Utility of hepatitis C viral load monitoring on direct-acting antiviral therapy

Time required to achieve optimum viral load suppression with Ravidasvir/sofosbuvir in chronic hepatitis C patients with or without compensated cirrhosis

A study indicated that ravidasvir (RDV) has excellent safety and tolerability when used with sofosbuvir (SOF) to treat chronic HCV infection. The aim of this study was to determine the time taken by RDV/SOF to achieve optimum viral load suppression in chronic hepatitis C patients with or without compensated cirrhosis. Data from the open-label, multicentre, single-arm, phase II/III clinical trial (STORM-C-1) were utilized. Time‒to-event analysis via Kaplan-Meier curves was performed to determine the time required to achieve optimum viral load suppression in both the cirrhotic and noncirrhotic groups. Multivariate logistic regression analyses were performed to identify potential predictors of achieving suppression within four and eight weeks. The time to achieve optimum viral load suppression ranged from six to 85 days and from five to 148 days among noncirrhotic and cirrhotic patients, respectively. Among noncirrhotic patients, 80.6% achieved optimum viral load suppression within 4 weeks, and 92.6% achieved this within 8 weeks. Among cirrhotic patients, 76.1% and 90.4% achieved optimum viral load suppression within 4 and 8 weeks, respectively. Notably, optimum viral load suppression differs from sustained virological response (SVR12), which is defined as undetectable HCV RNA 12 weeks after treatment completion. While the study demonstrates promising early viral suppression, it does not evaluate the efficacy of a shortened regimen. Further research is needed to assess whether shorter treatment durations maintain high SVR12 rates without compromising treatment success.

Comparison of a dual antibody and antigen HCV immunoassay to standard of care algorithmic testing

The Centers for Disease Control and Prevention (CDC) guidelines for hepatitis C virus (HCV) testing, although effective, may miss crucial diagnostic opportunities. The goal of this study was to assess the utility of an antibody (Ab) and antigen (Ag) combination immunoassay as an alternative to traditional HCV screening. Remnant specimens from 1,341 patients with concurrent third-generation serologic (Roche anti-HCV-II) and nucleic acid amplification testing (NAAT) were assessed using the HCV Duo Ab/Ag immunoassay (Roche). Patient demographics, risk factors, and standard of care (SOC) laboratory results from the medical records were recorded. Overall, 99.0% (197/199) of the HCV Duo Ab+/Ag+specimens accurately identified active infections as confirmed by NAAT, and 99.9% (670/671) Ab-/Ag- samples corresponded to those without HCV infections. Individually, the HCV Duo Ab component demonstrated a 95.6% positive percent agreement (PPA) (95% CI = 93.8-96.9) and 99.1% negative percent agreement (NPA) (98.8-99.6) compared with SOC anti-HCV II Ab assay. The HCV Duo Ag had a 73.5% PPA (67.9-78.4) and 99.8% NPA (99.3-100) with NAAT. Among RNA+ specimens, 73.4% (197/267) were HCV Duo Ag+, and 265/267 (99.3%) were successfully detected on the HCV Duo Ab component. Notably, 5/7 (71.4%) Ab-/RNA +specimens were detected by HCV Duo, which would have been missed by traditional algorithmic testing. Fourth generation HCV Duo Ab/Ag assay demonstrated comparable performance to SOC testing and shortens the diagnostic window but does not eliminate the need for NAAT in all patients. Ab/Ag testing identified several Ab-/RNA+ cases, a subgroup often undiagnosed by current algorithmic testing, demonstrating promise for improved diagnostic efficiency and accuracy in HCV detection.IMPORTANCEThis study highlights the potential of a combined hepatitis C virus (HCV) Duo antibody (Ab) and antigen (Ag) immunoassay to improve early detection of HCV infections. Traditional Ab-only screening methods recommended by the Centers for Disease Control and Prevention may miss early-stage infections. The HCV Duo assay showed high accuracy, detecting nearly all active infections confirmed by nucleic acid amplification testing. Dual detection of HCV Ab and Ag shortens the diagnostic window, enabling intervention and treatment in a single visit, which is crucial for improving patient outcomes and reducing HCV transmission, especially in areas with limited access to confirmatory molecular testing.

Performance Evaluation of the Roche Cobas 5800 HBV and HCV Tests: Comparison of the 200 and 500 μL Protocols

Background

Clinical management of patients infected with hepatitis B virus (HBV) or hepatitis C virus (HCV) relies on the viral load (VL). The Cobas 5800 system (Roche Diagnostics) can determine VLs in 200 and 500 μL samples, but the performance of each protocol has not been compared. We evaluated the performance of both protocols for the HBV and HCV tests.

Methods

Precision and linearity were verified using commercial panels. Probit analyses were used to determine limits of detection (LoDs). The results obtained with 336 samples were compared using the 200 and 500 μL protocols. Data from 6,737 retrospective HBV and 768 HCV samples were compared to estimate the effects of the different LoDs on the diagnostic results of the protocols. Correlations between protocols were tested with Spearman's rank correlation coefficients (rho).

Results

The precision and linearity of both protocols were verified. The LoDs for the 200 and 500 μL protocols were 6.5 and 2.7 IU/mL for HBV and 29.7 and 8.2 IU/mL for HCV, respectively. The agreement between the protocols ranged from 0.8 to 1.0. The results obtained with the HBV and HCV tests showed a strong correlation (rho=0.994). Only 0.4% of HBV and 0.4% of HCV test results were affected by the LoDs of the 200 μL protocol.

Conclusions

The Cobas 5800 200 and 500 μL protocols for the HBV DNA and HCV RNA tests demonstrated excellent performance. These findings establish the 200 μL protocol as a new option for low-volume samples, especially for pediatric and difficult-to-bleed patients.

Evaluation of GeneXpert and advanced biological laboratories UltraGene HCV diagnostic detection and performance against Roche real time PCR in Myanmar

BACKGROUND

Developing countries experience limited access to HCV laboratory tests for different reasons. Providing near to real-time HCV testing and results especially to at-risk populations including those in rural settings for timely initiation to treatment is key. Within a rural Myanmar setting, we compared HCV diagnostic detection and quantification of the GeneXpert, and Advanced Biological Laboratories UltraGene-HCV assays against the gold standard and reference method Roche real-time HCV in Myanmar.

METHODS

Blood samples from 158 high-risk individuals were assessed using three different methods at baseline. Results were checked for normality and log transformed. Log differences and bias between methods were calculated and correlated. Pearson's correlation coefficient was used to determine the association of HCV viral loads across all methods. The level of agreement with the standard method (Roche real time HCV) was assessed using Bland-Altman analyses.

RESULTS

There was a strong positive correlation coefficient between all three methods with GeneXpert and Roche having the strongest, r = 0.96, (p<0.001). Compared to Roche, ABL (mean difference, 95 % limits of agreement; -0.063 and -1.4 to 1.3 Log10IU/mL) and GeneXpert (mean difference, 95 % limits of agreement; -0.28 and -0.7 to 1.8 Log10IU/mL) showed a good level of agreement with the GeneXpert being slightly superior.

CONCLUSION

We demonstrate the excellent performance and no-inferiority, in terms of levels of agreements of both GeneXpert and ABL compared to the Roche platform and supporting the use of the POC assays as alternative a cost-effective methods in HCV detection and diagnosis in developing and low resource settings countries.

Does a detectable HCV RNA at the end of DAA therapy herald treatment failure?

BACKGROUND & AIMS

The study aimed to assess the phenomenon of achieving sustained virologic response (SVR) in patients with detectable ribonucleic acid (RNA) of hepatitis C virus (HCV) at the end of treatment (ET) with direct-acting antivirals (DAA), find how this is affected by the type of regimen, and how patients experiencing this differed from non-responders with detectable HCV RNA at the ET.

METHODS

The study included all consecutive patients with detectable HCV RNA at the ET selected from the EpiTer-2 database, a retrospective national multicentre project evaluating antiviral treatment in HCV-infected patients in 2015-2023.

RESULTS

Of the 16106 patients treated with IFN-free regimens with available HCV RNA assessment at the ET and at follow-up 12 weeks after treatment completion (FU), 1253 (7.8%) had detectable HCV RNA at the ET, and 1120 of them (89%) finally achieved SVR. This phenomenon was significantly more frequent in pangenotypic regimens, 10.3% vs. 4.7% in genotype-specific options (p < 0.001), and the highest proportion was documented for glecaprevir/pibrentasvir (13.7%), and velpatasvir/sofosbuvir ± ribavirin (6.9%). Patients ET + FU- treated with these two pangenotypic regimens (n = 668) had less advanced liver disease, were less frequently infected with genotype (GT) 3, and were significantly more likely to be treatment-naïve than 61 non-responders.

CONCLUSIONS

We documented 7.8% rate of patients with detectable HCV RNA at the ET, of whom 89% subsequently achieved SVR, significantly more frequently in the population treated with pangenotypic regimens. Less severe liver disease, more often GT3 infection, and a higher percentage of treatment-naive patients distinguished this group from non-responders.

Meta-analysis: diagnostic accuracy of hepatitis C core antigen detection during therapy with direct-acting antivirals

BACKGROUND

Treatment of hepatitis C virus (HCV) infection with direct-acting antivirals (DAAs) is monitored by assessing plasma HCV-RNA load. However, detection of HCV core antigen (HCVcAg) may be an alternative.

AIM

To evaluate the diagnostic performance of the HCVcAg assay to monitor the efficacy of DAAs in HCV-infected patients METHODS: We performed searches in multiple electronic databases until 6 July 2022, of studies evaluating the HCVcAg detection in plasma or serum compared with the HCV-RNA test (gold standard). We calculated pooled measurement at 2 and 4 weeks of treatment, and at end-of-treatment (EOT), as well as sustained virological response (SVR; 12 weeks after EOT).

RESULTS

We selected 16 studies from 2016 to 2022, with 3237 patients and 8958 samples. Overall, the diagnostic performance and clinical utility of the HCVcAg assay were poor at week 2 (sensitivity = 0.40, specificity = 0.96, positive likelihood ratio (PLR) = 9.16, negative likelihood ratio (NLR) = 0.63, and area under the summary receiver operating curve (SROC) = 0.57), fair at week 4 (sensitivity = 0.30, specificity = 0.90, PLR = 3.18, NLR = 0.77, and AUC = 0.79), acceptable at EOT (sensitivity = 0.40, specificity =0.98, PLR = 16.54, NLR = 0.62, and AUC = 0.97) and excellent for SVR (sensitivity = 0.94, specificity = 0.99, PLR = 107.54, NLR = 0.06, and AUC = 0.99).

CONCLUSIONS

The HCVcAg assay may be helpful for monitoring the efficacy of HCV treatment with DAAs in HCV-infected patients at EOT and for documenting SVR, but not at weeks 2 and 4 of treatment due to poor diagnostic performance.

Utility of On-Treatment Viral Loads During Treatment With Direct-Acting Antivirals in Patients Infected With Chronic Viral Hepatitis C

Background: Direct-acting antiviral (DAA) agents have revolutionized the treatment of chronic hepatitis C virus (HCV) infection. Current data regarding the utility of on-treatment HCV viral load (VL) monitoring are conflicting and limited data are available in HIV-coinfected patients. Objective: The objective of the study was to determine whether on-treatment VLs are predictive of HCV cure in a real-world population. Method: A single-center, retrospective cohort study was conducted using patients who received a prescription for DAA therapy for HCV treatment at a large, tertiary ambulatory care clinic. Results: A total of 219 patients were included in the final analysis. The average age was 56 years. Most patients were male (64.4%), African American (73.1%), and insured by Medicaid (61.6%). Most patients were treatment-naive, noncirrhotic, and infected with HCV genotype 1a (73.1%). About 22.4% of patients were coinfected with HIV. The most common regimen was 12 weeks of ledipasvir/sofosbuvir (53.9%). On-treatment VLs were most commonly obtained at treatment week 4 (42.5%), of which 45.2% of patients were detectable. Sustained virologic response (SVR) was achieved in 96.8% of the total population and 95.9% of HIV-coinfected patients. Of the 7 patients who did not achieve SVR, 3 patients had undetectable on-treatment VLs in the first 8 weeks of therapy. Conclusion: Sustained virologic response rates were similar between HCV-monoinfected patients and HCV-HIV-coinfected patients. This research further supports that on-treatment VLs may not be a valuable indicator of treatment failure but may be helpful to engage patients in care and ensure treatment adherence and ultimately cure.

Blood Levels of Glutamine and Nitrotyrosine in Patients with Chronic Viral Hepatitis

Purpose

Oxidative stress is involved in pathogenesis of chronic viral hepatitis. Glutamine is an antioxidant, but there is a controversy about its risk-benefits. Nitrotyrosine is an oxidative stress marker. This observational cross-sectional study was designed to compare blood levels of glutamine and nitrotyrosine in treated versus untreated chronic viral hepatitis patients.

Patients and Methods

Five groups (n = 250) were included: hepatitis B untreated (HBV), hepatitis C untreated (HCV), HBV treated (HBVT), and HCV treated (HCVT) groups plus a normal control group. Liver function tests and blood levels of glutamine, nitrotyrosine, viral loads, and HBsAg were measured.

Results

Blood levels of glutamine and nitrotyrosine in all patient groups significantly increased compared with normal controls with non-significant differences in-between. Both tests showed significant large correlations with HBV-DNA or HCV-RNA test positivity, high accuracies, and cutoff scores with high sensitivities and specificities. The viral loads and HBsAg levels were significantly lower in treated versus untreated groups. However, they poorly correlated with levels of glutamine and nitrotyrosine in all patient groups.

Conclusion

Blood levels of glutamine and nitrotyrosine significantly increased in treated and untreated chronic viral hepatitis B and C patients compared with normal controls. Both tests showed high accuracies and cutoff scores with high sensitivities and specificities. However, they did not differ significantly in treated versus untreated patients. To our knowledge, this is the first data showing elevation of glutamine and nitrotyrosine in treated and untreated chronic viral hepatitis. A prospective longitudinal study with repeated measurements of glutamine and nitrotyrosine is recommended to verify if they can predict response to treatment. Study of other oxidative stress markers is also advised to clarify if the elevated nitrotyrosine could be an oxidative stress marker in these patients, and whether the increased glutamine could act as an antioxidant or as a predictive agent for deleterious consequences.

Hepatitis C Virus Core Antigen as an Alternative to RNA in the Assessment of Response to Treatment with Direct-acting Oral Antivirals

Background: Affordable and effective diagnostic and treatment monitoring algorithms are urgently needed to achieve the global elimination of hepatitis C virus (HCV) infection. Methods: A total of 274 patients were treated with direct-acting antivirals (DAAs) in the Spanish Hospital of Albacete between 2004 and 2020. This study compared the enzyme-immunoassay technique for HCV core antigen (HCVcAg) with the determination of RNA of HCV (HCV RNA) by polymerase chain reaction (PCR) in monitoring treatment with DAA, setting the lower limit of detection of HCVcAg < 3 fmol/L and RNA < 10 IU/mL. In all cases, the P value of differences associated with the contrast test was less than or equal to 0.05. Results: We evaluated the viral loads of our patients before treatment, during their treatment, and after its completion. The HCV RNA quantification at diagnosis was 2309327 IU/mL. The mean HCVcAg load was 5972 fmol/L. There was a strong correlation between HCVcAg levels and RNA levels with a Spearman rho of 0.832 (P < 0.01). The HCVcAg sensitivity at diagnosis was 99%, but the specificity could not be calculated because there were no true negatives or false positives at this point. Twelve weeks after treatment, in patients with treatment failure, we obtained a mean of 19084 IU/mL for RNA, while for HCVcAg, the mean was 103 fmol/L. At this time point, we also found a strong correlation between HCVcAg levels and HCV RNA levels with a Spearman rho of 0.775 (P < 0.01). Finally, the virological cure was achieved in 99% of our patients. The results for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 100%, 99.87%, 86.33%, and 100%, respectively. Conclusions: HCVcAg determination is an excellent alternative to HCV RNA in the assessment of treatment response. This is particularly relevant in lower- and middle-income countries and resource-limited settings where the high cost of labor, equipment, and reagents can prohibit molecular testing.

COVID-19 Diagnostics: Past, Present, and Future

In winter of 2020, SARS-CoV-2 emerged as a global threat, impacting not only health but also financial and political stability. To address the societal need for monitoring the spread of SARS-CoV-2, many existing diagnostic technologies were quickly adapted to detect SARS-CoV-2 RNA and antigens as well as the immune response, and new testing strategies were developed to accelerate time-to-decision. In parallel, the infusion of research support accelerated the development of new spectroscopic methods. While these methods have significantly reduced the impact of SARS-CoV-2 on society when coupled with behavioral changes, they also lay the groundwork for a new generation of platform technologies. With several epidemics on the horizon, such as the rise of antibiotic-resistant bacteria, the ability to quickly pivot the target pathogen of this diagnostic toolset will continue to have an impact.

The predictors of sustained virological response with sofosbuvir and ribavirin in patients with chronic hepatitis C genotype 2

BACKGROUND/AIMS

Real-world, clinical practice data are lacking about sofosbuvir/ ribavirin (SOF/RBV) treatment of Korean patients with hepatitis C virus genotype 2 (HCV GT2) infection. This study investigated the efficacy and safety of SOF/RBV in Korean patients with HCV GT2 infection and clinical factors predicting sustained virological response 12 weeks (SVR12) after the end of SOF/RBV treatment.

METHODS

A total of 181 patients with HCV GT2 with/without cirrhosis were treated with SOF/RBV for 16/12 weeks. Rapid virological response (RVR) was defined as non-detectable HCV RNA at 4 weeks.

RESULTS

The RVR rate was 80.7% (146/181), the end of treatment response rate was 97.8% (177/181) and the SVR12 rate was 92.8% (168/181). Of eight patients with relapse, four did not achieve RVR. Three patients had a history of hepatocellular carcinoma (HCC). Multivariable analysis showed that RVR (p = 0.015) and no previous history of HCC (p = 0.007) were associated with SVR12. Factors significantly contributing to RVR included cirrhosis, creatinine concentration, and pre-treatment HCV RNA level. SVR12 rate was significantly higher in RVR (+) than RVR (-) patients (95.2% vs. 82.9%, p = 0.011) and also significantly higher in patients without than with a history of HCC (94.1% vs. 72.7%, p = 0.008). During treatment, 80/181 patients (44.2%) experienced mild to moderate adverse events, with 32 (17.7%) requiring RBV dose reductions due to anemia.

CONCLUSION

SOF/RBV treatment was effective and tolerable in HCV GT2 patients. RVR and no previous history of HCC were positive predictors of SVR12.

Sofosbuvir/velpatasvir for patients with chronic hepatitis C virus infection and compensated liver disease: real-world data in Taiwan

BACKGROUND

Data regarding the real-world effectiveness and safety of sofosbuvir/velpatasvir (SOF/VEL) for East Asian patients with chronic hepatitis C virus (HCV) infection and compensated liver disease are limited. We evaluated the performance of SOF/VEL for 12 weeks for HCV-infected patients with compensated liver disease in a large real-world cohort in Taiwan.

METHODS

Between July 2019 and March 2020, 1880 HCV-infected patients with compensated liver disease who received SOF/VEL 400/100 mg once daily for 12 weeks were included at 15 academic centers in Taiwan. The sustained virologic response at off-treatment week 12 (SVR12) was assessed for evaluable (EP) and per-protocol populations (PP). The tolerance was also reported.

RESULTS

The SVR12 rates by EP and PP analyses were 95.6% [1798 of 1880 patients; 95% confidence interval (CI) 94.6-96.5%] and 99.3% (1798 of 1811 patients; 95% CI 98.8-99.6%), respectively. Among 82 patients who failed to achieve SVR12, 13 (15.9%) were attributed to virologic failures. The SVR12 rates were comparable regardless of baseline characteristics. A total of 1859 (98.9%) patients completed 12-week SOF/VEL treatment. Four (0.2%) patients discontinued treatment due to adverse events (AEs). All patients with serious AEs or deaths were judged not related to SOF/VEL. The AEs occurring in ≥ 10% included headache (16.8%), fatigue (16.2%), nausea (11.8%), and insomnia (11.1%). Nine (0.5%) and 2 (0.1%) patients had grade 3 total bilirubin and alanine aminotransferase elevations.

CONCLUSIONS

SOF/VEL for 12 weeks is efficacious and well-tolerated by chronic HCV-infected patients with compensated liver disease in Taiwan.

Intrahepatic Viral Kinetics During Direct-Acting Antivirals for Hepatitis C in Human Immunodeficiency Virus Coinfection: The AIDS Clinical Trials Group A5335S Substudy

BACKGROUND

Direct-acting antivirals (DAAs) targeting hepatitis C virus (HCV) have revolutionized outcomes in human immunodeficiency virus (HIV) coinfection.

METHODS

We examined early events in liver and plasma through A5335S, a substudy of trial A5329 (paritaprevir/ritonavir, ombitasvir, dasabuvir, with ribavirin) that enrolled chronic genotype 1a HCV-infected persons coinfected with suppressed HIV: 5 of 6 treatment-naive enrollees completed A5335S.

RESULTS

Mean baseline plasma HCV ribonucleic acid (RNA) = 6.7 log10 IU/mL and changed by -4.1 log10 IU/mL by Day 7. In liver, laser capture microdissection was used to quantify HCV. At liver biopsy 1, mean %HCV-infected cells = 25.2% (95% confidence interval [CI], 7.4%-42.9%), correlating with plasma HCV RNA (Spearman rank correlation r = 0.9); at biopsy 2 (Day 7 in 4 of 5 participants), mean %HCV-infected cells = 1.0% (95% CI, 0.2%-1.7%) (P < .05 for change), and DAAs were detectable in liver. Plasma C-X-C motif chemokine 10 (CXCL10) concentrations changed by mean = -160 pg/mL per day at 24 hours, but no further after Day 4.

CONCLUSIONS

We conclude that HCV infection is rapidly cleared from liver with DAA leaving <2% HCV-infected hepatocytes at Day 7. We extrapolate that HCV eradication could occur in these participants by 63 days, although immune activation might persist. Single-cell longitudinal estimates of HCV clearance from liver have never been reported previously and could be applied to estimating the minimum treatment duration required for HCV infection.

Update on Guidelines for Sexually Transmitted Infection Treatment and Management in the Adult and Adolescent Population

Sexually transmitted infections (STIs) are a prevalent global health care problem. Incidence rates are rising yearly. STI incidence is highest for adolescents and young adults ages 15 to 24, who are diagnosed with half of all new STIs. Chlamydia trachomatis and Neisseria gonorrhea are common STIs caused by bacteria. Treatment guidelines change frequently as a result of antimicrobial resistance and public health trends. It is important for primary care providers to remain up to date with new guidelines. This article provides updates on pharmacologic treatment as well as patient education and follow-up specific to the primary care setting.

Response guided therapy for reducing duration of direct acting antivirals in chronic hepatitis C infected patients: a Pilot study

The advent of direct-acting antivirals (DAAs) has transformed the landscape of hepatitis C virus (HCV) management. We aimed to prospectively (real-time) evaluate the feasibility of using a response-guided therapy approach, based on mathematical modeling of early viral kinetics, to reduce the duration of DAAs therapy. Patients were treated with DAAs according to the physicians' preference. HCV was measured at baseline and at day 2 and weeks 1, 2 and 4 after treatment initiation. The primary endpoint was the proportion of patients with sustained-virological response (SVR) at 12 and/or 24 weeks post-treatment. Twenty-nine patients (mean age 54 ± 16, 44% females, 73% with HCV genotype 1), were enrolled and all completed therapy. Treatment duration was shortened in 11 of the 29 patients (38%). SVR was achieved in 28 of the 29 patients (97%). Relapse occurred post treatment in a single case of a non-cirrhotic male with genotype 3, who was treated with sofosbuvir/velpatasvir for 6 weeks. Virus sequencing did not identify baseline or treatment emergent resistance associated substitutions. Real-time mathematical modeling of early HCV kinetics can be utilized for shortening DAAs duration in approximately 40% of patients without compromising treatment efficacy.Clinical trial registration: ClinicalTrials.gov Identifier: NCT03603327.

Decrease of T-cells exhaustion markers programmed cell death-1 and T-cell immunoglobulin and mucin domain-containing protein 3 and plasma IL-10 levels after successful treatment of chronic hepatitis C

During chronic hepatitis C virus (HCV) infection, both CD4+ and CD8+ T-cells become functionally exhausted, which is reflected by increased expression of programmed cell death-1 (PD-1) and T-cell immunoglobulin and mucin domain-containing protein 3 (Tim-3), and elevated anti-inflammatory interleukin 10 (IL-10) plasma levels. We studied 76 DAA-treated HCV-positive patients and 18 non-infected controls. Flow cytometry measured pretreatment frequencies of CD4+PD-1+, CD4+PD-1+Tim-3+ and CD8+PD-1+Tim-3+ T-cells and IL-10 levels measured by ELISA were significantly higher and CD4+PD-1-Tim-3- and CD8+PD-1-Tim-3- T-cells were significantly lower in patients than in controls. Treatment resulted in significant decrease of CD4+Tim-3+, CD8+Tim-3+, CD4+PD-1+Tim-3+ and CD8+PD-1+Tim-3+ T-cell frequencies as well as IL-10 levels and increase in CD4+PD-1-Tim-3- and CD8+PD-1-Tim-3- T-cells. There were no significant changes in the frequencies of CD4+PD-1+ T-cells, while CD8+PD-1+ T-cells increased. Patients with advanced liver fibrosis had higher PD-1 and lower Tim-3 expression on CD4+T-cells and treatment had little or no effect on the exhaustion markers. HCV-specific CD8+T-cells frequency has declined significantly after treatment, but their PD-1 and Tim-3 expression did not change. Successful treatment of chronic hepatitis C with DAA is associated with reversal of immune exhaustion phenotype, but this effect is absent in patients with advanced liver fibrosis.

Simple predictors of nonresponse to direct-acting antivirals in chronic hepatitis C patients

OBJECTIVES

The introduction of direct acting antivirals (DAAs) has resulted in very high sustained virological response rates (SVR) in patients with chronic hepatitis-C (CHC). There are still a minority who fails to achieve SVR. This study aims to identify simple factors associated with nonresponse to DAAs using routine pretreatment workup.

METHODS

A retrospective study included 10 655 CHC patients who were candidates for anti-viral therapy. Pretreatment demographics, laboratory results, ultrasonography and FIB-4were obtained.

RESULTS

At post-treatment week 4, 10 495 patients (98.5%) were responders and 160 (1.5%) were non-responders. About 50.6% of non-responders were males and 61.3% were cirrhotic. Non-responders had significantly higher baseline BMI, liver enzymes, AFP and a significantly lower albumin, platelet count by univariate analysis ((P < 0.001). Sex, previous treatment, BMI, liver cirrhosis, AST, Albumin and platelet counts were the independent predictors of non-response. At post-treatment week 12, HCV-PCR results were available only for 7259 patients and 210 (2.9%) were non-responders. 54.8% of non-responders were cirrhotic and 51.4% were males. Non-responders had significantly higher AST, AFP and INR and a significantly lower albumin level, platelet count by univariate analysis (P < 0.05). Sex, previous treatment, AST, Albumin, WBC and platelet counts were the independent predictors of non-response. SVR-4 among treatment naive patients was 98.6% while among treatment experienced was 96.8%. SVR-12 among treatment naive patients was 97.9% while among treatment experienced was 87.9%.Cirrhotics had SVR-4 rate 97.7% and SVR-12 rate 96.21%.

CONCLUSION

Routine pre-treatment work up for HCV G4 patients receiving DAAs can help in prediction of non-response.

Effect of Low Positive End of Treatment Viral Load with Direct-Acting Antiviral Therapy on Sustained Virologic Response

BACKGROUND

Direct-acting antivirals (DAAs) are highly effective treatments against hepatitis C virus (HCV), with sustained virologic response (SVR) rates of 93-100% against all genotypes. In most patients, viral load (VL) becomes undetectable four weeks into treatment, but rarely a low positive VL may be observed at the end of treatment (EOT). This study was conducted to determine the effect of low positive EOT VLs with DAA therapies on SVR at 12 and 24 weeks.

METHODS

A retrospective chart review was conducted from January 2014 to December 2018 on 1256 HCV patients of all genotypes (1-6) who had received DAA therapy at two large hepatology referral centers. Baseline demographic data, along with VL at week four, EOT, and SVR12/24 time points were collected for patients that had positive EOT VL. Treatment outcome for any patient with positive EOT VL was noted.

RESULTS

Eight out of 1256 patients treated with varying DAA therapies were observed to have low positive EOT VLs ranging from <15 to 235 IU/mL. One patient had a negative EOT VL, but 23 IU/mL at week four after EOT. All eight patients who had low positive EOT VLs and one patient who had a low positive VL at four weeks after EOT achieved SVR at weeks 12 and 24. One of the eight patients had cirrhosis. The majority of patients were genotype 1a.

CONCLUSION

In the DAA treatment era, low levels of detectable HCV RNA at EOT does not predict treatment failure.

Reversal of T Cell Exhaustion in Chronic HCV Infection

The long-term consequences of T cell responses’ impairment in chronic HCV infection are not entirely characterized, although they may be essential in the context of the clinical course of infection, re-infection, treatment-mediated viral clearance and vaccine design. Furthermore, it is unclear whether a complete reinvigoration of HCV-specific T cell response may be feasible. In most studies, attempting to reverse the effects of compromised immune response quality by specific blockades of negative immune regulators, a restoration of functional competence of HCV-specific T cells was shown. This implies that HCV-induced immune dysfunction may be reversible. The advent of highly successful, direct-acting antiviral treatment (DAA) for chronic HCV infection instigated investigation whether the treatment-driven elimination of viral antigens restores T cell function. Most of studies demonstrated that DAA treatment may result in at least partial restoration of T cell immune function. They also suggest that a complete restoration comparable to that seen after spontaneous viral clearance may not be attained, pointing out that long-term antigenic stimulation imprints an irreversible change on the T cell compartment. Understanding the mechanisms of HCV-induced immune dysfunction and barriers to immune restoration following viral clearance is of utmost importance to diminish the possible long-term consequences of chronic HCV infection.

Real-life efficacy of generic sofosbuvir/ledipasvir for treatment of Iranian patients with chronic hepatitis C: A cohort study

BACKGROUND

Treatment of hepatitis C virus (HCV) infection with recently introduced direct-acting antiviral agents (DAA) is effective and safe, however there is little known regarding safety and efficacy of generic DAAs in the real-life clinical setting. This study aimed to evaluate the efficacy and safety of generic sofosbuvir/ledipasvir (SOF/LDV) in a real-life clinical experience.

METHODS

In this prospective cohort study, patients with chronic HCV infection who referred to Middle East Liver Diseases (MELD) Center were included. Based on the patients' condition, they were treated with SOF/LDV fixed-dose combination with or without ribavirin (RBV) for 12 or 24 weeks.

RESULTS

A total of 30 (M/F: 19/11) patients with chronic HCV genotype 1 infection with a mean age of 49.8 years were treated with generic SOF/LDV with (9 patients) or without (11 patients) RBV for 12 (27 patients) or 24 (3 patients) weeks. Ten (33.3%) had cirrhosis and 13 (43.3%) with a previous history of treatment with interferon (IFN)-based regimens. Among the 30 patients, 26 (86.7%, 95% CI=70.3%-94.7%) achieved a rapid virologic response, 30 (100%, 95% CI=88.7%-100%) achieved the end of treatment response and 30 (100%, 95% CI=88.7%-100%) achieved a sustained virologic response. No severe treatment adverse event was observed however, 6 (20%) patients experienced mild to moderate adverse events.

CONCLUSION

The treatment of HCV genotype 1 infection with generic SOF/LDV found to be safe and effective even in patients with cirrhosis and previous history of treatment with IFN-based treatments.

Pangenotypic direct acting antivirals for the treatment of chronic hepatitis C virus infection: A systematic literature review and meta-analysis

BACKGROUND

Recent approval and adoption of pangenotypic direct acting antivirals (DAAs) necessitated a revision of the 2015 World Health Organization guidelines for the management of persons with hepatitis C virus (HCV) infection.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and relevant conference proceedings to identify randomized and non-randomized trials, as well as prospective observational studies of DAAs. The proportions of persons with events were pooled for sustained virological response at 12 weeks post-treatment (SVR12), discontinuations due to adverse events (DAEs), serious adverse events (SAEs), and all-cause mortality. Analyses were stratified by HCV genotype and antiviral treatment experience, with subgroup analyses based on presence of cirrhosis and HIV-HCV coinfection.

FINDINGS

The evidence base consisted of 238 publications describing 142 studies. In the overall analysis, which included all persons irrespective of treatment experience or comorbidities, the pooled proportion achieving SVR12 exceeded 0.94 for all pangenotypic regimens across genotypes 1, 2, and 4. Some heterogeneity may have led to lower SVR rates in persons with genotype 3 infection. High SVR12 (>0.90) was observed in persons with genotype 1 infection with cirrhosis, though evidence varied and was limited for genotypes 2-4. Evidence was sparse for persons with HIV-HCV coinfection. All regimens were associated with small proportions of persons with DAEs, SAEs, or all-cause mortality.

INTERPRETATION

Based on this and other supporting evidence, the WHO issued updated guidelines with a conditional recommendation, based on moderate quality evidence, for the use of pangenotypic DAA regimens for persons with chronic HCV infection aged 18 years and older (July 2018).

FUNDING

This study was funded by the World Health Organization.

Incidence and predictors of direct-acting antiviral treatment failure in Turkish patients with chronic hepatitis C genotype 1b infection

Evaluation of the incidence and predictors of failure of direct-acting antiviral treatment for hepatitis C virus genotype 1b patients is important. Our retrospective cohort study assessed 172 Turkish patients who had received a full course of such treatment and could be checked for sustained virologic response. The overall treatment failure rate was 2.9% (5/172), all of whom relapsed. In three of these cases with sequencing data available, all had NS5A resistance-associated substitution. Multivariate analysis revealed that a 1 mg/dL increase in pre-treatment total bilirubin level was associated with a sevenfold increased likelihood of treatment failure. The baseline level of total bilirubin was the only significant independent predictor of direct-acting antiviral treatment failure.

Viral dynamics among HCV infected patients with different genotypes treated with genotypic specific or pan-genotypic direct-acting antiviral agent combinations

BACKGROUND

New hepatitis C virus (HCV) therapies have improved efficacy, allowed pangenotypic applications, increased barriers to drug resistance and shortened therapy duration.

METHODS

Patients infected with different HCV genotypes were divided into two groups: group 1 included 169 patients receiving genotypic specific regimens (GSR), while group 2 included 186 patients receiving pan-genotypic regimens (PGR). Patient's HCV RNA was quantified and sequenced.

RESULTS

Comparable sustained viral response (SVR) rates were observed in both GSR and PGR treated patients. Nevertheless, even if not significant, a greater proportion of non-detectable levels (NDL) of HCV RNA was observed in patients treated with PGR as compared with GSR. Overall, among patients in the GSR and PGR groups with residual viremia, 124/169 (73.4%) and 125/186 (67.2%) at four weeks, and 66/169 (39.1%) and 58/186 (31.2%) at eight weeks, achieved SVR. No difference was observed in the clinical outcome comparing patients in the GSR and PGR groups according to genotype. While, comparing patients between the two groups, the proportion of patients with NDL HCV RNA at four and eight weeks was higher in patients infected with genotype 1b treated with PGR (p=0.0015). A significantly higher number of patients infected with 1b had RASs at baseline (p=0.0001). In addition, the proportion of patients with treatment failure was higher in patients with RASs at baseline compared with those without (p=0.012). Overall, 2.5% patients failed to achieve SVR after DAA treatment.

CONCLUSION

A sharp HCV RNA decrease was observed in patients treated with both GSR and PGR. However, even if comparable, a slightly greater number of patients treated with PGR achieved NDL HCV RNA as compared with GSR. A significant difference was observed in patients with baseline RASs, both in relation to treatment failure and genotype. In conclusion, the use of new DAA combinations helps patients achieve a more rapid virologic response.

Interferon at the cellular, individual, and population level in hepatitis C virus infection: Its role in the interferon-free treatment era

The advent of powerful direct-acting antiviral agents (DAAs) has revolutionized the treatment of hepatitis C. DAAs cure nearly all patients with short duration, oral treatments. Significant efforts are now underway to optimize DAA-based treatments. We discuss the potential role of interferon in this optimization. Clinical studies present compelling evidence that DAAs perform better in treatment-naive individuals than in individuals who previously failed treatment with interferon, a surprising correlation because interferon and DAAs are thought to act independently. Recent mathematical models explore a mechanistic hypothesis underlying this correlation. The hypothesis invokes the action of interferon at the cellular, individual, and population levels. Strong interferon responses prevent the productive infection of cells, reduce viral replication, and impede the development of resistance to DAAs in infected individuals and improve cure rates elicited by DAAs in treated populations. The models develop descriptions of these processes, integrate them into a comprehensive framework, and capture clinical data quantitatively, providing a successful test of the hypothesis. Individuals with strong endogenous interferon responses thus present a promising subpopulation for reducing DAA treatment durations. This review discusses the conceptual advances made by the models, highlights the new insights they unravel, and examines their applicability to optimize DAA-based treatments.

Early HCV viral kinetics under DAAs may optimize duration of therapy in patients with compensated cirrhosis

BACKGROUND & AIMS

Detailed hepatitis C virus (HCV) kinetics modelling is scarce in patients with advanced liver disease receiving direct-acting antivirals (DAAs). Due to budget restrictions, patients and health systems would benefit from the shortest possible treatment course. We investigated whether modelling very early HCV kinetics in cirrhotic patients under DAAs therapy could be used to individualize care and reduce treatment duration to achieve cure.

METHODS

We included 74 patients with HCV-related cirrhosis who received interferon-free treatments for 12-24 weeks. HCV genotype, liver disease stage and treatment regimen were recorded. Viral load was determined prospectively at very frequent intervals until target not detected (TND, <15 IU/mL). A viral kinetic model was used to predict time to cure based on HCV clearance in extracellular body fluid (CL-EF).

RESULTS

Sixty-eight patients (92%) achieved cure. Thirteen (18%) had MELD ≥15, 35 (47%) were Child-Pugh (CTP) ≥7. Median time to reach TND was 2 weeks (IQR: 1-4 weeks). Modelling indicated an average DAAs efficacy in blocking viral production of ε = 99.1%. HCV half-life (t1/2 ) was significantly shorter in patients with CTP <7, LSM <21 kPa or MELD <15 (1.5 vs 2.5 hours; P = 0.0057). The overall median CL-EF was 5.6 weeks (4.1-7.8). A CTP >7 and a LSM ≥21 kPa were significantly (P = 0.016) associated with longer CL-EF.

CONCLUSIONS

The study provides insights into HCV dynamics during DAAs therapy in patients with compensated and decompensated cirrhosis. Viral kinetics modelling suggests that treatment duration may be optimized in patients with compensated cirrhosis.

Field evaluation of GeneXpert® (Cepheid) HCV performance for RNA quantification in a genotype 1 and 6 predominant patient population in Cambodia

GeneXpert^® (Cepheid) is the only WHO prequalified platform for hepatitis C virus (HCV) nucleic acid amplification testing that is suitable for point-of-care use in resource-limited contexts. However, its application is constrained by the lack of evidence on genotype 6 (GT6) HCV. We evaluated its field performance among a patient population in Cambodia predominantly infected with GT6. Between August and September 2017, we tested plasma samples obtained from consenting patients at Médecins Sans Frontières' HCV clinic at Preah Kossamak Hospital for HCV viral load (VL) using GeneXpert^® and compared its results to those obtained using COBAS^® AmpliPrep/Cobas^® TaqMan^® HCV Quantitative Test, v2.0 (Roche) at the Institut Pasteur du Cambodge. Among 769 patients, 77% of the seropositive patients (n = 454/590) had detectable and quantifiable VL using Roche and 43% (n = 195/454) were GT6. The sensitivity and specificity of GeneXpert^® against Roche were 100% (95% CI 99.2, 100.0) and 98.5% (95% CI 94.8, 99.8). The mean VL difference was -0.01 (95% CI -0.05, 0.02) log₁₀  IU/mL for 454 samples quantifiable on Roche and -0.07 (95% CI -0.12, -0.02) log₁₀  IU/mL for GT6 (n = 195). The limit of agreement (LOA) was -0.76 to 0.73 log₁₀  IU/mL for all GTs and -0.76 to 0.62 log₁₀ IU/mL for GT6. Twenty-nine GeneXpert^® results were outside the LOA. Frequency of error and the median turnaround time (TAT) for GeneXpert^® were 1% and 0 days (4 days using Roche). We demonstrated that the GeneXpert^® HCV assay has good sensitivity, specificity, quantitative agreement, and TAT in a real-world, resource-limited clinical setting among GT6 HCV patients.

HCV-Specific T Cell Responses During and After Chronic HCV Infection

Hepatitis C virus (HCV)-specific T cell responses are closely linked to the clinical course of infection. While T cell responses in self-limiting infection are typically broad and multi-specific, they display several distinct features of functional impairment in the chronic phase. Moreover, HCV readily adapts to immune pressure by developing escape mutations within epitopes targeted by T cells. Much of our current knowledge on HCV-specific T cell responses has been gathered under the assumption that this might eventually pave the way for a therapeutic vaccine. However, with the development of highly efficient direct acting antivirals (DAAs), there is less interest in the development of a therapeutic vaccine for HCV and the scope of T cell research has shifted. Indeed, the possibility to rapidly eradicate an antigen that has persisted over years or decades, and has led to T cell exhaustion and dysfunction, provides the unique opportunity to study potential T cell recovery after antigen cessation in a human in vivo setting. Findings from such studies not only improve our basic understanding of T cell immunity but may also advance immunotherapeutic approaches in cancer or chronic hepatitis B and D infection. Moreover, in order to edge closer to the WHO goal of HCV elimination by 2030, a prophylactic vaccine is clearly required. Thus, in this review, we will summarize our current knowledge on HCV-specific T cell responses and also provide an outlook on the open questions that require answers in this field.

Clinical significance of detectable and quantifiable HCV RNA at the end of treatment with ledipasvir/sofosbuvir in GT1 patients

BACKGROUND & AIMS

AASLD/IDSA treatment guidelines for hepatitis C virus (HCV) infection state that testing for quantitative HCV RNA can be considered at the end of antiviral treatment (EOT) with interferon-free regimens. However, it remains unclear how to respond to a detectable or even quantifiable HCV RNA result. The aim of this study was to analyse the frequency and predictive value of detectable and quantifiable HCV RNA results at the EOT in patients with HCV genotype 1 infection treated with ledipasvir (LDV) and sofosbuvir (SOF) ± ribavirin (RBV) in a large real-world cohort.

METHODS

A retrospective analysis of the DHC-R (Deutsches Hepatitis C-Register, German Hepatitis C-Registry) cohort was performed including all patients who were treated with LDV/SOF ± RBV and in whom HCV RNA testing was done with either the Roche COBAS AmpliPrep/COBAS TaqMan (CAP/CTM) or the Abbott RealTime HCV assay (ART).

RESULTS

The frequency of detectable HCV RNA at the EOT was 7% in this real-world study involving 471 patients. Furthermore, 3% of the patients (n = 14/471) even had quantifiable viral load at the EOT. Detectable and quantifiable results were more frequent if the ART was used for testing. However, SVR was achieved by 32/33 patients (97%) with detectable and even by all 14 patients (100%) with quantifiable HCV RNA results at the EOT.

CONCLUSION

Detectable and even quantifiable HCV RNA results are quite frequent if highly sensitive HCV RNA assays are used. However, treatment prolongation is not indicated, as SVR rates remain high in these patients.

Short-term histological evaluations after achieving a sustained virologic response to direct-acting antiviral treatment for chronic hepatitis C

BACKGROUND

Interferon-free, direct-acting antiviral treatments can result in a sustained virologic response in nearly 100% of patients with chronic hepatitis C virus infection.

AIMS

The purpose of this study was to evaluate histological improvement after achieving a sustained virologic response to direct-acting antiviral treatments in patients with chronic hepatitis C.

METHODS

Among 691 patients with chronic hepatitis C who achieved a sustained virologic response to direct-acting antivirals, 51 underwent liver biopsy 41 ± 20 weeks after the end of treatment despite normal transaminase levels. In 20 patients, liver biopsy specimens obtained a median of 1.2 years before the start of treatment were available.

RESULTS

Among the 51 patients who underwent post-sustained virologic response biopsies, the grade of inflammation was A0 in 18 patients, A1 in 24, A2 in eight, and A3 in one; the stage of fibrosis was F0 in three patients, F1 in 20, F2 in 15, F3 in nine, and F4 in four. Among the nine post-sustained virologic response biopsy specimens with moderate-to-severe inflammation (≥A2), four showed S1-to-S3 steatosis (>5% of hepatocytes affected). In the 20 paired biopsy specimens, the inflammation grade significantly regressed (p = 0.0043), but the fibrosis stage did not (p = 0.45). Histological improvement, defined as a ≥ 2-point decrease in the Knodell inflammatory score and no worsening of the fibrosis, was found in 11 (55%) patients. The iron accumulation had significantly regressed (p = 0.0093), but the steatosis had not (p = 0.10).

CONCLUSIONS

Even if transaminases become normal after obtaining a sustained virologic response, significant histological inflammation of unknown cause was found in some patients. Additionally, improvement in liver fibrosis was not evident in the short term.

Modeling how reversal of immune exhaustion elicits cure of chronic hepatitis C after the end of treatment with direct-acting antiviral agents

A fraction of chronic hepatitis C patients treated with direct‐acting antivirals (DAAs) achieved sustained virological responses (SVR), or cure, despite having detectable viremia at the end of treatment (EOT). This observation, termed EOT⁺/SVR, remains puzzling and precludes rational optimization of treatment durations. One hypothesis to explain EOT⁺/SVR, the immunologic hypothesis, argues that the viral decline induced by DAAs during treatment reverses the exhaustion of cytotoxic T lymphocytes (CTLs), which then clear the infection after treatment. Whether the hypothesis is consistent with data of viral load changes in patients who experienced EOT⁺/SVR is unknown. Here, we constructed a mathematical model of viral kinetics incorporating the immunologic hypothesis and compared its predictions with patient data. We found the predictions to be in quantitative agreement with patient data. Using the model, we unraveled an underlying bistability that gives rise to EOT⁺/SVR and presents a new avenue to optimize treatment durations. Infected cells trigger both activation and exhaustion of CTLs. CTLs in turn kill infected cells. Due to these competing interactions, two stable steady states, chronic infection and viral clearance, emerge, separated by an unstable steady state with intermediate viremia. When treatment during chronic infection drives viremia sufficiently below the unstable state, spontaneous viral clearance results post‐treatment, marking EOT⁺/SVR. The duration to achieve this desired reduction in viremia defines the minimum treatment duration required for ensuring SVR, which our model can quantify. Estimating parameters defining the CTL response of individuals to HCV infection would enable the application of our model to personalize treatment durations.

Real life efficacy of ledipasvir/sofosbuvir in hepatitis C genotype 4-infected patients with advanced liver fibrosis and decompensated cirrhosis

Limited clinical trial data has shown high efficacy of co-formulated ledipasvir/sofosbuvir (LDV/SOF) in the treatment of hepatitis C virus (HCV) genotype (GT)-4 infected cirrhotic patients. We assessed real-world safety and efficacy of LDV/SOF with or without ribavirin (RBV) in GT4-infected patients with compensated and decompensated cirrhosis.

PATIENTS & METHODS

This observational cohort (n = 213) included GT4 treatment-naïve (59.6%) and -experienced (40.4%) patients with advanced fibrosis (F3, Metavir; n = 30), compensated (F4, n = 135) and decompensated cirrhosis (n = 48) treated for 12 (n = 202) or 24 weeks (n = 11) with LDV/SOF. RBV was dosed by physician discretion between 600-1200 mg daily. Patients with prior DAA failure were excluded from the analysis. The primary efficacy endpoint was sustained virologic response 12 weeks after treatment (SVR12) on an intention-to-treat analysis, and occurrence of serious adverse events (SAEs).

RESULTS

The mean age of the overall cohort was 59.6 ± 12.1 years and 125 (58.7) were female. Overall, 197 (92.5%) of the patients achieved SVR12, including 93.3% of F3 fibrosis, 93.3% of compensated cirrhotics and 89.6% of the decompensated cirrhotics (P = 0.686). Addition of RBV (68.5%) did not enhance efficacy (91.8% vs. 94.0% without RBV, P = 0.563), including in F3 fibrosis, compensated and decompensated cirrhosis (P > 0.05, for all). There was no difference in SVR12 rates with 24 and 12 weeks therapy (90.9% and 92.6%, respectively; P = 0.586). Treatment failure (n = 16) was mostly related to relapse (n = 11), while on-treatment death (n = 3) and breakthrough (n = 2) comprised a minority. SAEs occurred in 9 (4.2%) patients requiring early treatment discontinuation in 4 (3 on-treatment deaths and 1 pregnancy).

CONCLUSION

LDV/SOF therapy yielded high SVR12 rates in both compensated and decompensated cirrhotic GT4 patients. The addition of RBV to this regimen did not improve efficacy. The safety profile of this regimen was comparable with that reported for other HCV genotypes.

Significance of detectable HCV RNA below the limit of quantification in patients treated with DAAs using standard and ultrasensitive protocols

Predictive factors of HCV relapse after treatment with DAAs are poorly understood. In this study, we aimed to assess whether the residual viral load positivity observed during or at the end of treatment (EOT) has an impact on viral outcome. Blood samples were collected from 337 patients with genotypes (GT) 1a, 1b, 2, 3, and 4 HCV chronic infection, treated with DAAs to determine HCV RNA load by the Abbott RealTime HCV (ART) assay at treatment week (W) 4, at EOT, and 4, 12, 24 weeks after discontinuation. EOT and other samples with "detected <12/mL" (DNQ) were retested by an ultrasensitive protocol (USP) to confirm the result. Frequency of DNQ was analyzed in subgroups of patients and clinical conditions to assess potential correlations. At W4, 22% and 30.9% of the samples were undetectable and DNQ by ART assay, respectively, but no correlation for achieving SVR was found. In contrast, an HCV RNA cut-off of ≥50/mL at W4 was a significant predictor of therapy failure (P = 0.036, univariate analysis). At EOT, DNQ was associated to 12W treatment duration (P < 0.001) and GT1a infection (P = 0.036). Overall, 20/41 (48.8%) of DNQ samples at EOT or post-treatment W4, were confirmed by USP but only in a single case the patient experienced viral relapse. HCV RNA at W4 can predict SVR, irrespective to genotype or DAA regimen. HCV RNA DNQ at EOT is associated to shorter treatment duration and to GT1a, but is not a predictor of therapy failure.

Sofosbuvir + velpatasvir + voxilaprevir for the treatment of hepatitis C infection

INTRODUCTION

Hepatitis C is a disease with a significant global impact. Over the last several years, the treatment of the disease has been revolutionized. Therapy has transformed over the last several years with the approval of second generation direct acting antivirals, and currently utilized medications for the treatment of hepatitis C are significantly more efficacious with better safety profiles than previously approved treatments. Treatment for individuals who have failed therapy on direct acting antivirals has, until recently, been complex and difficult to treat, but the approval of sofosbuvir/velpatasvir/voxilaprevir represents a new therapeutic option for these individuals. Areas covered: Sofosbuvir/velpatasvir/voxilaprevir is a recently approved therapeutic combination for the treatment of hepatitis C. This article reviews the studies leading to the approval of the combination, and its efficacy and safety profile. Expert opinion: Sofosbuvir/velpatasvir/voxilaprevir fills one of the previously unfilled niches for the treatment of hepatitis C, that of the treatment of individuals who have failed therapy with resistant virus. With the filling of this niche, there appears to be a general slowing of the development of new therapeutics. Although understandable, in the long term, there are considerable risks associated with the decreased development of new drugs to treat hepatitis C.

Viral kinetics analysis and virological characterization of treatment failures in patients with chronic hepatitis C treated with sofosbuvir and an NS5A inhibitor

BACKGROUND

The combination of sofosbuvir (SOF) plus an NS5A inhibitor for 12 weeks is highly efficacious in patients with chronic hepatitis C. As the costs of generic production of sofosbuvir and NS5A inhibitor are rapidly decreasing, the combination of these DAAs will be the standard treatment in most low- to middle-income countries in the future.

AIM

To identify key predictors of response that can be used to tailor treatment decisions.

METHODS

A cohort of 216 consecutive patients infected with HCV genotype 1 (1a: n = 57; 1b: n = 77), 2 (n = 4), 3 (n = 33) or 4 (n = 44) were treated with sofosbuvir (SOF) + daclatasvir (n = 176) or SOF + ledipasvir (n = 40) for 12 weeks. The viral kinetics was analysed using the biphasic model and the cure boundary was used to predict time to clear HCV.

RESULTS

The overall SVR rate was high (94.4%; n = 204), regardless of the time to viral suppression or low-level viraemia at the end of treatment. The model-based predicted HCV RNA levels at the end of treatment could not differentiate patients who did from those who did not achieve SVR. The presence of NS5A resistance-associated substitutions [position 28 (OR = 70.3, P<.001) and/or 31 (OR = 61.6, P = .002)] at baseline was predictive of virological failure in cirrhotic patients but was not associated with on-treatment viral kinetics.

CONCLUSION

This real-world study confirms the excellent results of clinical trials with therapies based on a combination of SOF plus an NS5A inhibitor. It suggests that a personalized approach including baseline NS5A inhibitor resistance testing may inform treatment decisions in cirrhotic patients.

Hepatitis C virus core antigen for screening organ donors and recipients

Organ donors and recipients are routinely screened for hepatitis C virus (HCV) infection, typically via anti-HCV detection. We analyze the utility of an alternative HCV core antigen (HCV-Ag) quantification system, the ARCHITECT HCV Ag Assay, in this setting. We simultaneously tested 315 samples from potential organ donors and recipients using two chemiluminescent microparticle immunoassays: ARCHITECT Anti-HCV and HCV Ag (Abbott, Germany). HCV-Ag was detected in 81 of the serum samples (25.71%) and anti-HCV in 87 (27.62%). Seventy-five of the HCV-Ag-positive samples were positive for anti-HCV (92.59%). Overall concordance between the two assays was 94.29%. Of the six HCV-Ag-positive/anti-HCV-negative patients, five had HCV-Ag values <32 fmol/L, and the sixth had a concentration of 477.50 fmol/L (viral load, 137,000 IU/mL). The HCV AG Assay detects HCV infections missed by the Anti-HCV Assay. Both markers should be used to screen for HCV infection in potential organ donors and recipients.

Values, preferences and current hepatitis B and C testing practices in low- and middle-income countries: results of a survey of end users and implementers

BACKGROUND

Access to hepatitis B virus (HBV) and hepatitis C virus (HCV) diagnostics remains a key bottleneck in scale-up of access to HBV and HCV treatment, particularly in low- and middle-income countries (LMICs) that lack laboratory resources and skilled personnel. To inform the development of World Health Organization (WHO) testing guidelines on who to test and how to test, we performed a "values and preferences" survey of end users and implementers of hepatitis testing in LMICs on current hepatitis B and C testing practices and acceptability of diagnostic approaches, as well as preferences for the future.

METHODS

The survey consisted of a four-part, 28 question online survey tool using SurveyMonkey software. The invitation to participate was sent via email to a network of contacts in hepatitis clinical care, research, advocacy and industry.

RESULTS

The survey collected responses on current testing practices from 48 respondents in 23 LMICs. Only a small proportion of hepatitis testing is currently funded through government-supported programmes. Most limit their testing programmes to blood donor screening and although testing is recommended in several populations, this is not well implemented. Also, there is still very limited access to virological testing.

CONCLUSIONS

The survey showed that HBV and HCV testing programmes in LMICs are inadequate and/or scarce. Lack of affordable diagnostic tests; lack of funding, public education and awareness; absence of national policies and guidelines; and a dearth of skilled health professionals are the most important barriers to scaling up HBV and HCV diagnosis and treatment.

Optimising diagnosis of viraemic hepatitis C infection: the development of a target product profile

Background

The current low access to virological testing to confirm chronic viraemic HCV infection in low- and middle-income countries (LMIC) is limiting the rollout of hepatitis C (HCV) care. Existing tests are complex, costly and require sophisticated laboratory infrastructure. Diagnostic manufacturers need guidance on the optimal characteristics a virological test needs to have to ensure the greatest impact on HCV diagnosis and treatment in LMIC. Our objective was to develop a target product profile (TPP) for diagnosis of HCV viraemia using a global stakeholder consensus-based approach.

Methods

Based on the standardised process established to develop consensus-based TPPs, we followed five key steps. (i) Identifying key potential global stakeholders for consultation and input into the TPP development process. (ii) Informal priority-setting exercise with key experts to identify the needs that should be the highest priority for the TPP development; (iii) Defining the key TPP domains (scope, performance and operational characteristics and price). (iv) Delphi-like process with larger group of key stakeholder to facilitate feedback on the key TPP criteria and consensus building based on pre-defined consensus criteria. (v) A final consensus-gathering meeting for discussions around disputed criteria. A complementary values and preferences survey helped to assess trade-offs between different key characteristics.

Results

The following key attributes for the TPP for a test to confirm HCV viraemic infection were identified: The scope defined is for both HCV detection as well as confirmation of cure. The timeline of development for tests envisioned in the TPP is 5 years. The test should be developed for use by health-care workers or laboratory technicians with limited training in countries with a medium to high prevalence of HCV (1.5–3.5% and >3.5%) and in high-risk populations in low prevalence settings (<1.5%). A clinical sensitivity at a minimum of 90% is considered sufficient (analytical sensitivity of the equivalent of 3000 IU/ml), particularly if the test increases access to testing through an affordable price, increase ease-of-use and feasibility on capillary blood. Polyvalency would be optimal (i.e. ability to test for HIV and others). The only characteristic that full agreement could not be achieved on was the price for a virological test. Discussants felt that to reach the optimal target price substantial trade-offs had to be made (e.g. in regards to sensitivity and integration).

Conclusion

The TPP and V&P survey results define the need for an easy-to-use, low cost test to increase access to diagnosis and linkage to care in LMIC.

Electronic supplementary material

The online version of this article (10.1186/s12879-017-2770-5) contains supplementary material, which is available to authorized users.

Shortening the duration of therapy for chronic hepatitis C infection

Combination direct-acting antiviral therapy of 8-24 weeks is highly effective for the treatment of chronic hepatitis C infection. However, shortening the treatment duration to less than 8 weeks could potentially reduce overall treatment costs and improve adherence. Here we explore the arguments for and against the development of short-duration regimens and existing data on treatment for 6 weeks or less among patients with chronic hepatitis C virus genotype 1 infection. Additionally, we identify potential predictors of response to short-course combination therapies with direct-acting antiviral drugs that might be explored in future clinical trials.

Implications of HCV RNA level at week 4 of direct antiviral treatments for hepatitis C

We aimed to determine whether the HCV viral load after four weeks of treatment (W4VL) with direct-acting antiviral agents (DAAs) predicts sustained virologic response (SVR) in a real-world clinical setting. We identified 21 095 patients who initiated DAA-based antiviral treatment in the national Veterans Affairs (VA) healthcare system from 01/01/2014 to 06/30/2015. Week 4 viral load was categorized as undetectable, detectable below quantification (DBQ), detectable above quantification (DAQ) with viral load ≤42 IU/mL and DAQ with viral load >42 IU/mL. Week 4 viral load was undetectable in 36.1%, detectable below quantification in 45.6%, DAQ ≤42 in 9.3%, DAQ >42 in 9.1%. Detectable above quantification was much more common and undetectable week 4 viral load much less common when tested with the Abbott RealTime HCV assay vs the Roche COBAS AmpliPrep/COBAS TaqMan Version 2 assay. Compared to patients with undetectable week 4 viral load (SVR=93.5%), those with detectable below quantification (SVR=91.8%, adjusted odds ratio [AOR] 0.79, P-value=.001), DAQ ≤42 (SVR=90.0%, AOR 0.63, P-value<.001) and DAQ >42 (SVR=86.2%, AOR 0.52, P-value<.001) had progressively lower likelihood of achieving SVR after adjusting for baseline characteristics and treatment duration. Among genotype 1-infected patients who were potentially eligible for 8-week sofosbuvir/ledipasvir monotherapy, we did not find evidence that treatment for 12 weeks instead of 8 weeks was associated with higher SVR, even among those with detectable above quantification. In summary, DBQ and DAQ W4VL are very common in real-world practice, contrary to what was reported in clinical trials, and strongly predict reduced SVR across genotypes and clinically relevant patient subgroups. Whether and how week 4 viral load results should influence treatment decisions requires further study.

Short article: Retreatment of chronic hepatitis C virus infection after unsuccessful therapy with all-oral direct-acting antiviral regimens: a real-life experience

OBJECTIVE

Few real-life data are available on the retreatment of patients who failed direct-acting antiviral (DAA)-regimens. We reported the outcome of retreatment with approved DAA regimens in a real-life cohort of patients who previously failed an all-oral DAAs combination and we analyzed the association with resistance substitutions (RASs) performed at the time of virological failure.

AIM AND METHODS

Next-generation sequencing of the NS3, NS5A, and NS5B regions was performed by Illumina deep sequencing. The sequence reads were analyzed by an in-house pipeline.

RESULTS

Of the 16/759 (2%) patients who failed to achieve a sustained virological response at 12 weeks to all-oral DAAs from December 2014 to January 2016, 10 were retreated with licensed DAAs regimens. In all the patients, retreatment was followed by sustained virological response at 12 weeks. Baseline NS3-RASs before retreatment were observed in two patients who failed a sofosbuvir/simeprevir regimen: D168V RAS was detected in a genotype-4 patient, whereas the complex RAS-pattern Q80K, I170V, R155K, D168E was observed in a genotype-1a patient. Only one of the two patients who previously failed ombitasvir, paritaprevir/ritonavir, and dasabuvir underwent RAS analysis at relapse and showed baseline NS5A RAS (M28V) before retreatment.

CONCLUSION

These real-life findings indicated a high efficacy of sofosbuvir+NS5A-inihbitors in retreating NS3-experienced patients and also NS5A-experienced patients by using a 24-week course ribavirin-containing regimen. The relevance of hepatitis C virus resistance testing before retreatment remains to be better defined to guide the choice of the new regimen before retreatment in DAA-experienced patients.

Analytical and clinical performance of the Hologic Aptima HCV Quant Dx Assay for the quantification of HCV RNA in plasma samples

BACKGROUND

Chronic hepatitis C virus (HCV) infection can be effectively treated with directly acting antiviral (DAA) therapy. Measurement of HCV RNA is used to evaluate patient compliance and virological response during and after treatment.

OBJECTIVES

To compare the analytical performance of the Aptima HCV Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HCV Test v2.0 (CAPCTMv2) for the quantification of HCV RNA in plasma samples, and compare the clinical utility of the two tests in patients undergoing treatment with DAA therapy.

STUDY DESIGN

Analytical performance was evaluated on two sets of plasma samples: 125 genotyped samples and 172 samples referred for quantification of HCV RNA. Furthermore, performance was evaluated using dilutions series of four samples containing HCV genotype 1a, 2b, 3a, and 4a, respectively. Clinical utility was evaluated on 118 plasma samples obtained from 13 patients undergoing treatment with DAAs.

RESULTS

Deming regression of results from 187 plasma samples with HCV RNA >2 Log IU/mL indicated that the Aptima assay quantified higher than the CAPCTMv2 test for HCV RNA >4.9 Log IU/mL. The linearity of the Aptima assay was excellent across dilution series of four HCV genotypes (slope of the regression line: 1.00-1.02). The Aptima assay detected significantly more replicates below targeted 2 Log IU/mL than the CAPCTMv2 test, and yielded clearly interpretable results when used to analyze samples from patients treated with DAAs.

CONCLUSIONS

The analytical performance of the Aptima assay makes it well suited for monitoring patients with chronic HCV infection undergoing antiviral treatment.

Chronic Hepatitis B, C, and D

Chronic hepatitis B, C, and D virus infections contribute significantly to the morbidity and mortality of immunocompromised individuals. To contextualize discussion of these infections in immunocompromised patients, this paper provides an overview of aspects of infection in normal hosts. It then describes differences in disease, diagnostic testing, and therapeutic management observed in immunocompromised patients.

Short article: Viral dynamics among hepatitis C virus chronic infected patients during direct-acting antiviral agents therapy: impact for monitoring and optimizing treatment duration

OBJECTIVES

Direct-acting antiviral agents (DAAs) have provided an ultimate treatment duration of 12 weeks for most hepatitis C virus (HCV)-infected patients. The opportunity to reduce treatment duration to 6 or 8 weeks is being evaluated. Here, the HCV viral dynamics at short times during HCV therapies and its implications for monitoring and optimizing treatment duration have been assessed.

PATIENTS AND METHODS

HCV chronic infected patients who began HCV therapy (March 2014 to June 2015) at a reference hospital of the Northwest of Spain were selected. HCV-RNA was quantified at different short time points during HCV therapy using Abbott RealTime HCV assay. Epidemiological, clinical, and virological data were recorded.

RESULTS

Eleven HCV-infected patients were included; 90.9% had cirrhosis (>12.5 kPa) and 72.7% were treatment-experienced. HCV genotype 1b was the most prevalent (72.7%). All of the combinations were pegylated interferon-free and all included ribavirin. The median HCV-RNA (log IU/ml) at baseline was 5.8 (5.4-6.1); the decline between baseline and day 3, weeks 4, 8, and 12 was 3.2, 4.8, 5.1, and 5.6, respectively. Fewer than 50% of patients achieved undetectable viral load at weeks 4 and 8; however, all patients achieved a sustained virologic response at 12 weeks.

CONCLUSION

Rapid and high HCV-RNA decline was observed among HCV-infected patients under DAA-based regimens, especially for those without cirrhosis. Despite low rates of patients with undetectable HCV-RNA at weeks 4 and 8, all achieved a sustained virologic response at 12 weeks. These findings suggest that the time points to monitor HCV-RNA during DAA therapies and the treatment duration need to be optimized.