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

Like a Rolling Stone? A Review on Spontaneous Clearance of Hepatitis C Virus Infection

Elimination of hepatitis C virus (HCV) without the need for medical intervention, known as spontaneous clearance (SC), occurs at a significantly lower rate than in the case of hepatitis B virus infection and only in selected individuals, such as reportedly in Keith Richards, a guitarist of The Rolling Stones. The present paper provides an updated narrative review of the research devoted to the phenomenon in order to identify and discuss the demographic, lifestyle-related, clinical, viral genotype-related, and host genetic factors underpinning the SC occurrence. The body of evidence indicates that the likelihood of SC is decreased in older individuals, men, Black people, HIV-coinfected subjects, and intravenous drug and alcohol users. In turn, HBV coinfection and specific polymorphism of the genes encoding interferon lambda 3 (particularly at rs8099917) and interferon lambda 4 (particularly at rs12979860) and HLA genes increase the odds of SC. Numerous other host-specific genetic factors could be implicated in SC, but the evidence is limited only to certain ethnic groups and often does not account for confounding variables. SC of HCV infection is a complex process arising from a combination of various factors, though a genetic component may play a leading role in some cases. Understanding factors influencing the likelihood of this phenomenon justifies better surveillance of high-risk groups, decreasing health inequities in particular ethnic groups, and may guide the development of a prophylactic vaccine, which at present is not available, or novel therapeutic strategies. Further research is needed to elucidate the exact mechanisms underlying SC and to explore potential interventions that could enhance this natural antiviral response.

Molecular Epidemiological Characteristics and Risk Factors for Acquiring HBV Among Li Ethnic in Baisha County, Hainan Island-Subgenotype D3 Was First Discovered in China

The residents of Baisha, a county of Hainan Island, mainly composed of Li ethnic population and relatively closed living environment with its unique geographical location. Our previous study showed that Li ethnic population of Baisha is an endemic center for hepatitis C virus, with significantly higher rates than in other parts of China. However, the epidemiology of HBV in this region remains unclear. Therefore, we conducted a comprehensive epidemiological survey of HBV in Baisha County, including 1,682 Li ethnic residents. The total seropositive rate for HBsAg was 10.2% and was higher than other parts of China. HBV-positive status was associated with the 20–40-year-old group (OR = 1.27, 95%CI 1.04–1.39, P < 0.01) and alcohol consumption (OR = 2.17, 95%CI 1.58–2.99, P < 0.01). Phylogenetic analysis showed that HBV subgenotype D3 was predominant in Baisha County which was first discovered in China, followed by C5, C1, B2, and undetermined subgenotypes which were significantly different from other geographical distribution of main genotypes in China. The most recent common ancestor (tMRCA) of the HBV genotype C in the Li ethnic of Baisha County was 1846 (95%CI: 1739–1932), and Baisha-C5 was earlier than Baisha-C1 and Baisha-C2. Most Baisha-D3 sequences were concentrated in one bundle and unrelated to those D3 genome sequences elsewhere in the world. According to the phylogenetic tree, D3 was introduced into Baisha County in 1884 (95%CI: 1816–1993) and became a local endemic virus. In conclusion, HBV infection in the Li ethnic group is characterized by a high prevalence rate in 20–40-year-old individuals and a unique genotype distribution which were significantly different from other geographical distribution of main genotypes in China, and subgenotype D3 was first discovered in China.

Gender-specific development of experimental autoimmune cholangitis induced by double-stranded RNA

Here we investigated the gender difference in murine cholangitis resembling human primary biliary cholangitis (PBC) caused by synthetic double-stranded RNA, and underlying hepatic innate immune responses. Female C57Bl/6 mice given repeated injections of polyinosinic-polycytidylic acid (poly I:C) for 24 weeks developed overt cholangitis with positive serum anti-mitochondria-M2 antibody, whereas male mice showed minimal pathological changes without induction in autoantibody. Poly I:C induced hepatic inflammatory cytokines and type-I interferons predominantly in females. Hepatic expression levels of toll-like receptor (TLR) 3 and melanoma differentiation-associated protein (MDA) 5 were equivalent in both genders; however, both mRNA and protein levels of retinoic acid-inducible gene (RIG)-I were nearly doubled in female livers. Following 4-week injections of poly I:C, not only hepatic RIG-I, but also TLR3 and MDA5 showed female-predominance. Moreover, hepatic RIG-I levels were 25% lower in ovariectomized mice, whereas supplementation of 17 β-estradiol enhanced hepatic RIG-I expression, as well as cytokine induction. These results clearly indicate that hepatic RIG-I expression is potentiated by estrogen, and triggers gender-dependent hepatic innate immune response against double-stranded RNA, which most likely play a pivotal role in the pathogenesis of autoimmune cholangiopathies including PBC.

Are Hepatitis C Positive Female Liver Transplant Recipients Still at Increased Risk for Graft Failure? Reexamining the Disparity in the Modern Era of Direct-acting Antiviral Agents

BACKGROUND

This study aimed to compare the outcomes of hepatitis C virus (HCV) positive (+) female liver transplant recipients to HCV negative (-) female and HCV+ male recipients before and after the direct-acting-antiviral (DAA) era.

METHODS

The United Network for Organ Sharing liver transplant database was retrospectively reviewed from 2002 to 2017. The DAA era was defined as ≥2014.

RESULTS

In the pre-DAA era, HCV+ female recipients had greater risk for graft failure compared with HCV+ male (hazard ratio [HR], 1.06; 95% confidence interval [CI], 1.01-1.11; P = 0.03) and HCV- female (HR, 1.51; 95% CI, 1.43-1.60; P < 0.001) recipients. In the post-DAA era, HCV+ female recipients had lower risk for graft failure compared with HCV+ male recipients (HR, 0.82; 95% CI, 0.70-0.97; P = 0.02) and equivalent outcomes to HCV- female recipients. HCV+ female recipients with graft failure had increased likelihood of graft failure due to disease recurrence compared with HCV+ male recipients in the pre-DAA era (odds ratio, 1.23; 95% CI, 1.08-1.39; P = 0.001) but not in the post-DAA era.

CONCLUSIONS

Although historically HCV+ female recipients were at disproportionately increased risk for graft failure and disease recurrence, this disparity has been eliminated in the DAA era.

Kyushu and Okinawa Population Study (KOPS): a large prospective cohort study in Japan

PURPOSE

The Kyushu and Okinawa Population Study (KOPS) was established to investigate gene-environmental interactions in non-communicable diseases in Japan. Besides collecting blood samples and anthropometric measurements, we also obtained medical histories, psychological status and lifestyle habits, including physical activities and dietary patterns.

PARTICIPANTS

KOPS is a community-based prospective cohort study and consists of participants from four southwestern areas in Japan. Baseline surveys were conducted between 2004 and 2007 (wave 1), and 2009 and 2012 (wave 2) at the sites of municipality-based health check-ups. A total of 17 077 participants were included, comprising 10 697 participants of wave 1 and 6380 participants of wave 2; the median age in both groups was 61 years. Among them, 3006 individuals participated in both wave 1 and wave 2 surveys.

FINDINGS TO DATE

We have focused on either risk or confounding factors for non-communicable diseases. We have assessed the clinical utility of the newly developed biomarkers for impaired glucose tolerance, such as urinary myo-inositol and glycated albumin, and atherosclerosis, such as small dense low-density lipoprotein cholesterol. We have conducted an international collaborative study with Framingham Offspring Study to investigate ethnic differences in impaired glucose tolerance and cardiovascular diseases. We have found that insulin resistance and deficiency might account for the ethnic differences in impaired glucose tolerance and cardiovascular disease risks. As gene-environmental interaction analyses, we found a synergic effect of interleukin 28B single nucleotide polymorphisms (SNPs) and gender on the spontaneous elimination of hepatitis C, and a beneficial interaction of SNPs of high-density lipoprotein cholesterol and gender on the impact of physical activity. In addition, we reported eight novel loci contributing to the development and severity of coronary artery disease from a large genome-wide association study.

FUTURE PLANS

We plan to investigate further the clinical utility of the newly developed biomarkers and the gene-environmental interactions using prospective data.

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.

A Multiancestry Sex-Stratified Genome-Wide Association Study of Spontaneous Clearance of Hepatitis C Virus

BACKGROUND

Spontaneous clearance of acute hepatitis C virus (HCV) infection is more common in women than in men, independent of known risk factors.

METHODS

To identify sex-specific genetic loci, we studied 4423 HCV-infected individuals (2903 male, 1520 female) of European, African, and Hispanic ancestry. We performed autosomal, and X chromosome sex-stratified and combined association analyses in each ancestry group.

RESULTS

A male-specific region near the adenosine diphosphate-ribosylation factor-like 5B (ARL5B) gene was identified. Individuals with the C allele of rs76398191 were about 30% more likely to have chronic HCV infection than individuals with the T allele (OR, 0.69; P = 1.98 × 10-07), and this was not seen in females. The ARL5B gene encodes an interferon-stimulated gene that inhibits immune response to double-stranded RNA viruses. We also identified suggestive associations near septin 6 and ribosomal protein L39 genes on the X chromosome. In box sexes, allele G of rs12852885 was associated with a 40% increase in HCV clearance compared with the A allele (OR, 1.4; P = 2.46 × 10-06). Septin 6 facilitates HCV replication via interaction with the HCV NS5b protein, and ribosomal protein L39 acts as an HCV core interactor.

CONCLUSIONS

These novel gene associations support differential mechanisms of HCV clearance between the sexes and provide biological targets for treatment or vaccine development.

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.

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.

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.

Delayed Viral Clearance after 6-Week Treatment with Peginterferon Plus Ribavirin in a Patient with Chronic Hepatitis C Virus Genotype 1b

Following interferon-based therapy for chronic hepatitis C, the negativity of hepatitis C virus RNA is essential to achieve viral clearance at the end of treatment. We report a case of clearance of chronic hepatitis C virus infection following early discontinuation (at 6 weeks) of peginterferon plus ribavirin therapy, without negativity for hepatitis C virus RNA during the treatment period. The patient was a 76-year-old Japanese male infected with hepatitis C virus genotype 1b and TT of IL28B rs8099917. Hepatitis C virus RNA remained positive at persistently low levels for more than 2 months after the cessation of therapy and became negative at 7 months after the discontinuation of therapy. Spontaneous clearance of hepatitis C virus RNA can occur following antiviral failure in patients with persistently low viral loads, and virological follow-up is therefore necessary in chronic hepatitis C virus infection, even after antiviral failure.