Beneficial IL28B genotype associated with lower frequency of hepatic steatosis in patients with chronic hepatitis C

HCV treatment outcome depends on SNPs of IFNL3-Gene polymorphisms (rs12979860) and cirrhotic changes in liver parenchyma

The allelic discrimination of IFNL3-(rs12979860 C > T) polymorphism reveals ambiguous associations with the effectiveness of oral HCV treatment. Solitary intra peripheral-blood-mononuclear-cells (PBMCs) HCV-RNA antisense-strands are independently detected in naïve and experienced cases regardless of viremia or hepatic-parenchymal alterations. We examined the frequencies of IFNL3-genetic variants with chronic-HCV-induced liver changes during the sustained virologic response (SVR) by evaluating the PBMCs- HCV-PCR after oral antiviral therapy. Methods: Twelve weeks after finishing oral antiviral therapy, the effects of IFNL3-genetic variants were evaluated in three groups of patients: Group-I (n = 25) showed HCV-RNA negativity in both serum and PBMCs-, group II (n = 52) showed positivity of HCV-RNA in PBMCs, and group-III (n = 25) had positive HCV-RNA in serum. The genetic variants of the IFNL3-gene were estimated for all the enrolled cases and correlated with their hepatic image changes. Results: IFNL3-(rs12979860) genotyping in post-direct acting antivirals (DAAs) SVR and HCV-relapse revealed: a) high frequency of CC-genotype and C-allele in group I compared to group II (P < 0.005) and group III(P ≤ 0.05) when hepatic-parenchyma looks normal by ultrasound b) frequent CT-genotype and T-allele in group II compared with I(P < 0.01) and III(P < 0.05) when liver tissues are bright (early cirrhotic-changes) c) frequent TT-genotype and T-allele in group III relative to I (P < 0.05) and II (P ≤ 0.08) when liver-tissues appear coarse by ultrasound. Conclusion: Outcomes of HCV treatment depend on host IFNL3-gene polymorphism and hepatic-parenchymal changes. A high frequency of wild-CC-genotype and C-allele is observed in patients with normal hepatic parenchyma and that achieved SVR. Solitary relapse in PBMCs occurs on increasing CT-genotype frequency when liver tissues are bright. Serologic relapse is detected when TT-genotype and T-allele are dominant in association with the cirrhotic liver. Therefore, IFNL3-gene-SNP analysis as a genetic predictor in relation to ultra-sonographic hepatic-parenchymal changes could be valuable for selecting the patients with the highest priority for treatment.

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

BACKGROUND

Autoimmune 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.

AIM

Our aim was to investigate for the first time the incidence and clinical significance of PD1.3 and IL28B rs12979860 in AIH.

METHODS

Two 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.

RESULTS

The 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.

CONCLUSIONS

The 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.

IL28B gene polymorphism is correlated with changes in low-density lipoprotein cholesterol levels after clearance of hepatitis C virus using direct-acting antiviral treatment

BACKGROUND

Direct-acting antivirals (DAAs) rapidly clear hepatitis C virus (HCV), but the lipid dynamics after DAA treatment remain unknown. Low-density lipoprotein (LDL) cholesterolemia is the predicting factor for the onset and death of atherosclerotic cardiovascular diseases. Thus, in this study, we examined the frequency and risk of hyper-LDL cholesterolemia in HCV patients who achieved sustained virologic response (SVR) with DAA treatment.

METHODS

A total of 121 patients with HCV genotype 1b, who achieved SVR with DAA treatment, were examined for serum levels of total cholesterol, LDL-cholesterol (LDL-C), high-density lipoprotein, and triglycerides from the start of treatment until 2 years after SVR (SVR-2y). ΔLDL-C was defined as the change in LDL-C levels from treatment initiation to SVR-2y. Hyper-LDL cholesterolemia was defined as ≥ 140 mg/dL LDL-C at SVR-2y. Stepwise multiple regression analysis was performed to determine whether ΔLDL-C and hyper-LDL cholesterolemia are associated with other factors, including viral kinetics.

RESULTS

A total of 63, 3, and 55 patients were administered daclatasvir + asunaprevir, ombitasvir + paritaprevir + ritonavir, and ledipasvir + sofosbuvir, respectively. ΔLDL-C in patients with the IL28B (rs8099917) TG/GG genotype was significantly higher than in those with IL28B TT (27.3 ± 27.0 and 9.6 ± 27.3 mg/dL; P < 0.001). In addition, IL28B TG/GG was an independent risk factor for hyper-LDL cholesterolemia (odds ratio: 8.47; P < 0.001).

CONCLUSIONS

An IL28B polymorphism is associated with ΔLDL-C and hyper-LDL cholesterolemia after achieving SVR. Thus, lipid markers should be carefully monitored in patients who achieve SVR with DAA.

IFNΛ3/4 locus polymorphisms and IFNΛ3 circulating levels are associated with COPD severity and outcomes

BACKGROUND

Interferon lambdas (IFNLs) have important anti-viral/bacterial and immunomodulatory functions in the respiratory tract. How do IFNLs impact COPD and its exacerbations?

METHODS

Five hundred twenty eight patients were recruited in a prospective observational multicentre cohort (PROMISE) study. The genetic polymorphisms (rs8099917 and rs12979860) within the IFNL3/4 gene region and circulating levels of IFNL3 in COPD patients were determined and associated with disease activity and outcome during a median follow-up of 24 months.

RESULTS

The GG genotype significantly influenced severe exacerbation rate (42 vs. 23%; p = 0.032) and time to severe exacerbation (HR = 2.260; p = 0.012). Compared to the TT or TG genotypes, the GG genotype was associated with severe dyspnoea (modified medical research council score ≥ median 3; 22 vs 42%, p = 0.030). The CC genotype of the rs12979860 SNP was associated with a poorer prognosis (body mass index, airflow obstruction, dyspnea and exercise capacity index ≥ median 4; 46 vs. 36% TC vs. 20.5% TT; p = 0.031). Patients with stable COPD and at exacerbation had significantly lower circulating IFNL3 compared to healthy controls (p < 0.001 and p < 0.001, respectively). Circulating IFNL3 correlated to post-bronchodilator FEV1%predicted and the tissue maturation biomarker Pro-collagen 3.

CONCLUSION

IFNL3/4 polymorphisms and circulating IFNL3 may be associated with disease activity and outcomes in COPD.

TRIAL REGISTRATION

Clinical Trial registration http://www.isrctn.com/ identifier ISRCTN99586989 on 16 April 2008.

Impact of PNPLA3 and IFNL3 polymorphisms on hepatic steatosis in Asian patients with chronic hepatitis C

BACKGROUND AND AIMS

A recent meta-analysis revealed that the genotype PNPLA3 rs738409 GG is associated with a higher risk of hepatic steatosis (HS) in Caucasian patients with chronic hepatitis C (CHC). However, controversial results were found regarding Asian populations. Furthermore, previous studies have shown a negative association between interferon lambda 3 (IFNL3) rs12979860 CC and HS in Caucasian CHC patients, but there have been no reports indicating any such association in Asian populations. In this study, then, we investigated the association of PNPLA3 and IFNL3 polymorphisms with HS in Asian CHC patients.

METHODS

We enrolled consecutive CHC patients who underwent liver biopsy prior to antiviral therapy. We excluded those patients with decompensated liver disease, any co-existing chronic liver disease, or HIV or HBV co-infection.

RESULTS

1080 CHC patients were enrolled, and HS was found in 453 (41.9%) patients. The frequency distribution of the G allele was significantly associated with HS (P<0.001), and this conferred a higher risk to G allele homozygotes (OR: 2.06, 95% CI: 1.46-2.88, P <0.001) than to G allele carriers (OR: 1.98, 95% CI: 1.52-2.58, P<0.001). There was a borderline significant difference in the prevalence of HS in rs12979860 CC versus non-CC (40.8% versus 49.3%, P = 0.059). After adjustment for age, sex, body mass index, diabetes, and excessive alcohol intake, the rs738409 G allele homozygote carriers still carried a higher risk for HS (OR: 1.93, 95% CI: 1.35-2.77, P = 0.003).

CONCLUSION

The PNPLA3 rs738409 GG genotype is positively associated with HS, while the IFNL3 rs 12979860 CC genotype may be negatively associated with HS, in Asian CHC patients.

Interferon lambda polymorphisms associate with body iron indices and hepatic expression of interferon-responsive long non-coding RNA in chronic hepatitis C

Single nucleotide polymorphisms (SNPs) within DNA region containing interferon lambda 3 (IFNL3) and IFNL4 genes are prognostic factors of treatment response in chronic hepatitis C (CHC). Iron overload, frequently diagnosed in CHC, is associated with unfavorable disease course and a risk of carcinogenesis. Its etiology and relationship with the immune response in CHC are not fully explained. Our aim was to determine whether IFNL polymorphisms in CHC patients associate with body iron indices, and whether they are linked with hepatic expression of genes involved in iron homeostasis and IFN signaling. For 192 CHC patients, four SNPs within IFNL3-IFNL4 region (rs12979860, rs368234815, rs8099917, rs12980275) were genotyped. In 185 liver biopsies, histopathological analyses were performed. Expression of five mRNAs and three long non-coding RNAs (lncRNAs) was determined with qRT-PCR in 105 liver samples. Rs12979860 TT or rs8099917 GG genotypes as well as markers of serum and hepatocyte iron overload associated with higher activity of gamma-glutamyl transpeptidase and liver steatosis. The presence of two minor alleles in any of the tested SNPs predisposed to abnormally high serum iron concentration and correlated with higher hepatic expression of lncRNA NRIR. On the other hand, homozygosity in any major allele associated with higher viral load. Patients bearing rs12979860 CC genotype had lower hepatic expression of hepcidin (HAMP; P = 0.03). HAMP mRNA level positively correlated with serum iron indices and degree of hepatocyte iron deposits. IFNL polymorphisms influence regulatory pathways of cellular response to IFN and affect body iron balance in chronic hepatitis C virus infection.

Significance of genetic polymorphisms in patients with nonalcoholic fatty liver disease

Because of recent advances in genetic research such as genome-wide association studies, the underlying genetic mechanisms of nonalcoholic fatty liver disease (NAFLD) pathophysiology have been elucidated. Here, we present a review of the current literature on the impact of genetic polymorphisms in patients with NAFLD. These genetic polymorphisms, which regulate lipid metabolism, glucose metabolism, and the renin-angiotensin system, are involved in NAFLD onset, steatosis, inflammation, fibrosis, and hepatocellular carcinoma (HCC). Among these genetic polymorphisms, many studies and meta-analyses have demonstrated that position 148 (rs738409 C/G) of the patatin-like phospholipase domain-containing protein (PNPLA3) is a genetic factor associated with NAFLD pathophysiological features, such as hepatic fat level, hepatic inflammation, fibrosis, and HCC. However, the impact of genetic polymorphisms on NAFLD pathophysiology appears to differ among ethnic groups. Therefore, further studies with larger sample sizes are needed for each ethnic group.

Genotype 3 Infection: The Last Stand of Hepatitis C Virus

Hepatitis C virus (HCV) represents a significant global disease burden, with an estimated 130-150 million people worldwide living with chronic HCV infection. Within the six major clinical HCV genotypes, genotype 3 represents 22-30% of all infection and is described as a unique entity with higher rates of steatosis, faster progression to cirrhosis, and higher rates of hepatocellular carcinoma. Hepatic steatosis in the setting of hepatitis C genotype 3 (HCV-3) is driven by viral influence on three major pathways: microsomal triglyceride transfer protein, sterol regulatory element-binding protein-1c, and peroxisome proliferator-associated receptor-α. Historically with direct-acting antivirals, the rates of cure for HCV-3 therapies lagged behind the other genotypes. As current therapies for HCV-3 continue to close this gap, it is important to be cognizant of common drug interactions such as acid-suppressing medication and amiodarone. In this review, we discuss the rates of steatosis in HCV-3, the mechanisms behind HCV-3-specific steatosis, and current and future therapies.

Hepatitis C Virus, Insulin Resistance, and Steatosis

Hepatitis C virus (HCV) is one of the main causes of liver disease worldwide. Liver steatosis is a common finding in many hepatic and extrahepatic disorders, the most common being metabolic syndrome (MS). Over time, it has been shown that the frequent coexistence of these two conditions is not coincidental, since many epidemiological, clinical, and experimental studies have indicated HCV to be strongly associated with liver steatosis and numerous metabolic derangements. Here, we present an overview of publications that provide clinical evidence of the metabolic effects of HCV and summarize the available data on the pathogenetic mechanisms of this association. It has been shown that HCV infection can induce insulin resistance (IR) in the liver and peripheral tissues through multiple mechanisms. Substantial research has suggested that HCV interferes with insulin signaling both directly and indirectly, inducing the production of several proinflammatory cytokines. HCV replication, assembly, and release from hepatocytes require close interactions with lipid droplets and host lipoproteins. This modulation of lipid metabolism in host cells can induce hepatic steatosis, which is more pronounced in patients with HCV genotype 3. The risk of steatosis depends on several viral factors (including genotype, viral load, and gene mutations) and host features (visceral obesity, type 2 diabetes mellitus, genetic predisposition, medication use, and alcohol consumption). HCV-related IR and steatosis have been shown to have a remarkable clinical impact on the prognosis of HCV infection and quality of life, due to their association with resistance to antiviral therapy, progression of hepatic fibrosis, and development of hepatocellular carcinoma. Finally, HCV-induced IR, oxidative stress, and changes in lipid and iron metabolism lead to glucose intolerance, arterial hypertension, hyperuricemia, and atherosclerosis, resulting in increased cardiovascular mortality.

Association of Overt Diabetes Mellitus with the Non-CC but not the CC Genotype of Interleukin-28B in Hepatitis C Virus Infected Patients

BACKGROUND

Interleukin-28B (IL-28B) polymorphism is an important predictor for hepatitis C virus (HCV) treatment response. Whether IL-28b genotypes also influence other nontreatment related clinical parameters is unclear.

METHODS

Patients with HCV-related chronic liver diseases who attended our department during 2012-2014 were retrospectively analyzed. The single nucleotide polymorphisms (SNPs) of rs12979860 (IL-28B) were correlated with various clinical parameters. We also compared these parameters in patients with and without overt diabetes to identify possible associations.

RESULTS

A total of 115 patients were included (median age 48, range 15-76 years; 70% males). Overall, 43/115 (37%) patients had chronic hepatitis, while the remaining 72/115 (63%) had cirrhosis. The most common IL-28B genotype was CC, which was found in 53% of patients (61/115), while the remaining 47% were nonCC [CT 42% (48/115) and TT 5% (6/115)]. Clinical and laboratory parameters like Hb, white blood cell (WBC), platelets, bilirubin, transaminases, and albumin were similar in the CC and nonCC genotypes. Overt diabetes mellitus was present in 22% (25/115) of patients. Patients with nonCC genotype had significantly higher prevalence of overt diabetes mellitus than patients with CC genotype (31% [17/54] versus 13% [8/61]; p < 0.05). When parameters were compared in patients with and without overt diabetes mellitus, only IL-28B and age were significantly associated with overt diabetes mellitus (p < 0.05).

CONCLUSION

In HCV patients, overt diabetes mellitus was more commonly associated with the nonCC genotype of IL-28B than the CC genotype. Carriers of the T-allele of SNP rs12979860 were more likely to have insulin resistance than CC homozygotes, and this finding may explain the higher prevalence of diabetes in non-CC genotypes. Thus, an IL-28B test may be useful in patients of HCV in order to determine their likelihood of developing diabetes mellitus.

Association between IL28B polymorphism, TNFα and biomarkers of insulin resistance in chronic hepatitis C-related insulin resistance

TNFα has been shown to play a role in hepatitis C virus (HCV)-induced insulin resistance (IR). Polymorphism of the IL28B gene that encodes IFN-lambda 3 may be associated with IR through modulation of TNFα. The aim of this study was to investigate the relationship between IL28B rs12979860 genotype, the level of TNFα activation and the degree of IR in patients with chronic hepatitis C. One hundred and thirty-three nondiabetic genotype 1 HCV-infected patients with biopsy proven noncirrhotic hepatitis C were investigated for IR (using HOMA index), IL28B rs12979860 genotype and fasting circulating levels of soluble receptor 1 of TNFα (sTNFR1) and adipokines: leptin, adiponectin and IL-6. The HOMA-IR was positively correlated with serum levels of leptin (r = 0.35, P < 0.0001) and sTNFR1 (r = 0.35, P < 0.0001) but not with IL-6 or adiponectin. IL28B rs12979860 CC genotype was observed in 35% patients. Genotype CC and nongenotype CC patients were similar in terms of HOMA-IR (means 1.6 ± 0.9 vs 1.7 ± 1.4) and had similar circulating levels of sTNFR1 and adipokines. Independent factors associated with IR were ferritin (OR = 1.002, P = 0.02), leptin (OR = 1.06, P = 0.02) and sTNFR1 (OR = 7.9, P = 0.04). This study suggests that in nondiabetic, noncirrhotic, HCV genotype 1-infected patients, there is no relationship between IL28B rs12979860 genotype and HOMA-IR or sTNFR1 level. HCV-related IR may be mediated through TNFα independent of IL28B genotype.

Genetic background in nonalcoholic fatty liver disease: A comprehensive review

In the Western world, nonalcoholic fatty liver disease (NAFLD) is considered as one of the most significant liver diseases of the twenty-first century. Its development is certainly driven by environmental factors, but it is also regulated by genetic background. The role of heritability has been widely demonstrated by several epidemiological, familial, and twin studies and case series, and likely reflects the wide inter-individual and inter-ethnic genetic variability in systemic metabolism and wound healing response processes. Consistent with this idea, genome-wide association studies have clearly identified Patatin-like phosholipase domain-containing 3 gene variant I148M as a major player in the development and progression of NAFLD. More recently, the transmembrane 6 superfamily member 2 E167K variant emerged as a relevant contributor in both NAFLD pathogenesis and cardiovascular outcomes. Furthermore, numerous case-control studies have been performed to elucidate the potential role of candidate genes in the pathogenesis and progression of fatty liver, although findings are sometimes contradictory. Accordingly, we performed a comprehensive literature search and review on the role of genetics in NAFLD. We emphasize the strengths and weaknesses of the available literature and outline the putative role of each genetic variant in influencing susceptibility and/or progression of the disease.

Lipid dysregulation in hepatitis C virus, and impact of statin therapy upon clinical outcomes

The hepatitis C virus (HCV) is one of the most common causes of chronic liver disease and the leading indication for liver transplantation worldwide. Every aspect of the HCV life cycle is closely tied to human lipid metabolism. The virus circulates as a lipid-rich particle, utilizing lipoprotein cell receptors to gain entry into the hepatocyte. It has also been shown to upregulate lipid biosynthesis and impair lipid degradation, resulting in significant intracellular lipid accumulation and circulating hypocholesterolemia. Patients with chronic hepatitis C (CHC) are at increased risk of hepatic steatosis, fibrosis, and cardiovascular disease including accelerated atherosclerosis. HMG CoA Reductase inhibitors, or statins, have been shown to play an important role in the modulation of hepatic steatosis and fibrosis, and recent attention has focused upon their potential therapeutic role in CHC. This article reviews the hepatitis C viral life cycle as it impacts host lipoproteins and lipid metabolism. It then describes the pathogenesis of HCV-related hepatic steatosis, hypocholesterolemia and atherosclerosis, and finally describes the promising anti-viral and anti-fibrotic effects of statins, for the treatment of CHC.

[Lipid kinetics during dual antiviral therapy in patients with chronic hepatitis C]

BACKGROUND AND OBJECTIVE

We analyzed baseline and kinetic characteristics of lipid metabolism during the first month of bitherapy in patients with chronic hepatitis C genotype 1 (CHC-1).

PATIENTS AND METHODS

A longitudinal, prospective study including 99 naïve CHC-1 patients with liver biopsy who were treated with bitherapy. Our patients were assigned to one of 5 different "degrees of lipid requirement" that we established depending on the degree of liver fibrosis, baseline viral load and infectivity ratio (ratio between the median level of triglycerides and high densitity lipoproteins-cholesterol during the first month). The goal was to achieve "a favorable lipid metabolism" (FLM) by establishing a necessary minimum level of low density lipoproteins (LDL)-cholesterol during this period for each one of them. We also analyzed the relationship with the rate of sustained virological response.

RESULTS

Patients with liver fibrosis F3-F4 who had higher baseline levels of LDL-cholesterol achieved higher rates of sustained virological response. Those patients who had a lower value of infectivity ratio and median levels of LDL-cholesterol during the first month of bitherapy also achieved higher rates of sustained virological response: SVR group 100 (23) mg/dl against non-SVR group: 89 (28) mg/dl; odds ratio 1.1; 95% confidence interval (1.0-1.2); P<.05, these differences being more significant for genotype IL-28B-CC (P=.013). Patients with sustained virological response had higher rates of FLM.

CONCLUSIONS

Not every patient with CHC-1 has the same lipid kinetics during the first month of bitherapy, and it is necessary to achieve a sustained virological response and/or a FLM to keep higher plasma levels of LDL-cholesterol during this period. Those subjects without FLM could benefit from statins.

Effect of sofosbuvir and ribavirin treatment on peripheral and hepatic lipid metabolism in chronic hepatitis C virus, genotype 1-infected patients

Hepatitis C virus (HCV) modulates intrahepatic cholesterol biosynthetic pathways to promote viral replication. Chronic HCV infection is associated with altered metabolism, including dyslipidemia and insulin resistance (IR), which contributes to disease progression and influences response to therapy. To further understand the impact of HCV infection on host metabolism, we examined changes in serum lipid profiles and intrahepatic expression of lipid-related genes during interferon (IFN)-free treatment of chronic HCV, genotype 1 infection with sofosbuvir and ribavirin (RBV), and explored associations with treatment outcome. Serum lipids (total cholesterol, low-density lipoprotein [LDL], high-density lipoprotein [HDL], and triglycerides [TGs]) and hemoglobin A1C (HbA1C) were measured during treatment, while gene expression of lipid-related genes was assessed using paired pre- and end-of-treatment (EOT) liver biopsies from 8 patients (n=7 sustained virologic response [SVR]; n=1 relapse) and unpaired EOT liver biopsies from 25 patients (n=17 SVR; n=8 relapse). Serum LDL concentration and particle size increased early in therapy, whereas TG concentration and very-low-density lipoprotein particle size decreased concomitantly, irrespective of treatment outcome. Whereas LDL increased in patients regardless of treatment outcome, average LDL concentration was lower at baseline and post-treatment in patients who relapsed. Analysis of paired liver biopsies revealed altered expression of genes associated with lipid transport, assembly, and signaling. In unpaired EOT liver biopsies, intrahepatic expression of fatty acid metabolism and lipid transport genes was lower in patients who experienced treatment relapse.

CONCLUSION

Clearance of HCV using an IFN-free antiviral regimen results in rapid changes in peripheral and intrahepatic metabolic pathways, implicating a direct effect of HCV replication on lipid homeostasis.

Influence of hepatitis C virus and IL28B genotypes on liver stiffness

OBJECTIVE

Liver fibrosis has been associated with hepatitis C virus (HCV) genotype and genetic variation near the interleukin 28B (IL28B) gene, but the relative contribution is unknown. We aimed to investigate the relation between HCV genotypes, IL28B and development of liver stiffness.

PATIENTS AND METHODS

This cross-sectional study consists of 369 patients with chronic hepatitis C (CHC). Liver stiffness was evaluated using transient elastograhy (TE). Factors associated with development of liver fibrosis were identified by logistic regression analysis.

RESULTS

We identified 369 patients with CHC. 235 were male, 297 Caucasians, and 223 had been exposed to HCV through intravenous drug use. The overall median TE value was 7.4 kPa (interquartile range (IQR) 5.7-12.1). HCV replication was enhanced in patients carrying the IL28B CC genotype compared to TT and TC (5.8 vs. 5.4 log10 IU/mL, p = 0.03). Patients infected with HCV genotype 3 had significantly higher TE values (8.2 kPa; IQR, 5.9-14.5) compared to genotype 1 (6.9 kPa; IQR, 5.4-10.9) and 2 (6.7 kPa; IQR, 4.9-8.8) (p = 0.02). Within patients with genotype 3, IL28B CC genotype had the highest TE values (p = 0.04). However, in multivariate logistic regression, using various cut-off values for fibrosis and cirrhosis, only increasing age (odds ratio (OR) 1.09 (95% confidence interval (CI), 1.05-1.14 per year increment)), ALT (OR 1.01 (95% CI, 1.002-1.011), per unit increment) and HCV genotype 3 compared to genotype 1 (OR 2.40 (95% CI, 1.19-4.81), were consistently associated with cirrhosis (TE>17.1 kPa).

CONCLUSIONS

Age, ALT and infection with HCV genotype 3 were associated with cirrhosis assessed by TE. However, IL28B genotype was not an independent predictor of fibrosis in our study.

Hepatitis C virus and interferon type III (interferon-λ3/interleukin-28B and interferon-λ4): genetic basis of susceptibility to infection and response to antiviral treatment

There has been a significant increase in our understanding of the host genetic determinants of susceptibility to viral infections in recent years. Recently, two single-nucleotide polymorphisms (SNPs), rs12979860 T/C and rs8099917 T/G, upstream of the interleukin (IL)-28B/interferon (IFN)-λ3 gene have been clearly associated with spontaneous and treatment-induced viral clearance in hepatitis C virus (HCV) infection. Because of their power in predicting the response to IFN/ribavirin therapy, the above SNPs have been used as a diagnostic tool, even though their relevance in the management of HCV infection will be blunt in the era of IFN-free regimens. The recent discovery of a new genetic variant, ss469415590 TT/ΔG, upstream of the IL-28B gene, which generates the novel IFN-λ4 protein, has opened up a new and alternative scenario to understand the functional architecture of type III IFN genomic regions and to improve our knowledge of the pathogenetic mechanism of HCV infection. A role of ss469415590 in predicting responsiveness to antiviral therapy has also been observed in HCV-infected patients receiving direct antiviral agents. The underlying biological mechanism that links the above IL-28B polymorphisms (in both IFN-λ3 and IFN-λ4) to spontaneous and treatment-induced clearance of HCV infection remains to be discovered. Despite this, shedding some light on this issue, which is the main aim of this review, may provide new insights into the general topic of 'host genetics and viral infections'.

Apolipoprotein H expression is associated with IL28B genotype and viral clearance in hepatitis C virus infection

BACKGROUND & AIMS

HCV requires host lipid metabolism for replication, and apolipoproteins have been implicated in the response to treatment.

METHODS

We examined plasma apolipoprotein concentrations in three cohorts of patients: mono-infected patients with symptomatic acute hepatitis C (aHCV); those undergoing treatment for chronic hepatitis C (cHCV); and HIV/HCV co-infected patients being treated for their chronic hepatitis C. We also evaluated associations between apolipoproteins and IL28B polymorphisms, a defined genetic determinant of viral clearance.

RESULTS

Plasma apolipoprotein H (ApoH) levels were significantly higher in patients who achieved spontaneous clearance or responded to pegylated-interferon/ribavirin therapy. Strikingly, patients carrying the IL28B rs12979860 CC SNP correlated with the plasma concentration of ApoH in all three cohorts. Both ApoH and IL28B CC SNP were associated with HCV clearance in univariate analysis. Additional multivariate analysis revealed that the association between IL28B and HCV clearance was closely linked to that of Apo H and HCV clearance, suggesting that both belong to the same biological pathway to clearance. The association between IL28B CC SNP and ApoH was not observed in healthy individuals, suggesting that early post-infection events trigger differential ApoH expression in an IL28B allele dependent manner.

CONCLUSIONS

This relationship identifies ApoH as the first induced protein quantitative trait associated with IL28B, and characterises a novel host factor implicated in HCV clearance.

Genotype CC of rs12979860 is providing protection against infection rather than assisting in treatment response for HCV genotype 3a infection

Recent discovery of single-nucleotide polymorphisms located in the upstream region of interleukin-28B (IL28B) has shown association with interferon (IFN) treatment response especially in hepatitis C virus (HCV) genotype 1-infected patients. Pakistan, being the country with second highest prevalence of HCV with predominantly 3a genotype infection, bears a significant disease burden. The present study was conducted to evaluate the effect of rs12979860 genotypes on treatment response in HCV-3a-infected patients. This study shows that the CC genotype is providing protection against infection to HCV. But once infected, the CC genotype patients show viral persistence following IFN therapy. The TT genotype is assisting the 3a patients in viral clearance after IFN treatment. To our knowledge, this is the first study showing rs12979860 genotype association with IFN response in Pakistani HCV-3a-infected patients.

Distinct patterns of the lipid alterations between genotype 1 and 2 chronic hepatitis C patients after viral clearance

Background

The hepatitis C virus (HCV) genotype-specific impacts on the host metabolic alterations remained inconclusive.

Methods

A prospective study including 229 (118 genotype 1 (G1) and 111 G2) consecutive chronic HCV patients who had completed a course of anti-HCV treatment and underwent pre- and 24 weeks post-treatment surveys of metabolic profiles was conducted. Patients were stratified according to the therapeutic response, viral genotype and baseline insulin resistance (IR: homeostasis model assessments of IR (HOMA-IR) ≥2.5). Paired t-tests were used to compare the pre- and post-treatment variables.

Results

Significant post-therapeutic increases in cholesterol, triglyceride, HDL, LDL, apolipoprotein A1 and apolipoprotein B were observed in patients with sustained virological response (SVR) but not in those without. Among those with SVR, post-therapeutic increases in HDL (p<0.001) and apolipoprotein A1 (p = 0.012) were only found in G2, whereas increased triglyceride/HDL (p = 0.01) ratios were only found in G1 patients. When stratified by baseline IR among those with SVR, a significant increase in post-treatment HDL (p = 0.019) and apolipoprotein A1 (p = 0.012) but a decrease in HOMA-IR (p = 0.04), C-peptide (p = 0.019) and hemoglobin A1c (p = 0.047) were found in patients with baseline IR; a significant increase in HOMA-IR (p = 0.002) was found in patients without baseline IR. The latter change was observed only in G1 (p = 0.01) but not G2 patients. Although the pre-treatment metabolic profiles of G1 and G2 patients were indifferent, G1 had higher post-treatment triglyceride/HDL ratios (p = 0.041) and triglyceride (p = 0.044) levels than G2 patients.

Conclusions

G2 benefit more than G1 patients from viral clearance in metabolic alterations, particularly in those without baseline IR.

IFNL4/IL-28B haplotype structure and its impact on susceptibility to hepatitis C virus and treatment response in the Japanese population

A new type III interferon, IFN lambda 4 (IFNL4), and its single-nucleotide polymorphism (SNP) ss469415590 causing a frame shift have been recently reported strongly to affect antiviral therapy for chronic hepatitis C virus (HCV) infection in African and Caucasian populations compared to previously reported IL-28B SNPs rs12979860 and rs8099917. To compare the predictability for treatment outcome among those polymorphisms, we estimated haplotype structure of IFNL4/IL-28B consisting of the three SNPs in 4630 Japanese chronic hepatitis C patients and 1122 healthy controls and then compared their impact on response to pegylated-IFN (PEG-IFN) plus ribavirin (RBV) combined therapy in 903 HCV-1b-infected patients. A total of five haplotypes were identified, although two major haplotypes accounted for >99 % of the variation. The SNPs were tightly linked but not in absolute linkage disequilibrium. We could not find any difference in the predictive impact of any of these three SNPs with regard to susceptibility to HCV and treatment response. However, patients with favourable rs8099917 TT, linked to unfavourable genotypes of ss469415590 and rs12979860, showed poor initial viral response compared with those with all favourable genotypes (P = 0.0022). These findings suggest that, in part, ss469415590 and rs12979860 may have better predictive impact on response to PEG-IFN plus RBV therapy in the Japanese population, especially in patients with any of the minor haplotypes consisting of these SNPs.

The association of IL28B genotype with the histological features of chronic hepatitis C is HCV genotype dependent

The interleukin 28B (IL28B) rs12979860 polymorphism is associated with treatment outcome in hepatitis C virus (HCV) genotype 1 and 4 patients. Its association with the histological features of chronic hepatitis C and disease severity needs further clarifications. To assess the correlation between IL28B genotype, HCV genotype and liver biopsy findings in untreated patients.

MATERIALS AND METHODS

Pre-treatment liver biopsies from 335 HCV Caucasian patients (59% males, age 50 years) enrolled in the MIST study were staged for fibrosis and inflammation according to the METAVIR and the Ishak scoring systems; steatosis was dichotomized as <5% or ≥5%. IL28B was typed by Taqman Single Nucleotide Polymorphism (SNP) genotyping assay. HCV genotype was 1 in 151 (45%), 2 in 99 (30%), 3 in 50 (15%) and 4 in 35 (10%) patients. IL28B genotype was CC in 117 (34%), CT in 166 (49%) and TT in 52 (15%). At univariate analysis, the IL28B CC genotype was associated with severe portal inflammation in HCV-1 patients (CC vs.

CT/TT

86% vs. 63%, p = 0.005), severe lobular inflammation in HCV-2 patients (CC vs.

CT/TT

44% vs. 23%, p = 0.03), and less fatty infiltration in HCV-1 patients (CC vs.

CT/TT

72% vs. 51%, p = 0.02). Despite the lack of any association between IL28B and fibrosis stage, in HCV-3 patients IL28B CC correlated with METAVIR F3-F4 (CC vs.

CT/TT

74% vs. 26%, p = 0.05). At multivariate analysis, the genotype CC remained associated with severe portal inflammation in HCV-1, only (Odds Ratio (OR): 95% Confidence Interval (CI): 3.24 (1.23-8.51)). IL28B genotype is associated with the histological features of chronic hepatitis C in a HCV genotype dependent manner, with CC genotype being independently associated with severe portal inflammation.

Impact of IL28B genetic variation on HCV-induced liver fibrosis, inflammation, and steatosis: a meta-analysis

BACKGROUND & AIMS

IL28B polymorphisms were shown to be strongly associated with the response to interferon therapy in chronic hepatitis C (CHC) and spontaneous viral clearance. However, little is known about how these polymorphisms affect the natural course of the disease. Thus, we conducted the present meta-analysis to assess the impact of IL28B polymorphisms on disease progression.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and the Cochrane Library. Integrated odds ratios (OR) were calculated with a fixed-effects or random-effects model based on heterogeneity analyses.

RESULTS

We identified 28 studies that included 10,024 patients. The pooled results indicated that the rs12979860 genotype CC was significantly associated (vs. genotype CT/TT; OR, 1.122; 95%CI, 1.003-1.254; P = 0.044), and that the rs8099917 genotype TT tended to be (vs. genotype TG/GG; OR, 1.126; 95%CI, 0.988-1.284; P = 0.076) associated, with an increased possibility of severe fibrosis. Both rs12979860 CC (vs. CT/TT; OR, 1.288; 95%CI, 1.050-1.581; P = 0.015) and rs8099917 TT (vs. TG/GG; OR, 1.324; 95%CI, 1.110-1.579; P = 0.002) were significantly associated with a higher possibility of severe inflammation activity. Rs8099917 TT was also significantly associated with a lower possibility of severe steatosis (vs. TG/GG; OR, 0.580; 95%CI, 0.351-0.959; P = 0.034), whereas rs12979860 CC was not associated with hepatic steatosis (vs. CT/TT; OR, 1.062; 95%CI, 0.415-2.717; P = 0.901).

CONCLUSIONS

IL28B polymorphisms appeared to modify the natural course of disease in patients with CHC. Disease progression seems to be promoted in patients with the rs12979860 CC and rs8099917 TT genotypes.

Role of FDFT1 polymorphism for fibrosis progression in patients with chronic hepatitis C

BACKGROUND

In chronic hepatitis C (CHC), steatosis is associated with fibrosis and impaired response to antiviral therapy. Recently, a polymorphism of single nucleotide polymorphism SNP rs2645424 of farnesyl diphosphate farnesyl transferase 1 (FDFT1) was identified in NAFLD/NASH as a possible causal link to steatosis and fibrosis progression. SNP rs738409 in the adiponutrin gene (PNPLA3) is a well described factor for steatosis. This study evaluated the relation of these SNPs on steatosis, fibrosis and treatment response in CHC.

METHODS

The SNPs rs738409478 and rs2645424 were determined by real-time PCR in 478 patients with CHC (m/f: 314/164; mean age: 44.9 ± 10.7; GT1: 387, GT4: 91) who completed treatment with peg-IFN-α-2a/ribavirin. All had a pretreatment liver biopsy. Steatosis and fibrosis were graded by board-certified pathologists according to Brunt and METAVIR respectively.

RESULTS

The distribution of FDFT1 rs2645424 was GG: 186 (38.9%), AG: 222 (46.4%) and AA: 70 (14.6%) and of the rs738409 PNPLA3 allele: CC: 269 (56.3%), CG: 177 (37.0%) and GG: 32 (6.7%). Overall, FDTF1 polymorphism was not linked to the extent of steatosis or fibrosis. However, in patients without steatosis the AA genotype was associated with advanced fibrosis [AA: 8/20 (40.0%), AG: 6/70 (8.5%), GG: 9/57 (16.1%), P = 0.003]. In contrast, the minor PNPLA3 allele was associated with both steatosis and advanced fibrosis (P < 0.001). Both SNPs did not influence treatment response.

CONCLUSION

The minor allele in FDFT1 was associated with advanced fibrosis in the non-steatotic but not in the steatotic subgroup. This may reflect different metabolic pathways in fibrosis progression for steatotic and non-steatotic patients with CHC.

Mysterious Linkages Between Hepatitis C Virus Genotypes, Interleukin-28B Genotypes and Viral Clearance- A Meta-Analysis

BACKGROUND

Recent genome wide association studies (GWAS) have shown important roles of single nucleotide polymorphisms (SNP) near region of interleukin B 28 (IL28B) gene in spontaneous and drug-induced clearance of hepatitis C virus (HCV) in genotype 1 HCV infection.

OBJECTIVES

This meta-analysis was designed to determine the world-wide distribution patterns of IL28B genotypes and alleles, and to find possible linkages between IL28B and HCV genotypes.

PATIENTS AND METHODS

Manual and electronic databases were searched. Critical appraisal was performed. According to the results of heterogeneity tests, we used fix/random model for the analysis. The data concerning patients' ethnicity and HCV genotypes were analyzed by using statistical analysis software.

RESULTS

A total of 255 articles were found. After article review and quality assessment, 50 studies, including 18662 patients and 1313 healthy subjects, were analyzed. Presence of HCV genotype 3 versus genotype 1 was significantly associated with a higher frequency of CC genotype and C allele, with an odds ratio (OR) of 1.68 (95% CI: 1.44-1.99) and 1.49 (95% CI: 1.33-1.67), respectively. Prevalence of the rs12979860 CC genotype among genotype 1 HCV infected patients of Asian ethnicity was 69.48% (95% CI: 65.20-73.77), which was significantly higher than its prevalence [33.27% (95% CI: 28.88-37.67)] in the Caucasian genotype 1 HCV infected patients. Prevalence of rs12979860 TT genotype in the African-American genotype 1 HCV infected patients was the highest [36.20% (95% CI: 32.91-39.49)], and significantly different compared to all other ethnicities.

CONCLUSIONS

There were significant linkages between HCV genotypes and IL28B genotypes/alleles. Patients with a favorable IL28B and genotypes 1 and 4 HCV infection stand a better chance to clear HCV in the acute phase.

Genetic predisposition in NAFLD and NASH: impact on severity of liver disease and response to treatment

Liver fat deposition related to systemic insulin resistance defines non-alcoholic fatty liver disease (NAFLD) which, when associated with oxidative hepatocellular damage, inflammation, and activation of fibrogenesis, i.e. non-alcoholic steatohepatitis (NASH), can progress towards cirrhosis and hepatocellular carcinoma. Due to the epidemic of obesity, NAFLD is now the most frequent liver disease and the leading cause of altered liver enzymes in Western countries. Epidemiological, familial, and twin studies provide evidence for an element of heritability of NAFLD. Genetic modifiers of disease severity and progression have been identified through genome-wide association studies. These include the Patatin-like phosholipase domain-containing 3 (PNPLA3) gene variant I148M as a major determinant of inter-individual and ethnicity-related differences in hepatic fat content independent of insulin resistance and serum lipid concentration. Association studies confirm that the I148M polymorphism is also a strong modifier of NASH and progressive hepatic injury. Furthermore, a few large multicentre case-control studies have demonstrated a role for genetic variants implicated in insulin signalling, oxidative stress, and fibrogenesis in the progression of NAFLD towards fibrosing NASH, and confirm that hepatocellular fat accumulation and insulin resistance are key operative mechanisms closely involved in the progression of liver damage. It is now important to explore the molecular mechanisms underlying these associations between gene variants and progressive liver disease, and to evaluate their impact on the response to available therapies. It is hoped that this knowledge will offer further insights into pathogenesis, suggest novel therapeutic targets, and could help guide physicians towards individualised therapy that improves clinical outcome.

Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for IFNL3 (IL28B) genotype and PEG interferon-α-based regimens

Pegylated interferon-α (PEG-IFN-α or PEG-IFN 2a and 2b)- and ribavirin (RBV)-based regimens are the mainstay for treatment of hepatitis C virus (HCV) genotype 1. IFNL3 (IL28B) genotype is the strongest baseline predictor of response to PEG-IFN-α and RBV therapy in previously untreated patients and can be used by patients and clinicians as part of the shared decision-making process for initiating treatment for HCV infection. We provide information regarding the clinical use of PEG-IFN-α- and RBV-containing regimens based on IFNL3 genotype.

Hepatitis C and lipid metabolism, hepatic steatosis, and NAFLD: still important in the era of direct acting antiviral therapy?

Chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) have an individual prevalence of 1.8-3% and at least 30%, respectively, in the United States. It is therefore not surprising that there is overlap between these two common chronic liver diseases, although the relationship appears to go beyond isolated co-existence. Hepatic steatosis is a common feature of CHC infection and can be related to both metabolic and viral specific factors. Steatosis in the setting of nongenotype 3 CHC has been predictive of response to therapy prior to the advent of the direct acting antiviral medications (DAAs). Similarly, lipid metabolism appears important in response to CHC treatment. The pathways for both lipid homeostasis and NAFLD as it pertains to CHC infection as well as the utilization of statin therapy in CHC infection will be reviewed with a focus on the relevance of these topics in the era of DAA therapy.

No correlation between PNPLA3 rs738409 genotype and fatty liver and hepatic cirrhosis in Japanese patients with HCV

Background

Hepatitis C virus (HCV) infection is associated with the development of cirrhosis and hepatocellular carcinoma and is also related to fatty change of the liver. Variation in patatin-like phospholipase domain-containing 3 (PNPLA3) gene is associated with disease progression in nonalcoholic fatty liver disease (NAFLD). Recent reports have suggested that PNPLA3, IL28B and TLR4-associated single nucleotide polymorphisms (SNPs) may have an impact on hepatic steatosis or fibrosis in patients with chronic HCV infection.

Methods and Findings

Four SNPs (PNPLA3 rs738409, TLR4 rs4986790, TLR4 rs4986791, IL28B rs8099917) were identified in Japanese patients infected with HCV. We examined the association between the distribution of these SNP alleles and fatty change of the liver or existence of hepatic cirrhosis diagnosed by ultrasonography, one of the widely accessible and easy-to-use methods. PNPLA3 rs738409 G-allele and IL28B rs 8099917 minor allele were found in 70.0% and 31.1%, respectively. These two TLR4 SNPs were uniform in Japanese. Fatty change of the liver developed independent of the abscence of hepatic cirrhosis on sonographic findings and younger age. Hepatic cirrhosis was associated with a higher aspartate aminotransferase/platelet ratio index (APRI), no fatty change of the liver, higher BMI and higher AFP levels. No association between PNPLA3 rs738409/IL28B rs8099917 genotypes and hepatic steatosis or liver fibrosis was observed.

Conclusions

According to ultrasound examinations, no association between PNPLA3 rs738409 genotype and fatty change of the liver or hepatic cirrhosis was found in Japanese patients infected with HCV. Together, our results suggested that the mechanism of hepatic steatosis underlying HCV infection might differ from that of NAFLD and should be explored.

No correlation between PNPLA3 rs738409 genotype and fatty liver and hepatic cirrhosis in Japanese patients with HCV

BACKGROUND

Hepatitis C virus (HCV) infection is associated with the development of cirrhosis and hepatocellular carcinoma and is also related to fatty change of the liver. Variation in patatin-like phospholipase domain-containing 3 (PNPLA3) gene is associated with disease progression in nonalcoholic fatty liver disease (NAFLD). Recent reports have suggested that PNPLA3, IL28B and TLR4-associated single nucleotide polymorphisms (SNPs) may have an impact on hepatic steatosis or fibrosis in patients with chronic HCV infection.

METHODS AND FINDINGS

Four SNPs (PNPLA3 rs738409, TLR4 rs4986790, TLR4 rs4986791, IL28B rs8099917) were identified in Japanese patients infected with HCV. We examined the association between the distribution of these SNP alleles and fatty change of the liver or existence of hepatic cirrhosis diagnosed by ultrasonography, one of the widely accessible and easy-to-use methods. PNPLA3 rs738409 G-allele and IL28B rs 8099917 minor allele were found in 70.0% and 31.1%, respectively. These two TLR4 SNPs were uniform in Japanese. Fatty change of the liver developed independent of the abscence of hepatic cirrhosis on sonographic findings and younger age. Hepatic cirrhosis was associated with a higher aspartate aminotransferase/platelet ratio index (APRI), no fatty change of the liver, higher BMI and higher AFP levels. No association between PNPLA3 rs738409/IL28B rs8099917 genotypes and hepatic steatosis or liver fibrosis was observed.

CONCLUSIONS

According to ultrasound examinations, no association between PNPLA3 rs738409 genotype and fatty change of the liver or hepatic cirrhosis was found in Japanese patients infected with HCV. Together, our results suggested that the mechanism of hepatic steatosis underlying HCV infection might differ from that of NAFLD and should be explored.

Study of PKRBD in HCV genotype 3a infected patients in response to interferon therapy in Pakistani population

Background

Hepatitis C virus (HCV) is a major cause of liver cirrhosis and hepatocellular carcinoma and infects about 3% world population. Response to interferon therapy depends upon the genotype of the virus and factors associated with the host. Despite a good response to interferon therapy, a considerable number of genotype 3a infected patients remains unalleviated.

Results

In total forty-nine patients including twenty-five non-responders (non-SVR) and twenty-four responders (SVR) were recruited. Patients were tested for viral status at different intervals and the isolated RNA was sequenced for the NS5A region in both groups. The comparison of PKRBD of HCV between the SVR and non-SVR patients did not confirm any significant difference in the number of mutations. However, when the sequence downstream to the PKRBD of NS5A was compared, two important statistically significant mutations were observed; at positions 2309 (Ala to Ser) and 2326 (Gly to Ala). These mutations were then analysed for tertiary protein structure and important structural changes were observed. Statistically significant difference was also observed when age groups of patients were compared; younger patients showed better response than the older ones.

Conclusions

The region between PKRBD and IRRDR may be important for prediction of response to IFN therapy for genotype 3a. ISDR and PKRBD have not shown any involvement in treatment response. Further functional analyses of these findings can help in understanding the involvement of the NS5A region in interferon treatment of HCV-3a infected patients.

Impact of Il28b-related single nucleotide polymorphisms on liver transient elastography in chronic hepatitis C infection

BACKGROUND AND AIMS

Recently, several genome-wide association studies have revealed that single nucleotide polymorphisms (SNPs) in proximity to IL28B predict spontaneous clearance of hepatitis C virus (HCV) infection as well as outcome following pegylated interferon and ribavirin therapy among genotype 1 infected patients. Additionally the presence of the otherwise favorable IL28B genetic variants in the context of HCV genotype 3 infection reportedly entail more pronounced liver fibrosis and steatosis. The present study aimed to evaluate the impact of IL28B SNP variability on liver stiffness as accessed by transient elastography.

METHODS

Seven hundred and seventy-one Swedish HCV infected patients sequentially undergoing liver stiffness measurement by means of Fibroscan® in the context of a real-life trial had samples available for IL28B genotyping (rs12979860) and HCV genotyping.

RESULTS

CC(rs12979860) was more common among HCV genotype 2 or 3 infected treatment-naïve patients than among those infected with genotype 1 (P<0.0001). Additionally CC(rs12979860) among HCV genotype 3 infected patients was associated with higher liver stiffness values (P = 0.004), and higher AST to platelet ratio index (APRI; p = 0.02) as compared to carriers of the T allele. Among HCV genotype 1 infected patients, CC(rs12979860) was significantly associated with higher viral load (P = 0.001), with a similar non-significant trend noted among HCV genotype 3 infected patients.

CONCLUSION

This study confirms previous reports that the CC(rs12979860) SNP is associated with more pronounced liver pathology in patients chronically infected with HCV genotype 3 as compared to genotype 1, suggesting that IL28B genetic variants differently regulates the course of HCV infection across HCV genotypes.

Are metabolic factors still important in the era of direct antiviral agents in patients with chronic hepatitis C?

The high rate of sustained viral response (SVR) to boceprevir or telaprevir-based triple therapy in hepatitis C (HCV)-related, non-cirrhotic naïve patients or relapsers to previous antiviral treatment leads clinicians to believe that the impact of metabolic host factors on SVR is minimal when triple therapy is used, unlike what is observed with the peginterferon and ribavirin schedules. This concept is strongly expressed by some opinion leaders on the basis of the data derived from sub-analyses of registrative trials as well as from a post-hoc analysis of the phase II C208 clinical trial. The perception of unrestrainable therapeutic success with the use of newer, more powerful antivirals is now reinforced by the brilliant results obtained with sofosbuvir, an HCV NS5B polymerase inhibitor, as well as by the data from the phase II and III studies on the various combinations of second-generation NS3/4A inhibitors and NS5A and/or NS5B inhibitors. However, a great deal of concern has emerged from the real world scenario in which patients are often older and have more comorbidities than patients in the “world of trials”. Furthermore, many of them have advanced fibrosis and previous failure with peginterferon and ribavirin treatment. Some data from the recent literature suggest that the host metabolic factors may play a minor but non-negligible role in these difficult-to-treat patients, an issue that will hopefully be investigated in further studies. This editorial aims to provide a detailed analysis of the role that host metabolic factors played in the past and what role they may play in the era of direct antiviral agents.

Interaction of IFNL3 with insulin resistance, steatosis and lipid metabolism in chronic hepatitis C virus infection

Metabolic changes are inextricably linked to chronic hepatitis C (CHC). Recently polymorphisms in the IFNL3 (IL28B) region have been shown to be strongly associated with spontaneous and treatment induced recovery from hepatitis C virus (HCV) infection. Further, circumstantial evidence suggests a link between IFNL3 single nucleotide polymorphisms and lipid metabolism, steatosis and insulin resistance in CHC. The emerging picture suggests that the responder genotypes of IFNL3 polymorphisms are associated with a higher serum lipid profile, and less frequent steatosis and insulin resistance. This review analyzes the current data regarding this interaction and its meaning for HCV pathogenesis and disease progression.

Association of IL28B genotype with fibrosis progression and clinical outcomes in patients with chronic hepatitis C: a longitudinal analysis

Interleukin (IL)28B polymorphisms are associated with spontaneous clearance of hepatitis C virus (HCV) infection and response to therapy. Whether IL28B genotype affects fibrosis progression or clinical outcome is unclear. Our aim was to study the relationship between IL28B genotype and both histological and clinical outcomes in patients with chronic hepatitis C (CHC). Hepatic fibrosis was scored using the Ishak (0-6) scale; progression was defined as a 2-point increase in Ishak score between biopsies. Multiple logistic and Cox regressions were used to identify variables associated with fibrosis progression. In all, 1,483 patients were included in a baseline cross-sectional analysis, from which 276 were eligible for a paired biopsy analysis (median time between biopsies 4 years), and 400 for a clinical outcome analysis. At baseline biopsy, patients with IL28B CC genotype had significantly higher portal inflammation (2.4 versus 2.2) and alanine aminotransferase (ALT) levels (133 versus 105 U/L; P < 0.05 for all). In the paired biopsy analysis, there was no difference in the frequency of fibrosis progression between patients with IL28B CC and non-CC genotypes (17% versus 23%). In logistic regression, only higher baseline alkaline phosphatase, lower platelets, and greater hepatic steatosis were associated with fibrosis progression. Patients with IL28B CC were twice as likely to develop adverse clinical outcomes compared to non-CC (32% versus 16%; P = 0.007).

CONCLUSION

IL28B CC genotype was associated with greater hepatic necroinflammation, higher ALT, and worse clinical outcomes in CHC patients. This suggests that IL28B CC is associated with a state of enhanced immunity that, on the one hand, can promote viral clearance, but alternately can increase necroinflammation and hepatic decompensation without enhancing fibrosis progression.

Investigation of PNPLA3 and IL28B genotypes on diabetes and obesity after liver transplantation: insight into mechanisms of disease

To identify genetic risks for obesity and diabetes postliver transplantation (LT), LT recipients underwent genotyping for IL28B rs12979860 (n = 295) and PNPLA3 rs738409 (n = 205) polymorphism in both donors and recipients. The development of obesity and diabetes/impaired fasting glucose (IFG) was determined 1-5 years post-LT. Recipient PNPLA-3 genotype was independently associated with obesity (BMI > 30) at 3 years posttransplant (genotype CC 33.7%, CG 48.3% and GG 82.4%, p = 0.002), with an odds ratio (OR 2.54, CI 1.38-4.66, p = 0.003), associated with the G allele. Diabetes/IFG diagnosed within 5 years posttransplant associated with PNPLA-3 non-CC genotype (HR 1.59, 1.12-2.26, p = 0.010), but not IL28B TT genotype (HR 1.46, 0.94-2.27, p = 0.092). No genotype variable was independently predictive of diabetes/IFG. The combination of PNPLA-3 non-CC and IL28B TT genotype was associated with increased risk of diabetes/IFG compared to PNPLA-3 CC, IL28B non-TT (HR 2.64, CI 1.30-5.39, p = 0.008). Donor genotypes were not associated with any of the outcomes analyzed. In conclusion, PNPLA-3 non-CC genotype is associated with posttransplant obesity but not independently with diabetes/IFG. The lack of donor related risk suggests a peripheral rather than central mechanism of insulin resistance in liver transplant recipients.

Polymorphism Near the Interleukin-28B Gene and Anti-Hepatitis C Viral Response

In a recent genome-wide association study, single nucleotide polymorphisms (SNPs) located near the interleukin-28B gene (IL28B), which encodes type III interferon (IFN) λ3, were shown to be strongly associated with a viral response to pegylated IFNα (PEG-IFNα) and ribavirin (RBV) combination therapy and spontaneous viral clearance in patients chronically and acutely infected with hepatitis C virus (HCV), respectively. The global distribution of allele frequencies shows a remarkable pattern, in which a favorable allele is nearly fixed in East Asia, has an intermediate frequency in Europe, and is least frequent in Africa. Although the underlying mechanisms responsible for viral responses associated with IL28B SNPs have not been completely elucidated, IFN-stimulated gene expression in patients with unfavorable IL28B genotypes tends to be high at baseline and is insufficiently induced by exogenous IFN administration, resulting in poor treatment outcomes. Clinically, triple therapy with PEG-IFNα/RBV together with direct-acting antiviral agents (DAAs) is currently used to treat chronic hepatitis C as a first-line therapy. Although the predictive power of IL28B status may be attenuated, the IL28B genotype will remain relevant to the outcomes of DAA therapy when used in combination with PEG-IFNα as a backbone. Even with the introduction of IFN-free therapies with a new class of highly effective DAAs, IL28B SNPs are still useful predictors of treatment outcomes and can be used to individualize treatment strategies to maximize cost-effectiveness and identify patients at risk of being refractory to treatment. This review summarizes the current understanding of the clinical significance and role of IL28B in HCV infection and response to therapy.

Insulin resistance, steatosis and hepatitis C virus

Epidemiological studies have shown an increased occurrence of metabolic disorders such as insulin resistance (IR) and steatosis in patients with hepatitis C virus (HCV) infection. IR is believed to represent one of the central clinical features of the "metabolic syndrome" and the major pathogenetic factor for type 2 diabetes mellitus. In patients with chronic HCV hepatitis, IR may have several dangerous consequences such as accelerated progression of liver fibrosis, resistance to antiviral therapy and development of hepatocellular carcinoma. According to recent evidence, the global epidemic of metabolic disorders related to incorrect diets will lead physicians to deal with 1.2 billion patients with diabetes in the world in 2025. Given the high prevalence of HCV infection in several countries, metabolic manifestations will contribute to increasing morbidity and mortality in patients with HCV chronic infection in the near future. HCV treatment, shown able to decrease both the occurrence of HCV-related IR and diabetes, may reduce the risk of the associated morbidities.

Association between hepatic steatosis and hepatic expression of genes involved in innate immunity in patients with chronic hepatitis C

BACKGROUNDS/AIMS

We investigated the association between hepatic steatosis and hepatic expression of genes involved in innate immunity, both of which are reportedly associated with resistance to peginterferon (PEG-IFN) and ribavirin combination therapy for hepatitis C virus (HCV) infection.

METHODS

A total of 122 patients infected with HCV genotype 1b who underwent and completed PEG-IFN and ribavirin combination therapy were studied. Hepatic steatosis was evaluated on the basis of the liver specimen biopsied prior to antiviral therapy. The levels of mRNA of innate immunity genes (RIG-I, MDA5, LGP2, Cardif, RNF125, ISG15, and USP18) were measured by real-time polymerase chain reaction in RNA extracted from biopsied liver tissue and compared between patients with and without hepatic steatosis.

RESULTS

The proportion of patients with hepatic steatosis, the hepatic expression levels of RIG-I gene, and RIG-I/Cardif and RIG-I/RNF125 ratios were significantly higher in patients in whom serum HCV RNA did not disappear throughout the treatment period. Hepatic expression of RIG-I and the ratios of RIG-I/Cardif and RIG-I/RNF125 were significantly higher in patients with steatosis than those without.

CONCLUSIONS

Changes in hepatic expression of some genes involved in innate immunity were observed along with hepatic steatosis, possibly playing a mechanistic role in resistance to IFN-based therapy in patients with hepatic steatosis.

Clinico-pathological significance of hepatitis C virus core antigen levels in chronic infection

Hepatitis C virus core antigen (HCVcoreAg) may be measured in serum with a sensitive, recently validated assay. Beyond its value as a marker of viral infection, there are little data on its relation with clinical, histological, and virological parameters. In this study, the significance of HCVcoreAg levels was studied in a prospective cohort of 114 patients with chronic hepatitis C. HCVcoreAg was measured by a commercial chemiluminescent microparticle immunoassay. Clinical and virological data included quantitative HCV-RNA, HCV genotype, ALT, GGT, IL28B rs12979860 polymorphism as well as liver histology parameters. HCVcoreAg levels were correlated significantly with HCV-RNA (r=0.56; P<0.0001) but also with ALT levels (r=0.258; P<0.01) and liver necroinflammatory activity (r=0.205; P<0.04). Patients harbouring HCV genotype 3 showed lower levels of HCVcoreAg than both genotype 1 and two patients. In genotype 3, a direct correlation between steatosis and HCVcoreAg was found. Levels of HCVcoreAg also varied according to the IL28B genotype. These data suggest that the evaluation of HCVcoreAg serum levels may provide relevant data for the baseline clinical evaluation of chronic hepatitis C patients. HCVcoreAg serum levels may be a useful tool to further the understanding of chronic hepatitis C pathobiology.

Role of IL28B and inosine triphosphatase polymorphisms in the treatment of chronic hepatitis C virus genotype 6 infection

IL28B and inosine triphosphatase (ITPA) polymorphisms are able to predict treatment response and degree of ribavirin-related anaemia, respectively, in the treatment of chronic hepatitis C virus (HCV) infection. However, their roles in the treatment of chronic HCV genotype 6 remain undetermined. Sixty patients who were infected with HCV genotype 6 were commenced on 48 weeks of combination pegylated interferon and ribavirin therapy. Response to therapy, profiles of haemoglobin changes and platelet counts during therapy and their associations with IL28B rs8099917 and ITPA rs1127354 polymorphisms were analysed. The overall sustained virologic response (SVR) rate was 91.7%. 18 patients (30.0%) required a reduction in ribavirin dosage. The distribution of IL28B rs8099917 TT/TG genotypes and ITPA rs1127354 CC/CA genotypes were in Hardy-Weinberg equilibrium. IL28B rs8099917 TT genotype, when compared to TG genotype, was significantly associated with an increased SVR rate (96.2% and 62.5%, respectively) and was the only clinical parameter that predicted SVR (P = 0.014). The same significant association was observed when analysing allelic frequencies (T vs G, P = 0.001). ITPA rs1127354 CA genotype, when compared to CC genotype, was associated with lesser degree of anaemia throughout therapy (P < 0.05 for all time points). ITPA polymorphisms showed no association with changes in platelet count throughout therapy (P > 0.05 for all time points) and was not associated with SVR (P = 0.640). In chronic HCV genotype 6 infection, IL28B polymorphisms were associated with response to therapy. ITPA polymorphisms influenced the degree of anaemia but not thrombocytopenia during therapy.

Effects of IL28B rs12979860 CC genotype on metabolic profile and sustained virologic response in patients with genotype 1 chronic hepatitis C

BACKGROUND & AIMS

Patients with genotype 1 chronic hepatitis C (G1 CHC) frequently develop steatosis and insulin resistance (IR), caused by metabolic and viral factors. These accelerate the progression of liver disease and reduce the response to therapy. A sustained virologic response (SVR) to therapy in patients with G1 CHC is associated strongly with polymorphisms near the interleukin-28B (IL28B) gene, but the interaction between IL28B genotype and IR, and their combined effects on SVR, have not been defined. We tested the association between the IL28B rs12979860 single-nucleotide polymorphism and metabolic features, including IR, and evaluated their effects on SVR.

METHODS

We performed genotype analysis of IL28B rs12979860 for 434 white G1 CHC patients who underwent consecutive biopsy analysis at 3 tertiary centers. Metabolic profile analyses included assessments of lipid levels and IR by the homeostasis model assessment.

RESULTS

Patients with the CC polymorphism in IL28B had higher levels of total and low-density lipoprotein cholesterol, lower levels of triglycerides, and a lower prevalence of IR and moderate-severe steatosis (P < .05) than patients without this genotype. By multiple logistic regression analysis, body mass index (odds ratio [OR], 1.223; P < .001), level of triglycerides (OR, 1.007; P = .006), the CC polymorphism in IL28B (OR, 0.378; P = .001), and levels of HCV RNA greater than 850,000 IU/mL (OR, 1.803; P = .01) were associated with IR. The CC polymorphism in IL28B (OR, 8.350; P < .001) and IR (OR, 0.432; P = .005), but not steatosis (OR, 0.582; P = 0.25), was associated with an SVR.

CONCLUSIONS

In white patients with G1 CHC, the IL28B rs12979860 CC genotype is associated with reduced IR. IL28B rs12979860 genotype and IR by the homeostasis model assessment strongly affect the outcome of antiviral therapy.

Hepatitis C virus diversity and hepatic steatosis

Hepatitis C virus (HCV) infection is closely associated with lipid metabolism defects throughout the viral lifecycle, with hepatic steatosis frequently observed in patients with chronic HCV infection. Hepatic steatosis is most common in patients infected with genotype 3 viruses, possibly due to direct effects of genotype 3 viral proteins. Hepatic steatosis in patients infected with other genotypes is thought to be mostly due to changes in host metabolism, involving insulin resistance in particular. Specific effects of the HCV genotype 3 core proteins have been observed in cellular models in vitro: mechanisms linked with a decrease in microsomal triglyceride transfer protein activity, decreases in the levels of peroxisome proliferator-activating receptors, increases in the levels of sterol regulatory element-binding proteins, and phosphatase and tensin homologue downregulation. Functional differences between the core proteins of genotype 3 viruses and viruses of other genotypes may reflect differences in amino acid sequences. However, bioclinical studies have failed to identify specific 'steatogenic' sequences in HCV isolates from patients with hepatic steatosis. It is therefore difficult to distinguish between viral and metabolic steatosis unambiguously, and host and viral factors are probably involved in both HCV genotype 3 and nongenotype 3 steatosis.

Interleukin-28B polymorphism in hepatitis C and liver transplantation

The discovery of interleukin-28B (IL-28B) single-nucleotide polymorphisms has opened an important new area of research in liver transplantation (LT) for hepatitis C virus (HCV). Both recipient- and donor-derived IL-28B genotypes affect the post-LT treatment response, with sustained virological response (SVR) rates oscillating from >50% in homozygotes for the favorable allele (up to 90% when this is present in both the recipient and the donor) to <15% in homozygotes for the unfavorable allele and from 30% to 50% in heterozygotes. Other key posttransplant outcomes affected by the IL-28B genotype are the time to histological recurrence, HCV RNA and alanine aminotransferase levels, histological variables (including the rate of fibrosis progression), and hepatocellular carcinoma. Interactions between donor and recipient IL-28B genotypes are complex and may affect outcomes not directly related to HCV infections, such as acute cellular rejection (ACR) and metabolic diseases. A preferential allocation system in which livers from donors homozygous for the favorable allele are given to HCV patients might be postulated to improve SVR rates and post-LT outcomes in recipients with HCV infections (a 25% increase in SVR and an 8% decrease in mortality at 5 years). Although negative effects from this are difficult to predict, they could include an accelerated progression of fibrosis in patients with failed HCV eradication and an increase in ACR in non-HCV patients. Our knowledge of the precise role of IL-28B genotypes in the course of post-LT HCV is evolving, but existing knowledge suggests the possibility of exploring strategies that use IL-28B genotyping to reduce the impact of post-LT adverse outcomes.

Genomics and HCV infection: progression of fibrosis and treatment response

HCV infection is a global health problem that affects 170 million people worldwide. The severity of the disease varies from asymptomatic chronic infection to cirrhosis and hepatocellular carcinoma (HCC). Recently, the standard of care for genotype 1 patients has greatly improved with the addition of protease inhibitors (telaprevir or boceprevir) to pegylated interferon (PegIFN) and ribavirin (RBV). The prediction of fibrosis progression and the response to antiviral treatment are two major issues in the management of patients with chronic hepatitis C. Differential expression of mRNAs was first analyzed for both progression of fibrosis and treatment response. Specific polymorphisms, associated with either fibrosis or viral response, were identified thanks to major improvements in genome scanning technologies. Since 2009, several independent genome wide association studies (GWAS) have reported an association between genetic polymorphisms within the IL-28B promoter and both natural and treatment-induced clearance in genotype 1 infected patients. These different studies showed the strong association and the importance of IL-28B polymorphisms in the treatment response. Combining the different genetic factors could improve their predictive value and help identify patients at a high risk of progression of fibrosis as well as those with a lower chance of responding to treatment. The aim of this review was to discuss the genomic factors (mRNAs, miRNAs, and SNPs) and HCV infection with clinical implications for either progression of fibrosis or treatment response. Recent findings on the IL-28B polymorphism and its application in clinical practice will also be discussed.