NS5A sequence heterogeneity of hepatitis C virus genotype 4a predicts clinical outcome of pegylated-interferon-ribavirin therapy in Egyptian patients. J Clin Microbiol. 2012;50:3886-3892. [PMID: 22993188 DOI: 10.1128/jcm.02109-12]

Effectiveness of Sofosbuvir, Ribavirin and PEG-IFNα-2a in the Treatment of Naïve Egyptian Patients With Chronic Hepatitis C Virus Genotype 4

BACKGROUND

Egypt is one of the largest epidemic areas of hepatitis C virus (HCV) in the world. Its prevalent genotype is 4 with a majority of subtype 4a. In 2013, the Food and Drug Administration approved a new direct-acting antiviral drug (sofosbuvir) to treat patients with chronic HCV infection. In Egypt, the patients are already being treated with sofosbuvir in conjunction with ribavirin and pegylated interferon alfa-2a (PEG-IFNα-2a) for 12 weeks since 2015. The present study was planned to explain the efficacy of this treatment regimen against the HCV genotype 4a in Egyptian patients and its pretreatment predictive factors of virological response.

METHODS

In this population-based study, serum samples were biochemically analyzed and the HCV RNA levels were quantified. The direct sequencing and bioinformatics analysis were utilized to investigate the mutation of the core protein.

RESULTS

The sustained virological response (SVR) and non-SVR were 72% and 16% respectively, but the nonvirological response was only 12% following the treatment regimen. The multivariable analysis recognized viral (level of viremia and substitution of aa70) and host-related factors (age, alanine aminotransferase and aspartate aminotransferase levels) affecting the virological response in patients infected with high viral load of HCV 4a.

CONCLUSIONS

Overall, these results concluded that sofosbuvir with ribavirin and PEG-IFNα-2a are highly efficient in HCV-4a Egyptian patients where a high SVR was achieved (72%). In addition to this, there is a significant association between core protein mutations and treatment outcome predominantly at amino acid position 70 (Arg or Gln).

Hepatitis C virus infection: Are there still specific problems with genotype 3?

Hepatitis C virus (HCV) infection is one of the most common causes of chronic liver disease and the main indication for liver transplantation worldwide. As promising specific treatments have been introduced for genotype 1, clinicians and researchers are now focusing on patients infected by non-genotype 1 HCV, particularly genotype 3. Indeed, in the golden era of direct-acting antiviral drugs, genotype 3 infections are no longer considered as easy to treat and are associated with higher risk of developing severe liver injuries, such as cirrhosis and hepatocellular carcinoma. Moreover, HCV genotype 3 accounts for 40% of all HCV infections in Asia and is the most frequent genotype among HCV-positive injecting drug users in several countries. Here, we review recent data on HCV genotype 3 infection/treatment, including clinical aspects and the underlying genotype-specific molecular mechanisms.

Sustained virological response and its treatment predictors in hepatitis C virus genotype 4 compared to genotypes 1, 2, and 3: a meta-analysis

BACKGROUND

Pegylated interferon and ribavirin (PEG-IFN+RBV) may be more cost-effective than direct-acting antivirals in resource-limited settings. Current literature suggests sustained virological response (SVR) in hepatitis C virus genotype 4 (HCV-4) is similar to genotype 1 (HCV-1), but worse than 2 and 3 (HCV-2/3). However, few studies have compared treatment response between these groups and these have been limited by small sample sizes with heterogeneous designs. We performed a meta-analysis of SVR predictors in HCV-4 versus HCV-1, 2, and 3 patients treated with PEG-IFN+RBV.

METHODS

In November 2013, we searched for 'genotype 4' in MEDLINE/EMBASE databases and scientific conferences. We included original articles with ≥25 treatment-naïve HCV-4 and comparisons to HCV-1, 2, and/or 3 patients treated with PEG-IFN+RBV. Random effects modelling was used with heterogeneity defined by Cochrane Q-test (p value<0.10) and I(2) statistic (>50%).

RESULTS

Five studies with 20 014 patients (899 HCV-4; 12 033 HCV-1; and 7082 HCV-2/3 patients) were included. SVR was 53% (CI 43% to 62%) for HCV-4, 44% (CI 40% to 47%) for HCV-1; and 73% (CI 58% to 84%) for HCV-2/3. SVR with EVR (early virological response) was 75% (CI 61% to 86%) in HCV-4; 64% (CI 46% to 79%) in HCV-1; and 85% (CI 71% to 93%) in HCV-2/3. SVR without EVR was 10% (CI 6% to 17%) for HCV-4; 13% (CI 12% to 15%) for HCV-1; and 23% (CI 16% to 33%) for HCV-2/3.

CONCLUSIONS

SVR rates are similar in HCV-4 (∼50%) and HCV-1 (∼40%). Lack of EVR is a good stopping rule for HCV-4 and HCV-1 since only 10% subsequently achieve SVR. In HCV-4 patients with EVR, three-quarters can expect to achieve SVR with PEG-IFN+RBV.

P53 rs1042522 and CD95 rs1800682 genetic variations in HCV-4a response to antiviral therapy

Current estimates indicate that the hepatitis C (HCV) is the leading cause of mortality around the world, with infection rates steadily increasing in Egypt. The dual therapy for this silent epidemic with pegylated-interferon-α2b/ribavirin has markedly improved the success rates in genotype-4 patients. It was reported that apoptosis plays a vital mechanistic role in limiting viral replication. P53, a key regulator of apoptosis, induces CD95 gene expression and subsequently initiates apoptotic cascade to be activated. The current study examined the impact of P53 rs1042522 and CD95 rs1800682 polymorphisms on the treatment response. Three groups of 240 volunteers were enrolled in this study; 86 in sustained virological responders group, 74 in non-responders group, and 80 in control group. All patients had HCV genotype-4a and were interferon treatment naïve. Quantizations of HCV-RNA by qRT-PCR and histological scores were performed for all patients. In addition, genotyping of HCV-RNA, P53 rs1042522 Arg/Pro and CD95 rs1800682 A/G polymorphisms were investigated in all subjects. It was resulted that P53 Pro/Pro homozygous genotype has high significant increase, while CD95 A/A homozygous genotype has high significant decrease when comparing non-responders with responders. Finally, it was concluded that Pro variant of P53 rs1042522 may be used as a genetic predictor for non-responsiveness, while A/A variant of CD95 rs1800682 may be used as a sensitive biomarker for responsiveness to antiviral therapy of HCV genotype-4a infection. In addition, low prolactin, high total testosterone, and high GH levels may provide promising biomarkers for early prediction of the response when associated with these genetic polymorphisms.

Twenty-five years of type I interferon-based treatment: a critical analysis of its therapeutic use

The clinical exploitation of type I interferon (IFN) as an antiviral and antineoplastic agent is based on the properties originally attributed to this cytokine family, with schedules reflecting only their antiviral and antiproliferative activities. Nevertheless, type I IFN has emerged as a central activator of the innate immunity. As current schedules of treatment for chronic hepatitis C and for hematological and solid tumors, based on the continuous administration of recombinant type I IFN or pegylated formulations, disregard viral resistance, host genetic variants predicting treatment outcome and mechanisms of refractoriness, new administration schedules, the combination of type I IFN with new drugs and the increased monitoring of patients' susceptibility to type I IFN are expected to provide a new life to this valuable cytokine.

Prior to the oral therapy, what do we know about HCV-4 in Egypt: a randomized survey of prevalence and risks using data mining computed analysis

Hepatitis C virus (HCV) affects over 180 million people worldwide and it's the leading cause of chronic liver diseases and hepatocellular carcinoma. HCV is classified into seven major genotypes and a series of subtypes. In general, HCV genotype 4 (HCV-4) is common in the Middle East and Africa, where it is responsible for more than 80% of HCV infections. Although HCV-4 is the cause of approximately 20% of the 180 million cases of chronic hepatitis C worldwide, it has not been a major subject of research yet. The aim of the current study is to survey the morbidities and disease complications among Egyptian population infected with HCV-4 using data mining advanced computing methods mainly and other complementary statistical analysis. Six thousand six hundred sixty subjects, aged between 17 and 58 years old, from different Egyptian Governorates were screened for HCV infection by ELISA and qualitative PCR. HCV-positive patients were further investigated for the incidence of liver cirrhosis and esophageal varices. Obtained data were analyzed by data mining approach. Among 6660 subjects enrolled in this survey, 1018 patients (15.28%) were HCV-positive. Proportion of infected-males was significantly higher than females; 61.6% versus 38.4% (P=0.0052). Around two-third of infected-patients (635/1018; 62.4%) were presented with liver cirrhosis. Additionally, approximately half of the cirrhotic patients (301/635; 47.4%) showed degrees of large esophageal varices (LEVs), with higher variceal grade observed in males. Age for esophageal variceal development was 47±1. Data mining analysis yielded esophageal wall thickness (>6.5 mm), determined by conventional U/S, as the only independent predictor for esophageal varices. This study emphasizes the high prevalence of HCV infection among Egyptian population, in particular among males. Egyptians with HCV-4 infection are at a higher risk to develop cirrhotic liver and esophageal varices. Data mining, a new analytic technique in medical field, shed light in this study on the clinical importance of esophageal wall thickness as a useful predictor for risky esophageal varices using decision tree algorithm.

Meta-analysis: influence of host and viral factors in patients with chronic hepatitis C genotype 4 treated with pegylated interferon and ribavirin

The burden of hepatitis C virus genotype 4 (HCV-4) is high in Africa and East Mediterranean countries. Previous reports estimate sustained virologic response (SVR) rates in HCV-4 to be ∼20-70%. However, many of these studies are limited by different study designs and small sample sizes. Our aim was to evaluate treatment outcome and host/viral factors on SVR in HCV-4 patients treated with pegylated interferon and ribavirin (PEG IFN+RBV) in a systematic and quantitative manner. A comprehensive literature search in MEDLINE and EMBASE for 'genotype 4' was conducted in November 2013. Abstracts from American Association for the Study of Liver Diseases, Asian Pacific Study of the Liver, Digestive Disease Week, and European Association for the Study of the Liver in 2012/2013 were reviewed. Inclusion criteria were original studies with at least 25 treatment-naive HCV-4 patients treated with PEG IFN+RBV. Exclusion criteria were coinfection with HIV, hepatitis B virus, or other genotypes. Effect sizes were calculated using random-effects models. Heterogeneity was determined by Cochrane Q-test (P<0.05) and I statistic (>50%). We included 51 studies (11 102 HCV-4 patients) in the primary analysis. Pooled SVR was 53% [95% confidence interval (CI): 50-55%] (Q-statistic=269.20, P<0.05; I=81.43). On subgroup analyses, SVR was significantly associated with lower viral load, odds ratio (OR) 3.05 (CI: 1.80-5.17, P<0.001); mild fibrosis, OR 3.17 (CI: 2.19-4.59, P<0.001); and favorable IL28B polymorphisms, rs12979860 CC versus CT/TT, OR 4.70 (CI: 2.87-7.69, P<0.001), and rs8099917 TT versus GT/GG, OR 5.21 (CI: 2.31-11.73, P<0.001). HCV-4 patients treated with PEG IFN+RBV may expect SVR rates of ∼50%. Lower viral load, mild fibrosis, and favorable IL28B (rs12979860 CC and rs8099917 TT) are positively associated with SVR.

Impact of hepatitis C virus heterogeneity on interferon sensitivity: an overview

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. HCV is able to evade host defense mechanisms, including both innate and acquired immune responses, to establish persistent infection, which results in a broad spectrum of pathogenicity, such as lipid and glucose metabolism disorders and hepatocellular carcinoma development. The HCV genome is characterized by a high degree of genetic diversity, which can be associated with viral sensitivity or resistance (reflected by different virological responses) to interferon (IFN)-based therapy. In this regard, it is of importance to note that polymorphisms in certain HCV genomic regions have shown a close correlation with treatment outcome. In particular, among the HCV proteins, the core and nonstructural proteins (NS) 5A have been extensively studied for their correlation with responses to IFN-based treatment. This review aims to cover updated information on the impact of major HCV genetic factors, including HCV genotype, mutations in amino acids 70 and 91 of the core protein and sequence heterogeneity in the IFN sensitivity-determining region and IFN/ribavirin resistance-determining region of NS5A, on virological responses to IFN-based therapy.

Hepatitis C virus NS5A inhibitors and drug resistance mutations

Some direct-acting antiviral agents for hepatitis C virus (HCV), such as telaprevir and boceprevir have been available since 2011. It was reported that HCV NS5A is associated with interferon signaling related to HCV replication and hepatocarcinogenesis. HCV NS5A inhibitors efficiently inhibited HCV replication in vitro. Human studies showed that dual, triple and quad regimens with HCV NS5A inhibitors, such as daclatasvir and ledipasvir, in combination with other direct-acting antiviral agents against other regions of HCV with or without peginterferon/ribavirin, could efficiently inhibit HCV replication according to HCV genotypes. These combinations might be a powerful tool for “difficult-to-treat” HCV-infected patients. “First generation” HCV NS5A inhibitors such as daclatasvir, ledipasvir and ABT-267, which are now in phase III clinical trials, could result in resistance mutations. “Second generation” NS5A inhibitors such as GS-5816, ACH-3102, and MK-8742, have displayed improvements in the genetic barrier while maintaining potency. HCV NS5A inhibitors are safe at low concentrations, which make them attractive for use despite low genetic barriers, although, in fact, HCV NS5A inhibitors should be used with HCV NS3/4A inhibitors, HCV NS5B inhibitors or peginterferon plus ribavirin. This review article describes HCV NS5A inhibitor resistance mutations and recommends that HCV NS5A inhibitors be used in combination regimens potent enough to prevent the emergence of resistant variants.

The role of pharmacogenetics in the treatment of chronic hepatitis C infection

Hepatitis C virus (HCV) chronically infects 170 million people worldwide. Until recently, combination therapy with peginterferon-α (pegIFN) and ribavirin (RBV) has been the standard of care. However, for many patients, especially those infected with the most common HCV genotype 1 (HCV-1), this treatment has resulted in unsatisfactory treatment response rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. Genetic variation in the interleukin 28B (IL28B) gene is the major determinant of treatment response, a finding that has been replicated in multiple independent cohorts. This review focuses on the association between pharmacogenetics and conventional pegIFN/RBV therapy in patients infected with HCV non-genotype 1; patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. We also review the pharmacogenetic data for boceprevir and telaprevir triple therapy in patients with HCV-1 infection, as well as viral genomic polymorphisms and genetic variants that may protect against anemia. Pharmacogenetic information offers a personalized medicine approach to help clinicians and patients make better informed decisions to maximize response and minimize toxicity for the treatment of chronic HCV infection.

The predictive value of IL28B rs12979860, rs11881222 and rs8099917 polymorphisms and IP-10 in the therapeutic response of Egyptian genotype 4 patients

Interleukin-28B (IL28B) polymorphisms have previously been reported to be strongly associated with spontaneous and treatment-induced HCV viral clearance.

AIM

To assess the impact of four different IL28B polymorphisms and their haplotype combination and interferon-c inducible protein 10 (IP-10) in response to treatment in Egyptian genotype 4 patients.

METHOD

159 HCV-genotype 4 patients were included. All patients were treated with Peginterferon alph2a/Ribavirin for 48 wk. The following polymorphisms rs12979860, rs11881222, rs8103142 and rs8099917 and rs80803142 of Il-28 were known to be associated with the sustained virological response. They were genotyped using the TaqMan assay. IP-10 was assessed by Eliza.

RESULTS

The data indicated that all SNPs are within the Hardy-Weinberg Equilibrium (HWE) except for rs8103142 (p=6.255(-9)), therefore it was excluded from the study since it deviates from HWE-P. The CC, AA and TT genotypes of rs12979860, rs11881222 and rs8099917 were the more frequent genotypes among the responders at RVR, EVR, ETR and SVR, respectively. The frequency of CC, CT, and TT genotype was 46.4%, 38.1% and 15.5% among responders of RVR, and was 46.9%, 45.9% and 7.2 among responders of SVR for rs12979860, respectively. The relapse rate was 18.0% and 16.0 % during EVR and ETR, while the response rate was 52.8%, 58.5%, 59.7% and 61.6% after 4, 12, 48 and 72 weeks of treatment. The transient virological response (TVR) was 6.9% among HCV patients. The results showed that the odds ratio and 95% CI of HCV genotype 4 patients to have a better sustained response to treatment (SVR) was 2.92, (1.83-4.68, p=2.01(-5)), 2.89 (1.79-4.70, p=2.53(-5)), and 2.73 (0.21-0.65, p=0.0007) for those with the major allele "C" of rs12979860, the "A" allele of rs11881222, and the "T" allele of rs8099917, respectively. Furthermore, the positive predictive value (PPV) of the major homozygous alleles for SVR with better response to therapy was in the following order: 78.69%, 68.42%, and 32.14% with a positive likelihood ratio of 1.95, 1.25, and 0.86 for rs12979860, rs11881222 and rs8099917, respectively. The haplotype formed between the 3 studied SNPs (rs12979860, rs11881222 and rs8099917) showed that two haplotypes (TGG and TGT) increased the probability of a poor response to therapy, but the CAT haplotype had the opposite effect. Multinomial logistic regression analysis revealed that the viral load and rs12979860 are the only significant actors involved in the efficacy of the treatment response among the cohort study. In addition, patients with SVR had significantly lower values of IP-10 than non-responder patients (NR), with a P-value<=0.001.

CONCLUSIONS

In genotype 4 cases, the IL28B SNPs rs12979860 rs8099917, and rs11881222 are the strongest predictors of a response, while IP-10 is a strong negative biomarker of a response. Accounting for this factor is important in the individualization of treatment and enhances the degree of predictiveness of the IL28 polymorphism in the final treatment outcome. The frequent distribution of C, A and T alleles of IL28 polymorphism are higher among TVR, which may reflect sensitivity to prolonged course.

Role of different regions of the hepatitis C virus genome in the therapeutic response to interferon-based treatment

Hepatitis C virus (HCV) is considered a significant risk factor in HCV-induced liver diseases and development of hepatocellular carcinoma (HCC). Nucleotide substitutions in the viral genome result in its diversification into quasispecies, subtypes and distinct genotypes. Different genotypes vary in their infectivity and immune response due to these nucleotide/amino acid variations. The current combination treatment for HCV infection is pegylated interferon α (PEG-IFN-α) with ribavirin, with a highly variable response rate mainly depending upon the HCV genotype. Genotypes 2 and 3 are found to respond better than genotypes 1 and 4, which are more resistant to IFN-based therapies. Different studies have been conducted worldwide to explore the basis of this difference in therapy response, which identified some putative regions in the HCV genome, especially in Core and NS5a, and to some extent in the E2 region, containing specific sequences in different genotypes that act differently with respect to the IFN response. In the review, we try to summarize the role of HCV proteins and their nucleotide sequences in association with treatment outcome in IFN-based therapy.

Impact of host and virus genome variability on HCV replication and response to interferon

Since the discovery of hepatitis C virus (HCV), treatment has proven difficult and the regimen of pegylated interferon-α and ribavirin is only effective for half of patients. Evidence suggests that host and viral genome variations play a role in either viral clearance or persistence. Powerful genomic technologies have made it possible to study genome-wide associations with treatment response, which yielded critical genetic polymorphisms that predict treatment response. This has important implications for treatment of HCV infection and opened the door to the possibility of genetic marker-guided treatment (personalized medicine). This review will focus on the recent advances in understanding host and viral genetic variations with regards to treatment and the importance for future therapeutic intervention.

How to optimize HCV therapy in genotype 4 patients

HCV is a worldwide disease with an estimated prevalence by WHO of 3%. Hepatitis C virus 4 is prevalent in Africa and the Middle East, especially Egypt. The treatment of HCV4 is affected by many factors, related to the virus itself (genotype, pretreatment viral load and prevalent quasispecies), to the host (genetic factors, age, ethnicity and liver histology), to the presence of comorbidities (obesity, insulin resistance and co-infections) and to the therapeutic drugs (type, dose and duration). Optimizing treatment is the goal of daily practice to obtain the best results for the patient.