IFN-λ Research Articles

The relation between interleukin 28B gene polymorphisms (rs8099917 and rs12980275) and the response of treatment of Hepatitis C Virus genotype 4 patients to Sofosbuvir and Daclatasvir therapy

Background: The main line of treatment of hepatitis C in Egypt is direct acting antiviral drugs (DAAs) Objectives: the current study aimed to explore the effect of IL28B genetic polymorphism on HCV infection progression and response to the new treatment in difficulty to treat individuals with HCV genotype 4. Methods: we collected blood samples from 50 healthy individuals as a control and 150 HCV- patients receiving SOF/DCV with ribavirin combination. IL28B (rs8099917, rs12980275) genotyping was implemented using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method to detect its impact on HCV disease outcome. Results: Out of patients, 141(94%) were responders to treatment and 9 (6%) were non- responders. A total of 112 (74.7%) of patients belonged to mild to moderate stages of liver fibrosis and 38(25.3%) had moderate to severe stages. There was a significant increase in severity of fibrosis among non-responders (p value .0.05). significant differences between the different genotypes of IL28B rs12980275 are not detected among the study population. Conclusion: TT genotype of IL28B (rs8099917) may be a protective factor against infection and associated with probability of achieving SVR to combined SOF and DCV therapy in genotype 4 HCV patients. However, GG genotype is negatively associated with HCV infection outcome. IL28B rs12980275 variants had no association with HCV infection.

Programmed cell death-1 rs11568821 and interleukin-28B rs12979860 polymorphisms in autoimmune hepatitis

BackgroundAutoimmune hepatitis (AIH) is a relatively rare chronic liver disease of unknown etiology. The genetic background affects susceptibility, clinical phenotype, and prognosis. The programmed cell death-1 rs11568821 polymorphism (PD1.3) has been associated with susceptibility to autoimmune diseases. The interleukin-28B (IL28B) rs12979860 polymorphism has been associated with steatosis, inflammation, and fibrosis in liver diseases. AimOur aim was to investigate for the first time the incidence and clinical significance of PD1.3 and IL28B rs12979860 in AIH. MethodsTwo hundred patients with AIH were evaluated, while 100 healthy subjects were used as controls. Genotyping was performed with in-house allelic discrimination End-Point PCR. ResultsThe SNP PD1.3/A was present in 36/200 (18%) AIH patients compared to 28/100 (28%) healthy controls (p = 0.065). The AA/GA genotypes were not associated with the mode of presentation of AIH, the histological grade or stage, the presence of cirrhosis, risk of disease progression, response to treatment and survival. The IL28B rs12979860 genotype distribution was CC 79/200 (39.5%), TT 36/200 (18%) and CT 85/200 (42.5%), in similar rates with healthy controls (p = 0.878). Inflammatory activity and fibrosis stage did not differ between CC homozygotes and CT/TT carriers. LDL cholesterol was significantly higher in CC than CT/TT patients (P = 0.027), though no differences was found regarding the presence of steatosis or steatohepatitis. On-treatment response to immunosuppressive treatment was not affected by the IL28B rs12979860 polymorphism. However, CC homozygotes AIH patients achieved treatment withdrawal in significantly higher rates (OR 2.3, 95%CI: 1.1–4.7, P = 0.02) irrespective of the presence of steatosis or steatohepatitis. ConclusionsThe PD1.3 and IL28B rs12979860 variants are unlikely to contribute to AIH susceptibility, disease presentation and prognosis. The IL28B rs12979860 is not associated with the presence of concurrent steatosis or steatohepatitis. However, although on-treatment response rates to immunosuppression were not affected by the IL28B rs12979860 polymorphism, AIH patients with CC homozygosity were more likely to achieve complete treatment withdrawal. This novel finding needs validation and further clarification from larger multicenter studies.

Role of IFNLR1 gene in PRRSV infection of PAM cells.

BackgroundInterferon lambda receptor 1 (IFNLR1) is a type II cytokine receptor that clings to interleukins IL-28A, IL29B, and IL-29 referred to as type III IFNs (IFN-λs). IFN-λs act through the JAK-STAT signaling pathway to exert antiviral effects related to preventing and curing an infection. Although the immune function of IFN-λs in virus invasion has been described, the molecular mechanism of IFNLR1 in that process is unclear.ObjectivesThe purpose of this study was to elucidate the role of IFNLR1 in the pathogenesis and treatment of porcine reproductive and respiratory syndrome virus (PRRSV).MethodsThe effects of IFNLR1 on the proliferation of porcine alveolar macrophages (PAMs) during PRRSV infection were investigated using interference and overexpression methods.ResultsIn this study, the expressions of the IFNLR1 gene in the liver, large intestine, small intestine, kidney, and lung tissues of Dapulian pigs were significantly higher than those in Landrace pigs. It was determined that porcine IFNLR1 overexpression suppresses PRRSV replication. The qRT-PCR results revealed that overexpression of IFNLR1 upregulated antiviral and IFN-stimulated genes. IFNLR1 overexpression inhibits the proliferation of PAMs and upregulation of p-STAT1. By contrast, knockdown of IFNLR1 expression promotes PAMs proliferation. The G0/G1 phase proportion in IFNLR1-overexpressing cells increased, and the opposite change was observed in IFNLR1-underexpressing cells. After inhibition of the JAK/STAT signaling pathway, the G2/M phase proportion in the IFNLR1-overexpressing cells showed a significant increasing trend. In conclusion, overexpression of IFNLR1 induces activation of the JAK/STAT pathway, thereby inhibiting the proliferation of PAMs infected with PRRSV.ConclusionExpression of the IFNLR1 gene has an important regulatory role in PRRSV-infected PAMs, indicating it has potential as a molecular target in developing a new strategy for the treatment of PRRSV.

Interferon-γ inducible protein-10 and interleukin 28B gene polymorphism as predictive markers for genotype 4 hepatitis C virus treatment response.

HCV genotype 4 dominates the HCV epidemic in Egypt. Drug resistance was the most serious side effect that reflects bad clinical outcome. Several studies had demonstrated that baseline serum interferon-γ-inducible-protein 10 (IP-10) levels and interleukin 28B polymorphisms were associated with the resistance to the standard of care pegylated interferon alpha and ribavirin (PEG-IFNα/RBV) therapy and development of post-treatment relapse. Our purpose was to assess the predictive value of combining IP-10 levels and IL28B genotypes to PEG-IFNα/RBV therapy response in Egyptian chronic HCV infection patients with genotype 4. Ninety Egyptian patients chronically infected by HCV genotype-4 treated with pegylated interferon alpha and ribavirin (PEG-IFNα/RBV) therapy were enrolled. Serum IP-10 levels were determined by enzyme linked immunosorbent assay pre- and post- treatment. IL-28B (rs12979860 and rs8099917) polymorphisms were performed by PCR-RFLP in all patients. Overall, 38 patients (42.2%) achieved sustained virologic response (SVR) and 52 (57.8%) patients have non-viral response (NVR). Pretreatment serum IP-10 mean levels were significantly lower in patients who achieved SVR than in NVR (P<0.05). CC genotype in IL28B polymorphism (rs12979860) was the favorable genotype as 65.8% achieved SVR, while TT genotype in IL-28B polymorphism (rs8099917) was the favorable genotype as 81.5% achieved SVR. Baseline IP-10 was significantly correlated to genotypes CC in rs12979860 and TT in rs8099917. Combined use of serum baseline IP-10 levels with IL-28B polymorphisms could improve the prediction of SVR to PEG-IFNα/RBV therapy in Egyptian chronic HCV infection patients with genotype 4.

PDCD1 and IFNL4 genetic variants and risk of developing hepatitis C virus-related diseases.

BackgroundGenetic variants of IFNL4 and PDCD1 genes have been shown to influence the spontaneous clearance of hepatitis C virus (HCV) infection. We investigated the IFNL4 rs12979860 and the PDCD1 polymorphisms in 734 HCV‐positive patients, including 461 cases with liver disease of varying severity and 273 patients with lymphoproliferative disorders to determine the association of these genes with patient's outcome.MethodsExpression levels of PDCD1 mRNA encoded by haplotypes were investigated by quantitative PCR in hepatocellular carcinoma (HCC) tissue and peripheral blood mononuclear cells. Flow cytometry was used to detect PD‐1 and its ligand PD‐L1.ResultsThe frequency of IFNL4 rs12979860 C/T or T/T genotypes was significantly higher in patients with HCV‐related diseases than blood donors (P < .0001). Patients expressing the IFNλ4 variant with one amino acid change that reduces IFNλ4 secretion was found increased in frequency in HCV‐related diseases compared to HCC PDCD1 mRNA levels in HCC tissue were significantly higher in cases carrying the PD‐1.3 A or the PD‐1.7 G allele (P = .0025 and P = .0167). Linkage disequilibrium (LD) between PD‐1.3 and IFNL4 was found in patients with mixed cryoglobulinaemia (MC) only (LD = 0 in HCC; LD = 72 in MC). PBMCs of MC patients expressed low levels of PD‐L1 in CD19+IgM+B cells and of PD‐1 in CD4+T cells suggesting the involvement of regulatory B cell‐T cell interaction to the pathogenesis of MC.ConclusionCollectively, our data indicate an important contribution of IFNλ4 expression to the development of HCV‐related HCC and an epistatic contribution of IFNL4 and PDCD1 in MC.Lay summaryStudies of IFNL4 and PDCD1 genes are helpful to better understand the role of host genetic factors and immune antigens influencing the outcome of HCV‐related diseases. Our data support an association between the expression of IFNλ4, which prevents the expression of IFNλ3, with all the different HCV‐related diseases studied, and besides, evidence that a higher IFNλ4 expression is associated with hepatocellular at a younger age. The expression pattern of low PD‐L1 on B cells and high PD‐1 on CD4+T‐cells in patients with HCV‐positive cryoglobulinaemia suggests a critical role of the PD‐1/PD‐L1 signaling in modulating B cell‐T cell interaction in this lymphoproliferative disease.

TLR2-mediated innate immune priming boosts lung anti-viral immunity.

We assessed whether Toll-like receptor (TLR)2 activation boosts the innate immune response to rhinovirus infection, as a treatment strategy for virus-induced respiratory diseases. We employed treatment with a novel TLR2 agonist (INNA-X) prior to rhinovirus infection in mice, and INNA-X treatment in differentiated human bronchial epithelial cells derived from asthmatic-donors. We assessed viral load, immune cell recruitment, cytokines, type I and III interferon (IFN) production, as well as the lung tissue and epithelial cell immune transcriptome. We show, in vivo, that a single INNA-X treatment induced innate immune priming characterised by low-level IFN-λ, Fas ligand, chemokine expression and airway lymphocyte recruitment. Treatment 7 days before infection significantly reduced lung viral load, increased IFN-β/λ expression and inhibited neutrophilic inflammation. Corticosteroid treatment enhanced the anti-inflammatory effects of INNA-X. Treatment 1 day before infection increased expression of 190 lung tissue immune genes. This tissue gene expression signature was absent with INNA-X treatment 7 days before infection, suggesting an alternate mechanism, potentially via establishment of immune cell-mediated mucosal innate immunity. In vitro, INNA-X treatment induced a priming response defined by upregulated IFN-λ, chemokine and anti-microbial gene expression that preceded an accelerated response to infection enriched for nuclear factor (NF)-κB-regulated genes and reduced viral loads, even in epithelial cells derived from asthmatic donors with intrinsic delayed anti-viral immune response. Airway epithelial cell TLR2 activation induces prolonged innate immune priming, defined by early NF-κB activation, IFN-λ expression and lymphocyte recruitment. This response enhanced anti-viral innate immunity and reduced virus-induced airway inflammation.

Genetic association study of interferon lambda 3, CD27, and human leukocyte antigen-DPB1 with dengue severity in Thailand

BackgroundDengue patients develop different disease severity ranging from mild (dengue fever [DF]) to severe forms (dengue hemorrhagic fever [DHF] and the fatal dengue shock syndrome [DSS]). Host genetics are considered to be one factor responsible for the severity of dengue outcomes. To identify genes associated with dengue severity that have not been studied yet, we performed genetic association analyses of interferon lambda 3 (IFNL3), CD27, and human leukocyte antigen-DPB1 (HLA-DPB1) genes in Thai dengue patients.MethodsA case–control association study was performed in 877 children (age ≤ 15 years) with dengue infection (DF, n = 386; DHF, n = 416; DSS, n = 75). A candidate single nucleotide polymorphism of each of IFNL3, CD27, and HLA-DPB1 was selected to be analyzed. Genotyping was performed by TaqMan real-time PCR assay, and the association with dengue severity was examined.ResultsThe rs9277534 variant of HLA-DPB1 was weakly associated with DHF. The genotype GG and G allele conferred protection against DHF (p = 0.04, odds ratio 0.74 for GG genotype, p = 0.03, odds ratio 0.79 for G allele). The association became borderline significant after adjusting for confounders (p = 0.05, odds ratio 0.82). No association was detected for IFNL3 or CD27.ConclusionsThe present study demonstrated the weak association of the rs9277534 variant of HLA-DPB1 with protection against DHF. This variant is in the 3′ untranslated region and affects HLA-DPB1 surface protein expression. Our finding suggests that HLA-DPB1 may be involved in DHF pathogenesis.

Interleukin-28B dampens protease-induced lung inflammation via IL-25 and TSLP inhibition in epithelial cells

Asthma is a chronic respiratory disease with high heterogeneity in human. Different mouse models have been applied for investigation of pathogenesis and treatment of asthma, which target on different cells, receptors and pathways. Interleukin (IL-) 28B, a member of λ-interferons, have been shown to play a protective role in OVA-induced asthma, which is antigen-specific and adaptive immune system dominant. However, the roles of IL-28B in protease-induced asthma, an adaptive immune system independent asthma, are still unclear. Here, we used plant-derived cysteine protease, papain to induce asthma in mice and found that IL-28B was capable of alleviating papain-induced asthma. Papain challenge lead to activation of epithelial cells and production of alarmin, such as IL-25 and thymic stromal lymphopoietin and IL-28B treatment down-regulated their production. Further mechanism was proved to be that IL-28B inhibited the phosphorylation of Erk in epithelial cells via interaction with their receptors. Our results reveal a protective role of IL-28B via regulation of epithelial cells in protease induced asthma.

The Key Roles of Interferon Lambda in Human Molecular Defense against Respiratory Viral Infections.

Interferons (IFN) are crucial for the innate immune response. Slightly more than two decades ago, a new type of IFN was discovered: the lambda IFN (type III IFN). Like other IFN, the type III IFN display antiviral activity against a wide variety of infections, they induce expression of antiviral, interferon-stimulated genes (MX1, OAS, IFITM1), and they have immuno-modulatory activities that shape adaptive immune responses. Unlike other IFN, the type III IFN signal through distinct receptors is limited to a few cell types, primarily mucosal epithelial cells. As a consequence of their greater and more durable production in nasal and respiratory tissues, they can determine the outcome of respiratory infections. This review is focused on the role of IFN-λ in the pathogenesis of respiratory viral infections, with influenza as a prime example. The influenza virus is a major public health problem, causing up to half a million lethal infections annually. Moreover, the virus has been the cause of four pandemics over the last century. Although IFN-λ are increasingly being tested in antiviral therapy, they can have a negative influence on epithelial tissue recovery and increase the risk of secondary bacterial infections. Therefore, IFN-λ expression deserves increased scrutiny as a key factor in the host immune response to infection.

Interferon-lambda (IFNL) germline variations and their significance for HCC and PDAC progression: an analysis of The Cancer Genome Atlas (TCGA) data

BackgroundHepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC) are malignancies with a leading lethality. With reference to interferons (IFNs) known to mediate antitumor activities, this study investigated the relationship between germline genetic variations in type III IFN genes and cancer disease progression from The Cancer Genome Atlas (TCGA) data. The genetic variations under study tag a gain-or-loss-of-function dinucleotide polymorphism within the IFNL4 gene, rs368234815 [TT/ΔG].MethodsThe entirety of the TCGA sequencing data was used to assess genotypes of 187 patients with HCC and of 162 patients with PDAC matched for ethnicity. Stratified for IFNL genotypes, both cohorts were subjected to time-to-event analyses according to Kaplan-Meier with regard to the length of the specific progression free interval (PFI) and the overall survival (OS) time as two clinical endpoints for disease progression.ResultsLogrank analysis revealed a significant relationship between IFNL genotypes and disease outcome for PDAC. This relationship was not found for HCC. A multiple Cox regression analysis employing patients’ age, tumor grade and tumor stage as further covariates proved IFNL genotypes to be independent predictors for PDAC disease outcome.ConclusionThis repository-based approach unveiled clinical evidence suggestive for an impact of IFNL germline variations for PDAC progression with an IFNL haplotype predisposing for IFNL4 expression being favorable.

Correction: Multi-ancestry fine mapping of interferon lambda and the outcome of acute hepatitis C virus infection

A Correction to this paper has been published: https://doi.org/10.1038/s41435-020-00119-z.

The Role of Structure in the Biology of Interferon Signaling.

Interferons (IFNs) are a family of cytokines with the unique ability to induce cell intrinsic programs that enhance resistance to viral infection. Induction of an antiviral state at the cell, tissue, organ, and organismal level is performed by three distinct IFN families, designated as Type-I, Type-II, and Type-III IFNs. Overall, there are 21 human IFNs, (16 type-I, 12 IFNαs, IFNβ, IFNϵ, IFNκ, and IFNω; 1 type-II, IFNγ; and 4 type-III, IFNλ1, IFNλ2, IFNλ3, and IFNλ4), that induce pleotropic cellular activities essential for innate and adaptive immune responses against virus and other pathogens. IFN signaling is initiated by binding to distinct heterodimeric receptor complexes. The three-dimensional structures of the type-I (IFNα/IFNAR1/IFNAR2), type-II (IFNγ/IFNGR1/IFNGR2), and type-III (IFNλ3/IFNλR1/IL10R2) signaling complexes have been determined. Here, we highlight similar and unique features of the IFNs, their cell surface complexes and discuss their role in inducing downstream IFN signaling responses.

Bovine Interferon Lambda Is a Potent Antiviral Against SARS-CoV-2 Infection in vitro.

Interferon lambda (IFN-λ) is an antiviral naturally produced in response to viral infections, with activity on cells of epithelial origin and located in the mucosal surfaces. This localized activity results in reduced toxicity compared to type I IFNs, whose receptors are ubiquitously expressed. IFN-λ has been effective in the therapy of respiratory viral infections, playing a crucial role in potentiating adaptive immune responses that initiate at mucosal surfaces. Human IFN-λ has polymorphisms that may cause differences in the interaction with the specific receptor in the human population. Interestingly, bovine IFN-λ3 has an in silico-predicted higher affinity for the human receptor than its human counterparts, with high identity with different human IFN-λ variants, making it a suitable antiviral therapeutic candidate for human health. Here, we demonstrate that a recombinant bovine IFN-λ (rbIFN-λ) produced in HEK-293 cells is effective in preventing SARS-CoV-2 infection of VERO cells, with an inhibitory concentration 50% (IC50) between 30 and 50 times lower than that of human type I IFN tested here (α2b and β1a). We also demonstrated the absence of toxicity of rbIFN-λ in human PBMCs and the lack of proinflammatory activity on these cells. Altogether, our results show that rbIFN-λ is as an effective antiviral potentially suitable for COVID-19 therapy. Among other potential applications, rbIFN-λ could be useful to preclude virus dispersion to the lungs and/or to reduce transmission from infected people. Moreover, and due to the non-specific activity of this IFN, it can be potentially effective against other respiratory viruses that may be circulating together with SARS-CoV-2.

Interferon lambda protects cattle against bovine viral diarrhea virus infection

Interferon lambda (IFN-λ) plays an important role in inducing an antiviral state in mucosal surfaces and has been used as an effective biotherapeutic against several viral diseases. Here we performed a proof of concept study on the activity of a biologically active recombinant bovine IFN-λ (rIFN-λ) produced in eukaryotic cells against Bovine Viral Diarrhea Virus (BVDV) in cattle. We first confirmed the lack of toxicity of different concentrations of rIFN-λ in bovine peripheral blood cells and the safety of its subcutaneous application in calves in doses up to 12 IU/kg. The antiviral activity of the rIFN-λ against BVDV was assessed in calves that were inoculated with 6 IU/kg of rIFN-λ (n = 4) or mock-treated (n = 2) two days before and after challenge with a BVDV type-2 non-cytopathic strain. Mock-treated animals developed respiratory disease, shedded the virus from 4 to 7 days post-infection (dpi) and had viremia between 4 and 14 dpi. Conversely, calves treated with rIFN-λ did not develop clinical symptoms. The virus was not found in nasal secretions or sera. Only one animal had a positive viral RNA detection in serum at 7 dpi. All infected animals treated with rIFN-λ increased systemic type-I IFNs levels at 4 dpi. The antiviral treatment induced an earlier onset of the anti-BVDV neutralizing antibodies. Altogether, these results constitute the proof-of-principle of bovine IFN-λ as an antiviral biotherapeutic to protect cattle against the clinical disease caused by BVDV.

Syncytia formation by SARS-CoV-2-infected cells.

Severe cases of COVID‐19 are associated with extensive lung damage and the presence of infected multinucleated syncytial pneumocytes. The viral and cellular mechanisms regulating the formation of these syncytia are not well understood. Here, we show that SARS‐CoV‐2‐infected cells express the Spike protein (S) at their surface and fuse with ACE2‐positive neighboring cells. Expression of S without any other viral proteins triggers syncytia formation. Interferon‐induced transmembrane proteins (IFITMs), a family of restriction factors that block the entry of many viruses, inhibit S‐mediated fusion, with IFITM1 being more active than IFITM2 and IFITM3. On the contrary, the TMPRSS2 serine protease, which is known to enhance infectivity of cell‐free virions, processes both S and ACE2 and increases syncytia formation by accelerating the fusion process. TMPRSS2 thwarts the antiviral effect of IFITMs. Our results show that SARS‐CoV‐2 pathological effects are modulated by cellular proteins that either inhibit or facilitate syncytia formation.

Interferon lambda 4 gene polymorphisms as a predicting tool of response to hepatitis C virus genotype 4 patients treated with Sofosbuvir and Ribavirin.

The relation between interferon lambda 4 gene (IFNL4) and direct acting antiviral (DAA) regimens in hepatitis C virus (HCV) infected patients is not clear. So, a single nucleotide polymorphisms (SNP) of IFNL4 gene genotypes and its relationship with Sofosbuvir (SOF) and Ribavirin (RBV) treatment response is under consideration. This study aims to investigate the relation between IFNL4 polymorphisms and clearance of HCV genotype 4 for HCV patients. Hence, the appropriate drug can be chosen for each patient. SNP genotyping assay for IFNL4 which formerly known as IL28B (rs368234815) was examined for genomic DNA. The DNA was extracted from whole blood of one hundred patients who documented to have infection with chronic HCV genotype 4 (positive PCR) and treated with SOF and RBV. Patients were diagnosed, previously, as HCV genotype 4 and classified according to drug response into two groups (responders, non-responders). All samples were compared with 50 of non-infected (negative PCR) people (control group). The TT/TT homozygous represents 48% of patients and 66% of non-infected people while the homozygous ∆G/∆G is 21% and 12%, respectively. There is significance to IFNL4 genotypes for the treatment response with the probability value p<0.001. The percentages of the appearance of genotypes TT/TT, TT/∆G and ∆G/∆G for responders were 60%, 28% and 12%, respectively. There is no significance for gender, age, ALT and PLC to treatment response to SOF and RBV, while INR has.

Multi-ancestry fine mapping of interferon lambda and the outcome of acute hepatitis C virus infection.

Clearance of acute infection with hepatitis C virus (HCV) is associated with the chr19q13.13 region containing the rs368234815 (TT/ΔG) polymorphism. We fine-mapped this region to detect possible causal variants that may contribute to HCV-clearance. First, we performed sequencing of IFNL1-IFNL4 region in 64 individuals sampled according to rs368234815 genotype: TT/clearance (N=16) and ΔG/persistent (N=15) (genotype-outcome concordant) or TT/persistent (N=19) and ΔG/clearance (N=14) (discordant). 25 SNPs had a difference in counts of alternative allele > 5 between clearance and persistence individuals. Then, we evaluated those markers in an association analysis of HCV clearance conditioning on rs368234815 in two groups of European (692 clearance/1 025 persistence) and African ancestry (320 clearance/1 515 persistence) individuals. 10/25 variants were associated (P < 0.05) in the conditioned analysis leaded by rs4803221 (P=4.9×10−04) and rs8099917 (P=5.5×10−04). In the European ancestry group, individuals with the haplotype rs368234815ΔG/rs4803221C were 1.7x more likely to clear than those with the rs368234815ΔG/rs4803221G haplotype (P=3.6×10−05). For another nearby SNP, the haplotype of rs368234815ΔG/rs8099917T was associated with HCV-clearance compared to rs368234815ΔG/rs8099917G (OR: 1.6, P=1.8×10−04). We identified four possible causal variants: rs368234815, rs12982533, rs10612351 and rs4803221. Our results suggest a main signal of association represented by rs368234815, with contributions from rs4803221, and/or nearby SNPs including rs8099917.

PNPLA3 polymorphisms are associated with raised alanine aminotransferase levels in hepatitis C virus genotype 3

Background and study aimsHepatitis C virus (HCV) infection is one of the leading causes of end-stage liver diseases. This study aimed to determine the association between polymorphisms in interleukin 28B (IL28B), PNPLA3, toll-like receptor 7 (TLR7), nucleotide-binding oligomerization domain-containing protein 2 (NOD2) and retinoic inducible gene-I (RIG-I) and HCV genotype and clinical presentation in an Indian population. Patients and methodsA total of 500 patients with chronic HCV were enrolled in 19 centres across India. Genomic DNA was extracted from whole blood samples, and single nucleotide polymorphisms (SNPs) for IL28B, PNPLA3, TLR7, NOD2 and RIG-I genes were genotyped by real-time PCR using a TaqManSNP genotyping assay. ResultsThe mean age of the patients was 45 + 13 years, and the most common genotype observed was HCV genotype 3 (54%), followed by genotype 1 (24%). Although the allelic frequencies of TLR7, NOD2 and RIG-I were in significant disequilibrium in HCV patients compared with those in controls, the PNPLA3 polymorphism correlated significantly with higher viral load and alanine aminotransferase (ALT) levels in genotype 3 patients. Patients with PNPLA3 CG/GG genotypes, along with IL28B genotype CC, had higher levels of ALT than those with other genotypes. ConclusionThese results indicate that PNPLA3 polymorphisms are associated with higher ALT levels in HCV genotype 3 patients in India and can help in identifying people who are at greater risk of developing HCV-associated liver diseases.

Impact of Interleukin 28B and ICAM-1 Genetic Polymorphisms on Response to Direct Antiviral Treatment Among HCV Infected Patients.

Single nucleotide polymorphisms (SNPs) of IL-28B and/or ICAM-1 could have a role in expecting a response from HCV infected patients to direct antiviral agents (DAAs). The aim of the current study was to investigate the impact of IL-28B rs12979860 and rs8099917, and, ICAM-1 rs281437 SNPs on response to treatment with sofosbuvir + Daclatsvir ± Ribavirin, among HCV-infected Egyptian patients. Whole blood genomic DNA was extracted from 120 participants (80 HCV-infected patients and 40 healthy volunteers). HCV-infected patients were subdivided into responders and nonresponders to DAAs. Liver function testing, anti-HCV antibodies, HCV-RNA viral load and HCV genotyping were performed. IL-28B and ICAM-1 SNPs were evaluated by real-time PCR. ALT and AST levels were significantly higher among non-responder HCV infected patients (P = 0.001*). 90% of the patients had HCV genotype 4a and the remaining 10% had 4l genotype. Allelic discrimination revealed that IL-28B rs12979860 T, IL-28B rs809917 T and ICAM-1 rs281437 C alleles were more frequent among HCV-infected patients (responders or non-responders) than controls. However, IL-28B rs8099917 G allele was more frequent among healthy controls. Regarding the response to DAAs treatment, HCV-infected patients with IL-28B rs8099917 GG genotype showed a significantly earlier viral response compared to those carrying TT alleles. ICAM-1 rs281437 CT alleles were non significantly more frequent among responders. However, IL-28B rs12979860 alleles did not show any difference. Genotyping of IL-28B rs8099917 is a useful independent tool for expecting a response of Egyptian HCV-infected patients to DAAs.

High-risk Allele for Herpes Labialis Severity at the IFNL3/4 Locus is Associated With Vestibular Neuritis.

Objective: Vestibular neuritis (VN) is a peripheral vestibular disorder leading to a sudden loss of unilateral vestibular function. Although the underlying etiological mechanisms for disease development are not yet known, there is evidence that a latent infection with herpes simplex virus type 1 (HSV-1) might be involved. The polymorphism rs12979860 has been associated with the severity of recurrent herpes labialis and hepatitis C virus (HCV) clearance and treatment outcome and is located within the first intron of the IFNL4 gene on chromosome 19.q13.2. This case control study was conducted to evaluate the association of rs12979860 with VN occurrence.Methods: DNA was extracted from EDTA blood of 151 VN patients and 1,775 healthy controls. Genotyping of rs12979860 was performed using iPLEX and MassARRAY Matrix Assisted Laser Desorption Ionization—Time of Flight (MALDI-TOF) mass spectrometry. For association analyses, an additive, dominant and recessive logistic regression model was calculated, using age and sex as covariates.Results: A significant association of rs12979860 with VN was obtained for the additive [OR = 1.51 (1.18–1.92); p = 9.23 × 10−4] and dominant models [OR = 2.15 (1.48–3.13); p = 5.86 × 10−5], with the T allele being more frequent in the VN group.Conclusion: By detecting a significant association of the rs12979860-T risk allele for herpes labialis severity with susceptibility to VN, this study gives further indirect evidence for an involvement of HSV-1 in VN pathology, thereby strengthening the virus hypothesis.