An IL28B genotype-based clinical prediction model for treatment of chronic hepatitis C

Assessment of IL-28: rs12979860 and rs8099917 Polymorphisms in a Cohort of Cuban Chronic HCV Genotype 1b Patients

Hepatitis C virus (HCV) is a significant global public health problem with >185 million infections worldwide. A series of genome-wide association studies (GWAS) has identified IL-28B polymorphisms as a predictor of sustained virologic response (SVR), as well as spontaneous clearance in chronic HCV genotype 1 patients. The objective of this work was to evaluate the prevalence of IL-28B rs12979860 and rs8099917 polymorphisms in Cuban chronic HCV patients. The study cohort included 73 chronic HCV patients treated with concomitant administration of CIGB-230 and nonpegylated IFN-α plus ribavirin (non-pegIFN-α/R) antiviral therapy. The genotype distribution of IL-28B rs12979860CC, -CT, and -TT was 29, 41, and 30%, respectively, and the distribution for rs8099917TT, -TG, and -GG was 63, 31, and 5%, respectively. The allele frequencies for rs12979860C and -T alleles were 51 and 49%, respectively, and for rs8099917G and -T alleles, the values were 21 and 79%, respectively. SVR rates were 55, 42, and 35% for rs12979860CC, -CT, and -TT, respectively, and 52, 30, and 25% for rs8099917TT, -GT, and -GG, respectively. The combined assessment of both single nucleotide polymorphisms (SNPs) resulted in 3 major genotypes (rs12979860CC/rs8099917TT, rs12979860CT/rs8099917TT, and rs12979860CT/rs8099917GG) with a frequency of 30.1, 21.9, and 20.5%, respectively. In patients with heterozygous variant rs12979860CT, the additional genotyping of rs8099917 contributed to increase the SVR rate. It is concluded that in Cuban HCV-infected patients, the responder homogeneous variant rs8099917TT is the most frequent genotype. The simultaneous genotyping of 2 IL-28B SNPs could improve the prediction of SVR contributing to better therapeutic decisions and treatment management.

Pretreatment Predictors of Response to PegIFN-RBV Therapy in Egyptian Patients with HCV Genotype 4

BACKGROUND

Egypt has the highest prevalence of a difficult to treat chronic hepatitis C virus (HCV), genotype 4. Pretreatment factors could guide individualization of therapy which aids in treatment optimization and interleukin IL28B gene polymorphism has been shown to closely relate to HCV treatment response. Polymorphisms in genes encoding inhibitors of T-cell response, which have role in disease progression as Programmed Cell Death 1 (PD-1), and Cytotoxic T-Lymphocytes Antigen-4 (CTLA-4), could be candidate markers predicting treatment response.

METHODS

This cohort study consisted of 200 chronic HCV genotype 4 infected patients treated with PegIFN α-2a and RBV in 2 hepatology centers. Genotyping of the polymorphisms in the IL28B gene region (rs12979860), PD1.3 (rs11568821) and CTLA-4 (rs231775) was performed on DNA collected from each patient using TaqMan® genotyping assay. Groups were classified according to response into sustained virological responders (SVR), or non-responders (NR). A multivariate logistic regression analysis was used to identify potential markers, host pretreatment clinical and viral predictive factors including viral load, insulin resistance, and alpha fetoprotein (AFP) related to treatment response.

RESULTS

Our results showed that in a multivariate analyses IL28B C/C genotype was the most significant predictor for SVR (OR = 10.86; p<0.0001) followed by AFP (OR = 0.915; p = 0.001) then CTLA-4/G genotypes (OR = 1.948; p = 0.022). However, PD-1.3/A genotypes and platelets count were significantly related to response in univariate analysis only (OR = 1.973; p = 0.023; OR = 1.007; p = 0.009 respectively).

CONCLUSION

IL28B SNP, AFP level, and CTLA-4 SNP could be used in conjunction to predict treatment response in HCV genotype 4 infected Egyptian patients.

Genotype 3 is the predominant hepatitis C genotype in a multi-ethnic Asian population in Malaysia

BACKGROUND

Genotypes of hepatitis C virus (HCV) are distributed differently across the world. There is a paucity of such data in a multi-ethnic Asian population like Malaysia. The objectives of this study were to determine the distribution of HCV genotypes between major ethnic groups and to ascertain their association with basic demographic variables like age and gender.

METHODS

This was a cross-sectional prospective study conducted from September 2007 to September 2013. Consecutive patients who were detected to have anti-HCV antibodies in the University of Malaya Medical Centre were included and tested for the presence of HCV RNA using Roche Cobas Amplicor Analyzer and HCV genotype using Roche single Linear Array HCV Genotyping strip.

RESULTS

Five hundred and ninety-six subjects were found to have positive anti-HCV antibodies during this period of time. However, only 396 (66.4%) were HCV RNA positive and included in the final analysis. Our results showed that HCV genotype 3 was the predominant genotype with overall frequency of 61.9% followed by genotypes 1 (35.9%), 2 (1.8%) and 6 (0.5%). There was a slightly higher prevalence of HCV genotype 3 among the Malays when compared to the Chinese (P=0.043). No other statistical significant differences were observed in the distribution of HCV genotypes among the major ethnic groups. There was also no association between the predominant genotypes and basic demographic variables.

CONCLUSIONS

In a multi-ethnic Asian society in Malaysia, genotype 3 is the predominant genotype among all the major ethnic groups with genotype 1 as the second commonest genotype. Both genotypes 2 and 6 are uncommon. Neither genotype 4 nor 5 was detected. There is no identification of HCV genotype according to ethnic origin, age and gender.

Biomarkers in HCV Infection

Liver-related biomarkers have been developed and validated mainly in patients with chronic hepatitis C for the prediction of liver fibrosis or cirrhosis, which is a final pathway of chronic liver injury. They are noninvasive, traceable, and easy-to-use. Biomarkers provide implications related to screening, diagnosis, treatment, and prognosis of chronic hepatitis. For the improvement of performance and coverage, biomarker panels, imaging biomarkers, and even genetic biomarkers have been developed. With the advancement of genomics and proteomics, earlier and more precise prediction is expected in the near future. In this review, multiple biomarker panels for the estimation of the degree of fibrosis in chronic hepatitis C, biomarkers for the screening and diagnosis of hepatitis C, biomarkers for the treatment of hepatitis C, biomarkers for the prediction of complications related to the chronic hepatitis C, and future perspectives will be summarized.

Biomarkers of liver fibrosis

Liver fibrosis is the final common pathway for almost all causes of chronic liver injury. Liver fibrosis is now known to be a dynamic process having significant potential for resolution. Therefore, fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. As such, there is strong demand for reliable liver biomarkers that provide insight into disease etiology, diagnosis, therapy, and prognosis in lieu of more invasive approaches such as liver biopsy. Current diagnostic strategies range from use of serum biomarkers to more advanced imaging techniques including transient elastography and magnetic resonance imaging. In addition to these modalities, there are other approaches including the use of novel, but yet to be validated, biomarkers. In this chapter, we discuss the biomarkers of liver fibrosis including the use of invasive and noninvasive biomarkers and disease-specific biomarkers in various chronic liver diseases.

Processes to manage analyses and publications in a phase III multicenter randomized clinical trial

Background

The timely publication of findings in peer-reviewed journals is a primary goal of clinical research. In clinical trials, the processes leading to publication can be complex from choice and prioritization of analytic topics through to journal submission and revisions. As little literature exists on the publication process for multicenter trials, we describe the development, implementation, and effectiveness of such a process in a multicenter trial.

Methods

The Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial included a data coordinating center (DCC) and clinical centers that recruited and followed more than 1,000 patients. Publication guidelines were approved by the steering committee, and the publications committee monitored the publication process from selection of topics to publication.

Results

A total of 73 manuscripts were published in 23 peer-reviewed journals. When manuscripts were closely tracked, the median time for analyses and drafting of manuscripts was 8 months. The median time for data analyses was 5 months and the median time for manuscript drafting was 3 months. The median time for publications committee review, submission, and journal acceptance was 7 months, and the median time from analytic start to journal acceptance was 18 months.

Conclusions

Effective publication guidelines must be comprehensive, implemented early in a trial, and require active management by study investigators. Successful collaboration, such as in the HALT-C trial, can serve as a model for others involved in multidisciplinary and multicenter research programs.

Trial registration

The HALT-C Trial was registered with clinicaltrials.gov (NCT00006164).

Distribution of hepatitis C virus genotypes among patients with hepatitis C virus infection in hormozgan, iran

BACKGROUND

More than 170 million people in the world are infected with Hepatitis C virus (HCV). Determination of HCV genotype before starting the treatment is required, because HCV genotype affects the course of treatment and drug dosage.

OBJECTIVES

We aimed to evaluate HCV genotypes among patients with positive results for anti-HCV in Bandar Abbas from 2011 to 2012.

PATIENTS AND METHODS

Five hundred and nine consecutive patients with established chronic HCV infection referred to Behavioral Diseases Consultation Center, Blood Transfusion and Center for Special Diseases from March 2011 to March 2012 were enrolled in this cross sectional study. Five mL of peripheral blood was taken from precipitants and viral RNA extracted after plasma separation. Hepatitis C virus RNA was detected by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) assay and then HCV genotypes analyzed using restriction fragment length polymorphism (RFLP) method.

RESULTS

In overall, 509 patients enrolled to this study. The mean age of these patients was 38.87 ± 9.55 years ranging from 1 to 90 years. Routs of transmission were: 238 (46.7%) inject of substance, 149 (29.3%) unknown rout, 62 (12.2%) blood transfusion, 50 (9.8%) sexual contact, and 10 (2%) mother to child. Frequency of HCV genotypes were: 316 (62.1%) 1a, 117 (23%) 1b, and 76 (14.9%) 3a. there was no significant association between HCV genotypes and gender, educational degree, risk factor of Hepatitis C, job, monthly income, HIV infection, Hepatitis B virus (HBV) infection, Intravenous drug injection, and underlying disease (P > 0.05).

CONCLUSIONS

This results the same as many similar studies demonstrated that common HCV genotypes in Iranian patients were 1a, 3a and 1b, respectively. Patients with 1a and 1b genotypes have lower responses to interferon treatment, and it is reasonable to perform early screening to diagnose and determine HCV genotype for effective treatment and diagnose high-risk cases.

Serum peptides, represented by complement 3f des-arginine, are useful for prediction of the response to pegylated interferon-α plus ribavirin in patients with chronic hepatitis C

AIM

Biomarkers predicting sustained virological response (SVR) to pegylated interferon-α plus ribavirin (PEG IFN-α/RBV) were investigated.

METHODS

Peptides in pretreatment sera from 107 patients with hepatitis C virus (HCV) genotype 1 were comprehensively analyzed by mass spectrometry. Ion intensity of the peptides was used to generate discriminant models between the responders who achieved SVR (R) and the non-responders (NR) to PEG IFN-α/RBV.

RESULTS

In total, 107 peptides were detected in a training set (n = 23). A discriminant model using a peptide, complement 3f des-arginine (C3f-dR), showed sensitivity of 35% and specificity of 94% for SVR prediction in a testing set (n = 68). In all the R and NR (n = 96), an area under the receiver-operator curve (AUROC) of 0.64 in the C3f-dR model was increased to 0.78 by addition of platelet (PLT) counts (C3f-dR/PLT model). Another model using the 107 peptides (AUROC, 0.77) also showed higher AUROC (0.79) by addition of hemoglobin (Hb), body mass index (BMI) and age (107P/Hb/BMI/Age model). The sensitivity and specificity of the C3f-dR/PLT model were 59% and 88%, and those of the 107P/Hb/BMI/Age model were 70% and 92%, respectively. The C3f-dR/PLT model showed high AUROC (0.82), similar to that of interleukin-28B rs8099917 genotype analysis (0.86) in the 45 tested patients. Prediction by the combination of the C3f-dR/PLT model, the 107P/Hb/BMI/Age model and the rs8099917 genotype analysis was accurate in 44 out of the 45 patients (AUROC, 0.95).

CONCLUSION

Serum peptides, especially C3f-dR, would be useful predictors for SVR to PEG IFN-α/RBV. The complements may be involved in the HCV elimination.

Meta-analysis: implications of interleukin-28B polymorphisms in spontaneous and treatment-related clearance for patients with hepatitis C

BACKGROUND

Since 2009, several studies have identified single-nucleotide polymorphisms (SNPs) near the gene encoding for interleukin (IL)-28 (IL28B) that are strongly associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Because this large amount of data includes some inconsistencies, we consider assessment of the global estimate for each SNP to be essential.

METHODS

Relevant studies assessing IL28B polymorphisms associated with sustained virologic response (SVR) and spontaneous clearance (SC) were identified from a literature search of PubMed up to 9 July, 2012. Studies were eligible studies if they included patients infected with HCV or HCV/HIV, or assessed any SNP located within or near the IL28B gene, SVR data available under standard treatment, and/or SC data in patients with acute HCV infection. Pooled odds ratios were estimated by fixed or random effects models when appropriate. Variables such as HCV genotype, ethnicity, and type of co-infection were studied.

RESULTS

Of 282 screened studies, 67 were selected for SVR and 10 for SC. In total, 20,163 patients were studied for SVR and 3,554 for SC. For SVR, we found that all SNPs showed strong associations in patients with HCV genotypes 1 and 4, whereas the pooled ORs were almost three times lower for genotypes 2 and 3 (rs12979860 and rs8099917). Regarding ethnicity, the SNP most associated with SVR was rs12979860 in white patients, whereas in East Asians it seemed to be rs8099917. The most studied SNP (rs12979860) showed similar results for patients co-infected with HCV/HIV, as for those infected with HCV only. Finally, rs12979860 and rs8099917 both appeared to be associated with SC.

CONCLUSIONS

IL28B polymorphisms influence both the outcome of interferon treatment and the natural clearance of HCV. However we did not identify a universal predictor SNP, as the best genetic markers differed depending on patient ethnicity, genotype, and type of infection. Nevertheless, our results may be useful for more precise treatment decision-making.

Pharmacogenomics of hepatitis C infections: personalizing therapy

It is a widely held view that drug response genes have not proved as useful in clinical practice as anticipated at the start of the genomic era. An exception is in the treatment for chronic hepatitis C virus (HCV) genotype 1 infection with pegylated interferon α and ribavirin. In 2009, four independent genome-wide analyses identified IL28B polymorphisms that predict drug response in chronic hepatitis C (CHC). This discovery had immediate clinical impact. First, the IL28B genotype could be used to personalize therapy. In the 2 years since discovery, most of the more than 100,000 CHC patients commencing therapy for CHC in the West will have considered IL28B genotype testing. Second, the discovery has supported clinical trials for the use of the protein encoded by the gene known as interferon lambda. Third, it is expected that new insights into HCV pathogenesis will follow from studies of how IL28B affects HCV viral clearance and, ultimately, this will lead to new therapeutic strategies for CHC. This review discusses how IL28B genotyping is now used in personalizing therapy and, with the dramatically changing clinical landscape in CHC, with the advent of direct-acting antivirals, the prospects ahead.

Vitamin D binding protein gene polymorphisms and baseline vitamin D levels as predictors of antiviral response in chronic hepatitis C

Vitamin D deficiency seems to predict the unsuccessful achievement of sustained viral response (SVR) after antiviral treatment in hepatitis C virus (HCV) difficult-to-treat genotypes. Vitamin D binding protein (GC) gene polymorphisms are known to influence vitamin D levels. This study was performed to assess whether the interaction between basal circulating vitamin D and the GC polymorphism plays a role in influencing the rate of antiviral responses in patients affected by chronic hepatitis C. In all, 206 HCV patients treated with a combination therapy of pegylated (PEG)-interferon plus ribavirin were retrospectively evaluated. GC rs7041 G>T, GC rs4588 C>A, and IL-28B rs12979860 C>T polymorphisms were genotyped. Frequencies of GC rs7041 G>T and rs4588 C>A polymorphisms were: G/G = 64 (31.1%), G/T = 100 (48.5%), T/T = 42 (20.4%) and C/C = 108 (52.4%), C/A = 84 (40.8%), A/A = 14 (6.8%). Patients were divided into those carrying ≥3 major alleles (wildtype [WT]+: G-C/G-C, G-C/T-C, G-C/G-A, N = 100) and the remaining (WT-: G-C/T-A, T-A/T-C, T-A/T-A, T-C/T-C, N = 106). Four groups were identified: vitamin D ≤20 ng/mL and WT-, vitamin D ≤20 and WT+, vitamin D >20 and WT-, vitamin D >20 and WT+. In difficult-to-treat HCV genotypes the proportion of patients achieving SVR significantly increased with a linear trend from the first to the last group: 6/25 (24.0%), 9/24 (37.5%), 12/29 (41.4%), 19/29 (65.5%) (P = 0.003). At multivariate analysis, having basal vitamin D >20 ng/mL plus the carriage of GC WT+ was found to be an independent predictor of SVR (odds ratio 4.52, P = 0.015).

CONCLUSION

In difficult-to-treat HCV genotypes, simultaneous pretreatment normal serum vitamin D levels and the carriage of GC-globulin WT isoform strongly predicts the achievement of SVR after PEG-interferon plus ribavirin antiviral therapy.

Direct-acting antiviral agents in patients with hepatitis C cirrhosis

Patients with cirrhosis who are infected with hepatitis C virus (HCV) are the most in need of antiviral treatment. Virologic cure improves fibrosis and quality of life while reducing liver-related morbidity and mortality. In mid-2011, the addition of direct-acting antiviral agents (DAAs)-the protease inhibitors boceprevir (Victrelis, Merck) and telaprevir (Incivek, Vertex)-to pegylated interferon α-2a/b and ribavirin revolutionized the treatment of HCV infection by increasing cure rates across all fibrosis scores in patients with genotype 1 HCV infection. However, patients with advanced fibrosis or cirrhosis are the most difficult to treat, and the addition of DAAs increases treatment side effects as well as potency. Five phase III DAA trials have been published to date, but they contain limited data on patients with cirrhosis. This review will examine the available data and will describe the evolution of HCV therapy in patients with cirrhosis from the standard-of-care therapy of the past decade into the new era of DAAs.

Extensions of criteria for evaluating risk prediction models for public health applications

We recently proposed two novel criteria to assess the usefulness of risk prediction models for public health applications. The proportion of cases followed, PCF(p), is the proportion of individuals who will develop disease who are included in the proportion p of individuals in the population at highest risk. The proportion needed to follow-up, PNF(q), is the proportion of the general population at highest risk that one needs to follow in order that a proportion q of those destined to become cases will be followed (Pfeiffer, R.M. and Gail, M.H., 2011. Two criteria for evaluating risk prediction models. Biometrics 67, 1057-1065). Here, we extend these criteria in two ways. First, we introduce two new criteria by integrating PCF and PNF over a range of values of q or p to obtain iPCF, the integrated PCF, and iPNF, the integrated PNF. A key assumption in the previous work was that the risk model is well calibrated. This assumption also underlies novel estimates of iPCF and iPNF based on observed risks in a population alone. The second extension is to propose and study estimates of PCF, PNF, iPCF, and iPNF that are consistent even if the risk models are not well calibrated. These new estimates are obtained from case-control data when the outcome prevalence in the population is known, and from cohort data, with baseline covariates and observed health outcomes. We study the efficiency of the various estimates and propose and compare tests for comparing two risk models, both of which were evaluated in the same validation data.

Test of IL28B polymorphisms in chronic hepatitis C patients treated with PegIFN and ribavirin depends on HCV genotypes: results from a meta-analysis

BACKGROUND

Many studies have been published on the association between single nucleotide polymorphisms (SNP) near the IL28B gene and response to the combined treatments of pegylated-interferon (PegIFN) and ribavirin (RBV) in chronic HCV-infected patients, but without identical conclusions. The aim of this study was to assess impact of the IL28B polymorphisms on the effect of HCV standard treatment using meta-analysis based method.

METHODS

Association studies between polymorphisms of rs12979860 or rs8099917 and response to PegIFN/RBV treatment in chronic HCV patients were retrieved from PubMed. Data of qualified studies on sustained virological response (SVR) in different genotypes were extracted and analyzed using meta-analysis method in Stata 10 software.

RESULTS

Thirty-four papers, containing 46 independent studies, were included in the analysis. In the HCV G1/4 patients without treatment history, individuals carrying rs12979860 CC genotype were more likely to achieve SVR (OR 3.97, 95%CI 3.29-4.80) compared to those carrying CT/TT genotypes. Similar results were observed in the HCV G1/4 patients with unsuccessful or unknown treatment history (OR 3.76, 95%CI 2.67-5.28) or in the patients co-infected with human immunodeficiency virus (OR 5.20, 95%CI 3.04-8.90). However, associations could not be observed in HCV G2/3 patients. For rs8099917, similar results were obtained for genotype TT compared to genotypes TG/GG, indicating that TT genotype was significantly associated with better treatment response in patients infected with genotype 1 or 4 HCV, but not genotype 2 or 3 HCV.

CONCLUSION

Polymorphisms of rs12979860 and rs8099917 near IL28B only associate with the treatment response to PegIFN/RBV in patients infected with HCV genotype 1 or 4 but not with genotype 2 or 3, irrespective of the previous treatment history or HIV co-infected status. Therefore, identification of IL28B genotypes is necessary only in patients infected with relatively difficult-to-treat genotype 1 or 4 HCV.

Frequency of IL28B rs12979860 single-nucleotide polymorphism alleles in newborn infants and in patients with chronic hepatitis C in Morocco

BACKGROUND

Epidemiological and experimental evidence support the role of host genetics in treatment response and viral clearance in chronic hepatitis C (CHC). Recently, the CC genotype of IL28B single-nucleotide polymorphism (SNP) rs12979860 has been associated with spontaneous viral clearance and a better treatment response. The distribution of this polymorphism varies according to populations. Frequency of rs12979860 SNP alleles in the Moroccan population is unknown. The aim of our study was to estimate the frequency of the C allele of this SNP in the Moroccan population and, in parallel, in a cohort of Moroccan patients with CHC treated with pegylated interferon-alpha and ribavirin.

METHODS

We used real-time polymerase chain reaction assay based on TaqMan technology to determine the allele frequency of the rs12979860 SNP in 100 Moroccan newborn infants. We also compared the frequency of the CC genotype between two groups of patients with genotype 1-CHC treated by combination therapy: group1, n=30 patients, responders who achieved sustained viral response (SVR) and group2, n=30 patients, nonresponders.

RESULTS

The rs12979860 C allele frequency was estimated to be 73% in the Moroccan population. The frequency of this allele in the group of patients with CHC was only 58.3%, and the CC genotype is more prevalent in group1 (62.5%) than in group 2.

CONCLUSIONS

This is the first report providing genetic data related to the frequency of genetic polymorphisms of IL28B in Morocco. The C-allele frequency of the IL28B gene SNP rs12979860 in Morocco is higher than in the African populations. Distribution of this SNP distinguishes in a population of CHC between SVR and nonresponders. This result merits consideration and should be studied by analyzing a larger sample size of patients.

Meta-analysis: IL-28B genotype and sustained viral clearance in HCV genotype 1 patients

BACKGROUND

Polymorphisms in the IL-28B region are a strong predictor of sustained virologic response (SVR) in individual studies of HCV genotype 1 patients receiving peginterferon (pegIFN) and ribavirin.

AIM

To obtain a pooled odds ratio (OR) of SVR in patients of varying race with the favourable IL-28B genotype compared to those with the unfavourable genotype.

METHODS

A literature search was conducted using online databases and a review of conference abstracts. A random effects meta-analysis was performed and study heterogeneity and publication bias were assessed.

RESULTS

There were 21 individual studies of HCV genotype 1 patients of varying ethnicity treated with pegIFN and ribavirin. The pooled prevalence of the favourable IL-28B genotype varied by race (73% vs. 41% vs. 13% in 2612 Asians, 3110 Caucasians and 452 African-Americans, respectively, P < 0.001). However, the strength of association of the IL-28B genotype with SVR was similar in all three racial groups (Caucasians: odds ratio (OR) 3.88, 2.75-5.49, African-Americans: OR 4.63, 2.52-8.50 and Asians OR 5.66, 3.99-8.02, all P < 0.001). The IL-28B genotype was also associated with SVR in 263 HIV/HCV co-infected Caucasians (OR 5.49, 3.02-9.96, P < 0.001). Study quality score and anti-viral treatment regimen did not impact the strength of the association in patient subgroups nor in the pooled population.

CONCLUSIONS

IL-28B genotype is significantly associated with SVR in HCV genotype 1 patients of varying race, as well as in HIV co-infected patients, receiving pegIFN and ribavirin. IL-28B testing in conjunction with other pre-treatment parameters may prove useful in counselling HCV patients.

Genetics of IL28B and HCV--response to infection and treatment

The IL28B locus attracted the attention of HCV researchers after a series of genome-wide association studies independently identified a strong association between common IL28B polymorphisms and the outcome of PEG-IFN-α plus ribavirin combination therapy in patients chronically infected with HCV genotype 1. This association was subsequently replicated for other HCV genotypes and has been linked to spontaneous eradication of HCV, development of steatosis and biochemical changes (such as altered levels of γ-glutamyl transpeptidase and LDL). Despite the introduction of direct-acting antiviral drugs, IL28B genetics are likely to play a part in patient selection and treatment decisions-moving towards a personalized approach to therapy. In HCV-infected patients with the so-called favourable IL28B genotype (rs12979860 CC; associated with better treatment response), hepatic expression levels of IL28B and interferon-stimulated genes seem to be reduced at baseline, but are induced more strongly after IFN-α administration, perhaps resulting in more effective elimination of the virus. Clarification of the mechanisms underlying these biological phenomena will lead to improved understanding of the antiviral effects of IFN-λ and, ideally, to the development of better therapies against HCV infection. This Review summarizes current understanding of the role of IL28B in HCV infection and response to therapy.

YKL-40 genetic polymorphisms and the risk of liver disease progression in patients with advanced fibrosis due to chronic hepatitis C

BACKGROUND/AIMS

The aim of this study was to explore the association of a functional YKL-40 promoter polymorphism (rs4950928) with baseline disease stage, response to antiviral therapy and risk of liver disease progression in a group of patients with chronic hepatitis C (CHC).

METHODS

YKL-40 promoter polymorphisms were determined in 456 Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial patients with bridging fibrosis or cirrhosis entering a prerandomization lead-in peginterferon/ribavirin 24-week treatment phase and in 462 patients followed for a mean of 3.8 years after randomization to maintenance peginterferon or observation.

RESULTS

Mean patient age was 49.5 years, 70.4% were men and 71.2% were Caucasian. The 17% frequency of the YKL-40 minor allele (T) was similar to that reported in the general population. YKL-40 genotype was associated significantly with baseline serum YKL-40 levels but was not associated with the likelihood of a virological response following 24-48 weeks of peginterferon/ribavirin therapy. Serum YKL-40 levels remained significantly lower during follow-up in the randomized TT homozygotes compared with CT heterozygotes and CC homozygotes (P < 0.001). Despite this association, YKL-40 genotype was not associated with the risk of clinical or histological liver disease progression.

CONCLUSIONS

A reduced frequency of the protective YKL-40 promoter polymorphism was not observed in the HALT-C Trial patient population. The absence of an association between YKL-40 promoter polymorphisms and baseline liver disease severity as well as with the risk of liver disease progression over time suggests that this polymorphism is not associated with disease progression in CHC patients with established fibrosis.

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.

IL28B rs12979860 genotype and spontaneous clearance of hepatitis C virus in a multi-ethnic cohort of injection drug users: evidence for a supra-additive association

Among 1369 Urban Health Study participants, we evaluated genetic models for the association of IL28B genotype (rs12979860 and rs8099917) with hepatitis C virus (HCV) clearance. For rs12979860, adjusted odds ratios for spontaneous HCV clearance were as follows: IL28B-CC, 3.88 (P < .001); IL28B-CT, 1.48 (P = .08). On the basis of Akaike information criteria values and χ(2) tests, a supra-additive (quadratic) model fit these data best. Models based on rs8099917 provided poorer fit. Evidence that a supra-additive rs12979860-based model best fits the association of IL28B-genotype with HCV clearance may improve clinical prediction models and foster a better understanding of functional mechanisms underlying this association.

Prediction of effect of pegylated interferon alpha-2b plus ribavirin combination therapy in patients with chronic hepatitis C infection

Treatment with pegylated interferon alpha-2b (PEGIFN) plus ribavirin (RBV) is standard therapy for patients with chronic hepatitis C. Although the effectiveness, patients with high titres of group Ib hepatitis C virus (HCV) respond poorly compared to other genotypes. At present, we cannot predict the effect in an individual. Previous studies have used traditional statistical analysis by assuming a linear relationship between clinical features, but most phenomena in the clinical situation are not linearly related. The aim of this study is to predict the effect of PEG IFN plus RBV therapy on an individual patient level using an artificial neural network system (ANN). 156 patients with HCV group 1b from multiple centres were treated with PEGIFN (1.5 µg/kg) plus RBV (400–1000 mg) for 48 weeks. Data on the patients' demographics, laboratory tests, PEGIFN, and RBV doses, early viral responses (EVR), and sustained viral responses were collected. Clinical data were randomly divided into training data set and validation data set and analyzed using multiple logistic regression analysis (MLRs) and ANN to predict individual outcomes. The sensitivities of predictive expression were 0.45 for the MLRs models and 0.82 for the ANNs and specificities were 0.55 for the MLR and 0.88 for the ANN. Non-linear relation analysis showed that EVR, serum creatinine, initial dose of Ribavirin, gender and age were important predictive factors, suggesting non-linearly related to outcome. In conclusion, ANN was more accurate than MLRs in predicting the outcome of PEGIFN plus RBV therapy in patients with group 1b HCV.

Interferon-lambda and therapy for chronic hepatitis C virus infection

Interferon (IFN)-α, a type-I IFN, is widely used to treat chronic hepatitis C virus infection, but the broad expression of IFN-α receptors often leads to adverse reactions in many organs. Here, we examine IFN-λ, a type-III IFN, as a therapeutic alternative to IFN-α. Like IFN-α, IFN-λ also induces antiviral activity in hepatocytes, but might induce fewer adverse reactions because its receptor is largely restricted to cells of epithelial origin. We also discuss the recent discovery of single nucleotide polymorphisms (SNPs) near the human IFN-λ3 gene, IL28B, that correlate strongly with the ability to achieve a sustained virological response to therapy with pegylated IFN-α plus ribavirin in patients with chronic hepatitis C.