitivity.

CONCLUSIONS

The IL28B polymorphism and mutations in the ISDR of HCV were significant pre-treatment predictors of response to PEG-IFN/RBV. The decision model, including these host and viral factors may support selection of optimum treatment strategy for individual patients.

Pretreatment prediction of response to peginterferon plus ribavirin therapy in genotype 1 chronic hepatitis C using data mining analysis

BACKGROUND

This study aimed to develop a model for the pre-treatment prediction of sustained virological response (SVR) to peg-interferon plus ribavirin therapy in chronic hepatitis C.

METHODS

Data from 800 genotype 1b chronic hepatitis C patients with high viral load (>100,000 IU/ml) treated by peg-interferon plus ribavirin at 6 hospitals in Japan were randomly assigned to a model building (n = 506) or an internal validation (n = 294). Data from 524 patients treated at 29 hospitals in Japan were used for an external validation. Factors predictive of SVR were explored using data mining analysis.

RESULTS

Age (<50 years), alpha-fetoprotein (AFP) (<8 ng/mL), platelet count (≥ 120 × 10(9)/l), gamma-glutamyltransferase (GGT) (<40 IU/l), and male gender were used to build the decision tree model, which divided patients into 7 subgroups with variable rates of SVR ranging from 22 to 77%. The reproducibility of the model was confirmed by the internal and external validation (r (2) = 0.92 and 0.93, respectively). When reconstructed into 3 groups, the rate of SVR was 75% for the high probability group, 44% for the intermediate probability group and 23% for the low probability group. Poor adherence to drugs lowered the rate of SVR in the low probability group, but not in the high probability group.

CONCLUSIONS

A decision tree model that includes age, gender, AFP, platelet counts, and GGT is useful for predicting the probability of response to therapy with peg-interferon plus ribavirin and has the potential to support clinical decisions regarding the selection of patients for therapy.

Predictive value of the IL28B polymorphism on the effect of interferon therapy in chronic hepatitis C patients with genotypes 2a and 2b

BACKGROUND & AIMS

Common IL28B locus polymorphisms (SNPs rs8099917 and rs12979860) have been reported to affect peg-interferon plus ribavirin combination therapy (PEG-RBV) for hepatitis C virus (HCV) genotype 1b, but few reports have examined their effect on other two common genotypes, 2a and 2b.

METHODS

We analyzed predictive factors for sustained virological response (SVR) in a retrospective study of 719 patients with either genotype 2a (530) or 2b (189). Of these patients, 160 were treated with PEG-RBV and 559 were treated with interferon monotherapy. We evaluated predictive factors including HCV RNA, histological findings, IL28B SNP genotypes (rs8099917, rs12979860, and rs12980275), and the effect of treatment regimen and prior treatment history.

RESULTS

HCV RNA viral load, treatment regimen, and rs8099917 genotypes independently contributed to the effect of the therapy. For patients treated with PEG-RBV, rs8099917 and viral load were independent predictive factors for SVR in genotype 2b but not in genotype 2a. Conversely, in patients treated with interferon monotherapy, viral load and rs8099917 were independent predictive factors for SVR in genotype 2a but not in genotype 2b. The favorable rs8099917 genotype is also associated with a steep decline in viral load by the second week of treatment.

CONCLUSIONS

Initial viral load and rs8099917 genotype are significant independent predictors of SVR in genotype 2 patients.

Polymorphisms of hepatitis C virus non-structural protein 5A and core protein and clinical outcome of pegylated-interferon/ribavirin combination therapy

OBJECTIVE

Hepatitis C virus (HCV genome) polymorphisms are thought to influence the outcome of pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy. This study aimed to examine non-structural protein 5A (NS5A) polymorphisms, e.g. IFN/RBV resistance-determining region (IRRDR) and IFN sensitivity-determining region (ISDR), and core protein polymorphism as predictive therapeutic markers.

METHODS

Pretreatment sequences of NS5A and core regions were analyzed in 68 HCV-1b-infected patients treated with PEG-IFN/RBV.

RESULTS

Of 24 patients infected withHCV having an IRRDR with 6 or more mutations (IRRDR≥6), 18 (75%) patients achieved sustained virological response (SVR), whereas only 11 (25%) of 44 patients infected with HCV having IRRDR≤5 did. IRRDR≥6 was significantly associated with SVR (p < 0.0001). On the other hand, ISDR≥2 was significantly associated with relapse (either before [breakthrough] or after end-of-treatment response [ETR[-]relapse]) (p < 0.05) and a point mutation of the core protein from Arg to Gln at position 70 (Gln(70)) was significantly associated with null-response (p < 0.05). Multivariate analysis identified IRRDR≥6 as the only viral genetic factor that independently predicted SVR.

CONCLUSION

NS5A (IRRDR and ISDR) and core protein polymorphisms are associated with the outcome of PEG-IFN/RBV therapy for chronic hepatitis C. In particular, IRRDR≥6 is a useful marker for prediction of SVR.

Simple formula to predict response to peginterferon alpha2b and ribavirin combination therapy in genotype 1 chronic hepatitis C patients with high viral loads

AIM

  We advocate a simple formula which can conveniently predict the outcome of Peg-interferon (IFN) alpha2b and ribavirin (RBV) combination therapy for genotype 1 chronic hepatitis C (CH-C) with high viral load.

METHODS

  A total of 338 (group A: 230, Group B: 108) genotype 1 CH-C patients treated with Peg-IFN alfa-2b and RBV were enrolled. Clinical parameters differing significantly between sustained virological responders (SVRs) and non-SVRs in group A were categorized, then a simple formula to predict SVR was constructed and re-evaluated in group B. Another formula containing hepatitis C virus amino acid mutations/substitutions also was constructed.

RESULTS

  In group A, gender and HCV RNA load <1000 KIU were significant predictors of SVR by multivariate logistic regression analysis. A simple formula was constructed (formula A): male gender (point 2) + HCV RNA load <1000 KIU (3) + platelet counts ≥15 × 10(4) /mm(3) (1) + age <60 (1). In group A, score (0-1) predicted SVR rate 23.8% (2-4): 48.1% and (5-7): 70.2%. According to this formula, score (0-1) predicted SVR rate 7.1% (2-4): 38.6%, and (5-7): 70.3% in group B. Information on HCV amino acid mutations/substitutions seemed to add some accuracy.

CONCLUSIONS

  This simple formula can be used to roughly determine, at the patients' first/second visit, the probability of response to Peg-IFN alpha2b and RBV combination therapy for genotype 1 CH-C with high viral load.

Reappraisal of the importance of mutations in the NS5A-PKR-binding domain of hepatitis C-1b virus in the era of optimally individualized therapy

Past studies have reported that mutations in the protein kinase R-binding domain (PKRBD) sequences of hepatitis C virus (HCV) NS5A proteins are correlated with response to fixed-duration interferon (IFN)-based therapy in patients infected with HCV-1b. In this study, we investigated whether the substitutions in PKRBD, including the IFN sensitivity-determining region (ISDR) and 26 additional downstream amino acids from ISDR, will have effects upon patients infected with chronic HCV-1b in the era of individualized therapy with peginterferon and ribavirin. Thirty-seven patients were treated with optimally tailored therapy guided by baseline viral load combined with rapid and early virological responses while 23 patients were treated without guidance and/or assigned suboptimal treatment duration. The amino acid sequences of the PKRBD were determined by PCR and sequencing. The overall sustained virological response (SVR) rate of patients who received optimally individualized therapy was 78.4%, which was better than the SVR rate of patients who received suboptimal therapy (47.8%, P = 0.015). Multivariate analysis showed that optimally individualized therapy (P = 0.019) and 80/80/80 adherence (P = 0.006) were independent favourable predictors of SVR in the entire cohort. Further sub-analysis of the predictive factors of SVR in patients treated with optimally individualized therapy showed that mutations in the 26-amino acid downstream from the ISDR (P = 0.024) were the only independent predictor of SVR. We concluded that mutations in 26-amino acid downstream portion from the ISDR remained a prognosticator of SVR in the era of optimally tailored therapy.