Factors associated with hepatitis C virus RNA levels in early chronic infection: the InC3 study

Hepatitis C Contamination of Medication Vials Accessed with Sterile Needles and Syringes

BACKGROUND

Health care-associated hepatitis C virus outbreaks from contaminated medication vials continue to be reported even though most practitioners deny reusing needles or syringes. The hypothesis was that when caring for hepatitis C virus-infected patients, healthcare providers may inadvertently contaminate the medication vial diaphragm and that subsequent access with sterile needles and syringes can transfer hepatitis C virus into the medication, where it remains stable in sufficient quantities to infect subsequent patients.

METHODS

A parallel-arm lab study (n = 9) was performed in which contamination of medication vials in healthcare settings was simulated using cell culture-derived hepatitis C virus. First, surface-contaminated vials were accessed with sterile needles and syringes, and then hepatitis C virus contamination was assessed in cell culture. Second, after contaminating several medications with hepatitis C virus, viral infectivity over time was assessed. Last, surface-contaminated vial diaphragms were disinfected with 70% isopropyl alcohol to determine whether disinfection of the vial surface was sufficient to eliminate hepatitis C virus infectivity.

RESULTS

Contamination of medication vials with hepatitis C virus and subsequent access with sterile needles and syringes resulted in contamination of the vial contents in sufficient quantities to initiate an infection in cell culture. Hepatitis C virus remained viable for several days in several commonly used medications. Finally, a single or 2- to 3-s wipe of the vial diaphragm with 70% isopropyl alcohol was not sufficient to eliminate hepatitis C virus infectivity.

CONCLUSIONS

Hepatitis C virus can be transferred into commonly used medications when using sterile single-use needles and syringes where it remains viable for several days. Furthermore, cleaning the vial diaphragm with 70% isopropyl alcohol is not sufficient to eliminate the risk of hepatitis C virus infectivity. This highlights the potential risks associated with sharing medications between patients.

Deriving the optimal limit of detection for an HCV point-of-care test for viraemic infection: Analysis of a global dataset

BACKGROUND & AIMS

Affordable point-of-care tests for hepatitis C (HCV) viraemia are needed to improve access to treatment in low- and middle-income countries. Our aims were to determine the target limit of detection (LOD) necessary to diagnose the majority of people with HCV eligible for treatment, and identify characteristics associated with low-level viraemia (LLV) (defined as the lowest 3% of the distribution of HCV RNA) to understand those at risk of being misdiagnosed.

METHODS

We established a multi-country cross-sectional dataset of first available quantitative HCV RNA measurements linked to demographic and clinical data. We excluded individuals on HCV treatment. We analysed the distribution of HCV RNA and determined critical thresholds for detection of HCV viraemia. We then performed logistic regression to evaluate factors associated with LLV, and derived relative sensitivities for significant covariates.

RESULTS

The dataset included 66,640 individuals with HCV viraemia from across the world. The LOD for the 95th and 99th percentiles were 3,311 IU/ml and 214 IU/ml. The LOD for the 97th percentile was 1,318 IU/ml (95% CI 1,298.4-1,322.3). Factors associated with LLV, defined as HCV RNA <1,318 IU/ml, were younger age 18-30 vs. 51-64 years (odds ratios [OR] 2.56; 95% CI 2.19-2.99), female vs. male sex (OR 1.32; 95% CI 1.18-1.49), and advanced fibrosis stage F4 vs. F0-1 (OR 1.44; 95% CI 1.21-1.69). Only the younger age group had a decreased relative sensitivity below 95%, at 93.3%.

CONCLUSIONS

In this global dataset, a test with an LOD of 1,318 IU/ml would identify 97% of viraemic HCV infections among almost all populations. This LOD will help guide manufacturers in the development of affordable point-of-care diagnostics to expand HCV testing and linkage to care in low- and middle-income countries.

LAY SUMMARY

We created and analysed a dataset from 12 countries with 66,640 participants with chronic hepatitis C virus infection. We determined that about 97% of those with viraemic infection had 1,300 IU/ml or more of circulating virus at the time of diagnosis. While current diagnostic tests can detect as little as 12 IU/ml of virus, our findings suggest that increasing the level of detection closer to 1,300 IU/ml would maintain good test accuracy and will likely enable development of more affordable portable tests for use in low- and middle-income countries.

Options for reducing HIV transmission related to the dead space in needles and syringes

BACKGROUND

When shared by people who inject drugs, needles and syringes with different dead space may affect the probability of HIV and hepatitis C virus (HCV) transmission differently.

METHODS

We measured dead space in 56 needle and syringe combinations obtained from needle and syringe programs across 17 countries in Europe and Asia. We also calculated the amounts of blood and HIV that would remain in different combinations following injection and rinsing.

RESULTS

Syringe barrel capacities ranged from 0.5 to 20 mL. Needles ranged in length from 8 to 38 mm. The average dead space was 3 μL in low dead space syringes with permanently attached needles, 13 μL in high dead space syringes with low dead space needles, 45 μL in low dead space syringes with high dead space needles, and 99 μL in high dead space syringes with high dead space needles. Among low dead space designs, calculated volumes of blood and HIV viral burden were lowest for low dead space syringes with permanently attached needles and highest for low dead space syringes with high dead space needles.

CONCLUSION

The dead space in different low dead space needle and syringe combinations varied substantially. To reduce HIV transmission related to syringe sharing, needle and syringe programs need to combine this knowledge with the needs of their clients.

Association of interferon lambda polymorphisms with elevated baseline viral loads in chronic hepatitis C virus genotype 6 infection

Globally, hepatitis C virus (HCV) is one of the major causes of hepatocellular carcinoma and liver cirrhosis. For clinical decision making, genetic variation in the interferon-λ (IFNL) cluster has been utilised as a baseline predictor of natural and interferon-based treatment-induced viral clearance. In Vietnam, where HCV genotypes 1 (g1) and g6 predominate, no prior studies have been conducted investigating associations of IFNL3/4 polymorphisms with spontaneous clearance (SC) or HCV viral load (VL) in chronic infection. In this study, we have investigated the host genetic variations in IFNL loci to determine the association of IFNL3/4 polymorphisms with HCV SC and baseline VLs in a Vietnamese HCV-seropositive cohort. The majority of the cohort harboured major homozygous polymorphisms in IFNL3/4 cluster (i.e. rs12979860-CC: 82.7%; rs8099917-TT: 84.8% and rs368234815-TT/TT: 85.5%) and the SC rates in these groups were 15.8%, 16.3% and 15.7%, respectively. In the minor allele groups, the resolution rates were lower (12% in rs12979860 non-CC, 9.1% in rs8099917 non-TT and 9.5% in rs368234815 non-TT/TT). Furthermore, in individuals harbouring minor alleles, females achieved higher SC rates than males. HCV g6-infected rs12979860 major homozygous individuals had significantly higher viral loads than individuals with minor alleles (CC: 6.56 log IU/ml vs. non-CC: 5.66 log IU/ml; P = 0.021). The association between IFNL3/4 genotypes with elevated HCV VL observed in HCV g6-infected individuals may have implications for the progression of liver disease in Southeast Asian countries where this viral genotype predominates and therefore warrants further studies.

HCV avidity as a tool for detection of recent HCV infection: Sensitivity depends on HCV genotype

Accurate detection of incident hepatitis C virus (HCV) infection is required to target and evaluate public health interventions, but acute infection is largely asymptomatic and difficult to detect using traditional methods. Our aim was to evaluate a previously developed HCV avidity assay to distinguish acute from chronic HCV infection. Plasma samples collected from recent seroconversion subjects in two large Australian cohorts were tested using the avidity assay, and the avidity index (AI) was calculated. Demographic and clinical characteristics of patients with low/high AI were compared via logistic regression. Sensitivity and specificity of the assay for recent infection and the mean duration of recent infection (MDRI) were estimated stratified by HCV genotype. Avidity was assessed in 567 samples (from 215 participants), including 304 with viraemia (defined as ≥250 IU/mL). An inverse relationship between AI and infection duration was found in viraemic samples only. The adjusted odds of a low AI (<30%) decreased with infection duration (odds ratio [OR] per week of 0.93; 95% CI:0.89-0.97), and were lower for G1 compared with G3 samples (OR = 0.14; 95% CI:0.05-0.39). Defining recent infection as <26 weeks, sensitivity (at AI cut-off of 20%) was estimated at 48% (95% CI:39-56%), 36% (95% CI:20-52%), and 65% (95% CI:54-75%) and MDRI was 116, 83, and 152 days for all genotypes, G1, and G3, respectively. Specificity (≥52 weeks infection duration, all genotypes) was 96% (95% CI:90-98%). HCV avidity testing has utility for detecting recent HCV infection in patients, and for assessing progress in reaching incidence targets for eliminating transmission, but variation in assay performance across genotype should be recognized.

17,β-estradiol inhibits hepatitis C virus mainly by interference with the release phase of its life cycle

BACKGROUND & AIMS

Oestrogen and oestrogen-mediated signalling protect from hepatitis C virus through incompletely understood mechanisms. We aimed to ascertain which phase(s) of hepatitis C virus life cycle is/are affected by oestrogens.

METHODS

Huh7 cells infected with the JFH1 virus (genotype 2a) were exposed to dehydroepiandrosterone, testosterone, progesterone and 17β-estradiol (tested with/without its receptor antagonist fulvestrant). Dose-response curves were established to calculate half maximal inhibitory concentration values. To dissect how 17β-estradiol interferes with phases of hepatitis C virus life cycle, its effects were measured on the hepatitis C virus pseudo-particle system (viral entry), the subgenomic replicon N17/JFH1 and the replicon cell line Huh7-J17 (viral replication). Finally, in a dual-step infection model, infectious supernatants, collected from infected cells exposed to hormones, were used to infect naïve cells.

RESULTS

Progesterone and testosterone showed no inhibitory effect on hepatitis C virus; dehydroepiandrosterone was only mildly inhibitory. In contrast, 17β-estradiol inhibited infection by 64%-67% (IC₅₀ values 140-160 nmol/L). Fulvestrant reverted the inhibition by 17β-estradiol in a dose-dependent manner. 17β-estradiol exerted only a slight inhibition (<20%) on hepatitis C virus pseudo-particles, and had no effect on cells either transiently or stably (Huh7-J17 cells) expressing the N17/JFH1 replicon. In the dual-step infection model, a significant half maximal inhibitory concentration decline occurred between primary (134 nmol/L) and secondary (100 nmol/L) infections (P=.02), with extracellular hepatitis C virus RNA and infectivity being reduced to a higher degree in comparison to its intracellular counterpart.

CONCLUSIONS

17β-estradiol inhibits hepatitis C virus acting through its intracellular receptors, mainly interfering with late phases (assembly/release) of the hepatitis C virus life cycle.

IFN-λ3 polymorphism indirectly influences NK cell phenotype and function during acute HCV infection

Introduction

Polymorphisms in the type III interferon IFN‐λ3 and the killer cell immunoglobulin‐like receptor (KIR) genes controlling the activity of natural killer (NK) cells can predict spontaneous resolution of acute hepatitis C virus (HCV) infection. We hypothesized that IFN‐λ3 polymorphism may modulate NK cell function during acute HCV.

Methods

We monitored the plasma levels of type III IFNs in relation to the phenotype and the function of NK cells in a cohort of people who inject drugs (PWID) during acute HCV infection with different outcomes.

Results

Early acute HCV was associated with high variability in type III IFNs plasma levels and the favorable IFN‐λ3 CC genotype was associated with higher viral loads. Reduced expression of Natural Killer Group Protein 2A (NKG2A) was associated with lower IFN‐λ3 plasma levels and the CC genotype. IFN‐γ production by NK cells was higher in individuals with the CC genotype during acute infection but this did not prevent viral persistence. IFN‐λ3 plasma levels did not correlate with function of NK cells and IFN‐λ3 prestimulation did not affect NK cell activation and function.

Conclusions

These results suggest that IFN‐λ3 polymorphism indirectly influences NK cell phenotype and function during acute HCV but other factors may act in concert to determine the outcome of the infection.

HCV Specific IL-21 Producing T Cells but Not IL-17A Producing T Cells Are Associated with HCV Viral Control in HIV/HCV Coinfection

BACKGROUND

Decreased hepatitis C virus (HCV) clearance, faster cirrhosis progression and higher HCV RNA levels are associated with Human Immunodeficiency virus (HIV) coinfection. The CD4+ T helper cytokines interleukin (IL)-21 and IL-17A are associated with virus control and inflammation, respectively, both important in HCV and HIV disease progression. Here, we examined how antigen-specific production of these cytokines during HCV mono and HIV/HCV coinfection was associated with HCV virus control.

METHODS

We measured HCV-specific IL-21 and IL-17A production by transwell cytokine secretion assay in PBMCs from monoinfected and coinfected individuals. Viral control was determined by plasma HCV RNA levels.

RESULTS

In acutely infected individuals, those able to establish transient/complete HCV viral control tended to have stronger HCV-specific IL-21-production than non-controllers. HCV-specific IL-21 production also correlated with HCV viral decline in acute infection. Significantly stronger HCV-specific IL-21 production was detected in HAART-treated coinfected individuals. HCV-specific IL-17A production was not associated with lower plasma HCV RNA levels in acute or chronic HCV infection and responses were stronger in HIV coinfection. HCV-specific IL-21/ IL-17A responses did not correlate with microbial translocation or fibrosis. Exogenous IL-21 treatment of HCV-specific CD8+ T cells from monoinfected individuals enhanced their function although CD8+ T cells from coinfected individuals were somewhat refractory to the effects of IL-21.

CONCLUSIONS

These data show that HCV-specific IL-21 and IL-17A-producing T cells are induced in HIV/HCV coinfection. In early HIV/HCV coinfection, IL-21 may contribute to viral control, and may represent a novel tool to enhance acute HCV clearance in HIV/HCV coinfected individuals.

Conditions for eradicating hepatitis C in people who inject drugs: A fibrosis aware model of hepatitis C virus transmission

It is estimated that 80% of new hepatitis C virus (HCV) infections occur among people who inject drugs (PWID). Eradicating HCV from this population is key for the complete eradication of the disease, and the advent of simple to use, high efficacy treatments could conceivably make this scenario possible. This paper presents a mathematical model where transmission of HCV is studied in a simulated population of PWID where fibrosis progression is explicitly tracked. The stability thresholds that determine whether HCV will remain endemic or become eradicated were established numerically, and analytically on a reduced version of the model. Conditions on testing and treatment rates for eradication to occur were determined, within the context of the new high efficacy therapies. The results show that HCV eradication in the PWID population of the Vancouver, BC test scenario is achievable, but testing and especially treatment rates will need to increase significantly from current rates. Parameter estimates were drawn from published data.

Interferon-λ polymorphisms and response to pegylated interferon in Iranian hepatitis C patients

AIM

To evaluate the efficacy of pegylated interferon in Iranian chronic hepatitis C patients in relation to interferon-λ (IFNL) polymorphisms.

METHODS

This study enrolled patients with chronic hepatitis C referred to the Tehran Blood Transfusion Hepatitis Clinic in 2011. Patients were included in the study if they had no concomitant hepatic illness, were negative for human immunodeficiency virus antibodies, and had no prior history of treatment with any type of pegylated interferon. Patients were treated with 180 μg pegylated interferon alpha-2a (Pegaferon(®)) weekly and 800-1200 mg ribavirin daily for 24 or 48 wk depending on weight and hepatitis C virus (HCV) genotype. Blood samples were collected from patients to obtain DNA for determination of IFNL rs12979860 and rs8099917 polymorphisms. The virologic response in patients was then evaluated and compared between the different IFNL genotypes.

RESULTS

A total of 152 patients with a mean age of 41.9 ± 10.0 years were included in the study, of which 141/152 were men (92.8%). The most frequent HCV genotype was type-1, infecting 93/152 (61.2%) patients. Sustained virologic response (SVR) was achieved in 81.9% of patients with HCV genotype-1 and 91.1% of patients with HCV genotype-3. Treatment success was achieved in 91.2% (52/57) of patients with the IFNL rs12979860 CC genotype and 82.1% (78/95) in those with other genotypes. Similar treatment response rates were also observed in patients with rs8099917 TT (39/45; 86.7%) and non-TT (61/68; 89.7%) genotypes. Univariate analyses identified the following factors which influenced treatment response for inclusion in a multivariate analysis: age, HCV RNA level, stage of liver fibrosis, rs12979860 CC genotype, and aspartate transaminase level. A logistic regression analysis revealed that only the rs12979860 CC genotype was significantly associated with achievement of SVR (OR = 6.2; 95%CI: 1.2-31.9; P = 0.03).

CONCLUSION

The rs12979860 CC genotype was associated with SVR in patients receiving pegylated interferon plus ribavirin, however, the SVR rate in other rs12979860 genotypes was also relatively high.

Acute Hepatitis C Virus Infection Induces Consistent Changes in Circulating MicroRNAs That Are Associated with Nonlytic Hepatocyte Release

Plasma microRNAs (miRNAs) change in abundance in response to disease and have been associated with liver fibrosis severity in chronic hepatitis C virus (HCV) infection. However, the early dynamics of miRNA release during acute HCV infection are poorly understood. In addition, circulating miRNA signatures have been difficult to reproduce among separate populations. We studied plasma miRNA abundance during acute HCV infection to identify an miRNA signature of early infection. We measured 754 plasma miRNAs by quantitative PCR array in a discovery cohort of 22 individuals before and during acute HCV infection and after spontaneous resolution (n = 11) or persistence (n = 11) to identify a plasma miRNA signature. The discovery cohort derived from the Baltimore Before and After Acute Study of Hepatitis. During acute HCV infection, increases in miR-122 (P < 0.01) and miR-885-5p (Pcorrected < 0.05) and a decrease in miR-494 (Pcorrected < 0.05) were observed at the earliest time points after virus detection. Changes in miR-122 and miR-885-5p were sustained in persistent (P < 0.001) but not resolved HCV infection. The circulating miRNA signature of acute HCV infection was confirmed in a separate validation cohort that was derived from the San Francisco-based You Find Out (UFO) Study (n = 28). As further confirmation, cellular changes of signature miRNAs were examined in a tissue culture model of HCV in hepatoma cells: HCV infection induced extracellular release of miR-122 and miR-885-5p despite unperturbed intracellular levels. In contrast, miR-494 accumulated intracellularly (P < 0.05). Collectively, these data are inconsistent with necrolytic release of hepatocyte miRNAs into the plasma during acute HCV infection of humans.

IMPORTANCE

MicroRNAs are small noncoding RNA molecules that emerging research shows can transmit regulatory signals between cells in health and disease. HCV infects 2% of humans worldwide, and chronic HCV infection is a major cause of severe liver disease. We profiled plasma miRNAs in injection drug users before, during, and (in the people with resolution) after HCV infection. We discovered miRNA signatures of acute and persistent viremia and confirmed these findings two ways: (i) in a separate cohort of people with newly acquired HCV infection and (ii) in an HCV cell culture system. Our results demonstrate that acute HCV infection induces early changes in the abundance of specific plasma miRNAs that may affect the host response to HCV infection.

Patterns of hepatitis C virus RNA levels during acute infection: the InC3 study

BACKGROUND

Understanding the patterns of HCV RNA levels during acute hepatitis C virus (HCV) infection provides insights into immunopathogenesis and is important for vaccine design. This study evaluated patterns of HCV RNA levels and associated factors among individuals with acute infection.

METHODS

Data were from an international collaboration of nine prospective cohorts of acute HCV (InC3 Study). Participants with well-characterized acute HCV infection (detected within three months post-infection and interval between the peak and subsequent HCV RNA levels ≤ 120 days) were categorised by a priori-defined patterns of HCV RNA levels: i) spontaneous clearance, ii) partial viral control with persistence (≥ 1 log IU/mL decline in HCV RNA levels following peak) and iii) viral plateau with persistence (increase or <1 log IU/mL decline in HCV RNA levels following peak). Factors associated with HCV RNA patterns were assessed using multinomial logistic regression.

RESULTS

Among 643 individuals with acute HCV, 162 with well-characterized acute HCV were identified: spontaneous clearance (32%), partial viral control with persistence (27%), and viral plateau with persistence (41%). HCV RNA levels reached a high viraemic phase within two months following infection, with higher levels in the spontaneous clearance and partial viral control groups, compared to the viral plateau group (median: 6.0, 6.2, 5.3 log IU/mL, respectively; P = 0.018). In the two groups with persistence, Interferon lambda 3 (IFNL3) CC genotype was independently associated with partial viral control compared to viral plateau (adjusted odds ratio [AOR]: 2.75; 95%CI: 1.08, 7.02). In the two groups with viral control, female sex was independently associated with spontaneous clearance compared to partial viral control (AOR: 2.86; 95%CI: 1.04, 7.83).

CONCLUSIONS

Among individuals with acute HCV, a spectrum of HCV RNA patterns is evident. IFNL3 CC genotype is associated with initial viral control, while female sex is associated with ultimate spontaneous clearance.