Virologic Nonresponders Research Articles

Brief Report: In cART-Treated HIV-Infected Patients, Immunologic Failure Is Associated With a High Myeloid-Derived Suppressor Cell Frequency.

During HIV infection, effective combined antiretroviral therapy suppresses viral replication and restores the number of circulating CD4+ T cells. However, 15%-30% of treated patients show a discordant response to combined antiretroviral therapy. Myeloid-derived suppressor cells (MDSC) are expanded in HIV+ patients; to better understand the role of MDSC on CD4 T-cell recovery, we evaluated the frequency of MDSC in HIV+ patients under combined antiretroviral therapy and its association with immunologic response. We enrolled 60 HIV+ patients, including complete responders (R, n = 44), virologic nonresponders (VNR, n = 5), and immunologic nonresponders (INR, n = 11). The frequency of circulating MDSC and the percentage of activated and naïve CD4 T cells were evaluated by flow cytometry. Plasmatic cytokine levels were analyzed by automated ELISA. As previously observed, polymorphonuclear MDSC (PMN-MDSC) frequency was higher in HIV+ patients compared with healthy donors. Furthermore, PMN-MDSC percentage was higher in INR than R patients, and a significant association between MDSC frequency and immunologic failure was confirmed by a receiver operator characteristic analysis. Accordingly, an inverse correlation was found between the percentages of PMN-MDSC and naïve CD4 T cells. A positive correlation was observed between PMN-MDSC frequency and the percentage of human leucocyte antigen locus DR + CD4 T cells and the plasmatic level of IL-1β and IL-8. Our results show that a high frequency of PMN-MDSC persists in INR, possibly because of immune activation, contributing to CD4 T-cell recovery failure. These findings further highlight the detrimental role of MDSC during HIV infection, suggesting these cells as a possible new therapeutic target.

Immunological factors associated with discordant virological response postcombination antiretroviral therapy in pediatric human immunodeficiency virus infection.

Evaluation of immunological factors responsible for discordant virological responses postcombination antiretroviral therapy (cART) in human immunodeficiency virus (HIV)-positive children aged <5 years. Immunological profiling of enrolled 30 HIV-positive children was done at enrollment, 6 and 12 months. Flow cytometric analysis was performed for enumeration of counts and percentage of CD4⁺, CD8⁺, and CD19⁺ cells; expression of CD19, CD86, PD-1, CD3, CD8 and CD28 on lymphocytes was evaluated using whole blood staining technique with monoclonal antibodies. HIV-1 viral load was quantified using a real-time polymerase chain reaction. Serum levels of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin (IgM), and interleukin (IL)-7 were quantitated using quantitative enzyme-linked immunosorbent assay kits. The HIV-infected children were categorized into virological responders (VRs; HIV-1 plasma viral load <47 copies/mL) and virological nonresponders (VNRs; HIV-1 plasma viral load >1000 copies/mL) following 1-year cART. The frequency of CD28⁺ CTLs cells was higher (P < 0.0001), and the frequency of CD28-CTLs cells was lower (P < 0.0001) in VRs than VNRs. CD28⁺ and CD28-CTLs cells correlated with HIV-1 plasma viremia (r = -0.4695, P = 0.01; r = 0.40, P = 0.03, respectively). VRs had higher CD19 percentage (P = 0.04) and count (P = 0.01) than VNRs. CD19⁺ B cells in the VRs had lower expression of CD86 (P = 0.03) and PD-1 (P = 0.002) than VNRs. VR had lower levels of serum IgG (P = 0.03), IgM (P = 0.04), and IL-7 (P = 0.01) than VNRs. High baseline B-cell counts, lower serum IgG, IgM, IL-7 levels, lower activation and exhaustion of B cells, and higher frequency of CD28⁺ CTLs are associated with positive virological response, whereas elevated CD28-CTLs are associated with the poor virological outcomes in HIV-infected children.

Genotype-specific versus pangenotypic regimens in patients infected with hepatitis C virus genotype 1b in real-world settings.

Introduction: The introduction of direct-acting antivirals (DAAs) has provided us with hope to eliminate hepatitis C virus (HCV) infection as a significant public health problem in the coming years. Objective: Our study aimed to compare the effectiveness and safety of genotype-specific and pangenotypic regimens in genotype 1b–infected patients treated in real-world settings. Patients and methods: Patients were selected from 990 HCV-infected individuals treated with DAAs in the Department of Infectious Diseases in Kielce, Poland, who had the therapy initiated between July 1, 2015 and December 31, 2020. Results: A total of 795 genotype 1b–infected patients with a median age of 51 years, female predominance (55%), and a 21.1% rate of cirrhosis were included in the analysis. A total of 69.9% of patients were treated with genotype-specific regimens. Those patients were significantly older, more often were treatment experienced, and had advanced liver fibrosis and cirrhosis compared with patients assigned to pangenotypic regimens. An overall sustained virologic response rate of 97.9% in the intention-to-treat (ITT) analysis and 99% after excluding nonvirologic nonresponders was achieved, with no significant difference between patients in the 2 treatment arms. Significantly higher proportions of men (P = 0.001) and DAA-experienced patients (P = 0.049) were documented among virologic nonresponders. Conclusions: We confirmed very high effectiveness and a good safety profile of both genotype-specific and pangenotypic regimens used in patients with genotype 1b HCV infection, and we found no differences between these 2 generations of medications. Male sex and previous treatment with DAAs were identified as negative predictors for therapy effectiveness.

High IL-5 levels possibly contributing to HIV viremia in virologic non-responders at one year after initiation of anti-retroviral therapy

Lack of viral monitoring in HIV infected patients on anti-retroviral therapy in low income countries may result in missing virologic non-responders (VNR) who show immunologic recovery in spite of unsuppressed viral replication. Biomarkers and drug resistance patterns in these discordant patients in comparison to the concordant treatment failure group need to be studied to understand possible risk factors associated with this condition. HIV infected patients on anti-retroviral therapy for one year were enrolled under three categories namely VNRs (n = 25), treatment failures (n = 18) and treatment responders (n = 40). They were assessed for HIV drug resistance by sequencing, plasma cytokines by luminex assay, T cell activation status by flow cytometry and total IgE levels by ELISA. VNR and failure patients had significantly lower median baseline CD4 counts than the responders. VNRs had significantly higher CD4 counts but lower viral load than treatment failures at one year of ART. VNRs had the highest eosinophil counts and the highest IL-5 levels among all the groups. IL-5 levels in them correlated with their viral load values. Frequency of Treg cells was also highest among the VNR group participants. More than 60% of the viremic patients irrespective of their groups harboured multiple HIV drug resistance mutations and mutation pattern did not differ between the groups. Low baseline CD4 counts and presence of multiple drug resistance mutations in the viremic groups highlighted the importance of early ART initiation and viral load monitoring irrespective of presence of immunologic failure. High IL-5 levels in VNR group indicated a need for investigating causal relationship between IL-5 and viral replication to devise therapeutic strategies to control viremia.

Predictive value of IL-28B rs12979860 variants for peg-IFN, sofosbuvir plus ribavirin treatment of HCV infection in Pakistani population.

The correlation of IL28-B genetic variants (rs12979860) with combinational therapy (peg-interferon, sofosbuvir plus ribavirin) of hepatitis C virus infection were studied in 154 chronic hepatitis C patients. The sustained virological response for efficient antiviral regimen was achieved in 75.32% treated individuals. Three genotypes of rs12979860 (CC, CT and TT) were compared both in sustained virological response and nonresponders groups (p=0.25, p≤ 0.001, p=0.10, respectively). CT genotype demonstrated a significant correlation (p≤ 0.001) in both groups with higher positive predictive value (81.55%). IL28 polymorphism and positive predictive value may be considered as the markers for the evaluation of the effectiveness of the treatment regimen. Further clinical trials are recommended to verify the role of IL28-B in hepatitis C virus treatment.

Clinical Impact of Virological Failure and Resistance Analysis Definitions used in Pivotal Clinical Trials of Initial Antiretroviral Treatment: A Systematic Review

There are no standardized criteria to characterize confirmed protocol-defined virological failure (PDVF) nor the inclusion criteria for the resistance analysis population (RAP) in Phase III randomized clinical trials (RCTs) of initial antiretroviral therapy (ART). We assessed the clinical impact of mismatching between virological non-response (HIV-1 RNA ≥50 copies/mL), confirmed PDVF (48 weeks), and RAP definition in studies with the newest first-line ART. A systematic review of all Phase III RCTs was performed, including preferred once-daily ART (EACS European AIDS guidelines) or recently approved by the US Food and Drug Administration. We identified 16 treatment arms (14 RCTs) with 6175 participants treated with dolutegravir, bictegravir, elvitegravir/cobicistat, raltegravir, darunavir/cobicistat, rilpivirine, or doravirine. Plasma HIV-1 RNA thresholds for PDVF or RAP ranged from 40 to 50, 200, 400, and 500 copies/mL. This led to discrepancies between trials regarding the participants defined as virological non-responders, PDVF, or included in RAP. Overall, 85/296 (29%) patients with PDVF were not genotyped. There was a linear correlation between the threshold of HIV RNA chosen to perform genotyping and rates of participants with PDVF but not genotyped. Only eight treatment arms genotyped all participants with PDVF. Most of the remaining eight arms genotyped roughly < 50% of those with PDVF. In summary, the absence of standardized definitions of VF and criteria for resistance testing in pivotal Phase III RCTs of the first-line ART leads to the possibility of underreporting of resistance mutations when genotypes are only performed at higher viral load cutoffs. Stringent homogeneous criteria should be defined to ensure that all participants with PDVF (e.g., confirmed HIV RNA ≥ 50 copies/mL and the second > 200 copies/mL) undergo genotyping.

Analysis of Host and Viral-Related Factors Associated to Direct Acting Antiviral Response in Hepatitis C Virus Patients.

Hepatitis C virus (HCV) signifies an important health issue as it is a globally prevalent pathogen and poses a great threat to human health. Direct antiviral therapy became a landmark in treatment against chronic HCV infection as they have proven to increase sustained virological response (SVR) rate, provide shortened and simplified regimens. This study aimed to evaluate efficacy of Sofosbuvir and classify factors of treatment success and their function in therapy continuation decision. We studied host and viral factors in 310 patients who received Sofosbuvir (DAA) at a dose of 400 mg daily along with ribavirin 10 mg/kg body weight for 24 weeks and followed by 12 weeks after completion of treatment. A total of 302 patients (97.42%) showed end-of-treatment response. However, 8 patients (2.58%) were virological nonresponders and 286 patients (94.70%) achieved SVR. Among 310 HCV positive, the percentage of viral genotype 3-infected patients was 89.6%, whereas only 10.32% were affected by HCV genotype 1. Multivariable analysis showed that baseline HCV RNA (≤8 × 106 IU/mL vs. >8 × 106 IU/mL) [95% confidence interval (CI), odds ratio (OR) 3.0, 2.0 to 8.4; p = 0.004], age (<50 vs. ≥50 years) (95% CI, OR 1.9, 3.0 to 10.1; p = 0.03), liver texture (normal liver vs. coarse) are related to virological response. None of the patients included in the study has S282T substitution in NS5b of HCV. No significant difference in response was observed in patients with different genotypes of rs12979860. Liver texture, age, and viral load are predictors of SVR. In this real-life data no substitution of S282T in NS5b was observed related to failure of therapy. Oral Sofosbuvir generally has a high tolerance and can effortlessly beat the safety concerns of past regimens.

Long-term follow-up of patients with chronic hepatitis C treated with α-interferon and ribavirin antiviral therapy: clinical and fibrosis impact of treatment response.

The slow progression of chronic hepatitis C (CHC) infection requires long observation periods to detect clinical changes. We compare the incidence of clinical events, hepatocellular carcinoma (HCC), overall mortality, liver-related mortality, and fibrosis progression between patients with a sustained virological response (SVR) and nonresponders (NR) after a 13-year follow-up period. One hundred and eighty-two CHC patients, who received interferon and ribavirin treatment between 1996 and 2000, were included. Clinical events were evaluated during follow-up. At the end of follow-up, transient elastography was used to assess fibrosis progression. Of the 182 patients, 46.7% (n=85) achieved an SVR. Twenty-seven patients developed hepatic decompensation (one SVR) and 15 developed HCC (three SVR). Twenty-nine patients died (eight SVR). Twelve of the 29 deaths were liver related (two SVR). Independent factors associated with hepatic decompensation were NR to treatment [hazard ratio (HR)=23.35; 95% confidence interval (CI): 2.90-189.25; P=0.003], advanced fibrosis at baseline (HR=9.11; 95% CI: 4.13-20.09), and treatment delay after diagnosis (HR=1.02; 95% CI: 1.00-1.03; P=0.012). Only the latter two were associated with HCC development and liver-related mortality. An assessment of liver fibrosis was performed on 125 patients (66 SVR). Fibrosis values were significantly lower in SVR patients, showing less progression to advanced stages of fibrosis [SVR: 6.6 (2.8); 95% CI: 5.8-7.3] than NR [NR: 14.0 (11.1); 95% CI: 11.1-16.9; P<0.001]. In patients with CHC, SVR is durable and reduces clinical events. The risk of HCC development is lower, but not eliminated. Sustained responders showed fibrosis stabilization or improved fibrosis values.

Interferon Lambda-3 rs12979860 Variants and Response to Pegylated Interferon in Chronic Hepatitis-C Genotype-3.

To assess the role of single nucleotide polymorphisms (SNPs) near the interferon lambda-3 (IFNλ3) (formal IL-28B) gene rs12979860 in predicting sustained virologic response (SVR) in hepatitis-C virus genotype-3 (HCV-3). Descriptive, analytical study. Department of Medicine, The Aga Khan University Hospital, Karachi, from July 2012 to June 2014. Patients with HCV-3 were classified as sustained virologic response (SVR), relapsers and non-responders. SNPrs12979860 was determined by PCR-RFLPprotocol. Differences between categorical variables were assessed by chi-square or Fisher's exact test, while those between continuous variables were evaluated using the Mann-Whitney U-test. Binary logistic regression analysis by forward conditional method was performed by using significant variables with p-values less than 0.05 as the criteria for model inclusion. Out of 115 patients, rs12979860 genotype-CC, CT, TTwas found in 37 (32.2%), 70 (60.9%), and 8 (7%) patients. 72 patients were male with median age of 45 years. Cirrhosis was present in 32 patients. Patients with response failures (no response and relapse, n=36 and 29, respectively) had higher baseline gamma glutamyl transferase (GGT) level (p < 0.001), higher alanine aminotransferase (p=0.027) and cirrhosis (p=0.001) than patients with SVR. Genotype-CC was present in 16/65 in response failures compared to 21/50 who achieved SVR (p=0.048). Rapid virologic response (RVR) (p < 0.001), low GGT(p=0.001) and absence of cirrhosis (p=0.039) were the independent predictive factors for SVR. In patients who could not achieve RVR and in patients with cirrhosis, SVR was seen more in with genotype-CC (p=0.007 and 0.038). In patients infected with HCV-3, IFNλ3 rs12979860, SNPhas less impact on SVR.

Prediction of long-term treatment outcome in HCV following 24 day PEG-IFN alpha-2b therapy using population pharmacokinetic-pharmacodynamic mixture modeling and classification analysis

Mathematical models have been widely used for understanding the dynamics of the hepatitis C virus (HCV). We propose a method to predict final clinical outcome for 24 HIV–HCV - coinfected patients with the help of a mathematical model based on the first two weeks of PEG-IFN therapy. Applying a pharmacokinetic-pharmacodynamic (PKPD) approach, together with mixture models, to the adapted model of viral dynamics developed by Neumann et al., we have analyzed the influence of PEG-IFN on the kinetics and interaction of target cells, infected cells and virus mRNA. It was found that PEG-IFN pharmacokinetic parameters were similar in sustained virological responders and nonresponders, while the plasma PEG-IFN concentration that decreases HCV production by 50% (EC50) and the rate of infected cell death were different. The treatment outcome depended mainly on the initial viral mRNA concentration and the rate of infected cell death. The population PKPD approach with a mixture model enabled the determination of individual PKPD parameters and showed high sensitivity (93.5%) and specificity (97.4%) for the prediction of the treatment outcome.

Expression patterns of immune-associated genes in external genital and perianal warts treated with sinecatechins.

The role of human papillomavirus (HPV) in human disease includes external genital and perianal warts (EGW), with some HPV genotypes having oncogenic potential (i.e., HPV-16 and -18). While green-tea extracts have antitumor and antiproliferative effects in vitro, the mechanism of action of sinecatechins in the treatment of EGW is not well understood. To investigate the role of immune-regulated genes further, an open-label, single institution, prospective study was conducted enrolling patients with clinically diagnosed EGW. Thirty subjects were enrolled, and 18 completed the trial. All patients applied sinecatechins 15% ointment to target lesions in the study. RNA expression microarrays were obtained from treated EGW lesions and analyzed for differential gene expression of immune-regulated genes. HPV types were analyzed and, based on copy number, were stratified into virological responders (VR) or nonresponders (VNR). Gene expression analysis of RNA samples was performed using TaqMan arrays for human T cell receptor and CD3 complex (TCR), Toll-like receptors (TLR) pathway, interferon (IFN) pathway, and antigen processing pathway. A total of 256 genes were analyzed across the four arrays. Genes that were significantly regulated between VRs and VNRs were CREB3L4, HIST1H3A, HIST1H3H, IFNA1, IFNA4, IFNA5, IFNA6, IFNA8, IFNA14, IFNG, IFNAR1, IL6, IRF9, MAPK4, MAPK5, MAPK14, NET1, and PIK3C2A in the IFN array. In the TCR array, HLA_B was found to be statistically significantly upregulated in both the VR and VNR groups; concomitantly, CD8A was found to be statistically significantly downregulated only in VRs. In the TLR array, only LBP and MAPK8 were found to be differentially regulated. In the antigen processing array, HLA-A, HLA-C, HLA-DMA, HLA-DMB, HLA-F, PSMA5, PSMB8, and PSMB9 were differentially downregulated. Based on these findings, it was determined that sinecatechins treatment modulates and downregulates genes involved in the pro-inflammatory response to HPV infection.

Evolution of simeprevir‐resistant variants in virological non‐responders infected with HCV genotype 1b

The present study was designed to assess the evolution of simeprevir-resistant variants (amino acid substitutions of aa80, aa155, aa156, and aa168 positions in HCV NS3 region) over time in virological non-responders (patients with positive HCV-RNA during and at end of treatment). The study enrolled 136 patients infected with HCV genotype 1b who received 12-week simeprevir-PEG-IFN-ribavirin therapy, and data of 87 patients were available for analysis. Twelve patients (14%) were considered virological non-responders, including 9 (75%) who showed absolute no-response (HCV RNA: ≥3.0 log IU/ml at 12 weeks after start of therapy). Multivariate analysis of these patients identified lack of response to prior treatment, use of low ribavirin dose, and old age as independent and significant determinants of virological non-response. Using ultra-deep sequencing, de novo variants of D168 were detected in all of 9 absolute non-responders. The majority of these variants emerged within 5 weeks of triple therapy. In comparison, de novo variants of Q80 were detected in only 3 of 9 absolute non-responders and emerged at 6-12 weeks. Variants of Q80 detected at baseline increased during the course of treatment in 5 of 9 absolute non-responders, while no such increase was noted in variants of R155 and/or A156 detected at baseline during the 12-week course. De novo variants of R155 and/or A156 were not detected in this study. The results demonstrated the emergence of simeprevir-resistant variants during the early stage of triple therapy.

Apoptotic Gene Expression in Sinecatechins-Treated External Genital and Perianal Warts

External genital and perianal warts (EGW)—the most common viral sexually transmitted disease in the United States—are caused by the human papillomavirus (HPV), a family of DNA viruses with more than 150 genotypes characterized to date (7). In 2006, sinecatechins ointment 15% (trade name Veregen ) was approved by the Food and Drug Administration for the treatment of EGW. Sinecatechins ointment is comprised of a proprietary blend of eight different catechins, the chief family of flavonoids believed to account for the wide array of health benefits attributed to green tea (12). In decreasing order of concentration, the four major catechins found in green tea are epigallocatechin gallate, epigallocatechin, epicatechin gallate, and epicatechin. Prior to their application for treating viral disease, catechins had been associated with a wide array of health benefits (10). Although it is believed that the majority of these health benefits are due to the catechins’ antioxidative activity, green tea catechins have also displayed poorly understood antiproliferative and antiviral properties (10). In vitro, epigallocatechin gallate can induce apoptotic growth inhibition of four HPV-infected tumor cell lines, and in vivo, green tea catechins were found to be effective in treating cervical HPV lesions, as determined by positive morphological changes of cervical lesions and a decrease of HPV DNA levels following treatment (8,11). However, despite these observations and FDA approval nearly a decade ago, the mechanism of action of sinecatechins-induced growth inhibition of EGW is unknown. To begin to answer this question, we performed an openlabel, single-site study enrolling subjects with a clinical diagnosis of EGW, and used specialized microarrays to determine the expression-level changes specific to apoptosis of EGW before and after sinecatechins treatment. A total of 30 subjects were recruited for the study, 24 male and 6 female, with a mean age of 39.2 – 10.6 years. Of these, 18 subjects remained enrolled and were available for follow-up for the duration of the study. Veregen ointment, 15%, was dispensed to the patient with instructions to apply to the target warts three times daily for 16 weeks. Three biopsies were taken from each patient—excised at baseline (B1), at the first visit with 50% or more clearance of target warts (B2), and at the first visit with complete clearance of target lesions (B3). Tissue samples were stored in RNAlater (Ambion) solution until processing, and nucleic acids were extracted from the samples using Trizol reagent (Sigma). HPV types from extracted DNA samples were detected by a nested polymerase chain reaction (PCR) approach as previously described (1), and copy number was determined with a custom-made real time PCR kit (Quantification of HPV6_15979, L1 protein, L1 gene, PrimerDesign Ltd.). Extracted and applied RNA, measured at A260/A280 nm, produced a ratio between 1.8 and 2.0. Subjects were stratified based on their response to treatment, which was quantitatively determined by measuring change in viral copy number between B1 and B3. Subjects were classified as virological responders (VR) if viral copy number decreased by at least 60% from B1, and were classified as virological nonresponders (VNR) if viral copy number remained the same or increased from B1. Of these, seven were found to be VR, and 11 were defined as VNR. In addition to the detection of HPV-6 in all lesions, one VR and three VNR were positive for co-infection with other HPV types (VR: HPV-18 and -35; VNR: HPV-7, -8, and -35). Next, the Applied Biosystems High Capacity RNAto-cDNA master mix was utilized for cDNA synthesis, and analysis of apoptotic gene expressions was then performed using TaqMan array 96-well plates. Initially, gene expression level was surveyed individually as an independent variable, and subsequently, group-based response values were generated using DataAssist v3.01 Software. Quantification of group-based responses for each gene were determined by calculating a fold change from biopsy 1 to biopsy 2 (B1_2), from biopsy 1 to biopsy 3 (B1_3), and from biopsy 2 to biopsy 3 (B2_3). Gene expression changes were categorized as biologically significant if there was at least a twofold change. To determine statistical significance of these fold changes, the statistical significance of these fold changes was evaluated using a nonparametric two-sided Wilcoxon signed-rank test with a significance level of p< 0.05.

Genotypic Analysis of the V3 Region of HIV from Virologic Nonresponders to Maraviroc-Containing Regimens Reveals Distinct Patterns of Failure

Changes in HIV tropism from R5 to non-R5 or development of drug resistance is often associated with virologic failure in patients treated with maraviroc, a CCR5 antagonist. We sought to examine changes in HIV envelope sequences and inferred tropism in patients who did not respond to maraviroc-based regimens. We selected 181 patients who experienced early virologic failure on maraviroc-containing therapy in the MOTIVATE trials. All patients had R5 HIV by the original Trofile assay before entry. We used population-based sequencing methods and the geno2pheno algorithm to examine changes in tropism and V3 sequences at the time of failure. Using deep sequencing, we assessed whether V3 sequences observed at failure emerged from preexisting subpopulations. From population genotyping data at failure, 90 patients had R5 results, and 91 had non-R5 results. Of the latter group, the geno2pheno false-positive rate (FPR) value fell from a median of 20 at screening to 1.1 at failure. By deep sequencing, the median percentage of non-R5 variants in these patients rose from 1.4% to 99.5% after a median of 4 weeks on maraviroc. In 70% of cases, deep sequencing could detect a pretreatment CXCR4-using subpopulation, which emerged at failure. Overall, there were two distinct patterns of failure of maraviroc. Patients failing with R5 generally had few V3 substitutions and low non-R5 prevalence by deep sequencing. Patients with non-R5 HIV who were failing developed very-high-prevalence non-R5 HIV (median, 99%) and had very low geno2pheno values.

The importance of HCV RNA measurement for tailoring treatment duration

The introduction of telaprevir and boceprevir in the treatment of chronically HCV genotype 1 infected patients has led to substantially improved sustained virologic response rates and shorter treatment duration for a growing group of patients. Management and monitoring of patients receiving protease inhibitor-based triple therapy is of major importance and has become more complicated. Close monitoring of HCV RNA levels for patients on protease inhibitor-based therapy to identify subjects who are eligible for shortening of treatment duration, are virological non-responders or are in danger of experiencing a viral breakthrough is strongly recommended. Several virological tools including qualitative and quantitative HCV RNA assays for detection and quantification of HCV RNA are commercially available. We review these methods and their implications for HCV therapy as well as current sustained virologic response definition, stopping rules and recommendations for protease inhibitor-based treatment durations.

Mutations in the NS5A gene are associated with response to interferon+ribavirin combination therapy in patients with chronic hepatitis C virus 3a infection

The clinical correlation between hepatitis C virus (HCV) NS5A gene mutations and response to antiviral treatment in HCV-3a-infected patients is not as well known as that in HCV-1a-infected and HCV-1b-infected patients. This study attempted to determine mutations in the NS5A gene in isolates of HCV-3a obtained from infected Pakistani patients treated with interferon-α standard therapy and to determine its association with several host factors. A total of 71 consecutive chronically infected HCV patients [43 men and 28 women, mean age 38 years (range, 16-70 years)] without previous antiviral therapy, who fulfilled other criteria of the current study were enrolled for antiviral therapy. Of the 71 patients enrolled, 53 completed the course of antiviral therapy. Among them, 23 (43.3%) patients showed an end-of-treatment response, 20 (41.4%) showed a sustained virological response, and three (5.6%) patients were HCV-RNA negative at the end of treatment but developed a relapse thereafter. Only seven (13.2%) patients were virologic nonresponders (NR). Probable transmission risk factors were previous major/minor surgery (20%), transfusion of blood or blood products (2%), dental surgery (10%), or sporadic (unknown; 60%). The estimated duration of infection varied from 6 months to 20 years. The correlation between the number of mutations and several factors was also studied. The first factor that was associated with the number of mutations in the NS5A gene was age older than 40 years, where the difference was statistically significant between viral sequences of patients showing an end-of-treatment response and NR (P<0.001). Further, the difference in the average number of mutations was statistically significant between patients showing sustained virological response and NR (P<0.005). The second and third factors that were found to be associated with number of mutations in the NS5A gene were sex and viral load, respectively. Along with host factors such as age older than 40 years, female sex, and low baseline viral load, the less number of mutations in the NS5A gene of HCV-3a is associated with a positive outcome of treatment response in HCV patients receiving interferon plus ribavirin therapy.

Persistence of a Large Population of Exhausted Monoclonal B cells in Mixed Cryoglobuliemia After the Eradication of Hepatitis C Virus Infection

Functionally exhausted and mostly autoreactive B-cells with a peculiar CD21(low)CD11c(+) phenotype accumulate in several human immunological disorders including common variable immunodeficiency, HIV infection and rheumatoid arthritis. In HCV-associated mixed cryoglobulinemia (MC) there is accumulation of exhausted clonal B cells expressing a V(H)1-69-encoded cross-reactive idiotype; these cells are phenotypically heterogeneous, displaying either a CD21(low)CD11c(+) or a marginal zone (MZ)-like (IgM(+)CD27(+)CD21(+)CD11c(-)) phenotype. Irrespective of their phenotype, V(H)1-69(+) B-cells are unresponsive to the stimulation of Toll-like receptor 9 (TLR9). We investigated the fate of these cells after the eradication of HCV. Fourteen MC patients were studied before and after antiviral therapy. V(H)1-69(+) B-cells were identified using the G6 monoclonal antibody and their phenotype and responsiveness to the stimulation of TLR9 were investigated. In seven virological non-responders, cryoglobulin levels and the number and phenotype of V(H)1-69(+) B cells remained substantially unchanged. By contrast, in sustained viral responders cryoglobulinemia subsided and the number of V(H)1-69(+) B cells declined. However, high proportions of MZ-like V(H)1-69(+) B cells retaining unresponsiveness to TLR9 stimulation persisted for several months in these patients. Clonal expansion of CD21(low) V(H)1-69(+) B cells may depend on continual stimulation by HCV, whereas their MZ-like counterparts may persist for years after the eradication of infection. Prolonged survival of exhausted MZ-like B cells after withdrawal of the initial inciting stimulus may contribute to the accumulation of autoreactive B cells in immunological disorders.

The future for the treatment of genotype 4 chronic hepatitis C

Hepatitis C virus genotype 4 (HCV-4) is the most common type of hepatitis C virus (HCV) in the Middle East and Africa, in particular Egypt. Since the development of new protease inhibitors, the response of HCV-4 to the standard regimen of treatment (pegylated interferon/ribavirin) lags behind other genotypes and has become the most resistant type to treat. The development of therapeutic strategies for all patients with HCV-4 whether they are naïve, have experienced a virological breakthrough, are relapsers or non-responders is still a considerable challenge. New types of interferon (Consensus Interferon, Y-shaped, Albinterferon...) and new direct action antiviral drugs (Nitazoxanide, Vit.D, other) may improve the treatment of patients with HCV-4. The IL28B CC polymorphism may be associated with sustained virological response.

Genetic Heterogeneity of Hepatitis C Virus in Association with Antiviral Therapy Determined by Ultra-Deep Sequencing

Background and AimsThe hepatitis C virus (HCV) invariably shows wide heterogeneity in infected patients, referred to as a quasispecies population. Massive amounts of genetic information due to the abundance of HCV variants could be an obstacle to evaluate the viral genetic heterogeneity in detail.MethodsUsing a newly developed massive-parallel ultra-deep sequencing technique, we investigated the viral genetic heterogeneity in 27 chronic hepatitis C patients receiving peg-interferon (IFN) α2b plus ribavirin therapy.ResultsUltra-deep sequencing determined a total of more than 10 million nucleotides of the HCV genome, corresponding to a mean of more than 1000 clones in each specimen, and unveiled extremely high genetic heterogeneity in the genotype 1b HCV population. There was no significant difference in the level of viral complexity between immediate virologic responders and non-responders at baseline (p = 0.39). Immediate virologic responders (n = 8) showed a significant reduction in the genetic complexity spanning all the viral genetic regions at the early phase of IFN administration (p = 0.037). In contrast, non-virologic responders (n = 8) showed no significant changes in the level of viral quasispecies (p = 0.12), indicating that very few viral clones are sensitive to IFN treatment. We also demonstrated that clones resistant to direct-acting antivirals for HCV, such as viral protease and polymerase inhibitors, preexist with various abundances in all 27 treatment-naïve patients, suggesting the risk of the development of drug resistance against these agents.ConclusionUse of the ultra-deep sequencing technology revealed massive genetic heterogeneity of HCV, which has important implications regarding the treatment response and outcome of antiviral therapy.

Killer cell immunoglobulin‐like receptors and response to antiviral treatment in Thai patients with chronic hepatitis C virus genotype 3a

Genetic factors of the host have been shown to influence the outcome of treatment for hepatitis C virus (HCV) infection. Killer cell immunoglobulin-like receptors (KIR) regulate natural killer (NK) cell activity by interaction with specific human leukocyte antigen (HLA) class I. In this study, KIR gene polymorphisms and their HLA ligands were investigated in 110 Thai patients with chronic HCV genotype 3a. Seventy-six patients were sustained virological responders and 34 patients were virological non-responders. KIR typing and HLA-C typing were performed using PCR-SSP (polymerase chain reaction with sequence specific primer). The frequency of HLA-C1C2 was significantly higher in sustained responders than in non-responders (P = 0.04). However, the frequencies of KIR2DL2/2DL3 genotype and KIR2DL2/2DL3-HLA-C1C1 genotype were significantly higher in non-responders than in sustained responders (P = 0.02, 0.004, respectively). In summary, this study showed the association of KIR genes and ligands with the outcome of antiviral treatment in chronic hepatic C virus genotype 3a infection.