Interferon Sensitivity-determining Region Research Articles

Role of hepatitis C virus substitutions and interleukin-28B polymorphism on response to peginterferon plus ribavirin in a prospective study of response-guided therapy

Recent studies have indicated that amino acid (aa) substitutions in the core region and NS5A interferon sensitivity-determining region (ISDR) of hepatitis C virus (HCV) as well as genetic polymorphisms in the interleukin-28B (IL-28B) locus affect the outcome of interferon (IFN)-based therapies. We aimed to investigate the role of these factors on response to peginterferon plus ribavirin in a prospective study of response-guided therapy. The aa sequences in core region and ISDR and rs12979860 genotypes were analysed in 115 HCV-1 patients. The treatment was 24 weeks for patients achieving a rapid virological response (RVR), 48 weeks for those with an early virological response (EVR) and early terminated in those without an EVR. A sustained virological response (SVR) was achieved in 82% of 34 RVR patients, 45% of 74 EVR patients and 0% of seven non-EVR patients. Logistic regression analysis showed that ISDR mutation (≥2) [odds ratio(OR): 6.024], double core 70/91 mutations (OR: 0.136), and platelet counts≥15×10(4) /μL (OR: 3.119) were independent pretreatment factors associated with SVR. Apart from rs12979860 CC genotype, low viral load and ISDR mutation (≥2) were significant factors predictive of RVR. Combination of rs12979860 genotype and baseline viral characteristics (viral load and core/ISDR mutations) could predict RVR and SVR with positive predictive value of 100% and 91%, and negative predictive value of 80% and 54%, respectively. In conclusion, pretreatment screening rs12979860 genotype and aa substitutions in the core region and ISDR could help identifying patients who are good candidates for peginterferon plus ribavirin therapy.

1160 HCV GENOTYPE 1 PROTEASE INHIBITOR RESISTANCE MUTATIONS AT NS3 PROTEASE AMINO ACIDS 155 AND 156 CONFER RESISTANCE TO GENOTYPE 2A, 3A, 5A, AND 6A VIRUSES

for HCV genotyping released in 1994, in addition to the highly conserved 5′-UTR and Core regions. Whereas treatment response/resistance was assessed mainly in the Interferon sensitivity determining region (ISDR) region of NS5A. Conclusions: While sequence analysis of HCV is generally constricted to certain regions of the HCV genome there is little consistency in the positioning of population sequencing primers, with the exception of a few highly referenced manuscripts. This study demonstrates the heterogeneity of HCV sequencing in the field, and provides a comprehensive database of previously published primer sets that may be utilised in future sequencing studies.

Pegylated interferon monotherapy in patients with chronic hepatitis C with low viremia and its relationship to mutations in the NS5A region and the single nucleotide polymorphism of interleukin‐28B

Previous studies have suggested that patients with chronic hepatitis C with a low pretreatment hepatitis C virus (HCV) level have a high sustained virological response (SVR) rate, and that there would be a subpopulation of patients in which HCV can be eradicated with pegylated interferon (PEG IFN) alone without a decrease in SVR. However, the efficacy of PEG IFN monotherapy in patients with low HCV RNA levels is unclear. Several studies have reported that interferon sensitivity-determining region (ISDR) and the single-nucleotide polymorphism (SNP) of interleukin-28B (IL-28B) contribute to IFN response, but these relationships are controversial. The aim of this study was to determine whether the SNP of IL-28B (rs8099917) and amino acid substitutions in the ISDR among patients with low HCV levels affect the response to PEG IFN monotherapy. One hundred and four patients with low-level HCV infection were studied. Low HCV level was defined as 100 KIU/mL or less. SVR was achieved in 94 patients (92.2%). HCV levels (≤50 KIU/mL) and ISDR (≥2 mutations) were associated with SVR on univariate analysis. The rates of SVR in the patients with IL-28B genotypes TT, TG and GG were 94.5%, 77.8% and 100%, respectively. The G allele tended to be associated with poor response to IFN therapy (P = 0.0623). On multivariate analysis, the ISDR was the factor predictive of SVR (P = 0.004). The ISDR is significantly associated with a good response to PEG IFN monotherapy in patients with low HCV levels.

Perihepatic lymph node enlargement is a negative predictor for sustained responses to pegylated interferon‐α and ribavirin therapy for Japanese patients infected with hepatitis C virus genotype 1

Although perihepatic lymph node enlargement (PLNE) is reportedly associated with the negative outcome of interferon therapy for chronic hepatitis C, there were limitations in that the results were obtained in patients with various genotypes, viral loads and treatment regimens. We aimed to precisely clarify the significance of PLNE in interferon therapy for chronic hepatitis C. Between December 2004 and June 2005, 112 patients with hepatitis C virus (HCV) genotype 1 and HCV RNA of more than 100 KIU/mL were enrolled, who underwent pegylated interferon-α plus ribavirin therapy thereafter. PLNE was defined as a perihepatic lymph node of more than 1 cm in the longest axis by ultrasonography. The sustained virological response (SVR) rate was lower in patients with PLNE (4/22, 18.2%) than in those without (37/90, 41.1%; P = 0.045) and viral load decline was smaller in patients with PLNE than in those without (P = 0.028). The proportion of PLNE positive patients was the smallest in the SVR group (P = 0.033) among the patient groups divided by the treatment outcome. PLNE was retained as a negative predictor for SVR by multivariate logistic regression analysis (P = 0.012). Furthermore, PLNE was not significantly associated with the mutations at HCV core protein and at interferon sensitivity-determining region, or interleukin-28B polymorphism in 45 patients with HCV genotype 1, enrolled between December 2011 and March 2012. PLNE is a negative predictor for SVR in patients with HCV genotype 1 and HCV RNA of more than 100 KIU/mL treated with pegylated interferon-α plus ribavirin, independent of other known predictors for SVR.

Low-dose pegylated interferon-alpha-2a plus ribavirin therapy for elderly and/or cirrhotic patients with hepatitis C virus genotype-1b and high viral load

Pegylated interferon (PEG-IFN) plus ribavirin therapy is still recommended for elderly and/or cirrhotic patients. This study examined whether sustained virological response (SVR) to low-dose PEG-IFN-α2a plus ribavirin therapy for elderly and/or cirrhotic patients could be predicted based on viral reduction within 2 weeks after therapy initiation or interleukin IL-(28B) polymorphism and viral mutations. Participants comprised 115 elderly (≥65 years) and/or cirrhotic patients with genotype-1b and high viral load. Reduced doses of PEG-IFN-α2a (90 μg/kg/week) and ribavirin (400-800 mg/day) were administered for 48-72 weeks based on virological response of each patient. SVR was achieved in 34% (39/115), and treatment was discontinued in 15% (17/115). Univariate analysis identified age, α-fetoprotein, fibrosis marker, interferon sensitivity-determining region (ISDR), IL-28B polymorphism and level of viral reduction within 2 weeks as factors contributing significantly to SVR. However, no significant differences were noted in core amino acid substitutions. Multivariate analysis identified age, hyaluronic acid, ISDR and viral reduction as factors independently associated with SVR. Positive predictive value (PPV) and negative predictive value (NPV) of SVR based on the level of viral reduction at 2 weeks (cutoff level, 1.7 log IU/ml) were 83% and 84%, respectively. The PPV of SVR based on IL-28B major and ISDR mutant was 70%, and the NPV of SVR based on IL-28B minor and wild-type ISDR was 89%. Evaluations of viral reduction at 2 weeks or both IL-28B and ISDR are useful to predict SVR to low-dose PEG-IFN-α2a plus ribavirin therapy for elderly and/or cirrhotic patients.

Interferons as Immune Regulators: A Rivalry between HCV and Interferons

Interferons (IFNs) are an integral part of the immune system, which upon stimulation results in recruitment of cytokines for viral clearance. IFNs have been characterized as potent antiviral agents that which can reduce viral titer and have been found to act as critical mediators for tumor regression in few cases. During the course of time Hepatitis C virus (HCV) has evolved and influence IFN efficiency through various pathways. Rapidly occurring amino acid substitutions in HCV’s core protein, sequence homology with protein kinase (PKR), increased numbers of quasi-species and wild-type Interferon sensitivity determining region (ISDR) strains are linked with an inefficient response to IFN therapy. This article describes the pharmacodynamics of IFNs with an aim to decipher the possible involvement of HCV proteins in subverting these responses. We hereby discuss IFN-based therapies targeting the host and viral genetic factors, since they have a strong impact in determining the efficacy of an IFN in HCV infected host.

Evolution of viral RNA in a Chinese patient to interferon/ribavirin therapy for hepatitis C

The combination of interferon (IFN) and ribavirin (RBV) is the standard therapy for hepatitis C virus (HCV) infection. HCV genotype 2a has proved more amenable to the therapy, but its efficacy is yet limited. This study aimed to investigate the mechanism of the poor response in a case of HCV genotype 2a infection.We analyzed dynamic change of HCV RNA from a patient, infected with HCV genotype 2a, showing a poor virological response to IFN/RBV as judged 12 weeks after initiation of the therapy by HCV clone sequencing. Then we constructed subgenomic Japanese fulminant hepatitis-1 (JFH1) replicon and different chimeric replicons with humanized Gaussia luciferase gene. The chimeric replicons were derived from subgenomic JFH1 replicon, in which the NS5A region was replaced by the patient's sequence from the pre/post-treatment, and the chimeric replicons' susceptibility to IFN were evaluated by relative Gausia Luciferase activity.The pretreatment HCV sequences appeared almost uniform, and the quasispecies variation was further more simplified after 12 weeks of therapy. Besides, the quasispecies variation seemed to be more diversified in the NS5A, relatively, a region crucial for IFN response, and each of chimeric replicons exhibited distinct response to IFN.During the course of the chronic infection, HCV population seems to be adapted to the patient's immunological system, and further to be selected by combination of IFN/RBV therapy, indicating quasispecies may completely eliminated by addition of other drugs with targets different from those of IFN. In addition, each different response of chimeric replicon to IFN is most likely related to amino acid changes in or near the IFN-sensitivity determining region (ISDR) of NS5A during chronic infection and IFN/RBV therapy.

Evolution of viral RNA in a Chinese patient to interferon/ribavirin therapy for hepatitis C.

The combination of interferon (IFN) and ribavirin (RBV) is the standard therapy for hepatitis C virus (HCV) infection. HCV genotype 2a has proved more amenable to the therapy, but its efficacy is yet limited. This study aimed to investigate the mechanism of the poor response in a case of HCV genotype 2a infection. We analyzed dynamic change of HCV RNA from a patient, infected with HCV genotype 2a, showing a poor virological response to IFN/RBV as judged 12 weeks after initiation of the therapy by HCV clone sequencing. Then we constructed subgenomic Japanese fulminant hepatitis-1 (JFH1) replicon and different chimeric replicons with humanized Gaussia luciferase gene. The chimeric replicons were derived from subgenomic JFH1 replicon, in which the NS5A region was replaced by the patient's sequence from the pre/post-treatment, and the chimeric replicons' susceptibility to IFN were evaluated by relative Gausia Luciferase activity. The pretreatment HCV sequences appeared almost uniform, and the quasispecies variation was further more simplified after 12 weeks of therapy. Besides, the quasispecies variation seemed to be more diversified in the NS5A, relatively, a region crucial for IFN response, and each of chimeric replicons exhibited distinct response to IFN. During the course of the chronic infection, HCV population seems to be adapted to the patient's immunological system, and further to be selected by combination of IFN/RBV therapy, indicating quasispecies may completely eliminated by addition of other drugs with targets different from those of IFN. In addition, each different response of chimeric replicon to IFN is most likely related to amino acid changes in or near the IFN-sensitivity determining region (ISDR) of NS5A during chronic infection and IFN/RBV therapy.

Comprehensive analysis for viral elements and interleukin-28B polymorphisms in response to pegylated interferon plus ribavirin therapy in hepatitis C virus 1B infection

To comprehensively characterize the contribution of virological factors as well as interleukin-28B (IL28B) single-nucleotide polymorphisms (SNPs) in determining treatment responses in pegylated-interferon plus ribavirin (Peg-IFN/RBV) therapy for chronic hepatitis C virus (HCV)-1b infection, we undertook a retrospective cohort analysis for the pretreatment dominant complete HCV open reading frame (ORF) amino-acid (aa) sequence study in 103 consecutive HCV-1b Japanese patients. The dominant HCV sequences classified by the response were subjected to systematic sliding-window comparison analysis to characterize response-specific viral sequences, along with IL28B SNP analyses (rs8099917). In each comparison of the patients between with and without rapid viral response (RVR), nonearly viral response (nEVR), sustained virological response (SVR), or relapse, the following regions were extracted as most significantly associated with the different responses respectively: nonstructural protein 5A (NS5A) aa.2224-2248 (P = 1.2E-07); core aa.70 (P = 4E-04); NS5A aa.2340-2382 (P = 7.0E-08); and NS5A aa.2360-2377 (P = 1.1E-05). Those NS5A regions nearly coincided with the interferon (IFN) sensitivity-determining region (NS5A aa.2209-2248) and the IFN/RBV resistance-determining region (NS5A aa.2339-2379). In a multivariate analysis, the IL28B SNP (odds ratio [OR] = 16.8; P = 0.009) and NS5A aa.2340-2382 (OR = 13.8; P = 0.0003) were extracted as the two most-significant independent variables contributing to the final outcome. In Peg-IFN/RBV therapy, polymorphisms in IL28B, NS5A aa.2224-2248, core aa.70, and, most important, NS5A aa.2340-2382 have a tremendous influence on treatment response in association with viral kinetics, resulting in significantly different outcomes in chronic HCV-1b infection.

Mutations in different regions of the genome of hepatitis C virus genotype 1b and association with response to interferon therapy

The aim of this study was to investigate the association of mutations in the E2/NS1 [hypervariable regions 1 and 2 (HVR1 and HVR2)] and NS5A regions of the hepatitis C virus (HCV) genome and the effectiveness of interferon (IFN) therapy, and assess whether the degree of heterogeneity of HCV quasispecies predicts response to IFN treatment. Fourteen patients infected with HCV genotype 1b (HCV-1b) who were treated with pegylated IFN-α-2a and ribavirin for 24 weeks, were studied. E2/NS1 and NS5A gene segments were amplified by reverse-transcription polymerase chain reaction. HCV quasispecies heterogeneity in the E2/NS1 region was determined by cloning and sequencing. Mutations in the NS5A region were detected by direct sequencing. The heterogeneity of HCV quasispecies in the HVR1 was significantly greater in the non-responder group than in the responder group, but was not significant for HVR2 or NS5A. The correlation between mutations in IFN sensitivity-determining region (ISDR, NS5A2209-2248) and IFN sensitivity could not be supported. The degree of quasispecies heterogeneity in HVR1, but not in HVR2 and NS5A, may be predictive of response to IFN therapy. An ISDR may not apply to patients infected with HCV-1b.

Hepatitis C virus: The role of molecular mimicry in response to interferon treatment

Chronic hepatitis C virus (HCV) infection is one of the major causes of chronic liver disease worldwide. In order for HCV to persist, the virus must escape immune recognition or inhibit the host immune response. The NS5A protein contains the interferon sensitivity-determining region (ISDR) and is able to repress dsRNA-dependent protein kinase (PKR) thus influencing the response to interferon (IFN) therapy. Patients who respond to IFN therapy have stronger antibody reactivity against the NS5A compared to IFN non-responders. Therefore, given the possible role for the ISDR in IFN resistance and differential antibody reactivity, it is possible that variation in ISDR may be involved in viral immune escape and development of persistent HCV infection employing aspects of host mimicry. In this study, pre-treatment samples obtained from HCV infected patients were used to investigate the effect of different NS5A ISDR variants on the IFN antiviral response and their involvement in immune evasion. The NS5A was identified as a homologue of the variable region of immunoglobulins (Ig). The IFN resistant genotypes had higher levels of similarity to Ig compared to IFN sensitive genotypes. Expression of NS5A-6003 (HCV genotype 1b) and NS5A-6074 (HCV genotype 2a) was able to rescue vesicular stomatitis virus (VSV) from IFN inhibition and restore luciferase activity. A correlation between Ig-like NS5A structure and also antibody response with the outcome of IFN treatment was observed.

Mutations in non-structural 5A and rapid viral response to pegylated interferon-α-2b plus ribavirin therapy are associated with therapeutic efficacy in patients with genotype 1b chronic hepatitis C

For patients chronically infected with hepatitis C virus (HCV), mutations in the non-structural 5A (NS5A) gene are important predictive factors for the response to interferon (IFN) therapy. In the present study, factor analysis of the therapeutic response of patients following pegylated IFN and ribavirin combination therapy was assessed in a multicenter study. Chronic HCV-infected patients with genotype 1b and high viral load (n=96, mean age 56.5 years; 59 males, 68 females) treated with pegylated IFN-α-2b and ribavirin combination therapy were enrolled. This study was conducted at Kobe University Hospital and 25 affiliated hospitals in Hyogo prefecture. Sixty-five patients (68%) completed treatment with both pegylated IFN and ribavirin at >80% of the weight-based scheduled dosages. Patients who reduced or terminated therapy were frequently aged women (mean age 60.8 years; 11 males, 17 females). Overall, a sustained viral response (SVR) was achieved in 42 (44%) patients out of 96. Based on per-protocol-based (PPB) analysis, the SVR rate in patients with ≥6 amino acid (aa) mutations in the IFN resistance-determining region (IRRDR) (75%) or ≥1 aa mutation in the IFN sensitivity-determining region (ISDR) (61%) was significantly higher than that in patients with <5 aa mutations in IRRDR (30%) or no mutation in ISDR (29%). Multivariate analysis revealed that rapid viral response (RVR) (odds ratio, 18.1) and mutations of ≥6 in IRRDR (odds ratio, 15.5) were significantly associated with SVR. In conclusion, mutations in the NS5A region, particularly in patients with ≥6 aa mutations in IRRDR were strongly associated with a therapeutic response to pegylated IFN and ribavirin combination therapy.

Novel Cell Culture-Adapted Genotype 2a Hepatitis C Virus Infectious Clone

Although the recently developed infectious hepatitis C virus system that uses the JFH-1 clone enables the study of whole HCV viral life cycles, limited particular HCV strains have been available with the system. In this study, we isolated another genotype 2a HCV cDNA, the JFH-2 strain, from a patient with fulminant hepatitis. JFH-2 subgenomic replicons were constructed. HuH-7 cells transfected with in vitro transcribed replicon RNAs were cultured with G418, and selected colonies were isolated and expanded. From sequencing analysis of the replicon genome, several mutations were found. Some of the mutations enhanced JFH-2 replication; the 2217AS mutation in the NS5A interferon sensitivity-determining region exhibited the strongest adaptive effect. Interestingly, a full-length chimeric or wild-type JFH-2 genome with the adaptive mutation could replicate in Huh-7.5.1 cells and produce infectious virus after extensive passages of the virus genome-replicating cells. Virus infection efficiency was sufficient for autonomous virus propagation in cultured cells. Additional mutations were identified in the infectious virus genome. Interestingly, full-length viral RNA synthesized from the cDNA clone with these adaptive mutations was infectious for cultured cells. This approach may be applicable for the establishment of new infectious HCV clones.

Changes in sequences of core region, interferon sensitivity‐determining region and interferon and ribavirin resistance‐determining region of hepatitis C virus genotype 1 during interferon‐alpha and ribavirin therapy, and efficacy of retreatment

Some regions associated with sensitivity to interferon-α and ribavirin have been identified in the hepatitis C virus (HCV) genome, including amino acid 70 in the core region (core a.a. 70), a.a. 2209-2248 (interferon sensitivity-determining region, ISDR) and a.a. 2334-2379 (interferon and ribavirin resistance-determining region, IRRDR). We examined changes in the sequences of these regions in 25 patients with chronic HCV genotype 1 infection who had not had sustained virological response (SVR) to interferon-α and ribavirin for 24-48 weeks and subsequently received retreatment for 48-72 weeks. At baseline, the core a.a. 70 was mutant (resistant) type in seven patients. At the start of retreatment, the core a.a. 70 had changed from sensitive to resistant type in 2 patients, and SVR was not achieved by retreatment. The ISDR variations were resistant type (0-1 mutations) in 17 patients at baseline. After 2 weeks of treatment, amino acid change was found in two patients; in one, the substitutions returned to baseline status after treatment, and in the other, the substitution persisted. At the start of retreatment, ISDR sequences had changed from resistant to sensitive type in two patients and SVR was achieved and from sensitive to resistant type in three patients and SVR was not achieved. The IRRDR variations were resistant type (<6 mutations) in 19 patients at baseline and at the start of retreatment. Sequences of the core region and ISDR sometimes change during anti-HCV therapy, potentially affecting the outcomes of retreatment.

942 The Effect of Peginterferon ALPHA-2A vs. Peginterferon alpha-2B in Treatment of NaïVE Chronic HCV Genotype-4 Patients: A Cohort Egyptian Study

3a affect the response to pegylated-interferon-alpha 2b and ribavirin combination therapy. METHODS: Six hundred sixty-five patients with chronic hepatitis C were enrolled. There were 375 men and 290 women (mean age, 57.7 ± 13.5 years). HCV genotypes 1a (N = 18), 1b (N = 428), 2a (N = 137), 2b (N = 71), and 3a (N = 11) were detected. The NS5A region (IFN sensitivity-determining region (ISDR)) in each genotype was examined by direct sequencing. The proto-type for each genotype were defined and the counting the number of mutations to the sequence of proto-type in the ISDR and the strains which have more than two mutations were defined as mutant-type. Detection of the SNP of IL28B (rs8099917) was done by a real-time PCR system with specific probes. Patients received pegylated-IFNalpha 2b once each week plus oral ribavirin daily for 24 -72weeks. RESULTS: Of the 665 patients, 365 (54.9%) showed sustained virologic response (SVR). SVR rates according genotype 1a, 1b, 2a, 2b, and 3a were 44.4, 43.6, 72.9, 70.4, and 80.1%, respectively. Factors related to SVR in genotype 1a were IL28B TT allele (p=0.0359) and ISDR mutanttype (p=0.0229). The IL28B and mutation in the ISDR were the factors related to SVR on multivariate analysis in patients with genotype1b. The best SVR was achieved in patients with mutant-type ISDR and IL28B T allele (70.5%), and the worst was achieved in patients with wild-type ISDR and IL28B G allele (11.1%) in genotype 1a and 1b. Of the 137 patients, 100 (72.9%) achieved SVR in patients with genotype 2a. SVR was achieved in 65.5% of patients with wild-type ISDR and 86% of patients with mutant-type (p = 0.0097). Achievement of SVR occurred in patients with T allele (66.7%) and those with G allele (74.8%). There were no significant differences in SVR according to IL28B in genotype 2a. Similar results were found in genotype 2b. Both ISDR and IL28B in patients with genotype 3a were not associated with SVR. CONCLUSIONS: Both ISDR and IL28B were significantly associated with SVR in genotype 1a and 1b. Only ISDR was useful for predicting the IFN response in genotype 2a and 2b. The impact of ISDR and IL28B on SVR was different in each genotype and these concepts should consider in choosing optimal therapy.

A retrospective case-control study of hepatitis C virus infection and oral lichen planus in Japan: association study with mutations in the core and NS5A region of hepatitis C virus

BackgroundThe aims of this study were to assess the prevalence of hepatitis C virus (HCV) infection in Japanese patients with oral lichen planus and identify the impact of amino acid (aa) substitutions in the HCV core region and IFN-sensitivity-determining region (ISDR) of nonstructural protein 5A (NS5A) associated with lichen planus.MethodsIn this retrospective study, 59 patients (group 1-A) with oral lichen planus among 226 consecutive patients who visited our hospital and 85 individuals (group 1-B, controls) with normal oral mucosa were investigated for the presence of liver disease and HCV infection. Risk factors for the presence of oral lichen planus were assessed by logistic regression analysis. We compared aa substitutions in the HCV core region (70 and/or 91) and ISDR of NS5A of 12 patients with oral lichen planus (group 2-A) and 7 patients who did not have oral lichen planus (group 2-B) among patients (high viral loads, genotype 1b) who received interferon (IFN) therapy in group1-A.ResultsThe prevalence of anti-HCV and HCV RNA was 67.80% (40/59) and 59.32% (35/59), respectively, in group 1-A and 31.76% (27/85) and 16.47% (14/85), respectively, in group 1-B. The prevalence of anti-HCV (P < 0.0001) and HCV RNA (P < 0.0001) in group 1-A was significantly higher than those in group 1-B. According to multivariate analysis, three factors - positivity for HCV RNA, low albumin level (< 4.0 g/dL), and history of smoking - were associated with the development of oral lichen planus. The adjusted odds ratios for these three factors were 6.58, 3.53 and 2.58, respectively, and each was statistically significant. No significant differences in viral factors, such as aa substitutions in the core region and ISDR of NS5A, were detected between the two groups (groups 2-A and -B).ConclusionWe observed a high prevalence of HCV infection in patients with oral lichen planus. Longstanding HCV infection, hypoalbuminemia, and smoking were significant risk factors for the presence of oral lichen planus in patients. It is advisable for Japanese patients with lichen planus to be tested for HCV infection during medical examination.

Prediction of response to pegylated interferon/ribavirin combination therapy for chronic hepatitis C genotype 1b and high viral load

This study explores pretreatment predictive factors for ultimate virological responses to pegylated interferon-α (1.5 μg/kg/week) and ribavirin (600-1000 mg/day) (PEG-IFN/RBV) combination therapy for patients infected with hepatitis C virus (HCV)-1b and a high viral load. A total of 75 patients underwent PEG-IFN/RBV combination therapy for 48 weeks. HCV amino acid (aa) substitutions in non-structural protein 5a, including those in the IFN/RBV resistance-determining region (IRRDR) and the IFN sensitivity-determining region and the core regions, as well as the genetic variation (rs8099917) near the interleukin 28B (IL28B) gene (genotype TT) were analyzed. Of the 75 patients, 49 % (37/75) achieved a sustained virological response (SVR), 27 % (20/75) showed relapse, and 24 % (18/75) showed null virological response (NVR). Multivariate logistic regression analysis identified IRRDR with 6 or more mutations (IRRDR ≥6) [odds ratio (OR) 11.906, p < 0.0001] and age <60 years (OR 0.228, p = 0.015) as significant determiners of SVR and IL28B minor (OR 14.618, p = 0.0019) and platelets <15 × 10(4)/mm(3) (OR 0.113, p = 0.0096) as significant determiners of NVR. A combination of IRRDR ≥6 and age <60 years improved SVR predictability (93.3 %), and that of IRRDR ≤5 and age ≥60 years improved non-SVR predictability (84.0 %). Similarly, a combination of IL28B minor and platelets <15 × 10(4)/mm(3) improved NVR predictability (85.7 %), and that of IL28B major and platelets ≥15 × 10(4)/mm(3) improved non-NVR (response) (97.1 %) predictability. IRRDR ≥6 and age <60 years were significantly associated with SVR. IL28B minor and platelets <15 × 10(4)/mm(3) were significantly associated with NVR. Certain combinations of these factors improved SVR and NVR predictability and could, therefore, be used to design therapeutic strategies.

An open‐label randomized controlled study of pegylated interferon/ribavirin combination therapy for chronic hepatitis C with versus without fluvastatin

Pegylated interferon (PEG-IFN)/ribavirin combination therapy is the standard-of-care (SOC) treatment for chronic hepatitis C patients infected with hepatitis C virus (HCV) genotype 1b and high viral load. The addition of fluvastatin to SOC treatment has been suggested to be effective for better outcome in retrospective pilot analyses. We investigated whether the combination of fluvastatin with PEG-IFN/ribavirin could actually improve sustained viral response (SVR) in patients with HCV genotype 1b and high viral load. A randomized, open-labeled, controlled study was conducted between July 2008 and December 2009 in 101 chronic hepatitis C patients allocated to PEG-IFN/ribavirin combination therapy with or without fluvastatin. SVR rates were calculated in groups, stratifying host and viral factors. We also analyzed predictive factors for SVR among patients on fluvastatin with multivariate regression analysis. Rapid and early virological, and end of treatment response rates in the fluvastatin group were not significantly different from those in the non-fluvastatin group. Notwithstanding, SVR rate was significantly higher in the fluvastatin group than in the non-fluvastatin group (63.0%vs 41.7%, P = 0.0422). Comparison of the two groups stratifying demographic data and HCV characteristics showed significantly higher SVR rates to more than 80% in males, more than two mutations in the interferon sensitivity determining region (ISDR), and a history of relapse among the fluvastatin group than the non-fluvastatin group. Being male and major genotype IL28B single nucleotide polymorphisms (SNPs) were independent predictive factors for SVR among patients on fluvastatin with multivariate analysis. Fluvastatin-combined with PEG-IFN/ribavirin therapy significantly improves SVR rates in patients with HCV genotype 1b and high viral load. Male and major genotype IL28B SNPs were independent predictors for SVR among patients on fluvastatin combination therapy.

Sequence Heterogeneity in NS5A of Hepatitis C Virus Genotypes 2a and 2b and Clinical Outcome of Pegylated-Interferon/Ribavirin Therapy

Pegylated-interferon plus ribavirin (PEG-IFN/RBV) therapy is a current standard treatment for chronic hepatitis C. We previously reported that the viral sequence heterogeneity of part of NS5A, referred to as the IFN/RBV resistance-determining region (IRRDR), and a mutation at position 70 of the core protein of hepatitis C virus genotype 1b (HCV-1b) are significantly correlated with the outcome of PEG-IFN/RBV treatment. Here, we aimed to investigate the impact of viral genetic variations within the NS5A and core regions of other genotypes, HCV-2a and HCV-2b, on PEG-IFN/RBV treatment outcome. Pretreatment sequences of NS5A and core regions were analyzed in 112 patients infected with HCV-2a or HCV-2b, who were treated with PEG-IFN/RBV for 24 weeks and followed up for another 24 weeks. The results demonstrated that HCV-2a isolates with 4 or more mutations in IRRDR (IRRDR[2a]≥4) was significantly associated with rapid virological response at week 4 (RVR) and sustained virological response (SVR). Also, another region of NS5A that corresponds to part of the IFN sensitivity-determining region (ISDR) plus its carboxy-flanking region, which we referred to as ISDR/+C[2a], was significantly associated with SVR in patients infected with HCV-2a. Multivariate analysis revealed that IRRDR[2a]≥4 was the only independent predictive factor for SVR. As for HCV-2b infection, an N-terminal half of IRRDR having two or more mutations (IRRDR[2b]/N≥2) was significantly associated with RVR, but not with SVR. No significant correlation was observed between core protein polymorphism and PEG-IFN/RBV treatment outcome in HCV-2a or HCV-2b infection. Conclusion: The present results suggest that sequence heterogeneity of NS5A of HCV-2a (IRRDR[2a]≥4 and ISDR/+C[2a]), and that of HCV-2b (IRRDR[2b]/N≥2) to a lesser extent, is involved in determining the viral sensitivity to PEG-IFN/RBV therapy.

Prevalence of hepatitis C virus genotype 1a in Japan and correlation of mutations in the NS5A region and single‐nucleotide polymorphism of interleukin‐28B with the response to combination therapy with pegylated‐interferon‐alpha 2b and ribavirin

Hepatitis C virus (HCV) genotype 1a is rare in Japanese patients and the clinical characteristics of this genotype remain unclear. The interferon (IFN) sensitivity-determining region (ISDR) and single-nucleotide polymorphisms (SNPs) of interleukin-28B (IL28B) among patients with HCV genotype 1b are associated with IFN response, but associations among patients with genotype 1a are largely unknown. This study investigated the clinical characteristics of genotype 1a and examined whether genomic heterogeneity of the ISDR and SNPs of IL28B among patients with HCV genotype 1a affects response to combination therapy with pegylated-IFN-α2b and ribavirin. Subjects comprised 977 patients infected with HCV genotype 1, including 574 men and 412 women (mean age, 55.2 ± 10.6 years). HCV was genotyped by direct sequencing of the 5'-untranslated region and/or core regions and confirmed by direct sequencing of the NS5A region. HCV genotypes 1a (n = 32) and 1b (n = 945) were detected. Twenty-three (71.9%) of the 32 patients with genotype 1a were patients with hemophilia who had received imported clotting factors. Prevalence of genotype 1a after excluding patients with hemophilia was thus 0.9%. Of the 23 patients with genotype 1a who completed IFN therapy, 11 (47.8%) were defined as achieving sustained virological response. Factors related to sustained virological response by univariate analysis were IL28B and ISDR. In conclusion, HCV genotype 1a is rare in Japan. The presence of IL28B genotype TT, and more than two mutations, in the ISDR are associated with a good response to IFN therapy in patients with HCV genotype 1a.