HCV RNA levels in a multiethnic cohort of injection drug users: human genetic, viral and demographic associations

The IFN-λ4 Conundrum: When a Good Interferon Goes Bad

Since its discovery in 2013, interferon lambda 4 (IFN-λ4) has received a reputation as a paradoxical type III IFN. Difficulties in detecting IFN-λ4, especially in secreted form even led to questions about its existence. However, the genetic ability to generate IFN-λ4, determined by the presence of the rs368234815-ΔG allele, is the strongest predictor of impaired clearance of hepatitis C virus (HCV) infection in humans. Significant modulation of IFN-λ4 activity by a genetic variant (P70S) supports IFN-λ4, and not other type III IFNs encoded in the same genomic locus, as the primary functional cause of the association with HCV clearance. Although the ability to produce IFN-λ4 is associated with decreased HCV clearance, the recombinant IFN-λ4 is active against HCV and other viruses. These observations present an apparent conundrum-when and how does a presumably good IFN, with anti-HCV activity, interfere with the ability to clear HCV? In this review, we discuss findings that suggest potential mechanisms for explaining this conundrum.

Direct-Acting Antiviral Prophylaxis in Kidney Transplantation From Hepatitis C Virus-Infected Donors to Noninfected Recipients: An Open-Label Nonrandomized Trial

BACKGROUND

Given the high mortality rate for patients with end-stage kidney disease receiving dialysis and the efficacy and safety of hepatitis C virus (HCV) treatments, discarded kidneys from HCV-infected donors may be a neglected public health resource.

OBJECTIVE

To determine the tolerability and feasibility of using direct-acting antivirals (DAAs) as prophylaxis before and after kidney transplantation from HCV-infected donors to non-HCV-infected recipients (that is, HCV D+/R- transplantation).

DESIGN

Open-label nonrandomized trial. (ClinicalTrials.gov: NCT02781649).

SETTING

Single center.

PARTICIPANTS

10 HCV D+/R- kidney transplant candidates older than 50 years with no available living donors.

INTERVENTION

Transplantation of kidneys from deceased donors aged 13 to 50 years with positive HCV RNA and HCV antibody test results. All recipients received a dose of grazoprevir (GZR), 100 mg, and elbasvir (EBR), 50 mg, immediately before transplantation. Recipients of kidneys from donors with genotype 1 infection continued receiving GZR-EBR for 12 weeks after transplantation; those receiving organs from donors with genotype 2 or 3 infection had sofosbuvir, 400 mg, added to GZR-EBR for 12 weeks of triple therapy.

MEASUREMENTS

The primary safety outcome was the incidence of adverse events related to GZR-EBR treatment. The primary efficacy outcome was the proportion of recipients with an HCV RNA level below the lower limit of quantification 12 weeks after prophylaxis.

RESULTS

Among 10 HCV D+/R- transplant recipients, no treatment-related adverse events occurred, and HCV RNA was not detected in any recipient 12 weeks after treatment.

LIMITATION

Nonrandomized study design and a small number of patients.

CONCLUSION

Pre- and posttransplantation HCV treatment was safe and prevented chronic HCV infection in HCV D+/R- kidney transplant recipients. If confirmed in larger studies, this strategy should markedly expand organ options and reduce mortality for kidney transplant candidates without HCV infection.

PRIMARY FUNDING SOURCE

Merck Sharp & Dohme.

Interleukin gene polymorphisms and susceptibility to HIV-1 infection: a meta-analysis

Some subjects are repeatedly exposed to human immunodeficiency virus (HIV), yet they remain uninfected. This suggests the existence of host-resistance mechanisms. The current study synthesizes the evidence regarding the association between interleukin (IL) gene polymorphisms and HIV susceptibility. Medline, Scopus and the Web of Science databases were systematically searched, and a meta-analysis of case-control studies was conducted. Univariate and bivariate methods were used. The literature search identified 42 eligible studies involving 15,727 subjects. Evidence was obtained on eight single-nucleotide polymorphisms (SNPs): IL1A -889 C>T (rs1800587), IL1B +3953/4 C>T (rs1143634), IL4 -589/90 C>T (rs2243250), IL6 -174 G>C (rs1800795), IL10 -592 C>A (rs1800872), IL10-1082 A>G (rs1800896), IL12B -1188 A>C (rs3212227) and IL28B C>T (rs12979860). The IL1B +3953/4 C>T variant appears to increase the risk of HIV acquisition, under the assumption of a recessive genetic model (odds ratio (OR): 4.47, 95% CI: 2.35-8.52). The AA homozygotes of the IL10 -592 C>A SNP had an increased, marginally nonsignificant, risk (OR: 1.39, 95% CI: 0.97-2.01). It reached, however, significance in sub analyses (OR: 1.49, 95% CI: 1.04-2.12). Finally, the well-studied hepatitis C virus (HCV) infection IL28B (rs12979860) CT/TT genotypes were associated with a 27% decrease in HIV infection risk, especially in populations infected with HCV (OR: 0.73, 95% CI: 0.57-0.95). Interleukin signalling is perhaps important in HIV infection and some interleukin genetic variants may affect the risk of HIV acquisition. Approaches targeting specific genes and genome wide association studies should be conducted to decipher the effect of these polymorphisms.

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.

IFN-λ4 Attenuates Antiviral Responses by Enhancing Negative Regulation of IFN Signaling

Type III IFNs are important mediators of antiviral immunity. IFN-λ4 is a unique type III IFN because it is produced only in individuals who carry a dG allele of a genetic variant rs368234815-dG/TT. Counterintuitively, those individuals who can produce IFN-λ4, an antiviral cytokine, are also less likely to clear hepatitis C virus infection. In this study, we searched for unique functional properties of IFN-λ4 that might explain its negative effect on hepatitis C virus clearance. We used fresh primary human hepatocytes (PHHs) treated with recombinant type III IFNs or infected with Sendai virus to model acute viral infection and subsequently validated our findings in HepG2 cell line models. Endogenous IFN-λ4 protein was detectable only in Sendai virus-infected PHHs from individuals with the dG allele, where it was poorly secreted but highly functional, even at concentrations < 50 pg/ml. IFN-λ4 acted faster than other type III IFNs in inducing antiviral genes, as well as negative regulators of the IFN response, such as USP18 and SOCS1 Transient treatment of PHHs with IFN-λ4, but not IFN-λ3, caused a strong and sustained induction of SOCS1 and refractoriness to further stimulation with IFN-λ3. Our results suggest unique functional properties of IFN-λ4 that can be important in viral clearance and other clinical conditions.

Prevalence of hepatitis C virus infection and its correlates in a rural area of southwestern China: a community-based cross-sectional study

OBJECTIVES

Hepatitis C virus (HCV) infection is a major public health problem in southwestern China. Our aim of the study was to assess the prevalence of HCV infection and its correlates in the Yi population of this region.

METHODS

A community-based survey was conducted to investigate sociodemographic characteristics and other associated factors for HCV infection in a rural area of southwestern China. Blood samples were collected and tested for antibodies to HCV. Anti-HCV positive samples were further assessed for HCV RNA.

RESULTS

A total of 2558 participants aged ≥14 years were included in our analysis. Of them, 2.8% (95% CI 2.2% to 3.5%) were positive for HCV antibody. Multiple logistic regression analysis revealed that sex (male vs female: adjusted OR (aOR)=3.30, 95% CI 1.80 to 6.07), marital status (unmarried vs married: aOR=0.27, 95% CI 0.09 to 0.80), ever using injection drug (aOR=28.65, 95% CI 15.9 to 51.64) and ever having blood transfusion (aOR=7.64, 95% CI 1.94 to 30.16) were significantly associated with HCV infection (indicated by positive HCV antibody). Stratified analysis by HIV infection found that in HIV-negative individuals, sex (male vs female: aOR=3.84, 95% CI 1.88 to 7.85), ever using injection drug (aOR=22.15, 95% CI 8.45 to 58.04), having multiple sexual partners (aOR=2.57, 95% CI 1.26 to 5.23), and ever having blood transfusion (aOR=16.54, 95% CI 4.44 to 61.58) were significantly associated with HCV infection and in HIV-positive individuals, ever using injection drug (aOR=8.96, 95% CI 3.16 to 25.38) was associated with HCV infection.

CONCLUSION

The data suggested a higher risk of HCV infection in this area when compared with the rest of China and some unique associated factors. Rapid scale-up of targeted interventions are needed to prevent further transmission and consequent morbidities.

Global genotype distribution of hepatitis C viral infection among people who inject drugs

BACKGROUND & AIMS

Hepatitis C viral infection (HCV) after injection drug use is very prevalent. The kind of genotype determines the response to treatment. However, no systematic review update on the global genotype distribution of HCV in people who inject drugs (PWID) is currently available.

METHODS

A systematic review was performed by using the keywords: Genotype, Hepatitis C, Injection drug user/Intravenous drug user/Substance user/ PWID, Name of countries in Pubmed, Embase and PsycINFO. The results were compared with the review of Gower et al. in 2014, concerning the distribution of HCV genotypes in the general HCV population.

RESULTS

Using these keywords, 132 studies in 48 countries (from 1995 to 2015) were collected. After grading these results, the data of 48 studies were used to determine the distribution of genotypes in PWID. Genotype 1 is the most prevalent genotype all over the world in PWID. In Europe, genotypes 1, 3 and 4 are highly prevalent. In North and South America and in Australia genotype 1 and 3 are most prevalent. In Asia genotype 2 and 6, and Africa genotype 1a and 4 are mostly observed. Overall, the most important differences comparing with the general population are a lower prevalence of genotype 1b in the PWID population and higher prevalence of genotype 1a and 3.

CONCLUSIONS

There is a different prevalence of genotype distribution in PWID than in the general population. Genotype 3 is especially highly prevalent in the Western countries.

LAY SUMMARY

Hepatitis C viral infection after injection drug use is very prevalent. The most important genotype causing HCV infection in PWID globally is genotype 1, as is the case in the general population, but also genotype 3 is highly prevalent in PWID. Genotype 4 is most prevalent in Africa, spreading into Europe, whereas genotype 2 and 6 are more located in Asia. The most important difference comparing to the general population are generally lower prevalence of genotype 1b, and higher prevalence of genotype 1a and 3 in PWID. As the genotype nowadays still determines the treatment, and as there is a different genotype distribution than in the general population, it is important to identify the genotype also in PWID.

Association of genotypes with viral load and biochemical markers in HCV-infected Sindhi patients

The presented study had two objectives. The first was to examine distributions of Hepatitis C Virus (HCV) genotypes in Sindh, Pakistan, where HCV is prevalent. The other was to explore clinically relevant relationships between the genotypes, viral load (measured by real-time polymerase chain reaction assays) and biochemical markers. For this, 1471 HCV-infected patients in six cities in Sindh were recruited and sampled. HCV genotype distributions varied among the cities, but genotype 3a was most prevalent, followed by 3b, 1a and 1b (detected in 51.5, 22.7. 9.25 and 3.2% of the cases, respectively). No type-specific sequences were detected in serum samples from 189 (12.8%) of the 1471 patients. Frequencies of low (<200,000IU/mL serum), intermediate (200,000-600,000IU/mL serum) and high (>600,000IU/mL serum) viral loads were respectively 45.4, 16.5 and 38.1% for patients infected with genotype 3, and 16.9, 36.9 and 46.2%, respectively, for patients with other genotypes. Infection with genotype 1a was associated with significantly higher (p<0.005) alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase titers than infection with genotype 3a. The results will help in the formulation of treatment strategies.

Influence of IFNL3 and HLA-DPB1 genotype on postpartum control of hepatitis C virus replication and T-cell recovery

Chronic hepatitis C virus (HCV) infection is characterized by exhaustion of virus-specific T-cells and stable viremia. Pregnancy is an exception. Viremia gradually climbs during gestation but sometimes declines sharply in the months following delivery. Here, we demonstrated that postpartum HCV control was associated with enhanced virus-specific T-cell immunity. Women with viral load declines of at least 1 log10 between the third trimester and 3-mo postpartum exhibited HCV-specific T-cell responses of greater breadth (P = 0.0052) and magnitude (P = 0.026) at 3-mo postpartum than women who failed to control viremia. Moreover, viral dynamics were consistent in women after consecutive pregnancies, suggesting genetic underpinnings. We therefore searched for genetic associations with human leukocyte antigen (HLA) alleles and IFN-λ3 gene (IFNL3) polymorphisms that influence HCV infection outcome. Postpartum viral control was associated with the IFNL3 rs12979860 genotype CC (P = 0.045 at 6 mo) that predicts a positive response to IFN-based therapy. Suppression of virus replication after pregnancy was also strongly influenced by the HLA class II DPB1 locus. HLA-DPB1 alleles are classified by high and low patterns of expression. Carriage of at least one high-expression HLA-DPB1 allele predicted resurgent virus-specific T-cell immunity and viral control at 3-mo postpartum (P = 0.0002). When considered together in multivariable analysis, IFNL3 and HLA-DPB1 independently affected viral control at 3- and 6-mo postpartum. Together, these findings support a model where spontaneous control of HCV such as sometimes follows pregnancy is governed by genetic polymorphisms that affect type III IFN signaling and virus-specific cellular immune responses.

The Prevalence of Hepatitis C Virus Core Amino Acid 70 Substitution and Genotypes of Polymorphisms Near the IFNL3 Gene in Iranian Patients With Chronic Hepatitis C

BACKGROUND

Molecular studies have demonstrated that the hepatitis C virus (HCV) genotype and host genetics play predictive roles in the management of patients infected with HCV.

OBJECTIVES

This study aimed to investigate the HCV genotype, core amino acid (aa) 70 substitution, and polymorphisms near the IFNL3 gene (including rs12979860 and rs8099917) among Iranian patients with chronic hepatitis C (CHC).

PATIENTS AND METHODS

In this cross-sectional study, the molecular profiles of the HCV genotype, core aa 70 substitution, and rs12979860 and rs8099917 polymorphisms and plasma HCV RNA levels were determined in 429 CHC patients including 141 hemophilic, 84 thalassemic, and 204 non-hemophilic, non-thalassemic patients.

RESULTS

The hepatitis C virus subtype 1a was the most common subtype in the study population. Core aa substitution Arg70Gln was strongly associated with cirrhosis (OR = 2.49; 95% CI = 1.13 - 5.50; P = 0.020). Core aa 70 substitutions were more frequently observed in patients with the HCV subtype 1b than in patients with any other HCV subtypes (P < 0.001). Core aa 70 substitutions were also more common in patients with the rs12979860 TT genotype than in patients with non-TT genotypes (17.3% vs. 8.5%, P = 0.022) and also in rs8099917 non-TT genotypes than in the TT genotype (14.0% vs. 7.0%, P = 0.026). The HCV genotypes and rs8099917 polymorphisms were correlated in which HCV subtype 1b was in favor of rs8099917 GG and HCV subtype 3a favored rs8099917 TT (P = 0.021). Furthermore, the rs12979860 TT and rs8099917 GG genotypes showed significantly lower HCV RNA levels than the other genotypes (P < 0.001).

CONCLUSIONS

There is an as yet unexplained association between HCV and host parameters with unknown mechanisms in patients with chronic HCV infection. The assessments of core aa 70 substitution and polymorphisms near the IFNL3 gene could offer promising steps to improve the management of patients with HCV.

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

Improved understanding of natural history of hepatitis C virus (HCV) RNA levels in chronic infection provides enhanced insights into immunopathogenesis of HCV and has implications for the clinical management of chronic HCV infection. This study assessed factors associated with HCV RNA levels during early chronic infection in a population with well-defined early chronic HCV infection. Data were from an international collaboration of nine prospective cohorts studying acute HCV infection (InC(3) study). Individuals with persistent HCV and detectable HCV RNA during early chronic infection (one year [±4 months] postinfection) were included. Distribution of HCV RNA levels during early chronic infection was compared by selected host and virological factors. A total of 308 individuals were included. Median HCV RNA levels were significantly higher among males (vs females; 5.15 vs 4.74 log IU/mL; P < 0.01) and among individuals with HIV co-infection (vs no HIV; 5.89 vs 4.86; P = 0.02). In adjusted logistic regression, male sex (vs female, adjusted odds ratio [AOR]: 1.93; 95%CI: 1.01, 3.69), interferon lambda 4 (IFNL4) rs12979860 CC genotype (vs TT/CT; AOR: 2.48; 95%CI: 1.42, 4.35), HIV co-infection (vs no HIV; AOR: 3.27; 95%CI: 1.35, 7.93) and HCV genotype G2 (vs G3; AOR: 5.40; 95%CI: 1.63, 17.84) were independently associated with high HCV RNA levels (>5.6 log IU/mL = 400 000 IU/mL). In conclusion, this study demonstrated that IFNL4 rs12979860 CC genotype, male sex, HIV co-infection and HCV genotype G2 are associated with high HCV RNA levels in early chronic infection. These factors exert their role as early as one year following infection.

Expression of Interferon Lambda 4 Is Associated with Reduced Proliferation and Increased Cell Death in Human Hepatic Cells

Interferon lambda 4 (IFN-λ4) is a novel type-III interferon that can be generated only in individuals carrying a ΔG frame-shift allele of an exonic genetic variant (rs368234815-ΔG/TT). The rs368234815-ΔG allele is strongly associated with decreased clearance of hepatitis C virus (HCV) infection. Here, we further explored the biological function of IFN-λ4 expressed in human hepatic cells—a hepatoma cell line HepG2 and fresh primary human hepatocytes (PHHs). We performed live confocal imaging, cell death and proliferation assays, mRNA expression profiling, protein detection, and antibody blocking assays using transient and inducible stable in vitro systems. Not only did we observe significant intracellular retention of IFN-λ4 but also detected secreted IFN-λ4 in the culture media of expressing cells. Secreted IFN-λ4 induced strong activation of the interferon-stimulated genes (ISGs) in IFN-λ4-expressing and surrounding cells in transwell assays. Specifically, in PHHs, secreted IFN-λ4 induced expression of the CXCL10 transcript and a corresponding pro-inflammatory chemokine, IP-10. In IFN-λ4-expressing HepG2 cells, we also observed decreased proliferation and increased cell death. All IFN-λ4-induced phenotypes—activation of ISGs, decreased proliferation, and increased cell death—could be inhibited by an anti-IFN-λ4-specific antibody. Our study offers new insights into biology of IFN-λ4 and its possible role in HCV clearance.

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.

PCSK9, apolipoprotein E and lipoviral particles in chronic hepatitis C genotype 3: evidence for genotype-specific regulation of lipoprotein metabolism

BACKGROUND & AIMS

Hepatitis C virus (HCV) associates with lipoproteins to form "lipoviral particles" (LVPs) that can facilitate viral entry into hepatocytes. Initial attachment occurs via heparan sulphate proteoglycans and low-density lipoprotein receptor (LDLR); CD81 then mediates a post-attachment event. Proprotein convertase subtilisin kexin type 9 (PCSK9) enhances the degradation of the LDLR and modulates liver CD81 levels. We measured LVP and PCSK9 in patients chronically infected with HCV genotype (G)3. PCSK9 concentrations were also measured in HCV-G1 to indirectly examine the role of LDLR in LVP clearance.

METHODS

HCV RNA, LVP (d<1.07g/ml) and non-LVP (d>1.07g/ml) fractions, were quantified in patients with HCV-G3 (n=39) by real time RT-PCR and LVP ratios (LVPr; LVP/(LVP+non-LVP)) were calculated. Insulin resistance (IR) was assessed using the homeostasis model assessment of IR (HOMA-IR). Plasma PCSK9 concentrations were measured by ELISA in HCV-G3 and HCV-G1 (n=51).

RESULTS

In HCV-G3 LVP load correlated inversely with HDL-C (r=-0.421; p=0.008), and apoE (r=-0.428; p=0.013). The LVPr varied more than 35-fold (median 0.286; range 0.027 to 0.969); PCSK9 was the strongest negative predictor of LVPr (R(2)=16.2%; p=0.012). HOMA-IR was not associated with LVP load or LVPr. PCSK9 concentrations were significantly lower in HCV-G3 compared to HCV-G1 (p<0.001). PCSK9 did not correlate with LDL-C in HCV-G3 or G1.

CONCLUSIONS

The inverse correlation of LVP with apoE in HCV-G3, compared to the reverse in HCV-G1 suggests HCV genotype-specific differences in apoE mediated viral entry. Lower PCSK9 and LDL concentrations imply upregulated LDLR activity in HCV-G3.

BMI, male sex and IL28B genotype associated with persistently high hepatitis C virus RNA levels among chronically infected drug users up to 23 years following seroconversion

The natural course of serum HCV RNA levels during chronic infection remains unclear. We investigated HCV RNA levels and factors associated with HCV RNA levels for the entire course from HCV seroconversion. We measured HCV RNA levels of 54 HCV seroconverters from the Amsterdam Cohort Studies among drug users at yearly intervals up to 23 years using bDNA (VERSANT 3.0, lower limit of detection 615 IU/mL). Samples below the cut-off of the assay were tested by TMA (Siemens VERSANT, detection limit 5 IU/mL). We used a latent class linear mixed model to examine the HCV RNA patterns and factors associated with HCV RNA levels. The median follow-up time was 10.8 years (IQR 6.5-14.9). We found two distinct HCV RNA patterns characterized by 45/54 cases and 9/54 cases. In multivariable analyses, HCV RNA levels were 0.41 log(10) IU/mL (95% confidence interval (CI) 0.06-0.75) higher for males as compared to females. Individuals with the IL28B CC genotype had 0.40 log(10) IU/mL (95% 0.08-0.73) higher HCV RNA levels than individuals with IL28B CT/TT genotypes. Body mass index (BMI) was associated with higher HCV RNA levels, 0.055 log(10) IU/mL per BMI point (95% CI 0.027-0.083). In this unique study, which examines the HCV RNA patterns over an extended period and following seroconversion, male sex, IL28B CC genotype and BMI were independently associated with higher average HCV RNA levels. These results contribute to defining the natural history of HCV infection and could play an important part in clinical decision-making.

The correlation between hepatitis C core antigen and hepatitis C virus RNA levels with respect to human immunodeficiency virus status, hepatitis C virus genotype and interferon-lambda-4 polymorphism

OBJECTIVES

Serum hepatitis C virus (HCV) core antigen (HCVcAg) concentrations correlate with HCV RNA levels in HCV monoinfected patients. Data in HCV/HIV coinfected patients are still limited. We aim to compare the use of HCVcAg measurement with respect to HIV status, HCV genotypes, interferon-lambda-4 (IFNL4) polymorphism and clinical parameters.

METHODS

We analyzed an untreated cohort of 104 patients with HCV monoinfection and 85 patients with HCV/HIV coinfection. Serum HCVcAg was measured by a commercial chemiluminescent microparticle immunoassay. The presence of IFNL4 polymorphism ss469415590 was identified by real-time PCR.

RESULTS

log10 HCVcAg levels were significantly correlated with corresponding log10 HCV RNA levels (r = 0.889, p < 0.001), but not with ALT levels and liver stiffness. The correlation between HCV RNA and HCVcAg was particularly high in coinfected patients and those with high viremia. Mean log10 HCVcAg concentration was significantly higher in coinfected patients than in monoinfected patients. Patients harboring the TT/TT genotype of ss469415590 had significantly higher levels of log10 HCVcAg than those with the non-TT/TT genotype. HCVcAg levels were similar across HCV genotypes.

CONCLUSIONS

HCVcAg concentrations had an excellent correlation with HCV RNA levels, particularly in HCV/HIV-coinfected individuals and might be associated with IFNL4 polymorphism. HCVcAg testing could be used as an alternative to HCV RNA assays in resource-limited settings.

Interferon lambda 3 genotype predicts hepatitis C virus RNA levels in early acute infection among people who inject drugs: the InC(3) study

BACKGROUND AND OBJECTIVES

Hepatitis C virus (HCV) RNA level in acute HCV infection is predictive of spontaneous clearance. This study assessed factors associated with HCV RNA levels during early acute infection among people who inject drugs with well-defined acute HCV infection.

STUDY DESIGN

Data were from International Collaboration of Incident HIV and Hepatitis C in Injecting Cohorts (InC(3)) Study, an international collaboration of nine prospective cohorts studying acute HCV infection. Individuals with available HCV RNA levels during early acute infection (first two months following infection) were included. The distribution of HCV RNA levels during early acute infection were compared by selected host and virological factors.

RESULTS

A total of 195 individuals were included. Median HCV RNA levels were significantly higher among individuals with interferon lambda 3 (IFNL3, formerly called IL28B) CC genotype compared to those with TT/CT genotype (6.28 vs. 5.39logIU/mL, respectively; P=0.01). IFNL3 CC genotype was also associated with top tertile HCV RNA levels (≥6.3log IU/mL; vs. TT/CT genotype; adjusted Odds Ratio: 4.28; 95%CI: 2.01, 9.10; P<0.01).

CONCLUSIONS

This study indicates that IFNL3 CC genotype predicts higher HCV RNA levels in early acute HCV infection.

The "hidden" epidemic: a snapshot of Moroccan intravenous drug users

Background

Hepatitis C virus is a persistent epidemiological problem, with an estimated 170 million individuals infected worldwide, and the leading cause of asymptomatic chronic infection, liver cirrhosis and hepatocellular carcinoma. Injection drug users (IDUs) have the highest seroprevalence as compared to chronic hemodialysis and transfusion patients, and this cohort remains the most under-studied high-risk group in North Africa to date. This study first sought to characterize the demographic, epidemiological, and genotypic profile of a total sample size of 211 chronically-infected IDUs living in the Tangier region of Northern Morocco, and secondly to contrast this to other chronically-infected patients, in order to uncover possible discrepancies.

Results

The general ‘profile’ of local IDUs marks a stark contrast to chronically-infected HCV Moroccan patients, other African countries, and neighboring European countries. The majority of Moroccan drug users were found to be middle-aged and celibate. A relatively high seroprevalence was found among drug users (60%), and this increased with age. The majority of drug users shared their needles and this hold implications for transmission, as seropositive status was significantly different between those users that shared vs. those that did not share their needles. In addition, IDUs exhibited genotypes 1a and 3a predominantly, as compared to the predominant 1b and 2a/2c genotypes found in chronically HCV-infected patients. The IDU genotypic profile closely matches the one in other European countries (Portugal, Spain, France, and Italy), which are invariably speculated as the potential source of currently-circulating genotypes in Moroccan IDUs.

Conclusion

These findings have implications for disease prevention, transmission and treatment, as this distinct IDU subgroup cannot be collectively pooled along with other HCV-positive high-risk groups. Local government, practitioners, and health institutions should take this into account when treating, prescribing antiviral therapy, and designing preventative public health campaigns.

Association of the IFNL4-ΔG Allele With Impaired Spontaneous Clearance of Hepatitis C Virus

Interferon lambda 4 protein can be generated in IFNL4-ΔG carriers but not IFNL4-TT homozygotes. We studied 890 anti-hepatitis C virus (HCV)-positive participants in the Women's Interagency HIV Study. Among blacks (n = 555), HCV was more often cleared for those with genotype IFNL4-TT/TT (32.6%; odds ratio [OR], 3.59; P = 3.3 × 10(-5)) than IFNL4-TT/ΔG (11.3%; OR, 0.95; P = .86) or IFNL4-ΔG/ΔG (11.9%; referent). Pooling these data with published results in blacks (n = 1678), ORs were 3.84 (P = 8.6 × 10(-14)) for IFNL4-TT/TT and 1.44 (P = .03) IFNL4-TT/ΔG, and the area under the curve was 0.64 for IFNL4-ΔG genotype and 0.61 for rs12979860 (IL28B). IFNL4-ΔG is strongly associated with impaired spontaneous HCV clearance.

A variant upstream of IFNL3 (IL28B) creating a new interferon gene IFNL4 is associated with impaired clearance of hepatitis C virus

Chronic infection with hepatitis C virus (HCV) is a common cause of liver cirrhosis and cancer. We performed RNA sequencing in primary human hepatocytes activated with synthetic double-stranded RNA to mimic HCV infection. Upstream of IFNL3 (IL28B) on chromosome 19q13.13, we discovered a new transiently induced region that harbors a dinucleotide variant ss469415590 (TT or ΔG), which is in high linkage disequilibrium with rs12979860, a genetic marker strongly associated with HCV clearance. ss469415590[ΔG] is a frameshift variant that creates a novel gene, designated IFNL4, encoding the interferon-λ4 protein (IFNL4), which is moderately similar to IFNL3. Compared to rs12979860, ss469415590 is more strongly associated with HCV clearance in individuals of African ancestry, although it provides comparable information in Europeans and Asians. Transient overexpression of IFNL4 in a hepatoma cell line induced STAT1 and STAT2 phosphorylation and the expression of interferon-stimulated genes. Our findings provide new insights into the genetic regulation of HCV clearance and its clinical management.

Correlation of viral loads with HCV genotypes: higher levels of virus were revealed among blood donors infected with 6a strains

Background

Both HCV genotypes and viral loads are predictors of therapeutic outcomes among patients treated with α-interferon plus ribavirin; however, such correlation has only been studied for genotypes 1, 2, and 3 but not for genotype 6.

Methodology/Findings

299 voluntary blood donors were recruited who were HCV viremic. Their mean age was 31.8; the male/female ratio was 3.82 (225/59). The viral loads of HCV were measured using the COBAS AmpliPrep/COBAS TaqMan test (CAP/CTM) while HCV genotypes were determined by direct sequencing the partial NS5B region. HCV genotypes 1, 2, 3, and 6 were determined in 48.9%, 8.7%, 12.3%, and 30.1% of the donors, respectively, and the levels of mean viral loads in genotype 1 and 6 significantly higher than that of 2 and 3 (P<0.001). As a whole, the viral loads in male donors were higher than in female (P = 0.006). Moreover, the donors' gender and HCV genotypes are independently correlated with the measured viral loads.

Conclusion

HCV genotype 1 and 6 had significantly higher viral loads than genotype 2 and 3.