Female sex and IL28B, a synergism for spontaneous viral clearance in hepatitis C virus (HCV) seroconverters from a community-based cohort

Defining the key intrahepatic gene networks in HCV infection driven by sex

OBJECTIVE

The transcriptional response in the liver during HCV infection is critical for determining clinical outcomes. This issue remains relatively unexplored as tissue access to address this at scale is usually limited. We aimed to profile the transcriptomics of HCV-infected livers to describe the expression networks involved and assess the effect on them of major predictors of clinical outcome such as IFNL4 (interferon lambda 4) host genotype and sex.

DESIGN

We took advantage of a large clinical study of HCV therapy accompanied by baseline liver biopsy to examine the drivers of transcription in tissue samples in 195 patients also genotyped genome-wide for host and viral single nucleotide polymorphisms. We addressed the role of host factors (disease status, sex, genotype, age) and viral factors (load, mutation) on transcriptional responses.

RESULTS

We observe key modules of transcription which can be impacted differentially by host and viral factors. Underlying cirrhotic state had the most substantial impact, even in a stable, compensated population. Notably, sex had a major impact on antiviral responses in concert with IL28B (interleukin 28B)/IFNL4 genotype, with stronger interferon and humoral responses in females. Males tended towards a dominant cellular immune response. In both sexes, there was a strong influence of the underlying host disease status and of specific viral mutations, and sex-specific expression quantitative trait loci were also observed.

CONCLUSION

These features help define the major influences on tissue responses in HCV infection, impacting on the response to treatment and with broader implications for responses in other sex-biased infections.

Susceptibilidad genética y aclaramiento viral de la infección por Virus de la Hepatitis C

El virus de la hepatitis C (VHC) sigue siendo una de las principales causas de hepatitis crónica en el mundo occidental. Del 15 % al 40 % de los individuos con infección aguda por VHC logran el aclaramiento viral espontáneo; sin embargo, los factores y variables asociadas a este fenómeno no están completamente descritas. El análisis de los mecanismos de patogénesis de la infección por VHC es indispensable para identificar los factores y variables implicadas en el aclaramiento espontáneo o en la persistencia de la infección. En algunos estudios se han documentado los factores del huésped asociados al aclaramiento viral espontáneo durante la infección aguda, entre ellos el polimorfismo del gen de la interleucina -28 (IL28B) que codifica para el interferón lambda 3 (IFNL3). El objetivo de este artículo es realizar una revisión de la literatura sobre la fisiopatología de la infección por el VHC y describir la evidencia acerca del papel de los polimorfismos en el gen IL28B y su impacto en el proceso de aclaramiento viral espontáneo, así como en otros aspectos de la historia natural y el tratamiento de la infección.

Factors Associated with Spontaneous Clearance of Recently Acquired Hepatitis C Virus among HIV-Positive Men in Brazil

INTRODUCTION

The objective of the present study was to describe the clinical and epidemiological aspects of recently acquired hepatitis C virus (HCV) infection and the frequency of its spontaneous clearance in a people living with the human immunodeficiency virus (PLWH) cohort.

METHODS

We reviewed the medical records from all PLWH at the human immunodeficiency virus (HIV) outpatient reference clinic affiliated with the University of São Paulo, Brazil, and identified, by immunoassays and RNA-PCR individuals who acquired HCV infection between January 2015 and December 2017. The factors associated with subsequent spontaneous clearance of the infection in this group were identified and analyzed.

RESULTS

Among 3143 PLWH individuals, 362 (11.5%) were coinfected with HCV. Forty-eight (13.2%) of these subjects first became HCV-positive between January 2015 and December 2017. Spontaneous HCV clearance was documented in 23 individuals (47.9%). The majority of this latter group were male (83.3%), and the median age was 31 years (23-39). The main risk group for HCV acquisition was men who had sex with men (MSM) (89.5%). In a multivariate analysis, only an elevated CD4+ T lymphocyte count at the time of seroconversion was found to be associated with subsequent HCV clearance (p = 0.025).

CONCLUSIONS

In HIV-infected individuals in Sao Paulo, Brazil, most cases of recent HCV transmission were by sexual exposure. In PLWH, particularly in MSM, the individual's CD4+ T lymphocyte count is a determinant of whether an acquired HCV infection will be prolonged or will spontaneously clear.

The Role of Sex in Acute and Chronic Liver Damage

Acute and chronic hepatic damages are caused by xenobiotics or different diseases affecting the liver, characterized by different etiologies and pathological features. It has been demonstrated extensively that liver damage progresses differently in men and women, and some chronic liver diseases show a more favorable prognosis in women than in men. This review aims to update the most recent advances in the comprehension of the molecular basis of the sex difference observed in both acute and chronic liver damage. With this purpose, we report experimental studies on animal models and clinical observations investigating both acute liver failure, e.g., drug-induced liver injury (DILI), and chronic liver diseases, e.g., viral hepatitis, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), autoimmune liver diseases, and hepatocellular carcinoma (HCC).

Gender Differences in Urothelial Bladder Cancer: Effects of Natural Killer Lymphocyte Immunity

Men are more likely to develop cancer than women. In fact, male predominance is one of the most consistent cancer epidemiology findings. Additionally, men have a poorer prognosis and an increased risk of secondary malignancies compared to women. These differences have been investigated in order to better understand cancer and to better treat both men and women. In this review, we discuss factors that may cause this gender difference, focusing on urothelial bladder cancer (UBC) pathogenesis. We consider physiological factors that may cause higher male cancer rates, including differences in X chromosome gene expression. We discuss how androgens may promote bladder cancer development directly by stimulating bladder urothelium and indirectly by suppressing immunity. We are particularly interested in the role of natural killer (NK) cells in anti-cancer immunity.

Spontaneous Clearance After Relapse Following Direct-Acting Antiviral Treatment for Chronic HCV Infection

BACKGROUND & AIMS

Direct-acting antivirals (DAAs) cure most cases of chronic hepatitis C virus (HCV) infection. However, a small percentage of patients relapse with reappearance of viremia after a full course of therapy. Although most who relapse require retreatment, some patients spontaneously clear HCV without additional therapy. We studied patients who relapsed with detectable HCV RNA after a full course of DAA therapy and then spontaneously cleared the HCV infection without retreatment.

METHODS

We performed a case-control study of patients who spontaneously cleared chronic HCV infection following a documented relapse after DAA therapy at the Toronto Centre for Liver Disease, from January 2014 through December 2017. We collected clinical information at baseline, 12 weeks after treatment, and 6 months after relapse and compared data among spontaneous clearers, patients with persistent relapse, and patients who achieved a sustained virologic response to therapy 12 weeks after treatment (SVR12). The strength and breadth of interferon gamma cytokine secretion by HCV-specific T cells from peripheral blood were quantified using the ELISPOT assay.

RESULTS

Of the 1032 individuals with chronic HCV infection who were treated with DAAs, 93 patients had a documented relapse. Of these patients, 12 patients (13%) spontaneously cleared HCV within 6 months after the documented relapse without additional therapy. The spontaneous clearers had low levels of HCV RNA (<4 log IU/mL in 11 of 12) and normal levels of alanine aminotransferase at the time of relapse, much like patients with an SVR12. There was no significant difference between the spontaneous clearance group and the SVR12 group in magnitude and breadth of HCV-specific T cell responses.

CONCLUSIONS

In a case-control study of patients who spontaneously cleared chronic HCV infection following a relapse after DAA therapy, we found that it is important to confirm viremia prior to retreatment after the relapse-particularly for individuals with low levels of HCV RNA and normal or near-normal levels of alanine aminotransferase after treatment.

Lessons learned from the Amsterdam Cohort Studies among people who use drugs: a historical perspective

The Netherlands is well known for its early adoption of harm reduction (HR) programs at the height of its heroin crisis in the 1970s/1980s, including the implementation of the first needle and syringe program worldwide. In this manuscript, we describe how the Amsterdam Cohort Studies (ACS) among people who use drugs (PWUD) was conceived within the context of the Dutch HR approach, including the challenges scientists faced while establishing this cohort. This required striking a balance between public health and individual benefit, solving research dilemmas in the face of uncertainty, developing controversial innovative and cutting-edge interventions, which changed the prevention landscape for PWUD, and using longitudinal cohort data to provide unique insights. Studies from the ACS covering follow-up between 1985 and 2016 revealed that participation in both opioid agonist therapy and needle and syringe programs led to a major decrease in the risk of HIV and hepatitis B and C infection acquisition. ACS data have shown that the observed decrease in incidence also likely included shifts in drug markets and drug culture over time, selective mortality among those with the highest levels of risk behaviour, demographic changes of the PWUD population, and progression of the HIV and HCV epidemics. Moreover, HR programs in the Netherlands provided services beyond care for drug use, such as social support and welfare services, likely contributing to its success in curbing the HIV and viral hepatitis epidemics, increasing access and retention to HIV and HCV care and ultimately decreases in overdose mortality over time. Given the low coverage of HR programs in certain regions, it is unsurprising that continued HIV and HCV outbreaks occur and that transmission is ongoing in many countries worldwide. If we aim to reach the World Health Organization viral hepatitis and HIV elimination targets in 2030, as well as to improve the life of PWUD beyond infection risk, comprehensive HR programs need to be integrated as a part of prevention services, as in the Netherlands. We should use the evidence generated by longstanding cohorts, including the ACS, as a basis for which implementation and improved coverage of integrated HR services can be achieved for PWUD worldwide.

Correlation between female sex, IL28B genotype, and the clinical severity of bronchiolitis in pediatric patients

BACKGROUND

Single-nucleotide polymorphisms (SNPs) that impact on the differential expression of interleukin 28B (IL28B) are implicated in the progression of viral-induced diseases. In this prospective longitudinal cohort study, we evaluated the association between IL28B SNPs rs12979860 and rs8099917 and the clinical outcome of bronchiolitis in pediatric patients.

METHODS

A total of 682 infants suffering from bronchiolitis, categorized based on the final clinical outcome as mild or severe, were genotyped for IL28B SNPs rs12979860 and rs8099917.

RESULTS

When infants were categorized exclusively based on the final clinical outcome, no association was established between IL28B SNPs and the severity of bronchiolitis. However, when stratified by sex, the homozygotes for the minor alleles of rs12979860 (T) and rs8099917 (G) were associated with a mild disease in girls but not in boys.

CONCLUSION

SNPs rs12979860 and rs8099917 correlate with the severity of bronchiolitis and display a sex bias, where GG rs8099917 and TT rs12979860 genotypes are associated with a mild disease in girls but not in boys. These findings suggest that innate immunity and female sex links with the outcome of the diseases induced by respiratory viruses, such as RSV.

IL-28B genetic variation, gender, age, jaundice, hepatitis C virus genotype, and hepatitis B virus and HIV co-infection in spontaneous clearance of hepatitis C virus

BACKGROUND/AIMS

Spontaneous viral clearance observed in some patients is one of the variants of the hepatitis C virus (HCV) infection natural history. We aimed to look at the complexity of factors affecting the spontaneous clearance of HCV (SC HCV).

MATERIALS AND METHODS

A total of 357 anti-HCV positive patients (309 with chronic hepatitis C and 48 patients with SC HCV) were included into the study. We studied the effects of the interleukin-28B (IL-28B) gene polymorphism, gender, age, the routes of virus transmission, past hepatitis C with jaundice, HCV genotype, and hepatitis B virus (HBV) and HIV co-infection on the outcome of HCV infection.

RESULTS

Based on the study results, the SC HCV was found in 48 individuals (13.4%). The most significant positive factors affecting the SC HCV included IL-28B single nucleotide polymorphism (SNP) rs12979860 (CC) and SNP rs8099917 (TT) (OR 4.03, p<0.001) and (OR 3.14, p<0.002), female gender (OR 2.72, p<0.001), young age (OR 2.30, p<0.008), and past history of jaundice (OR 5.12, p<0.001). The markers of a past HBV infection were found significantly more often in SC.

CONCLUSION

Positive predictors of the SC HCV include favorable IL-28B genotype, female gender, young age, a history of jaundice, markers of a past HBV infection, the absence of HIV infection, but not the viral genotype.

Hepatitis C Virus Genetic Variability, Human Immune Response, and Genome Polymorphisms: Which Is the Interplay?

Hepatitis C virus (HCV) infection is the main cause of chronic hepatitis, affecting an estimated 150 million people worldwide. Initial exposure to HCV is most often followed by chronic hepatitis, with only a minority of individuals spontaneously clearing the virus. The induction of sustained and broadly directed HCV-specific CD4⁺ and CD8⁺ T cell responses, together with neutralizing antibodies (nAb), and specific genetic polymorphism have been associated with spontaneous resolution of the infection. However, due to its high variability, HCV is able to overwhelm the host immune response through the rapid acquisition of mutations in the epitopes targeted by T cells and neutralizing antibodies. In this context, immune-mediated pressure represents the main force in driving HCV evolution. This review summarizes the data on HCV diversity and the current state of knowledge about the contributions of antibodies, T cells, and host genetic polymorphism in driving HCV evolution in vivo.

Delayed spontaneous hepatitis C virus elimination in a renal transplant patient following graft rejection

While elimination of the hepatitis C virus (HCV) following acute infection is not uncommon, spontaneous clearance once the infection becomes chronic is extremely rare. The mechanisms involved in the clearance of chronic HCV infection without intervening antiviral therapy are not well known. Herein we describe a case of a renal transplant recipient who acquired HCV infection while immunosuppressed, experienced a rapid histological progression, and thereafter cleared the virus spontaneously long after withdrawal of immunosuppression following kidney graft rejection and failure. We review the literature and summarize the reports of spontaneous clearance of chronic HCV infection in various settings.

New patterns emerge after a sustained increase in the incidence of hepatitis C virus infection from 2004 to 2017: a joinpoint regression analysis

OBJECTIVES

Hepatitis C virus (HCV) infection continues to be a major public health concern in China. There is little information available in the literature about age- and sex-specific HCV incidence trends. The goal of this study was to examine recent trends in HCV incidence rates in Hunan, China, according to age and gender.

STUDY DESIGN

A descriptive study was implemented with a joinpoint analysis.

METHODS

Based on the annual reported incidence data of hepatitis C in Hunan, China, from 2004 to 2017, we performed a joinpoint regression analysis to examine trends in the annual percentage change (APC) and the average annual percentage change (AAPC) in the incidence of HCV infection throughout the study period; we stratified the analysis by gender and age. The software calculates the APC, AAPC and the 95% confidence intervals for each trend segment and tests whether the slope for each segment has a significant difference from the prior segment using a Z test.

RESULTS

From 2004 to 2017, the overall incidence rate of HCV infection rose from 0.93 per 100,000 to 20.88 per 100,000 (AAPC, 25.2%). In particular, women aged ≥65 years had the fastest increasing rate (AAPC, 29.9%). The incidence of different demographic groups showed no significant difference in increasing trends before 2013. However, new patterns emerged after 2013: the incidence of people aged 0-14 years was no longer significantly elevated; a significant yearly decline occurred in the incidence of HCV in people aged 15-29 years; the incidence of HCV in people aged ≥30 years continued to increase, with significantly slower increasing rates than before; and women aged ≥65 years showed a significantly higher yearly increase in incidence than that in men in the same age group (APC, 11.1% in women versus 5.3% in men).

CONCLUSION

The overall increasing rate of HCV infection significantly slowed after 2007 and 2013. The differences in incidence trends among demographic groups have obviously increased in the last 5 years, and the reasons underlying these different trends urgently require further study. People in older age groups, especially women aged ≥65 years, still experienced increases in incidence rates in the last 5 years. This finding indicates that programmes for the prevention and control of HCV infection in older people require continued strengthening.

High spontaneous clearance of symptomatic iatrogenic acute hepatitis C genotype 4 infection

Acute hepatitis C (AHC) infection resolves spontaneously in 15% to 40% of patients. Factors favoring spontaneous viral clearance remain undefined. In this study, predictors of spontaneous viral clearance in patients with symptomatic AHC were investigated. Epidemiological, clinical, and virologic parameters were also examined. Patients with symptomatic AHC were enrolled and followed up prospectively. The patients were followed up every 2 weeks in the first month and then monthly for the following 5 months, with a follow-up visit 6 months after the last hepatitis C virus (HCV)-RNA negative sample for those who had cleared the virus. Interleukin (IL)-28B.rs12979860 single-nucleotide polymorphism and HCV genotype were tested at baseline. HCV-RNA was tested during each visit. Patients who remained RNA-positive at 24 weeks were treated with pegylated interferon plus ribavirin for 24 weeks. A total of 30 patients, mostly with iatrogenically acquired AHC genotype 4 infections completed 6-months' follow-up, to either spontaneous clearance or start of treatment. The mean age of the patients was 37 ± 13 years. In total, 67% of patients were females, and the mean incubation period was 7.6 ± 3.5 weeks. Viral clearance occurred spontaneously in 19 (63.3%) patients. The average time to clearance was 24.3 ± 9.6 weeks. A total of 11 patients received therapy, and 8 (72.7%) cleared the virus and had a sustained virologic response to the treatment 24 weeks after the therapy. A total of three patients were treatment nonresponders. IL28B.rs12979860 CC genotype, female gender, and viremia level were not associated with self-limiting AHC in this cohort. In conclusion, patients with symptomatic AHC genotype 4 infection caused by an iatrogenic exposure had higher rates of spontaneous resolution than previously reported. Predicting spontaneous viral clearance after iatrogenic AHC exposure was not possible in this population.

Female predisposition to TLR7-driven autoimmunity: gene dosage and the escape from X chromosome inactivation

Women develop stronger immune responses than men, with positive effects on the resistance to viral or bacterial infections but magnifying also the susceptibility to autoimmune diseases like systemic lupus erythematosus (SLE). In SLE, the dosage of the endosomal Toll-like receptor 7 (TLR7) is crucial. Murine models have shown that TLR7 overexpression suffices to induce spontaneous lupus-like disease. Conversely, suppressing TLR7 in lupus-prone mice abolishes SLE development. TLR7 is encoded by a gene on the X chromosome gene, denoted TLR7 in humans and Tlr7 in the mouse, and expressed in plasmacytoid dendritic cells (pDC), monocytes/macrophages, and B cells. The receptor recognizes single-stranded RNA, and its engagement promotes B cell maturation and the production of pro-inflammatory cytokines and antibodies. In female mammals, each cell randomly inactivates one of its two X chromosomes to equalize gene dosage with XY males. However, 15 to 23% of X-linked human genes escape X chromosome inactivation so that both alleles can be expressed simultaneously. It has been hypothesized that biallelic expression of X-linked genes could occur in female immune cells, hence fostering harmful autoreactive and inflammatory responses. We review here the current knowledge of the role of TLR7 in SLE, and recent evidence demonstrating that TLR7 escapes from X chromosome inactivation in pDCs, monocytes, and B lymphocytes from women and Klinefelter syndrome men. Female B cells where TLR7 is thus biallelically expressed display higher TLR7-driven functional responses, connecting the presence of two X chromosomes with the enhanced immunity of women and their increased susceptibility to TLR7-dependent autoimmune syndromes.

Management of acute HCV infection in the era of direct-acting antiviral therapy

The management of acute HCV infection has not been standardized following the availability of direct-acting antiviral agents (DAAs) for chronic HCV infection, and substantial uncertainty exists regarding the optimal treatment regimen and duration. Despite the lack of direct evidence, the 2016 American Association for the Study of Liver Diseases (AASLD)-Infectious Diseases Society of America (IDSA) guidelines supported "the same regimens for acute HCV as recommended for chronic HCV infection … owing to high efficacy and safety", whereas the 2016 European Association for the Study of the Liver (EASL) guidelines recommended sofosbuvir-ledipasvir, sofosbuvir-velpatasvir or sofosbuvir plus daclatasvir for 8 weeks in acute HCV infection, with a longer duration of 12 weeks recommended for those infected with HIV and/or baseline HCV RNA levels >1,000,000 IU/ml. This Review outlines the epidemiology, natural history and diagnosis of acute HCV infection and provides contemporary information on DAAs for acute and recent HCV infection. The Review also discusses the 2016 AASLD-IDSA and EASL recommendations for acute HCV infection management in light of available evidence and highlights key differences in study populations and design that influence interpretation. We focus on populations at high risk of HCV transmission and acquisition, including people who inject drugs and HIV-positive men who have sex with men, and highlight the potential effects of diagnosis and treatment of acute HCV infection in contributing to HCV elimination.

Polymorphisms in the Th17 cell-related RORC gene are associated with spontaneous clearance of HCV in Chinese women

BACKGROUND

Female gender and favorable IFNL3 genotypes are the primary independent predictors of spontaneous clearance of HCV infection. However, chronic hepatitis C infection occurs in numerous women carrying favorable IFNL3 genotypes, indicating that other host and/or virological factors contribute to the prognosis of infection.

METHODS

A cohort of 137 anti-HCV-positive female Han Chinese cases, including 64 chronic HCV carriers and 73 HCV spontaneous resolvers, was recruited in the study. 111 SNPs in 23 genes encoding HCV co-receptors, transcription factors, Toll-like receptors, co-stimulating molecules, and cytokines were selected for SNP analysis.

RESULTS

After comparison of genotypes and allelotype frequencies of 111 SNPs in 23 genes in the primary cohort, the SNPs rs9826 (P = 0.024 for CC/TT/CT; P = 0.015 for C allele/T allele) and rs1521177 (P = 0.017 for GG/TT/GT; P = 0.006 for G allele/T allele) in the RORC gene were significantly associated with spontaneous HCV clearance. In the sub-cohort carrying favorable IFNL3 genotypes (rs12979860CC, rs8099917 TT, rs12980275 AA), rs1521177 (genotype: P = 0.040; allelotype: P = 0.021) remained significantly associated with spontaneous HCV clearance. Importantly, the most common RORC haplotype rs9826-T/rs1521177-T was presented at significantly different frequencies in resolvers and carriers in both the primary cohort (P = 0.0027) and the IFNL3 favorable sub-cohort (P = 0.0117).

CONCLUSIONS

This study indicates that genetic polymorphisms in human Th17-related RORC gene are associated with different natural prognosis of HCV infection. The RORC haplotype, rs9826-T/rs1521177-T, was favorable for spontaneous clearance of HCV infection.

Assessing hepatitis C spontaneous clearance and understanding associated factors-A systematic review and meta-analysis

New advances in the treatment of hepatitis C provide high levels of sustained viral response but their expense limits availability in publicly funded health systems. The aim of this review was to estimate the proportion of patients who will spontaneously clear HCV, to identify factors that are associated with clearance and to support better targeting of directly acting antivirals. We searched Ovid EMBASE, Ovid MEDLINE and PubMed from 1 January 1994 to 30 June 2015 for studies reporting hepatitis C spontaneous clearance and/or demographic, clinical and behavioural factors associated with clearance. We undertook meta-analyses to estimate the odds of clearance for each predictor. Forty-three studies met the inclusion criteria, representing 20 110 individuals, and 6 of these studies included sufficient data to estimate spontaneous clearance. The proportion achieving clearance within 3, 6, 12 and 24 months following infection were, respectively, 19.8% (95% CI: 2.6%-47.5%), 27.9% (95% CI: 17.2%-41.8%), 36.1% (95% CI: 23.5%-50.9%) and 37.1% (95% CI: 23.7%-52.8%). Individuals who had not spontaneously cleared by 12 months were unlikely to do so. The likelihood of spontaneous clearance was lower in males and individuals with HIV co-infection, the absence of HBV co-infection, asymptomatic infection, black or nonindigenous race, nongenotype 1 infection, older age and alcohol or drug problems. This study suggests that patients continue to spontaneously clear HCV for at least 12 months following initial infection. However, injecting drug users are comparatively less likely to achieve clearance; thus, they should be considered a priority for early treatment given the continuing risks that these individuals pose for onwards transmission.

Toll-like receptor 9 (TLR-9) promotor polymorphisms and gene expression are associated with persistent Staphylococcus aureus nasal carriage

OBJECTIVES

Toll-like receptor (TLR) 9 could have importance in human Staphylococcus aureus immunity, but population-level evidence for this hypothesis is missing.

METHODS

We phenotyped S. aureus nasal carriage of 603 volunteers using four consecutive swabs, genotyped TLR9 promotor variants in 106 persistent carriers and 219 noncarriers, measured TLR9-mRNA expression in whole blood after stimulation with viable S. aureus and studied mutual associations of carriage, transcriptional activity and single nucleotide polymorphisms while accounting for sex and hormone contraceptive use (HCU).

RESULTS

The -1486 (rs187084) and -1237 (rs5743836) CT haplotype was more common in noncarriers (185/438, 42%) than in carriers (63/212, 30%), with the TT haplotype showing a reverse association (noncarriers, 180/438, 41%; carriers 117/212, 55%) (χ² p 0.001). Mean TLR9 mRNA expression in whole blood was higher in noncarriers (ratio_{carriers/noncarriers} 0.63; 95% confidence interval, 0.43-0.92; p 0.017). A duplication of TLR9 transcriptional activity lowered the odds of persistent S. aureus carriage by 37% in the overall group (odds ratio = 0.63; 95% confidence interval, 0.42-0.94; p 0.022) and by 54% in women (odds ratio = 0.46; 95% confidence interval, 0.23-0.90; p 0.023). Promotor haplotype and HCU had a combined effect on TLR9 transcription (interaction model): women in the TT (risk) haplotype/HCU^- stratum (baseline) had lower mRNA levels than women in the CT (protective) haplotype/HCU^- (ratio 1.92; p 0.055), the CT haplotype/HCU⁺ (ratio 2.02; p 0.032) and the TT haplotype/HCU⁺ (ratio 2.59; p < 0.004) strata. No such associations were observed in men.

CONCLUSIONS

We provide evidence that TLR9 affects human S. aureus immunity and present potential explanations for differences according to sex in S. aureus colonization and infection.

Treatment Related Hematologic Changes in a Population of Iranian Patients with Chronic Hepatitis C Infection from 2009 to 2014

BACKGROUND

We aimed to assess the frequency of hematologic changes, response to treatment, rate of discontinuation and dose reduction in Hepatitis C positive patients, treated with Interferon and ribavirin from Apr 2009 to Mar 2014.

METHODS

In this cross-sectional study, out of registered patients, 554 were assessed and 150 patients with positive HCV PCR, regular patient visits to clinic and complete records were included. HCV viral load, complete blood count and liver enzyme levels were measured before initiation of treatment and monthly. Exclusion criteria's were other types of hepatitis and HIV infection, autoimmune or blood diseases, illegal drug use and treatment with bone marrow suppressors. The data was analyzed using SPSS.

RESULTS

Out of 150 patients, 135 (90%) were male. Mean age was 39.7±10.7 (range 23-74) yr old. Forty-six patients (30.7%) had genotype 1 and 99 (66%) genotypes 2 and 3. Treatment regimens were prescribed as Pegafron+Ribavirin in 125 (83.3%), Interfron+Ribavirin 9 (6%) and Pegintron+Ribavirin in 16 (10.7%) of patients... The prevalence of anemia in genotype 1 patients was higher (P=0.044). There was no association between sex and leukocyte changes. Thirty-four (22.7%) patients had moderate and severe thrombocytopenia. Six patients had severe anemia and Ribavirin dose was adjusted.

CONCLUSION

The hematological changes are common side effects of conventional hepatitis C treatment regiments. Although drug dose adjustment is not usually necessary, due to severe anemia in genotype 1 patients, we should treat high-risk patients cautiously and made the appropriate changes in drug dosage at the right time.

Germline genetic variants with implications for disease risk and therapeutic outcomes

Genetic testing has multiple clinical applications including disease risk assessment, diagnosis, and pharmacogenomics. Pharmacogenomics can be utilized to predict whether a pharmacologic therapy will be effective or to identify patients at risk for treatment-related toxicity. Although genetic tests are typically ordered for a distinct clinical purpose, the genetic variants that are found may have additional implications for either disease or pharmacology. This review will address multiple examples of germline genetic variants that are informative for both disease and pharmacogenomics. The discussed relationships are diverse. Some of the agents are targeted for the disease-causing genetic variant, while others, although not targeted therapies, have implications for the disease they are used to treat. It is also possible that the disease implications of a genetic variant are unrelated to the pharmacogenomic implications. Some of these examples are considered clinically actionable pharmacogenes, with evidence-based, pharmacologic treatment recommendations, while others are still investigative as areas for additional research. It is important that clinicians are aware of both the disease and pharmacogenomic associations of these germline genetic variants to ensure patients are receiving comprehensive personalized care.

Spontaneous Clearance of Hepatitis C Virus Infection Among Human Immunodeficiency Virus-Infected Men Who Have Sex With Men

We assessed spontaneous clearance in 27 human immunodeficiency virus-infected men who have sex with men (MSM) who seroconverted for hepatitis C virus (HCV). In contrast with a recent estimate of 45.8%, we found a spontaneous clearance rate of 11.1% (95% confidence interval = 2.4-29.2). This finding suggests that treatment deferral to await spontaneous clearance might not be justified for MSM with sexually acquired HCV.

Role of primary T-cell immunodeficiency and hepatitis B coinfection on spontaneous clearance of hepatitis C: The BC Hepatitis Testers Cohort

T-cell host immune response against hepatitis C virus (HCV) has been suggested to play an important role in determining HCV infection outcome. However, data from human studies are not available. This study examined the effect of primary T-cell deficiency along with other factors on the spontaneous clearance of HCV in a large population-based cohort in British Columbia, Canada. The BC Hepatitis Testers Cohort includes all individuals tested for HCV in BC in 1990-2013 linked with data on their medical visits, hospitalizations and prescription drugs. HCV-positive individuals with at least one valid HCV PCR test on/after HCV diagnosis (n=46 783) were included in this study. To examine factors associated with the spontaneous clearance of HCV, multivariable logistic regression was fitted on the full sample, and Cox proportional hazards model on the HCV seroconverters. Spontaneous clearance was observed in 25.1% (n=11 737) of those tested for HCV. After adjusting for potential confounders, the odds of spontaneous clearance of HCV was lower in people with primary T-cell immunodeficiency (adjusted odds ratio [aOR]: 0.55, 95% CI: 0.32-0.94), and higher in females (aOR: 1.61, 95% CI: 1.54-1.68) and in those coinfected with HBV (aOR: 2.31, 95% CI: 1.93-2.77). Similar results were observed in HCV seroconverters except HBV coinfection was not significant. In conclusion, primary T-cell immunodeficiency is associated with a lower spontaneous clearance of HCV while female sex and coinfection with HBV are associated with a higher spontaneous clearance.

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.

Gender differences in liver disease and the drug-dose gender gap

Although gender-based medicine is a relatively recent concept, it is now emerging as an important field of research, supported by the finding that many diseases manifest differently in men and women and therefore, might require a different treatment. Sex-related differences regarding the epidemiology, progression and treatment strategies of certain liver diseases have long been known, but most of the epidemiological and clinical trials still report results only about one sex, with consequent different rate of response and adverse reactions to treatment between men and women in clinical practice. This review reports the data found in the literature concerning the gender-related differences for the most representative hepatic diseases.

Maximum levels of hepatitis C virus lipoviral particles are associated with early and persistent infection

BACKGROUND & AIMS

Hepatitis C virus (HCV) is bound to plasma lipoproteins and circulates as an infectious lipoviral particle (LVP). Experimental evidence indicates that LVPs have decreased susceptibility to antibody-mediated neutralisation and higher infectivity. This study tested the hypothesis that LVPs are required to establish persistent infection, and conversely, low levels of LVP in recent HCV infection increase the probability of spontaneous HCV clearance.

METHODS

LVP in non-fasting plasma was measured using the concentration of HCV RNA bound to large >100 nm sized lipoproteins after ex vivo addition of a lipid emulsion, that represented the maximum concentration of LVP (maxi-LVP). This method correlated with LVP in fasting plasma measured using iodixanol density gradient ultracentrifugation. Maxi-LVP was measured in a cohort of 180 HCV participants with recent HCV infection and detectable HCV RNA from the Australian Trial in Acute Hepatitis C (ATAHC) and Hepatitis C Incidence and Transmission Study in prison (HITS-p) cohorts.

RESULTS

Spontaneous clearance occurred in 15% (27 of 180) of individuals. In adjusted analyses, low plasma maxi-LVP level was independently associated with spontaneous HCV clearance (≤827 IU/ml; adjusted odds ratio 3.98, 95% CI: 1.02, 15.51, P = 0.047), after adjusting for interferon lambda-3 rs8099917 genotype, estimated duration of HCV infection and total HCV RNA level.

CONCLUSIONS

Maxi-LVP is a biomarker for the maximum concentration of LVP in non-fasting samples. Low maxi-LVP level is an independent predictor of spontaneous clearance of acute HCV.

Hepatitis C virus Broadly Neutralizing Monoclonal Antibodies Isolated 25 Years after Spontaneous Clearance

Hepatitis C virus (HCV) is world-wide a major cause of liver related morbidity and mortality. No vaccine is available to prevent HCV infection. To design an effective vaccine, understanding immunity against HCV is necessary. The memory B cell repertoire was characterized from an intravenous drug user who spontaneously cleared HCV infection 25 years ago. CD27+IgG+ memory B cells were immortalized using BCL6 and Bcl-xL. These immortalized B cells were used to study antibody-mediated immunity against the HCV E1E2 glycoproteins. Five E1E2 broadly reactive antibodies were isolated: 3 antibodies showed potent neutralization of genotype 1 to 4 using HCV pseudotyped particles, whereas the other 2 antibodies neutralized genotype 1, 2 and 3 or 1 and 2 only. All antibodies recognized non-linear epitopes on E2. Finally, except for antibody AT12-011, which recognized an epitope consisting of antigenic domain C /AR2 and AR5, all other four antibodies recognized epitope II and domain B. These data show that a subject, who spontaneously cleared HCV infection 25 years ago, still has circulating memory B cells that are able to secrete broadly neutralizing antibodies. Presence of such memory B cells strengthens the argument for undertaking the development of an HCV vaccine.

Spontaneous viral clearance of hepatitis C virus (HCV) infection among people who inject drugs (PWID) and HIV-positive men who have sex with men (HIV+ MSM): a systematic review and meta-analysis

Background

Hepatitis C virus (HCV) infection causes significant morbidity and mortality among people who inject drugs (PWID) and HIV+ men who have sex with men (MSM). Characterizing spontaneous viral clearance of HCV infection among PWID and HIV+ MSM is important for assessing the burden of disease and treatment strategies in these populations.

Methods

Electronic and other searches of medical literature were conducted. Reports were eligible if they presented original data from upper-middle- and high-income countries on laboratory-confirmed HCV infection and spontaneous viral clearance among PWID or HIV+ MSM. Pooled estimates of spontaneous viral clearance were generated using fixed-effect and random-effects models. Meta-regression examined potential predictors related to individual characteristics and research methodology.

Results

The meta-analysis estimated that spontaneous viral clearance occurs in 24.4 % of PWID and 15.4 % of HIV+ MSM. In univariate meta-regression among PWID, male sex and age were significantly associated with spontaneous viral clearance, and in multivariate analysis, male sex and HIV positivity were predictors of spontaneous viral clearance; among HIV+ MSM no variables were found to affect spontaneous viral clearance.

Conclusion

The variability in estimates of spontaneous viral clearance between HIV+ MSM and PWID suggests the impact of HIV co-infection and HCV re-infection. Due to limited data on additional factors that may affect the natural history of HCV, more research is needed to further understand spontaneous viral clearance in these risk groups.

Protocol registration

The protocols for the PWID and HIV+ MSM research were registered with PROSPERO (CRD42014008805; CRD42013006462).

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1807-5) contains supplementary material, which is available to authorized users.

Factors associated with spontaneous clearance of chronic hepatitis C virus infection

BACKGROUND & AIMS

Spontaneous clearance of chronic hepatitis C virus (HCV) infection (CHC) is rare. We conducted a retrospective case-control study to identify rates and factors associated with spontaneous clearance of CHC.

METHODS

We defined cases as individuals who spontaneously resolved CHC, and controls as individuals who remained chronically infected. We used data obtained on HCV testing between 1994 and 2013 in the West of Scotland to infer case/control status. Specifically, untreated patients with ⩾2 sequential samples positive for HCV RNA ⩾6months apart followed by ⩾1 negative test, and those with ⩾2 positive samples ⩾6months apart with no subsequent negative samples were identified. Control patients were randomly selected from the second group (4/patient of interest). Case notes were reviewed and patient characteristics obtained.

RESULTS

25,113 samples were positive for HCV RNA, relating to 10,318 patients. 50 cases of late spontaneous clearance were identified, contributing 241 person-years follow-up. 2,518 untreated, chronically infected controls were identified, contributing 13,766 person-years follow-up, from whom 200 controls were randomly selected. The incidence rate of spontaneous clearance was 0.36/100 person-years follow-up, occurring after a median 50months' infection. Spontaneous clearance was positively associated with female gender, younger age at infection, lower HCV RNA load and co-infection with hepatitis B virus. It was negatively associated with current intravenous drug use.

CONCLUSIONS

Spontaneous clearance of CHC occurs infrequently but is associated with identifiable host and viral factors. More frequent HCV RNA monitoring may be appropriate in selected patient groups.

LAY SUMMARY

Clearance of hepatitis C virus infection without treatment occurs rarely once chronic infection has been established. We interrogated a large Scottish patient cohort and found that it was more common in females, patients infected at a younger age or with lower levels of HCV in the blood, and patients co-infected with hepatitis B virus. Patients who injected drugs were less likely to spontaneously clear chronic infection.

HCV monoinfection and HIV/HCV coinfection enhance T-cell immune senescence in injecting drug users early during infection

Background

Injecting drug users (IDU) are at premature risk of developing multimorbidity and mortality from causes commonly observed in the elderly. Ageing of the immune system (immune-senescence) can lead to premature morbidity and mortality and can be accelerated by chronic viral infections. Here we investigated the impact of HCV monoinfection and HIV/HCV coinfection on immune parameters in (ex-) IDU. We analyzed telomere length and expression of activation, differentiation and exhaustion markers on T cells at baseline (t = 1) and at follow-up (t = 2) (median interval 16.9 years) in IDU who were: HCV mono-infected (n = 21); HIV/HCV coinfected (n = 23) or multiple exposed but uninfected (MEU) (n = 8).

Results

The median time interval between t = 1 and t = 2 was 16.9 years. Telomere length within CD4⁺ and CD8⁺ T cells decreased significantly over time in all IDU groups (p ≤ 0.012). CD4⁺ T-cell telomere length in HCV mono-infected IDU was significantly reduced compared to healthy donors at t = 1 (p < 0.008). HIV/HCV coinfected IDU had reduced CD4⁺ and CD8⁺ T-cell telomere lengths (p ≤ 0.002) to healthy donors i at t = 1. This was related to persistent levels of immune activation but not due to increased differentiation of T cells over time. Telomere length decrease was observed within all T-cell subsets, but mainly found in immature T cells (CD27⁺CD57⁺) (p ≤ 0.015).

Conclusions

HCV mono-infection and HIV/HCV coinfection enhance T-cell immune-senescence. Our data suggest that this occurred early during infection, which warrants early treatment for both HCV and HIV to reduce immune senescence in later life.

Electronic supplementary material

The online version of this article (doi:10.1186/s12979-016-0065-0) contains supplementary material, which is available to authorized users.

Association of IL28B rs8099917 genotype and female sex with spontaneous clearance of hepatitis C virus infection: a Japanese cross-sectional study

Hepatitis C virus (HCV) infection is a serious global health problem. Previous studies have suggested that the interleukin 28B (IL28B) rs8099917 genotype is related to spontaneous clearance of HCV in Caucasian populations. Our objective was to investigate the association of the IL28B rs8099917 genotype with spontaneous clearance of HCV by community-dwelling Japanese. A cross-sectional community-based population study of 993 Japanese residents was conducted. Based on anti-HCV antibody and HCV RNA levels, 50 subjects were assigned to the spontaneous-clearance group, 155 to the chronic-infection group, and 788 to the control group. Logistic regression analysis was done to examine the roles of the IL28B rs8099917 genotype and sex. To analyze the interactions between these factors, an "IL28B rs809991 genotype × sex" interaction term was included in the multivariate analysis. Significantly more subjects in the spontaneous-clearance group than in the chronic-infection group had the favorable IL28B rs8099917 genotype and were female. Multivariate logistic regression analysis extracted the favorable IL28B rs8099917 TT genotype (odds ratio [OR] 9.39; 95% confidence interval [CI], 2.16-40.83, P = 0.003) and female sex (OR, 2.27; 95% CI, 1.16-4.45, P = 0.017) as factors contributing to the spontaneous clearance of HCV. No significant interaction was found between the IL28B rs8099917 genotype and sex (P for interaction = 0.428). Both the favorable IL28B rs8099917 genotype and female sex were associated with the spontaneous clearance of HCV in this Japanese population.

Natural History of Hepatitis C

Hepatitis C infection is a common cause of cirrhosis and indication for liver transplantation in the United States. The incidence of chronic hepatitis C has been declining, but rates of cirrhosis and hepatocellular carcinoma are projected to increase. The outcome of chronic hepatitis C is variable. It is estimated that 20% to 25% will develop cirrhosis over a 25-year to 30-year period. The rate of disease progression is influenced by many host, viral, and environmental factors. Few can be modified.

Genetic characterization of multiple hepatitis C virus infections following acute infection in HIV-infected men who have sex with men

OBJECTIVE

High rates of hepatitis C virus (HCV) reinfections among HIV-infected men who have sex with men (MSM) following clearance of a primary infection suggest absence of protective immunity. Here, we investigated the incidence of HCV super and reinfections in 85 HIV-infected MSM with incident HCV infection.

DESIGN AND METHODS

Serial sequencing of a fragment of NS5B and the HCV envelope was used to longitudinally characterize the virus. If the primary genotype was still present at the most recent viremic time point, as indicated by the NS5B sequence analysis, serial envelope 2/hypervariable region 1 (E2/HRV1) sequence analysis was performed to distinguish a new infection with the same genotype (clade switch) from intrahost evolution. Incidence rate and cumulative incidence of secondary infections were estimated, and the effect of the primary genotype (1a versus non1) on the risk of acquiring a second infection with the same genotype was determined using Cox proportional-hazards analysis.

RESULTS

Among 85 patients with a median follow-up of 4.8 years, incidence rate of secondary infections was 5.39 cases/100 person-years (95% confidence interval 3.34-8.26). Cumulative incidence of genotype switches was markedly higher than the cumulative incidence of clade switches (26.7 versus 4.8% at 5 years, respectively). In patients with HCV-1a as primary infection, the risk for acquiring another HCV-1a infection was reduced compared to those with a primary non-HCV-1a subsequently acquiring HCV-1a (hazard ratio 0.25, 95% confidence interval 0.07-0.93).

CONCLUSION

Risk of acquiring a secondary infection with the primary genotype was strikingly reduced compared with the risk of acquiring a secondary infection with a different genotype.

Sex Differences in Plasmacytoid Dendritic Cell Levels of IRF5 Drive Higher IFN-α Production in Women

Increased IFN-α production contributes to the pathogenesis of infectious and autoimmune diseases. Plasmacytoid dendritic cells (pDCs) from females produce more IFN-α upon TLR7 stimulation than pDCs from males, yet the mechanisms underlying this difference remain unclear. In this article, we show that basal levels of IFN regulatory factor (IRF) 5 in pDCs were significantly higher in females compared with males and positively correlated with the percentage of IFN-α-secreting pDCs. Delivery of recombinant IRF5 protein into human primary pDCs increased TLR7-mediated IFN-α secretion. In mice, genetic ablation of the estrogen receptor 1 (Esr1) gene in the hematopoietic compartment or DC lineage reduced Irf5 mRNA expression in pDCs and IFN-α production. IRF5 mRNA levels furthermore correlated with ESR1 mRNA levels in human pDCs, consistent with IRF5 regulation at the transcriptional level by ESR1. Taken together, these data demonstrate a critical mechanism by which sex differences in basal pDC IRF5 expression lead to higher IFN-α production upon TLR7 stimulation in females and provide novel targets for the modulation of immune responses and inflammation.

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.

Evolution and function of the HCV NS3 protease in patients with acute hepatitis C and HIV coinfection

Little is known about the importance of the hepatitis C virus (HCV) NS3 protease in acute hepatitis C. In this prospective study, 82 consecutive patients with acute hepatitis C and human immunodeficiency virus (HIV) coinfection were enrolled. Individuals were infected with highly related HCV strains and the baseline NS3 quasispecies diversity and complexity was higher compared to a chronic hepatitis C control group (P<0.0001). Both parameters were comparable in patients with spontaneous clearance (n=6) versus treatment-induced SVR (n=5) or development of chronic hepatitis C (n=9). Longitudinal NS3 quasispecies kinetics showed a trend to a decreasing diversity and complexity (P<0.05) within 4 weeks in patients with spontaneous clearance compared to the other groups. The innate immune signalling protein CARDIF was cleaved to a similar extent independent of the outcome. Together with a more pronounced viral load decline (P<0.05), an early decreasing NS3 quasispecies evolution indicates spontaneous clearance of acute hepatitis C.

Hepatitis C Virus Reinfection and Spontaneous Clearance of Reinfection--the InC3 Study

BACKGROUND

We aimed to characterize the natural history of hepatitis C virus (HCV) reinfection and spontaneous clearance following reinfection (reclearance), including predictors of HCV reclearance.

METHODS

Data were synthesized from the 9 prospective cohorts of the International Collaboration of Incident Human Immunodeficiency Virus and HCV in Injecting Cohorts study, which evaluated HCV infection outcomes among people who inject drugs. Participants with primary HCV infection were classified as having achieved viral suppression if they had negative results of at least 1 subsequent HCV RNA test. Those with positive results of an HCV RNA test following viral suppression were investigated for reinfection. Viral sequence analysis was used to identify reinfection (defined as detection of heterologous virus with no subsequent detection of the original viral strain).

RESULTS

Among 591 participants with acute primary HCV infection, 118 were investigated for reinfection. Twenty-eight participants were reinfected (12.3 cases/100 person-years; 95% confidence interval [CI], 8.5-17.8). Peak HCV RNA level was lower during reinfection than primary infection (P = .011). The proportion of individuals with reclearance 6 months after reinfection was 52% (95% CI, 33%-73%). After adjustment for study site, females with the IFNL4 (formerly IFNL3 and IL28B) rs12979860 CC genotype detected were more likely to have reclearance (hazard ratio, 4.16; 95% CI, 1.24-13.94; P = .021).

CONCLUSIONS

Sex and IFNL4 genotype are associated with spontaneous clearance after reinfection.

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.

Favourable IFNL3 genotypes are associated with spontaneous clearance and are differentially distributed in Aboriginals in Canadian HIV-hepatitis C co-infected individuals

Canadian Aboriginals are reported to clear Hepatitis C (HCV) more frequently. We tested the association of spontaneous clearance and three single nucleotide polymorphisms (SNPs) near the Interferon-lambda 3 (IFNL3) gene (rs12979860, rs8099917, functional variant rs8103142) and compared the SNP frequencies between HIV-HCV co-infected whites and Aboriginals from the Canadian Co-infection Cohort. HCV treatment-naïve individuals with at least two HCV RNA tests were included (n = 538). A spontaneous clearance case was defined as someone with two consecutive HCV RNA-negative tests, at least six months apart. Data were analyzed using Cox proportional hazards adjusted for sex and ethnicity. Advantageous variants and haplotypes were more common in Aboriginals than Caucasians: 57% vs. 46% had the rs12979860 CC genotype, respectively; 58% vs. 48%, rs8103142 TT; 74% vs. 67%, the rs12979860 C allele; and 67% vs. 64% the TCT haplotype with three favourable alleles. The adjusted Hazard Ratios (95% CI) for spontaneous clearance were: rs12979860: 3.80 (2.20, 6.54); rs8099917: 5.14 (2.46, 10.72); and rs8103142: 4.36 (2.49, 7.62). Even after adjusting for rs12979860, Aboriginals and females cleared HCV more often, HR (95% CI) = 1.53 (0.89, 2.61) and 1.42 (0.79, 2.53), respectively. Our results suggest that favourable IFNL3 genotypes are more common among Aboriginals than Caucasians, and may partly explain the higher HCV clearance rates seen among Aboriginals.

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.

Dynamic modelling of hepatitis C virus transmission among people who inject drugs: a methodological review

Equipment sharing among people who inject drugs (PWID) is a key risk factor in infection by hepatitis C virus (HCV). Both the effectiveness and cost-effectiveness of interventions aimed at reducing HCV transmission in this population (such as opioid substitution therapy, needle exchange programmes or improved treatment) are difficult to evaluate using field surveys. Ethical issues and complicated access to the PWID population make it difficult to gather epidemiological data. In this context, mathematical modelling of HCV transmission is a useful alternative for comparing the cost and effectiveness of various interventions. Several models have been developed in the past few years. They are often based on strong hypotheses concerning the population structure. This review presents compartmental and individual-based models to underline their strengths and limits in the context of HCV infection among PWID. The final section discusses the main results of the papers.

Predictors of spontaneous viral clearance and outcomes of acute hepatitis C infection

Background/Aims

This study evaluated the predictors of spontaneous viral clearance (SVC), as defined by two consecutive undetectable hepatitis C virus (HCV) RNA tests performed ≥12 weeks apart, and the outcomes of acute hepatitis C (AHC) demonstrating SVC or treatment-induced viral clearance.

Methods

Thirty-two patients with AHC were followed for 12-16 weeks without administering antiviral therapy.

Results

HCV RNA was undetectable at least once in 14 of the 32 patients. SVC occurred in 12 patients (37.5%), among whom relapse occurred in 4. SVC was exhibited in 8 of the 11 patients exhibiting undetectable HCV RNA within 12 weeks. HCV RNA reappeared in three patients (including two patients with SVC) exhibiting undetectable HCV RNA after 12 weeks. SVC was more frequent in patients with low viremia than in those with high viremia (55.6% vs. 14.3%; P=0.02), and in patients with HCV genotype non-1b than in those with HCV genotype 1b (57.1% vs. 22.2%; P=0.04). SVC was more common in patients with a ≥2 log reduction of HCV RNA at 4 weeks than in those with a smaller reduction (90% vs. 9.1%, P<0.001). A sustained viral response was achieved in all patients (n=18) receiving antiviral therapy.

Conclusions

Baseline levels of HCV RNA and genotype non-1b were independent predictors for SVC. A ≥2 log reduction of HCV RNA at 4 weeks was a follow-up predictor for SVC. Undetectable HCV RNA occurring after 12 weeks was not sustained. All patients receiving antiviral therapy achieved a sustained viral response. Antiviral therapy should be initiated in patients with detectable HCV RNA at 12 weeks after the diagnosis.

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.

Impact of a single nucleotide polymorphism upstream of the IL28B gene in patients positive for anti-HCV antibody in an HCV hyperendemic area in Japan

The influence of genetic variation at the interleukin-28B (IL28B) locus on the natural course of hepatitis C virus (HCV) infection has not been fully investigated. The goal of this study was to examine whether an IL28B polymorphism (rs8099917) is associated with natural clearance of HCV and with disease parameters of HCV infection in an HCV hyperendemic area of Japan. The patients were 502 anti-HCV antibody-positive residents who participated in liver disease screening program from 2002 to 2004. Patients who underwent interferon-based therapy or had hepatocellular carcinoma were excluded. Of these patients, 149 were negative for HCV RNA (prior infection) and 353 were positive for HCV RNA or HCV core antigen (HCV carriers). In multivariate analysis, the IL28B TT genotype was a predictor for prior HCV infection. In addition, nine of the patients with prior HCV infection were positive for anti-HCV antibody with positive for HCV core antigen or HCV RNA before 2001, and these nine patients all had the IL28B TT genotype. Furthermore, the IL28B TT genotype was associated independently with higher HCV core antigen levels in HCV carriers. In contrast, the IL28B genotype did not affect the biochemical markers, such as alanine aminotransferase, hepatic fibrosis markers, and α-fetoprotein, and the degree of hepatic fibrosis assessed by transient elastography in HCV carriers. We concluded that IL28B polymorphism (TT genotype) is associated with spontaneous clearance of HCV and conversely with high viral loads in HCV carriers. In contrast, the IL28B genotype does not affect disease progression such as hepatic fibrosis.

X-Chromosome complement and estrogen receptor signaling independently contribute to the enhanced TLR7-mediated IFN-α production of plasmacytoid dendritic cells from women

Human plasmacytoid dendritic cells (pDCs) play a major role in innate immunity through the production of type I IFNs after TLR engagement by pathogens. Sex-based differences in the innate function of human pDCs have been established, with pDCs from women exhibiting enhanced TLR7-mediated IFN-α production as compared with pDCs from males. In mice, we recently provided evidence for a role of estrogens as a positive regulator of pDC innate functions through cell-intrinsic estrogen receptor α signaling, but did not exclude a role for other X-linked factors, particularly in human pDCs. In this study, we investigated the respective contribution of X chromosome dosage and sex hormones using a humanized mouse model in which male or female NOD-SCID-β2m(-/-) were transplanted with human progenitor cells purified from either male or female cord blood cells. We showed that, in response to TLR7 ligands, the frequency of IFN-α- and TNF-α-producing pDCs from either sex was greater in female than in male host mice, suggesting a positive role for estrogens. Indeed, blockade of estrogen receptor signaling during pDC development in vitro inhibited TLR7-mediated IFN-α production by human pDCs, which expressed both ESR1 and ESR2 genes. Interestingly, we also found that X chromosome dosage contributed to this sex bias as female pDCs have an enhanced TLR7-mediated IFN-α response as compared with male ones, irrespective of the sex of the recipient mice. Together, these results indicate that female sex hormones, estrogens, and X chromosome complement independently contribute to the enhanced TLR7-mediated IFN-α response of pDCs in women.

HIV co-infection accelerates decay of humoral responses in spontaneous resolvers of HCV infection

Acute hepatitis C virus (HCV) infection is primarily followed by chronic infection, while spontaneous recovery of HCV infection (SR-HCV) occurs in a minority of those infected. Identification of SR-HCV clinically depends on two combined indicators, persistently undetectable peripheral HCV RNA and positivity for anti-HCV. However, the characteristics of dynamic variation in anti-HCV antibodies in SR-HCV, especially in those patients co-infected with HIV, are still undefined. In this study, a cohort of patients infected with HCV through commercial blood collection practices was studied. We found that the annual decreasing rate of anti-HCV presented a gradually accelerated process in HCV resolvers. However, the variation in the decline of anti-HCV presented a slowly accelerated process within the early decrease stage and a gradually decelerated process within the latter decrease stage. In addition, we deduced that it expended approximately 16 years from natural HCV recovery to undetectable peripheral anti-HCV in HCV resolvers co-infected with HIV, while this time was estimated to be 20 years in SR-HCV without HIV co-infection. Our data indicated that the decay of anti-HCV was accelerated by HIV-related impairment of immune function. The prevalence of HCV infection may be severely underestimated in this large-scale retrospective epidemiologic investigation in an HIV-infected population.

Differences in hepatitis C virus prevalence and clearance by mode of acquisition among men who have sex with men

We examined the characteristics associated with hepatitis C virus (HCV) antibody (anti-HCV) prevalence and HCV clearance between injection drug using (IDU) and non-IDU men who have sex with men (MSM). Stored serum and plasma samples were tested for anti-HCV and HCV RNA to determine the HCV status of 6925 MSM at enrolment into the Multicentre AIDS Cohort Study (MACS). Prevalence and clearance ratios were calculated to determine the characteristics associated with HCV prevalence and clearance. Multivariable analyses were performed using Poisson regression methods with robust variance estimation. Anti-HCV prevalence was significantly higher among IDU than among non-IDU MSM (42.9% vs 4.0%), while clearance was significantly lower among IDU MSM (11.5% vs 34.5% among non-IDU MSM). HIV infection, Black race, and older age were independently associated with higher prevalence in both groups, while smoking, transfusion history, and syphilis were significantly associated with prevalence only among non-IDU MSM. The rs12979860-C/C genotype was the only characteristic independently associated with HCV clearance in both groups, but the effects of both rs12979860-C/C genotype [clearance ratio (CR) = 4.16 IDUs vs 1.71 non-IDUs; P = 0.03] and HBsAg positivity (CR = 5.06 IDUs vs 1.62 non-IDUs; P = 0.03) were significantly larger among IDU MSM. HIV infection was independently associated with lower HCV clearance only among non-IDU MSM (CR = 0.59, 95% CI = 0.40-0.87). IDU MSM have higher anti-HCV prevalence and lower HCV clearance than non-IDU MSM. Differences in the factors associated with HCV clearance suggest that the mechanisms driving the response to HCV may differ according to the mode of acquisition.

The Impact of IFNL4 rs12979860 Polymorphism on Spontaneous Clearance of Hepatitis C; A Case-Control Study

BACKGROUND

About 30% of individuals with hepatitis C virus (HCV) infection are able to clear HCV spontaneously. Differences in host genetics affect the outcome of HCV infection. Single nucleotide polymorphisms (SNPs) of the Interferon lambda (IFNL) genes were associated with spontaneous and treatment-induced clearance of HCV infection.

OBJECTIVES

The aim of this study was to evaluate the association between the IFNL4 rs12979860 SNP and spontaneous clearance of HCV infection in Iranian population.

MATERIALS AND METHODS

A case-control study was designed on 91 cases with spontaneous HCV infection clearance and 259 patients with persistent HCV infection as the control group. The rs12979860 SNP was assessed as the most common IFNL polymorphism by PCR-RFLP method.

RESULTS

Distribution of rs12979860 CC genotype in the spontaneous clearance group was around two folds of its distribution in chronic hepatitis C group (P < 0.001, OR = 4.09, 95% CI = 2.44-6.86).

CONCLUSIONS

The rs12979860 SNP was observed as a strong host genetic factor associated with spontaneous clearance of hepatitis C infection.

Persistent hepatitis C virus infections and hepatopathological manifestations in immune-competent humanized mice

The majority of hepatitis C virus (HCV) infection develops chronic infection, which causes steatosis, cirrhosis and hepatocellular carcinoma. However, understanding HCV chronicity and pathogenesis is hampered by its narrow host range, mostly restricted to human and chimpanzee. Recent endeavour to infect a variety of humanized mice has not been able to achieve persistent HCV infection unless the essential innate immune responsive genes are knocked out. Nevertheless, such immune-compromised humanized mice still lacked HCV infection-induced hepatopathogenesis. Here we report that transgenic mice in ICR background harboring both human CD81 and occludin genes (C/O^Tg) are permissive to HCV infection at a chronicity rate comparable to humans. In this mouse model, HCV accomplishes its replication cycle, leading to sustained viremia and infectivity for more than 12 months post infection with expected fibrotic and cirrhotic progression. Host factors favorable for HCV replication, and inadequate innate immune-response may contribute to the persistence. Lastly, NS3/4 protease inhibitor telaprevir can effectively inhibit de novo RNA synthesis and acute HCV infection of C/O^Tg mice. Thus, chronic HCV infection with complete replication cycle and hepatopathologic manifestations is recapitulated, for the first time, in immune-competent mice. This model will open a new venue to study the mechanisms of chronic hepatitis C and develop better treatments.

Hepatitis C virus infection epidemiology among people who inject drugs in Europe: a systematic review of data for scaling up treatment and prevention

BACKGROUND

People who inject drugs (PWID) are a key population affected by hepatitis C virus (HCV). Treatment options are improving and may enhance prevention; however access for PWID may be poor. The availability in the literature of information on seven main topic areas (incidence, chronicity, genotypes, HIV co-infection, diagnosis and treatment uptake, and burden of disease) to guide HCV treatment and prevention scale-up for PWID in the 27 countries of the European Union is systematically reviewed.

METHODS AND FINDINGS

We searched MEDLINE, EMBASE and Cochrane Library for publications between 1 January 2000 and 31 December 2012, with a search strategy of general keywords regarding viral hepatitis, substance abuse and geographic scope, as well as topic-specific keywords. Additional articles were found through structured email consultations with a large European expert network. Data availability was highly variable and important limitations existed in comparability and representativeness. Nine of 27 countries had data on HCV incidence among PWID, which was often high (2.7-66/100 person-years, median 13, Interquartile range (IQR) 8.7-28). Most common HCV genotypes were G1 and G3; however, G4 may be increasing, while the proportion of traditionally 'difficult to treat' genotypes (G1+G4) showed large variation (median 53, IQR 43-62). Twelve countries reported on HCV chronicity (median 72, IQR 64-81) and 22 on HIV prevalence in HCV-infected PWID (median 3.9%, IQR 0.2-28). Undiagnosed infection, assessed in five countries, was high (median 49%, IQR 38-64), while of those diagnosed, the proportion entering treatment was low (median 9.5%, IQR 3.5-15). Burden of disease, where assessed, was high and will rise in the next decade.

CONCLUSION

Key data on HCV epidemiology, care and disease burden among PWID in Europe are sparse but suggest many undiagnosed infections and poor treatment uptake. Stronger efforts are needed to improve data availability to guide an increase in HCV treatment among PWID.

Factors associated with spontaneous clearance of hepatitis C virus in Chinese population

Hepatitis C virus (HCV) infections spontaneously clear in approximately 15-45% of infected individuals. Factors which influence spontaneous HCV clearance remain to be identified. The purpose of the present study was to identify variables associated with spontaneous HCV clearance in a referred population of Chinese patients. The prevalence of host, viral, and environmental factors known to influence the outcome of HCV infections was compared in 92 HCV spontaneous clearance subjects and 318 HCV persistent infection subjects. Univariate and multivariate analyses were performed to identify those factors associated with spontaneous HCV clearance. In univariate analysis, female gender, a history of icteric hepatitis, serologic evidence of concurrent HBV infection, and rs12979860 CC genotype were positively associated with spontaneous HCV clearance, while alcohol consumption was negatively associated with clearance. In multivariate analysis, female gender, a history of icteric hepatitis, concurrent HBV infection, and rs12979860 CC genotype remained independent variables associated with spontaneous HCV clearance. Spontaneous HCV clearance is more likely to occur in females, subjects with a history of icteric hepatitis, HBV coinfections, and those with the rs12979860 CC genotype.