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IL28B polymorphisms are associated with severity of liver disease in human immunodeficiency virus (HIV) patients coinfected with hepatitis C virus
Abstract
Objective:
To evaluate the association of IL28B polymorphisms and severity of liver disease among human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients.
Methods:
We carried out a cross-sectional study on 223 patients. Liver biopsies were evaluated according to Metavir score. IL28B polymorphisms (rs12980275, rs8099917, rs7248668, and rs11881222) were genotyped using GoldenGate(®) assay.
Results:
IL28B polymorphisms were in strong linkage disequilibrium, especially the couples rs12980275/rs11881222 and rs8099917/rs7248668. For all patients, the rs12980275 A allele increased the odds for significant fibrosis (F ≥ 2) odds ratio (OR) = 1.68; p = 0.018) and more rapid fibrosis progression (FPR ≥ 0.075 fibrosis units/year) (OR = 1.64; p = 0.035), and decreased the odds for liver steatosis (OR = 0.61; p = 0.046). Furthermore, the rs8099917 T allele increased the odds for F ≥ 2 (OR = 1.93; p = 0.020), FPR ≥ 0.075 (OR = 2.08; p = 0.021), and elevated ALT (≥80 IU/l) (OR = 1.78; p = 0.048). For HCV-genotype 1 patients, rs12980275 A and rs8099917 T alleles decreased the odds for liver steatosis (OR = 0.22; p < 0.001 and OR = 0.39; p = 0.048; respectively). For HCV-genotype 3 patients, the rs12980275 A allele increased the odds for F ≥ 2 ((OR = 6.30; p = 0.012), FPR ≥ 0.075 (OR = 6.40; p = 0.025), and elevated ALT (OR = 4.12; p = 0.037); and the rs8099917 T allele also increased the odds for F ≥ 2 (OR = 7.56; p = 0.027), FPR ≥ 0.075 (OR = 50.8; p = 0.012), and elevated ALT (OR = 5.39; p = 0.043). However, we did not find significant trends in patients infected with HCV-genotype 4.
Conclusion:
The major alleles of IL28B (rs12980275 A, rs11881222 A, rs8099917 T, and rs7248668 G) are associated with increased odds of liver disease severity in HIV patients infected with HCV-genotype 3. In contrast, HCV-genotype 1 patients carrying the major alleles of IL28B polymorphisms had lower odds for liver steatosis.
... The rs12980275 polymorphism is located downstream of the IL28B gene (Fig. 2). Guzmán-Fulgencio, et al. 28 showed that patients with rs12980275 A allele had higher odds of having significant fibrosis (F ≥ 2; OR: 6.3; 1.5-26.4) and higher fibrosis progression (fibrosis progression rate ≥ 0.075 fibrosis units/years; OR: 1.64; 1.03-2.61). ...
... The rs8099917 polymorphism is located upstream of the IFNL4 gene (Fig. 2). Guzmán-Fulgencio, et al. 28 have also found that the rs8099917 T allele was related to higher odds of attaining values of ALT ≥ 80 IU/l (OR: 1.78; 1.01-3.17), significant fibrosis (F ≥ 2; OR: 1.93; 1.11-3.60) ...
The pathogenic mechanisms of the accelerated progression of liver injury in HIV/HCV coinfection are incompletely understood. The progression of liver disease is variable between individuals having similar risk factors, suggesting that genetic background is an important contributor. The aim of this review is to give a summary of all single nucleotide polymorphisms associated with the severity of liver disease in patients coinfected with HIV and HCV reported in the literature. Therefore, a systematic search for articles published was made, 17 of which were selected for this review. In summary, a large number of single nucleotide polymorphisms have been associated with the severity of liver disease in HIV/HCV-coinfected patients. These genes are involved in different biological processes, including seven that correspond to cytokine genes (IFNL3-4, CXCL9-11, IL15, TNF), two to receptor genes (IL7R, TLR8), and three are genes related to metabolism (PNPLA3, FTO, GSTM1). In addition, two combinations of polymorphisms (cirrhosis risk score and mitochondrial haplogroups) have also been related to severity of liver disease in HIV/HCV-coinfected patients. Although determinants other than genetics, such as environmental and viral factors, may be implicated in liver disease progression, information about genetic variation might be useful in clinical practice, allowing prioritization of patients with a genetic background that predispose to a worse evolution of HCV-related liver disease.
... Some postulate no relationship [8] while others found, interestingly, a more rapid progression to fibrosis and cirrhosis in those with the "responder" genotype (that is, the genotype linked with spontaneous clearance and improved treatment response). [9,10] Conversely, other studies found a greater risk of severe fibrosis [11] associated with the nonresponder genotype. Given the role of inflammation in liver fibrosis progression, the high inflammation that persists in co-infected individuals despite HIV treatment, [1] and that IFNL SNPs have been linked with proinflammatory immune responses, it is possible that interferon responses play a role in the natural history of HCV infection and can affect necroinflammation, thereby driving liver fibrosis progression. ...
... Several cross sectional and cohort studies have suggested effect sizes similar to those we observed. In these other studies, the strongest relationships (OR=1.93 with rs8099917T) were those reported in co-infected patients, [10] though odds ratios for rs8099917 from mono-infected populations were also above 1.5. [19] A large study in patients without HIV infection (n=3,129 patients with 1500 fibrotic outcomes) reported that rs12979860CC and rs8099917TT were associated with over 60% increase in risk of fibrosis. ...
Background:
Liver fibrosis progresses faster in HIV-HCV co-infected individuals. Interferon Lambda 3 (IFNL3) protein has both antiviral and pro-inflammatory properties. Genotypes at IFNL SNPs (rs12979860CC, rs8099917TT) are linked to higher HCV clearance, potentially via rs8103142. We examined the relationship between IFNL genotypes and significant liver fibrosis in HIV-HCV co-infection.
Methods:
From the prospective Canadian Co-infection Cohort (n=1423), HCV RNA-positive participants with IFNL genotypes, free of fibrosis, end-stage liver disease and chronic Hepatitis B at baseline (n=485) were included. Time to significant fibrosis (AST-to-platelet ratio index (APRI) ≥1.5) by IFNL genotypes was analyzed using Cox proportional hazards, adjusting for age, sex, ethnicity, alcohol use, CD4 count, HCV genotype, GGT and baseline APRI. Haplotype analysis was performed, adjusting for ethnicity.
Results:
125 participants developed fibrosis over 1595 person-years (7.84/100 person-years, 95% CI: 6.58, 9.34). Each genotype increased fibrosis risk (aHR [95% CI]): rs12979860CC, 1.37 [0.94, 2.02]; rs8103142TT, 1.34 [0.91, 1.97]; rs8099917TT, 1.79 [1.24, 2.57]. Haplotype TCT was also linked with higher risk, 1.14 [0.73, 1.77].
Conclusions:
IFNL SNPs rs12979860, rs8099917 and rs81013142 were individually linked to higher rate of fibrosis in HIV-HCV co-infection. IFNL genotypes may be useful to target HCV treatments to those who are at higher risk of liver disease.
... 17 Another variable affecting liver fibrosis is the IL28B gene, which is similarly known to affect fibrosis progression in both HCV-monoinfected 18 and HIV/HCV-coinfected patients. 19,20 The most common HCV treatment in HCV/HIVcoinfected patients is still a combination of pegylated-interferon alpha plus ribavirin (pegIFNa/RBV), 21 which has a low rate response, a high cost, and numerous side effects. [22][23][24][25] However, the newer directly acting agents for HCV treatment have vastly improved the efficacy over current pegIFNa/RBV therapy, although these new directly acting agents are still costly. ...
... A link between the favorable IL28B genotype and increased odds of liver disease severity has been reported for both HCV-monoinfected patients 38,39 and for HIV/HCVcoinfected patients. 19,20 The IL28B gene encodes IFN-l3, a type III interferon cytokine with antiviral activity against HCV in the liver, via an innate immunity pathway and involving expression of inflammatory cytokines. 40,41 In addition, IL28B is able to modulate adaptive immune responses, promote the Th1 immune pathway, increase T regulatory cells, and increase CD8 T-cell cytotoxicity and memory responses. ...
To assess the ability of the cirrhosis risk score (CRS) to predict liver fibrosis progression in HIV/HCV coinfected patients.
Retrospective follow-up study.
Based on a minimum follow-up time of 10 years with HCV infection, 190 HIV/HCV coinfected patients were classified according to their METAVIR score: i) 25 non-progressor patients who did not develop fibrosis (F0); and ii) 165 progressor patients who developed fibrosis (F≥1). Seven polymorphisms of CRS signature and IL28B genotype were performed using the GoldenGate® assay. The CRS signature was calculated by Naïve Bayes formula as previously described.
Non-progressors had CRS values significantly lower than progressors (0.61 versus 0.67; p=0.043). Among the progressors, we observed similar CRS values through all the fibrosis stages (F1/F2/F3/F4). The percentage of patients with CRS>0.70 (high-risk of developing fibrosis) was higher in progressors than in non-progressors; but the percentages with values between 0.50-0.70 (intermediate risk) and <0.50 (low risk) were quite similar for each of the fibrosis stages (p=0.047). The area under the receiver operating characteristic curve (AUROC) of CRS for discriminating non-progressor versus progressor was 0.625 (p=0.043). When clinical variables were considered (age at HCV infection, IDU, gender, IL28B and HCV genotype), the AUROC of CRS improved up to 0.739 (p<0.001).
CRS itself seems not to be a good marker for identifying HIV/HCV coinfected patients who are at high risk of developing liver fibrosis. However, CRS score coupled with clinical factors might help to distinguish between non-progressors and progressors patients.
... A study showed that patients HIV-HCV coinfected with the rs12980275 A allele had higher fibrosis progression. In addition, considering the HCV genotype, patients infected with HCV-GT3 and with the rs12980275 A allele had higher odds of having values of alanine aminotransferase (ALT) ≥ 80 IU/L and reduced liver steatosis in HCV GT1 patients [154]. ...
Hepatitis C virus (HCV) infection is the main cause of chronic hepatitis, affecting an estimated 150 million people worldwide. Initial exposure to HCV is most often followed by chronic hepatitis, with only a minority of individuals spontaneously clearing the virus. The induction of sustained and broadly directed HCV-specific CD4+ and CD8+ T cell responses, together with neutralizing antibodies (nAb), and specific genetic polymorphism have been associated with spontaneous resolution of the infection. However, due to its high variability, HCV is able to overwhelm the host immune response through the rapid acquisition of mutations in the epitopes targeted by T cells and neutralizing antibodies. In this context, immune-mediated pressure represents the main force in driving HCV evolution. This review summarizes the data on HCV diversity and the current state of knowledge about the contributions of antibodies, T cells, and host genetic polymorphism in driving HCV evolution in vivo.
... The covariables used were gender, age, alcohol intake at biopsy study, BMI, HOMA, nadir CD4+ T-cells, AIDS, undetectable HIV-RNA (< 50 copies/ml), CD4+ T-cells, time on cART, type of cART, HCV-RNA ≥ 500,000 IU/ml, time of HCV infection, and HCV genotype. Besides, we also used data of the PNPLA3 rs738409 polymorphism and the IL28B rs12980275 polymorphism, which have already been published by us and showed significant association with liver fibrosis in HIV/HCV coinfected patients 36,37 . The genetic association study was carried out according to the genetic model that best fit our data (additive, recessive, dominant, codominant, and overdominant). ...
The mechanisms involved in the chronic hepatitis C progression are incompletely understood. The aim was to analyze the association between 2′5′oligoadenylate synthetase 1,2 and 3 (OAS1-3) and myxovirus resistance proteins 1 (Mx1) polymorphisms and severity of liver disease in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfected patients. We performed a cross-sectional study in 219 patients that underwent a liver biopsy. DNA genotyping for Mx1 (rs469390), OAS1 (rs2285934), OAS2 (rs1293762) and OAS3 (rs2010604) was performed by using GoldenGate assay. The outcome variables ion liver biopsy were: (i) significant fibrosis (F ≥ 2); (ii) moderate activity grade (A ≥ 2). Additive model of inheritance for genetic association test was used. The likelihood of having significant fibrosis (F ≥ 2) was lower in patients carrying OAS2 rs1293762 A allele [adjusted odds ratio (aOR) = 0.51; p = 0.040]. Besides, the likelihood of having moderate activity grade (A ≥ 2) was higher in patients carrying Mx1 rs464397 C allele (aOR = 1.63; p = 0.028) and Mx1 rs469390 G allele (aOR = 1.97; p = 0.005), while it was lower in patients carrying OAS1 rs2285934 A allele (aOR = 0.64; p = 0.039) and OAS2 rs1293762 A allele (aOR = 0.41; p = 0.009). In conclusion, Mx1 and OAS1-2 polymorphisms were associated with the severity of liver disease in HIV/HCV-coinfected patients, suggesting a significant role in the progression of hepatic fibrosis.
... However, rs10833 polymorphisms could exert its effect by altering NK and CD8+ T-cells function; IL28B polymorphisms have demonstrated to have effect on SVR independent of NK cells phenotype and function, as described by Oliviero et al. (28). Besides, IL28B SNPs have been linked to both SVR achievement (favourable event) as well as progression of liver injury (unfavourable event) in HIV-/HCV-co-infected patients (9,29,30). In this setting, although the mechanism of action is not probably the same, similar effects have been observed for IL15 rs10833 AA genotype. ...
Background & aims:
IL15 is an essential cytokine in both innate and adaptive immune response against HCV infection. The aim was to analyze whether IL15 rs10833 is associated with liver disease severity and response to pegylated-interferon-alpha plus ribavirin (pegIFN-alpha/RBV) therapy in human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients.
Methods:
A retrospective study was performed in 315 patients who started pegIFN-alpha/RBV therapy. Liver fibrosis stage was characterized in 286 patients. IL15 rs10833 and IL28B rs12980275 were genotyped by GoldenGate.The primary outcomes were: a) advanced liver fibrosis evaluated by liver biopsy (F3-F4) or transient elastography (liver stiffness values ≥9.5 Kpa); b) sustained virological response (SVR). The secondary outcome variable was the levels of serum biomarkers of inflammation.
Results:
Patients with rs10833 AA genotype had increased odds of having advanced fibrosis (adjusted odds ratio (aOR)=2.30; p=0.019), particularly in males (aOR=2.24; p=0.040), patients with HCV-RNA <500,000 IU/mL (aOR=5.14; p=0.018) and patients with IL28B rs12980275 AG/GG genotypes (aOR=2.51; p=0.046). Moreover, rs10833 AA genotype was significantly associated with higher levels of HGF (adjusted arithmetic mean ratio (aAMR)=1.50; p=0.016), sICAM-1 (aAMR=1.57; p=0.025) and sVCAM-1 (aAMR=1.56; p=0.007). Finally, patients with rs10833 AA genotype had increased odds of achieving SVR (aOR=3.12; p=0.006), particularly in males (aOR=3.69; p=0.005), GT1/4 patients (aOR=3.59; p=0.006), patients with advanced fibrosis (aOR=4.64; p=0.021), HCV-RNA ≥500,000 IU/mL (aOR=3.92; p=0.007) and patients with IL28B rs12980275 AG/GG genotype (aOR=2.98; p=0.041).
Conclusions:
The presence of IL15 rs10833 AA genotype in HIV/HCV-coinfected patients was associated with advanced liver fibrosis, inflammation-related biomarkers and increased rates of SVR to pegIFN-alpha/RBV therapy. This article is protected by copyright. All rights reserved.
... However, studies investigating the role of endocrine and metabolic factors have not conclusively answered the question whether these conditions promote, or are rather a consequence of, liver disease progression. Similar to HCV monoinfection, viral (HCV-GT3 [21]), genetic (interleukin 28B (IL28B) [31] and patatin-like phospholipase domain-containing protein 3 (PNPLA3) [21]) and alcohol accelerate liver disease progression. All these factors are associated with liver steatosis, which has been observed in up to 77 % of HIV/HCV-coinfected patients [32]. ...
HCV coinfection has emerged as a major cause of non-AIDS-related morbidity and mortality in HIV-positive patients. As a consequence of the availability of modern combined antiretroviral therapy regimens, for optimally managed HIV/HCV-coinfected patients, the rates of liver fibrosis progression and the risk of liver-related events are increasingly similar to those of HCV-monoinfected patients. Moreover, our understanding of modulators of liver disease progression has greatly improved. In addition to immune status, endocrine, metabolic, genetic and viral factors are closely interrelated and might be important determinants of liver disease progression. In the last decade, a variety of serologic and radiographic tests for noninvasive liver disease staging have been extensively validated and are commonly used in HIV/HCV-coinfected patients. Sustained virologic response prevents end-stage liver disease, hepatocellular carcinoma, and death, with an even greater effect size in HIV-positive compared to HIV-negative patients. As interferon-free regimens achieve comparable rates of sustained virologic response in HIV-negative and HIV-positive patients, HIV/HCV-coinfected patients should from now on be referred to as a special, rather than a difficult-to-treat, population. Our comprehensive review covers all relevant aspects of HIV/HCV coinfection. Beginning with the changing epidemiology, it also provides new insights into the natural history of this condition and gives an overview on non-invasive techniques for the staging of liver disease. Furthermore, it outlines current recommendations for the treatment of acute hepatitis C and summarizes the unprecedented advances in the field of chronic hepatitis C therapy.
... In the current study, we found little evidence that rs12979860 was associated with liver-related mortality, but we did observe a lower risk of liver-related death in women with the rs12980275 GG genotype, with the GG genotype being most common in African Americans (30%). Interestingly, the A allele of this SNP has been shown to increase the odds of rapid fibrosis progression in the setting of HIV/HCV coinfection [20]. The minor G allele of rs809917 has been shown to protect against HCV-related fibrosis progression in two studies [21,22], although a third found no association [18]. ...
African Americans coinfected with HIV and hepatitis C virus (HCV) have lower liver-related mortality than Caucasians and Hispanics. While genetic polymorphisms near the IFNL3 and IFNL4 genes explain a significant fraction of racial differences in several HCV-related outcomes, the impact of these variants on liver-related mortality has not been investigated. We conducted a cohort study of HIV/HCV-coinfected women followed in the multicentre, NIH-funded Women's Interagency HIV Study (WIHS) to investigate whether 10 polymorphisms spanning the IFN-λ region were associated with liver-related mortality by dominant, recessive or additive genetic models. We also considered whether these polymorphisms contributed to previously reported differences in liver-related death by race/ethnicity (ascertained by self-report and ancestry informative markers). Among 794 coinfected women, there were 471 deaths including 55 liver-related deaths during up to 18 years of follow-up. On adjusted analysis, rs12980275 GG genotype compared to AG+AA hazards ratios [(HR) 0.36, 95% CI 0.14-0.90, P = 0.029] and rs8109886 AA genotype compared to CC+AC (HR 0.67, 95% CI 0.45-0.99, P = 0.047) were most strongly associated with liver-related death although these associations were no longer significant after adjusting for race/ethnicity (HR 0.41, 95% CI 0.16-1.04, P = 0.060 and HR 0.78, 95% CI 0.51-1.19, P = 0.25, respectively). African American women had persistently lower liver-related death independent of IFN-λ variants (HRs ≤ 0.44, P values ≤ 0.04). The lower risk of death among African American HIV/HCV-coinfected women is not explained by genetic variation in the IFN-λ region suggesting, that other genetic, behavioural and/or environmental factors may contribute to racial/ethnic differences in liver-related mortality.
© 2015 John Wiley & Sons Ltd.
... While the IL28B C/C genotype is an important predictor of response to HCV treatment in HIV/ HCV-coinfected patients (47,50,63), the evidence for an association of this favourable genotype with liver fibrosis is limited in the setting of HIV/HCV coinfection (37). In our study, IL28B C/C genotype was not associated with highFPR. ...
Background & AimsTo perform a comprehensive study on independent modulators of liver fibrosis progression and determinants of portal pressure considering immune status, insulin resistance (IR), serum 25-hydroxyvitamin D (25(OH)D) levels, genetic variants of patatin-like phospholipase domain-containing protein 3 (PNPLA3) and interleukin 28B (IL28B) in a thoroughly documented cohort of HIV/hepatitis C-coinfected (HIV/HCV) patients.Patients & Methods25(OH)D deficiency (25(OH)DDEF), IR and low CD4+ T-lymphocyte nadir (lowCD4NAD) were defined as 25(OH)D <20 ng × ml−1, HOMA-IR >2 and CD4nadir <200 cells × μl−1 respectively. Liver fibrosis progression rate (FPR) was calculated as METAVIR F units divided by the number of years since HCV infection. Patients with a FPR > median FPR were assigned to the highFPR group.ResultsAmong 86 HIV/HCV, the median FPR was 0.167 units × years−1. While the prevalence of prior alcohol abuse, lowCD4NAD and 25(OH)DDEF was higher among highFPR patients, the prevalence of IR was comparable. The association between 25(OH)DDEF and FPR was confirmed in a subgroup of patients with METAVIR stage F0/F1/F2 in which 25(OH)D levels are not affected by the severity of liver disease. The distribution of IL28B C/C and PNPLA3 non-C/C was similar, while PNPLA3 G/G was exclusively observed in highFPR patients. LowCD4NAD (OR: 2.95; 95% CI: 1.05-8.24; P = 0.039) and 25(OH)DDEF (OR: 5.62; 95% CI: 2.05-15.38; P = 0.001) were independently associated with highFPR and showed an additive effect. Portal pressure correlated with prior alcohol abuse, HCV-genotype 3, CD4+ nadir and 25(OH)D levels.Conclusions
Two potentially modifiable factors, CD4+ nadir and 25(OH)D levels, were both independent modulators of liver fibrosis progression and determinants of portal pressure. Further studies are warranted to assess the relevance of PNPLA3 for FPR in HIV/HCV.
Risk and progression of liver fibrosis and cirrhosis in chronic hepatitis C (CHC) patients is significantly influenced by host genetic factors in a polygenic manner. The rs12979860 genetic polymorphism in the interferon-λ3–interferon-λ4 (IFNL3-IFNL4) region has been found to be a major determinant of hepatic inflammatory and fibrotic progression in CHC patients of mainly Caucasian origin; however, it is not known if this association applies to other ethnicities, including Pakistani CHC patients. Here, we genotyped IFNL3-IFNL4 rs12979860 genetic variants in a sample set of 502 Pakistani patients with CHC and used logistic regression analysis to determine its association with the risk and progression of HCV-related fibrosis and cirrhosis. We demonstrate that the rs12979860 major (CC) genotype, despite not determining the risk of stage-specific hepatic fibrosis independently, is associated with a marginally significant risk of liver cirrhosis (OR: 1.64, p = 0.049) after an adjustment for age, gender, body mass index, HCV viral load, and liver enzymes. In a subgroup of CHC patients with sustained ALT levels of <60 IU/L, a more pronounced impact of the IFNL3-IFNL4 rs12979860 major (CC) genotype on advanced liver fibrosis (OR: 4.99, p = 0.017) and cirrhosis (OR: 3.34, p = 0.005) was seen. The present study suggests that IFNL3-IFNL4 rs12979860 polymorphism may also be a significant predictor of hepatic fibrosis and cirrhosis in Pakistani CHC patients, especially in those with normal or near-normal liver enzyme levels.
Fibrosis is a highly conserved and coordinated wound healing response to injury. In the liver, injury is promoted by immune effector mechanisms that are common across various disease etiologies and even between organs such as lungs, kidneys, heart, and other organs. Thus, the liver represents a useful model to study inflammation and repair, particularly as it is frequently biopsied in clinical contexts. Currently, strong evidence implicates IFNL3/4 polymorphisms and interferon (IFN)-λ3 levels as determinants of the extent of hepatic inflammation and fibrosis in viral and nonviral liver diseases, as well as in governing the severity of nonhepatotropic viral diseases. Interestingly, IFNL3/4 polymorphisms and IFN-λ3 levels correlate with fibrosis extent in other organs such as the lung and kidney. In this review, we discuss the association between IFN-λ and tissue inflammation and fibrosis in human disease and the potential clinical utility of the findings.
Introduction: Type-III interferons (IFN-λ), the most recently discovered family of IFNs, shares common features with other family members, but also has many distinctive activities. IFN-λ uniquely has a different receptor complex, and a more focused pattern of tissue expression and signaling effects, from other classes of IFNs. Multiple genome-wide association studies (GWAS) and subsequent validation reports suggest a pivotal role for polymorphisms near the IFNL3 gene in hepatitis C clearance and control, as also for several other epithelial cell tropic viruses. Apart from its antiviral activity, IFN-λ possesses anti-tumor, immune-inflammatory and homeostatic functions. The overlapping effects of IFN-λ with type I IFN, with a restricted tissue expression pattern renders IFN-λ an attractive therapeutic target for viral infection, cancer and autoimmune diseases, with limited side effects.
Areas covered: This review will summarize the current and future therapeutic opportunities offered by this most recently discovered family of interferons.
Expert opinion: Our knowledge on IFN-λ is rapidly expanding. Though there are many remaining questions and challenges that require elucidation, the unique characteristics of IFN-λ increases enthusiasm that multiple therapeutic options will emerge.
Utilizing genome-wide association studies (GWASs) to examine the variation in hepatitis C virus (HCV) phenotypes has led to quantum improvements in our understanding of both the genetic basis and the underlying pathogenesis of HCV infection. In this context, the discovery of interferon lambda polymorphisms is unique with far reaching implications that extend well beyond HCV to various other liver and extrahepatic diseases. In this review, we summarize the data on the impact of GWASs on our understanding of HCV disease.
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Hepatitis C virus (HCV) infection is associated with insulin resistance (IR), although mechanisms leading to IR in these patients are not completely understood. The aim of this study was to evaluate the association of interleukin 28B (IL28B) and interleukin 28 receptor alpha (IL28RA) polymorphisms with IR among human immunodeficiency virus (HIV)/HCV-coinfected patients. We carried out a cross-sectional study on 203 patients. IL28B (rs8099917) and IL28RA (rs10903035) polymorphisms were genotyped by GoldenGate(®) assay. IR was defined as homeostatic model assessment (HOMA) values ≥3.00. Univariate and multivariate generalized linear models (GLM) were used to compare HOMA values and the percentage of patients with IR according to IL28B and IL28RA genotypes. In total, 32% (n = 65/203) of the patients had IR. IL28B rs8099917 TT was not significantly associated with HOMA values and IR. In contrast, rs10903035 AA was significantly associated with high HOMA values taking into account all patients (P = 0.024), as well as the subgroups of patients with significant fibrosis (P = 0.047) and infected with HCV genotype 3 (P = 0.024). Additionally, rs10903035 AA was significantly associated with IR (HOMA ≥3.00) in all patients (adjusted odds ratio (aOR) = 2.02; P = 0.034), in patients with significant fibrosis (aOR = 2.86; P = 0.039) and HCV genotype 3 patients (aOR = 4.89; P = 0.031). In conclusions, IL28RA polymorphism (rs10903035) seems to be implicated in the glucose homeostasis because AA genotype increases the likelihood of IR, but this association was different depending on hepatic fibrosis and HCV genotype.
Genetic polymorphisms near IL28B are associated with spontaneous and treatment-induced clearance of hepatitis C virus (HCV), two processes that require the appropriate activation of the host immune responses. Intrahepatic inflammation is believed to mirror such activation, but its relationship with IL28B polymorphisms has yet to be fully appreciated. We analyzed the association of IL28B polymorphisms with histological and follow-up features in 2335 chronically HCV-infected Caucasian patients. Assessable phenotypes before any antiviral treatment included necroinflammatory activity (n = 1,098), fibrosis (n = 1,527), fibrosis progression rate (n = 1,312), and hepatocellular carcinoma development (n = 1,915). Associations of alleles with the phenotypes were evaluated by univariate analysis and multivariate logistic regression, accounting for all relevant covariates. The rare G allele at IL28B marker rs8099917-previously shown to be at risk of treatment failure-was associated with lower activity (P = 0.04), lower fibrosis (P = 0.02) with a trend toward lower fibrosis progression rate (P = 0.06). When stratified according to HCV genotype, most significant associations were observed in patients infected with non-1 genotypes (P = 0.003 for activity, P = 0.001 for fibrosis, and P = 0.02 for fibrosis progression rate), where the odds ratio of having necroinflammation or rapid fibrosis progression for patients with IL28B genotypes TG or GG versus TT were 0.48 (95% confidence intervals 0.30-0.78) and 0.56 (0.35-0.92), respectively. IL28B polymorphisms were not predictive of the development of hepatocellular carcinoma. Conclusion: In chronic hepatitis C, IL28B variants associated with poor response to interferon therapy may predict slower fibrosis progression, especially in patients infected with non-1 HCV genotypes. (HEPATOLOGY 2012).
Copyright © 2011 American Association for the Study of Liver Diseases.
Unlabelled:
Polymorphisms in the interleukin-28B (IL28B) region are associated with spontaneous and treatment-induced viral clearance in hepatitis C virus (HCV) infection. Nevertheless, it is unknown whether genetic variation at the IL28B locus influences the natural history of chronic HCV infection. Thus, we asked whether an association between IL28B polymorphisms and liver fibrosis progression existed. We studied 247 consecutive patients with chronic HCV, an accurate estimate of the date of infection, and a liver biopsy performed before any treatment. No patient had a history of alcohol abuse or coinfection with other viruses. We assessed the role of rs8099917 and rs12979860 polymorphisms and the effect of host and environmental factors on fibrosis progression. Blood transfusion (75%) was the main modality of infection. Median age at infection was 21 years, and median interval between infection and liver biopsy was 25 years. One hundred twenty-nine patients (52%) were infected by HCV-1, 74 (30%) by HCV-2, 34 (14%) by HCV-3, and 10 (4%) by HCV-4. Bridging fibrosis/cirrhosis (Ishak ≥ 4) was detected in 24% of patients. Age at infection had a marked effect on fibrosis progression by both a linear model and Cox proportional-hazard regression (P < 2E-16). A 12.1% increase in the hazard of advanced fibrosis was estimated for each additional year at infection, suggesting that this was the major explanatory variable in this cohort. Male gender (P < 0.05), HCV genotype 3 (P < 0.001) and steatosis (P < 0.05) were also associated with faster fibrosis progression. Conversely, the two IL28B polymorphisms had no impact on fibrosis progression.
Conclusion:
In HCV patients with a known date of infection, IL28B genotype was not associated with fibrosis progression rate or with the risk of developing advanced liver fibrosis.
Polymorphism at the IL28B gene may modify the course of hepatitis C virus (HCV) chronic infection. Our aim was to study the influence of IL28B rs12979860 gene polymorphism on the biochemistry and pathology of HCV-induced disease in the clinical course from mild chronic hepatitis C to hepatocellular carcinoma.
We have determined the rs12979860 single nucleotide polymorphism (SNP) upstream IL28B gene in two groups of patients with HCV-induced chronic liver disease: 1) 268 patients (159 men) with biopsy-proven chronic hepatitis C, to analyse its relation with biochemical, virological and histological features; and 2) 134 patients (97 men) with HCV-related hepatocellular carcinoma. The distribution of the analysed SNP in hepatocellular carcinoma patients was compared with that found in untreated chronic hepatitis C patients. All patients were white and most were Spaniards.
In multivariate analysis ALT values were higher (P = 0.001) and GGT values were lower (P<0.001) in chronic hepatitis C patients homozygotes for the major rs12979860C allele as compared with carriers of the mutated rs12979860T allele. Steatosis was more frequent (Odds ratio = 1.764, 95% C.I. 1.053-2.955) and severe (P = 0.026) in carriers of the rs12979860T allele. No relation was found between the analysed SNP and METAVIR scores for necroinflammation and fibrosis, and there were no differences in the distribution of the analysed SNP between hepatocellular carcinoma and untreated chronic hepatitis C patients.
The IL28B rs12979860 polymorphism correlates with the biochemical activity and the presence and severity of liver steatosis in chronic hepatitis C.
Single-nucleotide polymorphisms (SNPs) in the IL28B and PNPLA3 gene regions have been associated with hepatic steatosis in genotype 1 (G1) chronic HCV infection but their clinical impacts remain to be determined.
We sought to validate these associations and to explore their impact on treatment response to peginterferon and ribavirin therapy.
A total of 972 G1 HCV-infected Caucasian patients were genotyped for the SNPs rs12979860 (IL28B) and rs2896019 (PNPLA3). Multivariable analysis tested IL28B and PNPLA3 for association with the presence of any steatosis (>0 %); clinically significant steatosis (>5 %); steatosis severity (grade 0-3/4); and the interacting associations of the SNPs and hepatic steatosis to sustained viral response (SVR).
IL28B and PNPLA3 polymorphisms were associated with the presence of any steatosis (rs12979860, p = 1.87 × 10(-7); rs2896019, p = 7.56 × 10(-4)); clinically significant steatosis (rs12979860, p = 1.82 × 10(-3); rs2896019, p = 1.27 × 10(-4)); and steatosis severity (rs12979860, p = 2.05 × 10(-8); rs2896019, p = 2.62 × 10(-6)). Obesity, hypertriglyceridemia, hyperglycemia, liver fibrosis, and liver inflammation were all independently associated with worse steatosis. Hepatic steatosis was associated with lower SVR, and this effect was attenuated by IL28B. PNPLA3 had no independent association with SVR.
IL28B and PNPLA3 are associated with hepatic steatosis prevalence and severity in Caucasians with G1 HCV, suggesting differing potential genetic risk pathways to steatosis. IL28B attenuates the association between steatosis and SVR. Remediable metabolic risk factors remain important, independently of these polymorphisms, and remain key therapeutic goals to achieve better outcomes for patients with HCV-associated hepatic steatosis.
Several single nucleotide polymorphisms (SNPs) within the interleukin 28B (IL28B) locus are associated with sustained viral response in chronic hepatitis C (HCV) patients who were treated with pegylated interferon (PEG-IFN) plus ribavirin (RBV) combination therapy. Recently, an association between γ-GTP level and IL28B genotype was identified. In this study, the relationship between IL28B genotype and liver steatosis was analyzed.
One hundred fifty-three patients who underwent liver biopsy before PEG-IFN plus RBV combination therapy were enrolled. The level of liver steatosis was measured using a BIOREVO BZ-9000 microscope, and the proportion of fatty change and clear cell change were calculated using Dynamic cell count BZ-H1C software. IL28B SNP genotype (rs8099917) was determined using the Invader Assay.
Vesicular change was significantly associated with body mass index (BMI), HCV RNA titer, serum aspartate aminotransferase, γ-GTP, IL28B genotype and liver fibrosis level (P < 0.05). Clear cell change was significantly associated with serum aspartate aminotransferase, γ-GTP and IL28B genotype by univariate logistic regression analysis (P < 0.05). Under multiple logistic regression, IL28B genotype (OR(adj) = 8.158; 95% CI 2.412-27.589), liver fibrosis (OR(adj) = 2.541; 95% CI 1.040-6.207) and BMI (OR(adj) = 1.147; 95% CI 1.011-1.301) were significant independent factors for vesicular change and IL28B genotype (OR(adj) = 3.000; 95% CI 1.282-7.019) for clear cell change.
In this study, a new quantitative method to objectively evaluate hepatic steatosis was described. IL28B genotypes were significantly associated with both vesicular and clear cell changes of livers in chronic hepatitis C patients.
Recently, several genome-wide association studies have revealed that single nucleotide polymorphisms (SNPs) in proximity to IL28B predict spontaneous clearance of HCV infection as well as outcome following peginterferon and ribavirin therapy among HCV genotype 1 infected patients. The present study aimed to evaluate the impact of IL28B SNP variability on liver histology in the context of a phase III treatment trial (NORDynamIC) for treatment-naïve patients with chronic HCV genotype 2 or 3 infection, where pretreatment liver biopsies were mandatory.
Three hundred and thirty-nine Caucasian patients had samples available for IL28B genotyping (rs12979860) of whom 314 had pretreatment liver biopsies that were evaluated using the Ishak protocol, allowing for detailed grading and staging of liver histopathology.
IL28B CC(rs12979860) genotype in HCV genotype 3 infected patients was associated with higher ALT levels (p<0.0001), higher AST to platelet ratio index (APRI; p = 0.001), and higher baseline viral load (p<0.0001) as compared to patients with the CT or TT genotypes. Additionally the CC(rs12979860) genotype entailed more pronounced portal inflammation (p = 0.02) and steatosis (p = 0.03). None of these associations were noted among HCV genotype 2 infected patients.
This study shows that the CC(rs12979860) SNP is associated with more pronounced liver histopathology in patients chronically infected with HCV genotype 3, which may be secondary to higher viral load. The finding that IL28B variability did not impact on liver pathology or viral load among genotype 2 infected patients implies that IL28B may differentially regulate the course of genotype 2 and 3 infection.
Polymorphisms in the IL28B gene have been associated with clearance of hepatitis C virus (HCV), indicating a role for type III interferons (IFNs) in HCV infection. Little is known about the function of type III IFNs in intrinsic antiviral innate immunity.
We used in vivo and in vitro models to characterize the role of the type III IFNs in HCV infection and analyzed gene expression in liver biopsy samples from HCV-infected chimpanzees and patients. Messenger RNA and protein expression were studied in HCV-infected hepatoma cell lines and primary human hepatocytes.
HCV infection of primary human hepatocytes induced production of chemokines and type III IFNs, including interleukin (IL)-28, and led to expression of IFN-stimulated genes (ISGs). Chimpanzees infected with HCV showed rapid induction of hepatic type III IFN, associated with up-regulation of ISGs and minimal induction of type I IFNs. In liver biopsy specimens from HCV-infected patients, hepatic expression of IL-28 correlated with levels of ISGs but not of type I IFNs. HCV infection produced extensive changes with gene expression in addition to ISGs in primary human hepatocytes. The induction of type III IFNs is regulated by IFN regulatory factor 3 and nuclear factor κB. Type III IFNs up-regulate ISGs with a different kinetic profile than type 1 IFNs and induce a distinct set of genes, which might account for their functional differences.
HCV infection results predominantly in induction of type III IFNs in livers of humans and chimpanzees; the level of induction correlates with hepatic levels of ISGs. These findings might account for the association among IL-28, level of ISGs, and recovery from HCV infection and provide a therapeutic strategy for patients who do not respond to IFN therapy.
Single-nucleotide polymorphisms (SNPs) near the IL28B gene have recently been associated with spontaneous hepatitis C virus (HCV) clearance and response to interferon-based therapies in patients with chronic hepatitis C. Because human immunodeficiency virus (HIV) coinfection appears to accelerate HCV-related liver fibrosis progression, any influence of IL28B SNP on the risk of developing cirrhosis might be more easily recognized in the coinfected population.
All HIV-HCV-coinfected patients who underwent hepatic elastography before initiating a course of pegylated interferon plus ribavirin therapy at 2 Spanish clinics were retrospectively identified. Liver cirrhosis was defined as >14.5 kPa by transient elastography. The IL28B rs12979860 SNP was examined in a blinded fashion.
A total of 304 HIV-HCV-coinfected individuals were analyzed (mean age, 43 years; 80% were male; and 85% were receiving antiretroviral therapy), of whom 18% had cirrhosis. IL28B genotype distribution was as follows: CC, 46%; CT, 43%; and TT, 11%. Cirrhosis was more frequent in CC than CT/TT carriers (24% vs 13%; P = .01). Logistic regression analysis revealed that older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 0.99-1.12]; P = .08), past alcohol abuse (OR, 1.97; 95% CI, 0.95-4.06; P = .07), and CC IL28B genotype (OR, 2.32; 95% CI, 1.22-4.41; P = .01) were predictors of cirrhosis. Interestingly, mean (SD) alanine aminotransferase (ALT) levels were greater (90 ± 53 vs 71 ± 33 IU/L;, P = .01) in IL28B CC than CT/TT carriers during the prior 4.8 ± 3.8 years.
The IL28B rs12979860 CC genotype is associated with a higher prevalence of cirrhosis in HIV-HCV-coinfected patients than CT/TT genotypes, suggesting that IL28B CC carriers may experience a more rapid progression of HCV-related liver fibrosis, perhaps as result of increased liver inflammation. Thus, access to HCV treatment is of utmost importance in IL28B CC carriers, in whom treatment response is better and in whom progression to cirrhosis might occur more rapidly.
For two decades the scientific community has sought to understand why some people clear hepatitis C virus (HCV) and others do not. Recently, several large genome-wide association studies have identified single nucleotide polymorphisms (SNPs) linked to interferon lambda 3 (IFNλ3) that are associated with the spontaneous resolution and successful treatment of HCV infection. These observations are generating intense research activity; the hope is that IFNλ3 genetic variants may serve as important predictive biomarkers of treatment outcome and offer new insights into the biological pathways involved in viral control. A pharmacogenomic treatment approach for HCV can now be envisaged, with the incorporation of host genetic variants into a predictive treatment algorithm with other factors. The SNPs associated with the clinical outcome of HCV infection are located some distance from the IFNλ3 gene itself, and causal genetic variants have yet to be clearly defined. Locating these causal variants, mapping in detail the IFNλ3 signalling pathways and determining the downstream genetic signature so induced will clarify the role of IFNλ3 in the pathogenesis of HCV. Clinical studies assessing safety and efficacy in the treatment of HCV with exogenous IFNλ3 are currently underway. Early results suggest that IFNλ3 treatment inhibits HCV replication and is associated with a limited side effect profile. However, hepatotoxicity in both healthy volunteers and HCV-infected patients has been described. This review discusses the genetic studies that link IFNλ3 to both the spontaneous resolution and treatment-induced clearance of HCV and the potential impact of this in clinical practice, the biology of IFNλ3 as currently understood and how this may impact on HCV infection, and describes the early studies that assess the role of this cytokine in the treatment of patients with HCV.
Hepatitis C virus (HCV) infects 3% of the world's population. Treatment of chronic HCV consists of a combination of PEGylated interferon-alpha (PEG-IFN-alpha) and ribavirin (RBV). To identify genetic variants associated with HCV treatment response, we conducted a genome-wide association study of sustained virological response (SVR) to PEG-IFN-alpha/RBV combination therapy in 293 Australian individuals with genotype 1 chronic hepatitis C, with validation in an independent replication cohort consisting of 555 individuals. We report an association to SVR within the gene region encoding interleukin 28B (IL28B, also called IFNlambda3; rs8099917 combined P = 9.25 x 10(-9), OR = 1.98, 95% CI = 1.57-2.52). IL28B contributes to viral resistance and is known to be upregulated by interferons and by RNA virus infection. These data suggest that host genetics may be useful for the prediction of drug response, and they also support the investigation of the role of IL28B in the treatment of HCV and in other diseases treated with IFN-alpha.
Chronic infection with hepatitis C virus (HCV) affects 170 million people worldwide and is the leading cause of cirrhosis in North America. Although the recommended treatment for chronic infection involves a 48-week course of peginterferon-alpha-2b (PegIFN-alpha-2b) or -alpha-2a (PegIFN-alpha-2a) combined with ribavirin (RBV), it is well known that many patients will not be cured by treatment, and that patients of European ancestry have a significantly higher probability of being cured than patients of African ancestry. In addition to limited efficacy, treatment is often poorly tolerated because of side effects that prevent some patients from completing therapy. For these reasons, identification of the determinants of response to treatment is a high priority. Here we report that a genetic polymorphism near the IL28B gene, encoding interferon-lambda-3 (IFN-lambda-3), is associated with an approximately twofold change in response to treatment, both among patients of European ancestry (P = 1.06 x 10(-25)) and African-Americans (P = 2.06 x 10(-3)). Because the genotype leading to better response is in substantially greater frequency in European than African populations, this genetic polymorphism also explains approximately half of the difference in response rates between African-Americans and patients of European ancestry.
Hepatic steatosis occurs in 40-70% of patients chronically infected with hepatitis C virus [chronic hepatitis C (CH-C)]. Hepatic steatosis in CH-C is associated with progressive liver disease and a low response rate to antiviral therapy.
Gene expression profiles were examined in CH-C patients with and without hepatic steatosis, non-alcoholic steatohepatitis (NASH) and fibrosis.
This study included 65 CH-C patients who were not receiving antiviral treatment. Total RNA was extracted from peripheral blood mononuclear cells, quantified and used for one-step reverse transcriptase-polymerase chain reaction to profile 153 mRNAs that were normalized with six 'housekeeping' genes and a reference RNA. Multiple regression and stepwise selection assessed differences in gene expression and the models' performances were evaluated.
Models predicting the grade of hepatic steatosis in patients with CH-C genotype 3 involved two genes: SOCS1 and IFITM1, which progressively changed their expression level with the increasing grade of steatosis. On the other hand, models predicting hepatic steatosis in non-genotype 3 patients highlighted MIP-1 cytokine encoding genes: CCL3 and CCL4 as well as IFNAR and PRKRIR. Expression levels of PRKRIR and SMAD3 differentiated patients with and without superimposed NASH only in the non-genotype 3 cohort (area under the receiver operating characteristic curve=0.822, P-value 0.006]. Gene expression signatures related to hepatic fibrosis were not genotype specific.
Gene expression might predict moderate to severe hepatic steatosis, NASH and fibrosis in patients with CH-C, providing potential insights into the pathogenesis of hepatic steatosis and fibrosis in these patients.
To compare the response to hepatitis C virus (HCV) therapy among human immunodeficiency virus (HIV)/HCV co-infected patients receiving a nucleos(t)ide reverse transcriptase inhibitor [N(t)RTI] backbone consisting of abacavir plus lamivudine with that observed in subjects who receive tenofovir plus lamivudine or emtricitabine.
A total of 256 subjects, enrolled in a cohort of 948 HIV-infected patients who received pegylated interferon and ribavirin from October 2001 to January 2006, were included in this study. All patients were taking one protease inhibitor or one non-nucleoside reverse transcriptase inhibitor and abacavir plus lamivudine or tenofovir plus lamivudine or emtricitabine as N(t)RTI backbone during HCV therapy. Sustained virological response (SVR) rates in both backbone groups were compared.
In an intention-to-treat analysis, 20 out of 70 (29%) individuals under abacavir and 83 out of 186 (45%) under tenofovir showed SVR (P = 0.02). N(t)RTI backbone containing tenofovir was an independent predictor of SVR in the multivariate analysis [adjusted odds ratio (95% CI), 2.6 (1.05-6.9); P = 0.03]. The association between abacavir use and lower SVR was chiefly seen in patients with plasma HCV-RNA load higher than 600 000 IU/mL and genotype 1 or 4. Among patients treated with ribavirin dose <13.2 mg/kg/day, 3 (20%) of those under abacavir versus 22 (52%) under tenofovir reached SVR (P = 0.03), whereas the rates were 31% and 38% (P = 0.4), respectively, in those receiving >/=13.2 mg/kg/day.
HIV-infected patients who receive abacavir plus lamivudine respond worse to pegylated interferon plus ribavirin than those who are given tenofovir plus lamivudine or emtricitabine as N(t)RTI backbone, especially in those receiving lower ribavirin doses.
To estimate stage-specific transition probabilities in individuals coinfected with HIV and hepatitis C virus (HCV), to examine the effect of covariates on these rates, and to investigate the effect of HIV on HCV-related cirrhosis in the era of highly active antiretroviral therapy (HAART).
Systematic review of natural history studies among HCV-infected individuals.
Markov maximum likelihood estimation method was used to estimate stage-specific transition probabilities. A meta-analysis was performed to obtain pooled transition probabilities, and a meta-regression to investigate the impact of covariates on these rates. Risk of cirrhosis between individuals monoinfected with HCV and coinfected with HIV/HCV were compared by HAART status.
The estimated mean (95% confidence intervals) annual transition probabilities of 3567 individuals coinfected with HIV/HCV (n = 17 studies) were as follows: fibrosis stage (F) F0 --> F1 0.122 (0.098-0.153); F1 --> F2 0.115 (0.095-0.140); F2 --> F3 0.124 (0.097-0.159); and F3 --> F4 0.115 (0.098-0.135) units/year. The prevalence of cirrhosis after 20 and 30 years of HCV infection was 21% (16-28%) and 49% (40-59%), respectively. Longer duration of HCV infection was significantly associated with slower rate of fibrosis progression. The overall rate ratio of cirrhosis between individuals coinfected with HIV/HCV and monoinfected with HCV (n = 27 studies) was 2.1 (1.5-3.0), 2.5 (1.8-3.4) in the non-HAART group, and 1.7 (1.1-2.8) in the HAART group.
The rate of fibrosis progression among individuals coinfected with HIV/HCV appears constant. Our results confirm that chronic hepatitis C outcomes are worse among coinfected individuals. Over the period studied, HAART did not appear to fully correct the adverse effect of HIV infection on HCV prognosis.
Insulin resistance is a frequent feature of chronic hepatitis C. Whether insulin resistance could be the cause or consequence of steatosis and fibrosis is unknown. The ability of HCV genotype 3 to promote steatosis by itself provides an unique opportunity to answer this question.
The aim of the present study was to assess the relationships between insulin resistance, steatosis, and fibrosis according to genotype in 141 non-diabetic patients with biopsy proven non-cirrhotic chronic hepatitis C.
All patients had fasting serum glycaemia and insulinaemia measurements. Insulin resistance was evaluated using the homeostasis model assessment (HOMA IR) method. Liver steatosis was determined according to hepatitis C virus genotype (1 or 3). Logistic regression and multivariate regression analysis were used to identify variables independently associated with insulin resistance, fatty liver, and fibrosis.
Although steatosis and fibrosis were more severe in genotype 3 patients, median HOMA IR was significantly higher in patients with genotype 1 related steatosis than in those with genotype 3 related steatosis (2.1 v 1; p = 0.001). Independent risk factors for steatosis were insulin resistance in genotype 1 patients (p = 0.001) and viral load in genotype 3 patients (p = 0.003). Among genotype 1 patients, independent parameters associated with insulin resistance were age (p = 0.04) and steatosis (p = 0.004). Steatosis was associated with more severe fibrosis whatever the genotype (p = 0.002). Among genotype 1 patients, although there was a significant relationship between circulating insulin level and fibrosis stage (p = 0.006), only steatosis and inflammatory score were independently associated with fibrosis.
This study shows that insulin resistance is the cause rather than the consequence of steatosis and fibrosis in genotype 1 patients and that increased circulating insulin is a risk factor for fibrosis through insulin resistance induced steatosis.
Type III interferons (IFNs) (interleukin-28/29 or lambda interferon [IFN-lambda]) are cytokines with IFN-like activities. Here we show that several classes of viruses induce expression of IFN-lambda1 and -lambda2/3 in similar patterns. The IFN-lambdas were-unlike alpha/beta interferon (IFN-alpha/beta)-induced directly by stimulation with IFN-alpha or -lambda, thus identifying type III IFNs as IFN-stimulated genes. In vitro assays revealed that IFN-lambdas have appreciable antiviral activity against encephalomyocarditis virus (EMCV) but limited activity against herpes simplex virus type 2 (HSV-2), whereas IFN-alpha potently restricted both viruses. Using three murine models for generalized virus infections, we found that while recombinant IFN-alpha reduced the viral load after infection with EMCV, lymphocytic choriomeningitis virus (LCMV), and HSV-2, treatment with recombinant IFN-lambda in vivo did not affect viral load after infection with EMCV or LCMV but did reduce the hepatic viral titer of HSV-2. In a model for a localized HSV-2 infection, we further found that IFN-lambda completely blocked virus replication in the vaginal mucosa and totally prevented development of disease, in contrast to IFN-alpha, which had a more modest antiviral activity. Finally, pretreatment with IFN-lambda enhanced the levels of IFN-gamma in serum after HSV-2 infection. Thus, type III IFNs are expressed in response to most viruses and display potent antiviral activity in vivo against select viruses. The discrepancy between the observed antiviral activity in vitro and in vivo may suggest that IFN-lambda exerts a significant portion of its antiviral activity in vivo via stimulation of the immune system rather than through induction of the antiviral state.
The findings of medical research are often met with considerable scepticism, even when they have apparently come from studies with sound methodologies that have been subjected to appropriate statistical analysis. This is perhaps particularly the case with respect to epidemiological findings that suggest that some aspect of everyday life is bad for people. Indeed, one recent popular history, the medical journalist James Le Fanu's The Rise and Fall of Modern Medicine , went so far as to suggest that the solution to medicine's ills would be the closure of all departments of epidemiology.1
One contributory factor is that the medical literature shows a strong tendency to accentuate the positive; positive outcomes are more likely to be reported than null results.2–4 By this means alone a host of purely chance findings will be published, as by conventional reasoning examining 20 associations will produce one result that is “significant at P = 0.05” by chance alone. If only positive findings are published then they may be mistakenly considered to be of importance rather than being the necessary chance results produced by the application of criteria for meaningfulness based on statistical significance. As many studies contain long questionnaires collecting information on hundreds of variables, and measure a wide range of potential outcomes, several false positive findings are virtually guaranteed. The high volume and often contradictory nature5 of medical research findings, however, is not only because of publication bias. A more fundamental problem is the widespread misunderstanding of the nature of statistical significance.
In this paper we consider how the practice of significance testing emerged; an arbitrary division of results as “significant” or “non-significant” (according to the commonly used threshold of P = 0.05) was not the intention of the founders of statistical inference. P values need to be …
As antiretroviral therapy has decreased human immunodeficiency virus (HIV)–associated mortality, cardiometabolic abnormalities
have become increasingly apparent in HIV-infected individuals. Many patients treated for HIV infection exhibit body composition
changes, including peripheral fat atrophy and visceral lipohypertrophy. In addition, HIV-infected individuals demonstrate
a higher prevalence of dyslipidemia, insulin resistance and diabetes, and cardiovascular risk, compared with the general population.
Although antiretroviral therapy appears to contribute to some of the cardiometabolic abnormalities in HIV infection, HIV itself,
immunologic factors, and lifestyle factors are also important mediators of cardiovascular risk. Treatment strategies for body
composition changes and cardiometabolic abnormalities in HIV infection include lifestyle modification, lipid-lowering agents,
insulin sensitizers, and treatments to reverse endocrine abnormalities in HIV, including growth hormone–releasing hormone.
None of these strategies has comprehensively addressed the abnormalities experienced by this population, however, and further
research is needed into combined strategies to improve body composition and ameliorate cardiovascular risk.
Insulin resistance, fibrosis and steatosis are established predictors of response to peg-interferon/ribavirin therapy in chronic hepatitis C (CHC). Several host genetic polymorphisms (IL28B, PNPLA3) modify treatment-outcome, the degree of steatosis or fibrosis. The aim of our study was to evaluate the role of these polymorphisms on insulin resistance (IR) in treatment-naïve patients with chronic hepatitis C.
Two hundred and two non-diabetic CHC patients (GT1: 181, GT4: 21; m = 126, f = 76) undergoing liver biopsy in two tertiary academic centers were studied. The SNPs rs12979860 (IL28B) and rs738409 (PNPLA3) were investigated by RT-PCR. HOMA-IR, BMI, stage of fibrosis, extent of steatosis, and genetic data were analyzed.
Insulin resistance (HOMA-IR ≥ 3.0) was associated with rs12979860 genotype, presence of advanced fibrosis, and higher BMI. HOMA-IR in CC and in TC/TT was 2.08 ± 1.61 (mean ± SD) and 2.94 ± 2.89 (p=0.041), respectively. HOMA-IR was higher in advanced than in mild fibrosis (F3-4: 3.92 ± 3.15; F0-2: 2.38 ± 2.38; p=0.004). The percentage of steatotic hepatocytes was higher in patients with advanced fibrosis (21.3 ± 21.5 vs. 9.1 ± 14.2; p<0.001), HOMA-IR ≥ 3.0 (17.7 ± 17.8 vs. 8.8 ± 15.4%; p<0.001), and BMI > 25.0 kg/m(2) (14.7 ± 17.0 vs. 9.1 ± 16.1; p<0.001). The rs738409 GG genotype was associated with advanced fibrosis and steatosis, but not with HOMA-IR. Multivariable logistic regression identified advanced fibrosis (OR: 2.820, 95% CI: 1.344-5.917; p = 0.006) and the IL28B genotype non-CC (OR: 3.000, 1.348-6.676; p = 0.007) as independent risk factors for insulin resistance.
Insulin resistance is more common in carriers of the T allele of SNP rs12979860 than in CC homozygotes and may partly explain the poor outcome of peginterferon/ribavirin therapy in these patients.
Unlabelled:
In patients with chronic hepatitis C virus (HCV) infection, several variants of the interleukin-28B (IL28B) gene have been shown to correlate significantly with a sustained virologic response (SVR). Recent evidence shows that determination of one single IL28B polymorphism, rs12979860, is sufficient for predicting treatment outcome. We examined whether the combined determination of the IL28B single-nucleotide polymorphisms (SNPs), rs12979860, rs8099917, rs12980275, and rs8103142, might improve the prediction of SVR in patients with HCV. In the study cohort, 54% of 942 patients with chronic HCV type 1 infection had SVR. The IL28B SNPs, rs12979860CC and rs8099917TT, correlated significantly with SVR (68% and 62%). The SNPs, rs12980275 and rs8103142, were in strong linkage disequilibrium with rs12979860 and were not included in further analysis. In homozygous carriers of the rs12979860 responder allele C, additional genotyping of the rs8099917 SNP had no effect on response prediction, whereas in carriers of the rs12979860 nonresponder allele, the rs8099917 SNP improved the response prediction. In heterozygous carriers of the rs12979860 nonresponder T allele, SVR rates were 55% in the presence of the rs8099917TT genotype and 40% in patients carrying the rs8099917 TG or GG genotype. Analysis of an independent confirmation cohort of 377 HCV type 1-infected patients verified the significant difference in SVR rates between the combined genotypes, rs12979860CT/rs8099917TT and rs12979860CT/rs8099917TG (38% versus 21%; P = 0.018).
Conclusion:
Treatment outcome prediction could not be improved in homozygous carriers of the IL28B rs12979860 C responder allele by the additional determination of the rs8099917 SNP. There is evidence that a significant proportion of heterozygous carriers of the rs12979860 T nonresponder allele can profit with respect to SVR prediction by further determination of the rs8099917 SNP. (HEPATOLOGY 2012;55:1700-1710).
Liver disease is an important cause of morbidity and mortality in the era of combination antiretroviral therapy in HIV/hepatitis C virus (HCV) co-infected patients. This review highlights the role of pegylated interferon-alpha (peg-IFN) and ribavirin (RBV) therapy and examines factors associated with response and strategies to maximize responses.
HCV viral clearance is lower in HIV co-infected patients than in HCV mono-infected patients. However, in patients who attain sustained response there is clinical benefit in terms of liver disease associated morbidity and mortality and treatment is costeffective. Predictors of response appear similar, although there are a number of modifiable patient-associated and HIV-associated factors that could be addressed. Moreover, the use of weight-based RBV and treatment length guided by early viral responses improve response rate. Avoidance of drug-drug interactions and use of haematopoietic growth factors reduce adverse events and dose reductions and ultimately increase response rates. Very early prediction of treatment futility is promising. Induction dosing strategies have not yielded positive results, though twice weekly peg-IFN-alpha-2a induction therapy merits further investigation.
Peg-IFN/RBV therapy plays an important role in the management of HCV in HIV-infected patients. Efforts to maximize response to current therapy need to continue while we await new therapies.
When more than one statistical test is performed in analysing the data from a clinical study, some statisticians and journal editors demand that a more stringent criterion be used for “statistical significance” than the conventional P<0.05.1 Many well meaning researchers, eager for methodological rigour, comply without fully grasping what is at stake. Recently, adjustments for multiple tests (or Bonferroni adjustments) have found their way into introductory texts on medical statistics, which has increased their apparent legitimacy. This paper advances the view, widely held by epidemiologists, that Bonferroni adjustments are, at best, unnecessary and, at worst, deleterious to sound statistical inference.
#### Summary points
Adjusting statistical significance for the number of tests that have been performed on study data—the Bonferroni method—creates more problems than it solves
The Bonferroni method is concerned with the general null hypothesis (that all null hypotheses are true simultaneously), which is rarely of interest or use to researchers
The main weakness is that the interpretation of a finding depends on the number of other tests performed
The likelihood of type II errors is also increased, so that truly important differences are deemed non-significant
Simply describing what tests of significance have been performed, and why, is generally the best way of dealing with multiple comparisons
Bonferroni adjustments are based on the following reasoning.1-3 If a null hypothesis is true (for instance, two treatment groups in a randomised trial do not differ in terms of cure rates), a significant difference (P<0.05) will be observed by chance once in 20 trials. This is the type I error, or α. When 20 independent tests are performed (for example, study groups are compared with regard to 20 unrelated variables) and the null hypothesis holds for all 20 comparisons, the chance of at least one test being significant is no longer 0.05, but 0.64. …
Single nucleotide polymorphisms (SNPs) associated with IL28B influence the outcome of peginterferon-α/ribavirin therapy of chronic hepatitis C virus (HCV) infection. We analyzed the kinetics of HCV RNA during therapy as a function of IL28B SNPs.
IL28B SNPs rs8099917, rs12979860, and rs12980275 were genotyped in 242 HCV treatment-naïve Caucasian patients (67% genotype 1, 28% genotype 2 or 3) receiving peginterferon-α2a (180 μg weekly) and ribavirin (1000-1200 mg daily) with serial HCV-RNA quantifications. Associations between IL28B polymorphisms and early viral kinetics were assessed, accounting for relevant covariates.
In the multivariate analyses for genotype 1 patients, the T allele of rs12979860 (T(rs12979860)) was an independent risk factor for a less pronounced first phase HCV RNA decline (log(10) 0.89IU/ml among T carriers vs. 2.06 among others, adjusted p < 0.001) and lower rapid (15% vs. 38%, adjusted p = 0.007) and sustained viral response rates (48% vs. 66%, adjusted p < 0.001). In univariate analyses, T(rs12979860) was also associated with a reduced second phase decline (p = 0.002), but this association was no longer significant after adjustment for the first phase decline (adjusted p = 0.8). In genotype 2/3 patients, T(rs12979860) was associated with a reduced first phase decline (adjusted p = 0.04), but not with a second phase decline.
Polymorphisms in IL28B are strongly associated with the first phase viral decline during peginterferon-α/ribavirin therapy of chronic HCV infection, irrespective of HCV genotype.
To provide detailed information about the natural history of HIV-hepatitis C virus (HCV)-coinfected patients with cirrhosis.
Prospective cohort including 340 HIV-HCV-coinfected patients with compensated (n = 248) or decompensated (n = 92) cirrhosis. We evaluated predictors of survival and of first hepatic decompensation.
The mortality rate for patients with decompensated and compensated cirrhosis was 27.14 deaths per 100 person-years [95% confidence interval (CI) 18.93-35.35] and 3.98 deaths per 100 person-years (95% CI 2.42-5.54), respectively. Rate of first hepatic decompensation in patients with compensated cirrhosis was 4.62 per 100 persons-years (95% CI 2.91-6.33). In the complete cohort, permanent HAART interruption during follow-up, CD4 cell count nadir and baseline Child-Pugh score (CPS) B or C were significantly associated with shorter survival. In patients with compensated cirrhosis factors significantly associated with decreased survival were having the first hepatic decompensation during follow-up, permanent HAART discontinuation, and CPS B and C at baseline. For patients with compensated cirrhosis, time since diagnosis of HCV infection, CPS B and C and permanent HAART discontinuation were significantly associated with the risk of first hepatic decompensation. Sustained viral response to anti-HCV therapy was not independently associated with better survival in patients with compensated cirrhosis.
HIV-HCV-coinfected patients with cirrhosis have a relatively good 3-year survival (87%). In contrast, 2-year survival of patients with decompensated liver cirrhosis is only 50%. Three-year survival was mostly impacted by liver-related factors and HAART maintenance.
In 2009, a correlated set of polymorphisms in the region of the interleukin-28B (IL28B) gene were associated with clearance of genotype 1 hepatitis C virus (HCV) in patients treated with pegylated interferon-alfa and ribavirin. The same polymorphisms were subsequently associated with spontaneous clearance of HCV in untreated patients. The link between IL28B genotype and HCV clearance may impact decisions regarding initiation of current therapy, the design and interpretation of clinical studies, the economics of treatment, and the process of regulatory approval for new anti-HCV therapeutic agents.
The host immune response during the chronic phase of hepatitis C virus infection varies among individuals; some patients have a no interferon (IFN) response in the liver, whereas others have full activation of IFN-stimulated genes (ISGs). Preactivation of this endogenous IFN system is associated with nonresponse to pegylated IFN-α (pegIFN-α) and ribavirin. Genome-wide association studies have associated allelic variants near the IL28B (IFNλ3) gene with treatment response. We investigated whether IL28B genotype determines the constitutive expression of ISGs in the liver and compared the abilities of ISG levels and IL28B genotype to predict treatment outcome.
We genotyped 109 patients with chronic hepatitis C for IL28B allelic variants and quantified the hepatic expression of ISGs and of IL28B. Decision tree ensembles, in the form of a random forest classifier, were used to calculate the relative predictive power of these different variables in a multivariate analysis.
The minor IL28B allele was significantly associated with increased expression of ISG. However, stratification of the patients according to treatment response revealed increased ISG expression in nonresponders, irrespective of IL28B genotype. Multivariate analysis of ISG expression, IL28B genotype, and several other factors associated with response to therapy identified ISG expression as the best predictor of treatment response.
IL28B genotype and hepatic expression of ISGs are independent predictors of response to treatment with pegIFN-α and ribavirin in patients with chronic hepatitis C. The most accurate prediction of response was obtained with a 4-gene classifier comprising IFI27, ISG15, RSAD2, and HTATIP2.
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Genetic variation in the IL28B (interleukin 28B; interferon lambda 3) region has been associated with sustained virological response (SVR) rates in patients with chronic hepatitis C (CHC) who were treated with peginterferon-α and ribavirin. We hypothesized that IL28B polymorphism is associated with intrahepatic expression of interferon-stimulated genes (ISGs), known to influence treatment outcome. IL28B genotyping (rs12979860) and whole-genome RNA expression were performed using liver biopsies from 61 North American patients with CHC. After correction for multiple testing (false discovery rate < 0.10), 164 transcripts were found to be differentially expressed by IL28B-type. The interferon signaling pathway was the most enriched canonical pathway differentially expressed by IL28B-type (P < 10(-5)), with most genes showing higher expression in livers of individuals carrying the poor-response IL28B-type. In 25 patients for which treatment response data were available, IL28B-type was associated with SVR (P = 0.0054). ISG expression was also associated with SVR; however, this was not independent of IL28B-type. Analysis of miR-122 expression in liver biopsies showed reduced miR-122 levels associated with poorer treatment outcome, independently of IL28B-type. No association was observed between IL28B-type and levels of liver IL28B or IL28A messenger RNA expression. IL28B protein sequence variants associated with rs12979860 were therefore investigated in vitro: no differences in ISG induction or inhibition of HCV replication were observed in Huh7.5 cells.
Conclusion:
The good response IL28B variant was strongly associated with lower level ISG expression. The results suggest that IL28B genotype may explain the relationship between hepatic ISG expression and HCV treatment outcome, and this is independent of miR-122 expression. IL28B-type was not associated with intrahepatic IL28B messenger RNA expression in vivo. Further investigation of the precise molecular mechanism(s) by which IL28B genetic variation influences HCV outcomes is warranted.
Patients with hepatitis C virus (HCV)-related liver disease frequently undergo orthotopic liver transplantation, but recurrent hepatitis C is still a major cause of morbidity. Patients are treated with peg-interferon and ribavirin (PEG-IFN/RBV), which has substantial side effects and is costly. We investigated genetic factors of host, liver donor, and virus that might predict sensitivity of patients with recurrent hepatitis C to PEG-IFN/RBV.
Liver samples were analyzed from 67 HCV-infected recipients and 41 liver donors. Liver recipient and donor DNA samples were screened for single nucleotide polymorphisms near the IL28B genes (rs12980275 and rs8099917) that affect sensitivity to PEG-IFN/RBV. HCV RNA was isolated from patients and analyzed for mutations in the core, the IFN sensitivity-determining region, and IFN/RBV resistance-determining regions in nonstructural protein 5A.
In liver recipients and donors, the IL28B single nucleotide polymorphism rs8099917 was significantly associated with a sustained viral response (SVR; P = 0.003 and P = .025, respectively). Intrahepatic expression of IL28 messenger RNA was significantly lower in recipients and donors that carried the minor alleles (T/G or T/T) in rs8099917 (P = .010 and .009, respectively). Genetic analyses of IL28B in patients and donors and of the core and nonstructural protein 5A regions encoded by HCV RNA predicted an SVR with 83% sensitivity and 82% specificity; this was more effective than analysis of any single genetic feature.
In patients with recurrent HCV infection after orthotopic liver transplantation, combination analyses of single nucleotide polymorphisms of IL28B in recipient and donor tissues and mutations in HCV RNA allow prediction of SVR to PEG-IFN/RBV therapy.
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Hepatic steatosis (HS) is frequent in patients with hepatitis C virus (HCV) infection, occurring in 40%-80%, associating with metabolic and virus-related factors, namely, genotype 3 and viral load. Human immunodeficiency virus (HIV) infection and antiretroviral treatment seem to be risk factors for HS. Several studies addressed this issue in coinfected patients, with discrepant results. A meta-analysis was performed on the HS risk factors in coinfected patients. Eligible studies were identified through structured keywords including coinfection, HCV, HIV, and steatosis in relevant databases including PubMed. Pooled odds ratios (ORs) and confidence limits (CIs) were obtained with the random-effects model and the DerSimonian-Laird method. Twelve studies, including 1,989 coinfected patients, were selected. Twenty percent were infected with HCV genotype 3. The overall prevalence of HS was 50.8% (23%-72%). Four studies also included 1,540 HCV monoinfected patients, not showing an increased risk for HS in coinfected patients (OR 1.61, 95% CI 0.84-3.10, P = 0.151). In coinfected patients, HS was associated with higher body mass index (OR 1.13, 95% CI 1.07-1.19, P < 0.001), diabetes mellitus (OR 2.32, 95% CI 1.32-4.07, P = 0.003), elevated alanine aminotransferase levels (OR 1.28, 95% CI 1.02-1.61, P = 0.035), necroinflammatory activity (OR 1.72, 95% CI 1.11-2.67, P = 0.016), and fibrosis (OR 1.67, 95% CI 1.20-2.34, P = 0.003). No associations were found between HS and gender, other metabolic factors (dyslipidemia, glucose, metabolic syndrome), HCV-related factors (genotype, viral load), or HIV-related factors (viral load, CD4 count, antiretroviral therapy, and class of medication).
Conclusion:
In coinfected patients, HS does not seem to be more frequent than in HCV monoinfected patients and is mostly associated with metabolic factors, such as increased weight, diabetes mellitus, and more severe liver disease. The fact that no associations with HCV factors were found may be due to the small percentage of genotype 3-infected patients.
A common genetic variation at the IL28 locus has been found to affect the response of peg-interferon and ribavirin combination therapy against chronic hepatitis C virus (HCV) infection. An allele associated with a favorable response (rs8099917 T), which is the major allele in the majority of Asian, American, and European populations, has also been found to be associated with spontaneous eradication of the virus.
As no studies have yet analyzed the effect of the polymorphism on biochemical and inflammatory changes in chronic infection, we analyzed a cohort of patients with chronic hepatitis C (n=364) for the effect of the IL28 polymorphism on viral, biochemical, and histological findings.
We found that the proportion of HCV wild type core amino acids 70 and 91 was significantly greater (p=1.21 x 10(-4) and 0.034) and levels of gamma-GTP significantly lower (p=0.001) in patients homozygous for the IL28 major allele. We also found that inflammation activity and fibrosis of the liver were significantly more severe in patients homozygous for the IL28 major allele (p=0.025 and 0.036, respectively). Although the higher gamma-GTP levels were also associated with higher inflammatory activity and fibrosis, multivariate analysis showed that only the IL28 allele polymorphism, sex, alcohol consumption, and liver fibrosis were independently associated with gamma-GTP levels (p=0.001, 0.0003, 0.0013, and 0.0348, respectively).
These results suggest that different cytokine profiles induced by the IL28 polymorphism resulted in different biochemical and inflammatory conditions during chronic HCV infection and contribute to the progression of liver diseases.
Multiple viral and host factors are related to the treatment response to pegylated-interferon and ribavirin combination therapy; however, the clinical relevance and relationship of these factors have not yet been fully evaluated.
We studied 168 patients with chronic hepatitis C who received pegylated-interferon and ribavirin combination therapy. Gene expression profiles in the livers of 91 patients were analyzed using an Affymetrix genechip (Affymetrix, Santa Clara, CA). The expression of interferon-stimulated genes (ISGs) was evaluated in all samples by real-time polymerase chain reaction. Genetic variation in interleukin 28B (IL28B; rs8099917) was determined in 91 patients.
Gene expression profiling of the liver differentiated patients into 2 groups: patients with up-regulated ISGs and patients with down-regulated ISGs. A high proportion of patients with no response to treatment was found in the up-regulated ISGs group (P=.002). Multivariate logistic regression analysis showed that ISGs (<3.5) (odds ratio [OR], 16.2; P<.001), fibrosis stage (F1-F2) (OR, 4.18; P=.003), and ISDR mutation (>or=2) (OR, 5.09; P=.003) were strongly associated with the viral response. The IL28B polymorphism of 91 patients showed that 66% were major homozygotes (TT), 30% were heterozygotes (TG), and 4% were minor homozygotes (GG). Interestingly, hepatic ISGs were associated with the IL28B polymorphism (OR, 18.1; P<.001), and its expression was significantly higher in patients with the minor genotype (TG or GG) than in those with the major genotype (TT).
The expression of hepatic ISGs is strongly associated with treatment response and genetic variation of IL28B. The differential role of host and viral factors as predicting factors may also be present.
The recommended treatment for patients with chronic hepatitis C, pegylated interferon-alpha (PEG-IFN-alpha) plus ribavirin (RBV), does not provide sustained virologic response (SVR) in all patients. We report a genome-wide association study (GWAS) to null virological response (NVR) in the treatment of patients with hepatitis C virus (HCV) genotype 1 within a Japanese population. We found two SNPs near the gene IL28B on chromosome 19 to be strongly associated with NVR (rs12980275, P = 1.93 x 10(-13), and rs8099917, 3.11 x 10(-15)). We replicated these associations in an independent cohort (combined P values, 2.84 x 10(-27) (OR = 17.7; 95% CI = 10.0-31.3) and 2.68 x 10(-32) (OR = 27.1; 95% CI = 14.6-50.3), respectively). Compared to NVR, these SNPs were also associated with SVR (rs12980275, P = 3.99 x 10(-24), and rs8099917, P = 1.11 x 10(-27)). In further fine mapping of the region, seven SNPs (rs8105790, rs11881222, rs8103142, rs28416813, rs4803219, rs8099917 and rs7248668) located in the IL28B region showed the most significant associations (P = 5.52 x 10(-28)-2.68 x 10(-32); OR = 22.3-27.1). Real-time quantitative PCR assays in peripheral blood mononuclear cells showed lower IL28B expression levels in individuals carrying the minor alleles (P = 0.015).
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A few studies have assessed the observed fibrosis progression between serial liver biopsies (LB) in human immunodeficiency virus (HIV) / hepatitis C virus (HCV)-coinfected patients. Approximately half of the patients progressed at least one fibrosis stage over a short period of time. The risk factors for this fast progression need clarification. Because of this, we evaluated the observed fibrosis progression rates of HIV/HCV-coinfected patients and the risk factors for accelerated progression. Overall, 135 HIV-infected patients with positive serum HCV RNA, without other possible causes of liver disease, who underwent two LB, separated at least by 1 year, were included in this retrospective cohort study. The median (Q1-Q3) time between both LBs was 3.3 (2.0-5.2) years. Patients showed the following changes in fibrosis stage: regression >or =1 stage: 23 (17%), no change: 52 (39%), progression 1 stage: 38 (28%), and progression > or =2 stages: 22 (16%). Seventeen (13%) patients had cirrhosis in the second biopsy. Factors independently associated with progression > or =1 stage were undetectable plasma HIV RNA during the follow-up (relative risk [RR] [95% confidence interval, 95% CI] 0.61 [0.39-0.93], P = 0.03), moderate-to-severe lobular necroinflammation (1.77 [1.16-2.7], P = 0.009), time between biopsies (1.11 [1.08-1.2], P = 0.01), and end of treatment response to anti-HCV therapy (0.41 [0.19-0.88], P = 0.02).
Conclusion:
Fibrosis progresses with high frequency in HIV/HCV-coinfected patients over a period of time of 3 years. Absent-to-mild lobular necroinflammation at baseline, achievement of response with anti-HCV treatment, and effective antiretroviral therapy are associated with slower fibrosis progression.
At least five groups have evaluated treatment for patients with decompensated cirrhosis preliminary to liver transplantation.330–334 In the earliest reported study, 32 patients awaiting liver transplantation were considered for antiviral treatment, but over one-half were found ineligible because of cytopenias.330 Among those treated with standard or low doses of interferon alfa-2b or low doses of both interferon alfa-2b and ribavirin, 33% became HCV RNA negative. Almost all developed adverse effects, most of which was graded as severe. In a second study, 30 patients with HCV-related cirrhosis destined for liver transplantation (half graded as CTP class A) were treated with interferon alfa-2b, 3 mU daily and ribavirin, 800 mg/day if their presumed time to liver transplantion was less than 4 months.331 After a median treatment duration of 12 weeks, 30% responded to treatment and then underwent liver transplantation, 2/3 of whom remained HCV RNA negative over a median follow-up period of 46 weeks. Sixty percent developed neutropenia. Reported in the same year was a study of 20 patients, most with genotype 1 infection, who were treated before transplantation for a mean of 14 months with interferon alfa-2b in a dose of 5 mU daily.332 At transplantation, 60% were HCV RNA negative, but only 20% remained negative after transplantation. A fourth study involved 124 patients with advanced cirrhosis (CTP classes A, B and C) treated mainly with interferon alfa-2b plus ribavirin, and less frequently, with pegylated interferon plus ribavirin.333 Treatment began with half doses that were increased incrementally as tolerated at 2 week intervals (referred to as a low accelerating dose regimen), and growth factors were used as needed. An SVR developed in 13% of patients with genotype 1 and in 50% with non-genotype 1 infections. Adverse events were frequent, requiring dose reductions or treatment termination, but among those who did become HCV RNA negative before transplantation, 80% remained negative 6 or more months after transplantation. The most recent study is the only one to include non-treated controls but these consisted of patients unwilling to participate in the study.334 The treatment administered was peginterferon alfa-2b, 1.0 μg/kg body weight given weekly and ribavirin, 800 to 1000 mg daily for 24 weeks. An SVR developed in 44% of the patients with HCV genotypes 2 or 3, and in 7% of those with genotypes 1 or 4. Treatment had to be discontinued in 20%, was reduced in 39%, and was tolerated in 41%. Over a 30-month follow-up period, decompensated events occurred in 83% of the controls, 62% of the non-responders, and in 23% of the patients who had developed an SVR. The conclusion of this study was that antiviral therapy can be life-saving, improves hepatic function, and that treatment seems appropriate for persons with genotype 2 and 3 infections particularly in those with cirrhosis, CTP classes A and B.
Our aim was to assess the natural history of liver fibrosis progression in hepatitis C and the factors associated with this progression.
We recruited 2235 patients from the Observatoire de l'Hépatite C (OBSVIRC) population, the Cohorte Hépatite C Pitié-Salpétrière (DOSVIRC) population, and the original METAVIR population. All the patients had a biopsy sample compatible with chronic hepatitis C as assessed by the METAVIR scoring system (grades the stage of fibrosis on a five-point scale, F0 = no fibrosis, F4 = cirrhosis, and histological activity on a four-point scale, A0 = no activity, A3 = severe activity). No patient had received interferon treatment before the liver biopsy sample was obtained. We assessed the effect of nine factors on fibrosis progression: age at biopsy; estimated duration of infection; sex; age at infection; alcohol consumption; hepatitis C virus C (HCV) genotype; HCV viraemia; cause of infection; and histological activity grade. We defined fibrosis progression per year as the ratio between fibrosis stage in METAVIR units and the duration of infection (1 unit = one stage, 4 units = cirrhosis).
The median rate of fibrosis progression per year was 0.133 fibrosis unit (95% CI 0.125-0.143), which was similar to the estimates from previous studies (0.146 to 0.154). Three independent factors were associated with an increased rate of fibrosis progression: age at infection older than 40 years, daily alcohol consumption of 50 g or more, and male sex. There was no association between fibrosis progression and HCV genotype. The median estimated duration of infection for progression to cirrhosis was 30 years (28-32), ranging from 13 years in men infected after the age of 40 to 42 years in women who did not drink alcohol and were infected before the age of 40. Without treatment, 377 (33%) patients had an expected median time to cirrhosis of less than 20 years, and 356 (31%) will never progress to cirrhosis or will not progress for at least 50 years.
The host factors of ageing, alcohol consumption, and male sex have a stronger association with fibrosis progression than virological factors in HCV infection.
The findings of medical research are often met with considerable scepticism, even when they have apparently come from studies with sound methodologies that have been subjected to appropriate statistical analysis. This is perhaps particularly the case with respect to epidemiological findings that suggest that some aspect of everyday life is bad for people. Indeed, one recent popular history, the medical journalist James Le Fanu's The Rise and Fall of Modern Medicine , went so far as to suggest that the solution to medicine's ills would be the closure of all departments of epidemiology.1
One contributory factor is that the medical literature shows a strong tendency to accentuate the positive; positive outcomes are more likely to be reported than null results.2–4 By this means alone a host of purely chance findings will be published, as by conventional reasoning examining 20 associations will produce one result that is “significant at P=0.05” by chance alone. If only positive findings are published then they may be mistakenly considered to be of importance rather than being the necessary chance results produced by the application of criteria for meaningfulness based on statistical significance. As many studies contain long questionnaires collecting information on hundreds of variables, and measure a wide range of potential outcomes, several false positive findings are virtually guaranteed. The high volume and often contradictory nature5 of medical research findings, however, is not only because of publication bias. A more fundamental problem is the widespread misunderstanding of the nature of statistical significance.
#### Summary points
P values, or significance levels, measure the strength of the evidence against the null hypothesis; the smaller the P value, the stronger the evidence against the null hypothesis
An arbitrary division of results, into “significant” or “non-significant” according to the P value, was not the intention of the …
Designing studies to examine hepatitis C virus (HCV) transmission via the shared use of drug injection paraphernalia other than syringes is difficult because of saturation levels of HCV infection in most samples of injection drug users (IDUs). The authors measured the incidence of HCV infection in a large cohort of young IDUs from Chicago, Illinois, and determined the risk of HCV seroconversion associated with specific forms of sharing injection paraphernalia. From 1997 to 1999, serum samples obtained from 702 IDUs aged 18-30 years were screened for HCV antibodies; prevalence was 27%. Seronegative participants were tested for HCV antibodies at baseline, at 6 months, and at 12 months. During 290 person-years of follow-up, 29 participants seroconverted (incidence: 10.0/100 person-years). The adjusted relative hazard of seroconversion, controlling for demographic and drug-use covariates, was highest for sharing "cookers" (relative hazard = 4.1, 95% confidence interval: 1.4, 11.8), followed by sharing cotton filters (relative hazard = 2.4, 95% confidence interval: 1.1, 5.0). Risks associated with syringe-sharing and sharing of rinse water were elevated but not significant. After adjustment for syringe-sharing, sharing cookers remained the strongest predictor of seroconversion (relative hazard = 3.5, 95% confidence interval: 1.3, 9.9). The authors conclude that sharing of injection equipment other than syringes may be an important cause of HCV transmission between IDUs.
Hepatic steatosis is common in hepatitis C, but the relative importance of host and viral factors is controversial. In the present prospective study, we examined metabolic factors associated with non-alcoholic fatty liver and viral genotype as predictors of steatosis and fibrosis in chronic hepatitis C infection.
In 124 chronic hepatitis C patients, the association between liver histology and the following was investigated: demographic and anthropometric data, alcohol intake, alanine aminotransferase (ALT), total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, triglyceride, transferrin saturation, ferritin, insulin, c-peptide, glucose and insulin resistance (homeostasis model).
By multivariate analysis, genotype 3 was associated with increased steatosis grade (P = 0.02). There were significant pairwise interactions between genotype 3 status and total cholesterol (P = 0.01), current alcohol intake (P = 0.04) and serum ALT (P = 0.01). This showed that the etiology of steatosis was different in patients with genotype 3 and those with non-genotype 3 chronic hepatitis C infection. In genotype 3 patients, the degree of steatosis was inversely associated with serum cholesterol (P = 0.005) and positively associated with serum triglyceride (P = 0.02). There was no association between body mass index (BMI) and the extent of steatosis. Among patients with other genotypes, the steatosis grade was strongly influenced by BMI (P < 0.0001) and serum ALT (P < 0.01). Independent predictors of fibrosis were age (P = 0.001), past alcohol intake (P = 0.04), ALT (P = 0.002), serum insulin (P = 0.001) and portal inflammation (P < 0.001).
Hepatitis C genotype 3 may interfere with pathways of hepatic lipid metabolism, whereas increased BMI appears to be a more important pathogenic factor in other genotypes. Although steatosis and BMI were not associated with hepatic fibrosis, their relationship with serum insulin suggests that metabolic factors related to insulin action could influence fibrogenesis in hepatitis C.
The progression of fibrosis in chronic hepatitis C determines the ultimate prognosis and thus the need and urgency of therapy. Fibrogenesis is a complex dynamic process, which is mediated by necroinflammation and activation of stellate cells. The liver biopsy remains the gold standard to assess fibrosis. Scoring systems allow a semiquantitative assessment and are useful for cross-sectional and cohort studies and in treatment trials. The rate at which fibrosis progresses varies markedly between patients. The major factors known to be associated with fibrosis progression are older age at infection, male gender, and excessive alcohol consumption. Viral load and genotype do not seem to influence significantly the progression rate. Progression of fibrosis is more rapid in immunocompromised patients. Hepatic steatosis, obesity, and diabetes may also contribute to more rapid progression of fibrosis. There are no tests that reliably predict the rate of progression of fibrosis in an individual patient. High serum alanine aminotransferase (ALT) levels are associated with a higher risk of fibrosis progression, and worsening of fibrosis is uncommon in patients with persistently normal serum aminotransferase levels. Serum markers for fibrosis are not reliable and need to be improved and validated. Liver biopsy provides the most accurate information on the stage of fibrosis and grade of necroinflammation, both of which have prognostic significance. Repeating the liver biopsy, 3 to 5 years after an initial biopsy is the most accurate means of assessing the progression of fibrosis.
It has been suggested that hepatitis C virus (HCV) and especially genotype 3 is associated with steatosis. We assess the effect of treatment with peginterferon or interferon alfa-2b and ribavirin on steatosis. We analyzed 1,428 naïve patients included in a randomized trial. A single pathologist scored steatosis at baseline and 24 weeks after the treatment. At baseline, steatosis was present in 935 of 1,428 patients (65%), including 175 (83%) of 210 patients with genotype 3 versus 760 (62%) of 1,218 with other genotypes (P <.001). The variables associated with steatosis in logistic regression were genotype 3 (P <.001), triglycerides greater than 1.7 mmol/L (P <.001), body mass index greater than 27 (P <.04), age greater than 40 years (P <.001), and septal fibrosis (P =.007). In genotype 3-infected patients, steatosis was associated with high viral load and with lower serum cholesterol. Steatosis was associated with lower sustained response rate, even after taking into account other factors (P <.001). Among virologic responders, steatosis was much improved in genotype 3, improvement of at least 1 grade in 77%, and disappearance in 46% compared with other genotypes, 46% and 29%, respectively (P <.001 both comparisons). In genotype 3 responders, the baseline low serum cholesterol was corrected by treatment (P <.001). Steatosis was associated with HCV genotype 3, triglycerides, high body mass index, age, fibrosis stage, and lower virologic response to treatment. In conclusion, sustained disappearance of the virus is associated with reduction of steatosis in genotype 3 as well as a correction of baseline low serum cholesterol.
Hepatitis C virus (HCV) and HIV coinfection constitutes an important epidemiological and clinical problem. We evaluated the safety and efficacy of Pegylated interferon alpha2b (Peg-IFN) and a fixed dose of ribavirin in the treatment of chronic hepatitis C in HIV coinfection.
Open, prospective study in HCV-HIV coinfected patients with persistently elevated alanine aminotransferase (ALT) levels and a liver biopsy showing either portal or bridging fibrosis. Therapy included Peg-IFN (50 micro g weekly) with ribavirin 800 mg for 48 weeks. The primary end point was sustained virological response (SVR). Univariate and multivariate analyses were performed to determine factors associated with response.
By intent-to-treat analysis, 11 of 35 patients (31%) reached SVR. SVR was significantly better for genotypes 2/3 than for genotype 1 (54% versus 21%; P < 0.05). By multivariate logistic regression analysis, only a non-1 genotype was an independent factor for SVR [odds ratio (OR), 6; 95% confidence interval (CI), 1.1-31.7; P < 0.005]. A decrease of at least 1.5 log10 HCV RNA at week 12 of therapy was highly predictive of SVR (OR, 49.9; 95% CI, 4.9-508.2; P < 0.001). Most patients developed adverse events, although only six patients (17%) discontinued treatment due to toxicity.
The combination of low doses of Peg-IFN plus a fixed dose of ribavirin resulted in a rate of SVR similar to that obtained with higher doses of the drugs in HIV-infected patients and lower than those obtained in non-HIV patients. Response at week 12 may be useful to help guide therapy in HCV-HIV co-infected patients.
Questions remain regarding the etiology of steatosis in hepatitis C, and its impact on disease progression and treatment outcomes.
We evaluated liver biopsies from 574 patients with chronic hepatitis C from a single center.
Severity of steatosis was associated with body mass index, HCV genotype 3 infection, age, and duration of infection (P</=0.01). Serum HCV RNA levels were associated with severity of steatosis in HCV genotype 3 infection (P</=0.03). In HCV genotype 1 infection, fibrosis was associated with severity of steatosis (P<0.01), and patients who achieved SVR had lesser degrees of pre-treatment steatosis compared to nonresponders (4.6+/-1.6 vs. 10.1+/-1.1%, P=0.02). Genotype 1 infected patients with an early virologic response were more likely to have grade 0 steatosis compared to those without an early response (71 vs. 42%; P=0.003). Evaluation of paired biopsies demonstrated a marked decline in steatosis in genotype 3 patients who achieved SVR (P<0.01).
In conclusion, steatosis is an important cofactor in hepatitis C as it is associated with fibrosis and reduces the likelihood of achieving early and sustained virologic response in genotype 1 infected patients.
Current therapies for chronic hepatitis C virus (HCV) in HIV co-infected patients have a low success rate and are poorly tolerated. We have evaluated the efficacy and safety of interferon alfa-2b (IFN) + ribavirin (RBV) versus pegylated interferon alfa-2b (PEG-INF) + RBV.
Randomized, single-centre, open-label clinical trial including patients with: detectable HCV-RNA, alanine aminotransferase > 1.5-fold upper limit of normal, abnormal liver histology, CD4 cell count > 250 x 10/l and HIV RNA < 10 000 copies/ml. Patients were assigned to INF (3 x 10 units three times/week) or PEG-IFN (100-150 microg/week) plus RBV (800-1200 mg/day). Duration of treatment was 48 weeks (only 24 weeks for HCV genotypes 2 or 3 and baseline HCV RNA < 800 000 IU/ml). The primary endpoint was a sustained virological response (SVR).
Ninety-five patients were randomized (43 INF + RBV, 52 PEG-INF + RBV), 68% males, 82% injecting drug users; 63% genotypes 1 or 4 and 36% genotypes 2 or 3; 62% fibrosis index grade >/=2 and 30% bridging fibrosis/cirrhosis. SVR was significantly higher in the PEG-INF + RBV arm, 44% versus 21% (intent to treat; P = 0.017). Among patients with genotypes 1 or 4, SVR were 38% versus 7% (P = 0.007) and 53% versus 47% (P = 0.730) for genotypes 2 or 3. CD4 cell count but not its percentage dropped in both arms and HIV RNA viral load did not change from baseline. Side effects were very frequent in both arms leading to treatment discontinuation in 14 patients without statistical differences between arms (P = 0.565).
PEG-INF + RBV was significantly more effective than INF + RBV for the treatment of chronic hepatitis C in HIV co-infected patients, mainly of genotype 1 or 4.
This article is the first in a series of seven that will provide an overview of central concepts and topical issues in modern genetic epidemiology. In this article, we provide an overall framework for investigating the role of familial factors, especially genetic determinants, in the causation of complex diseases such as diabetes. The discrete steps of the framework to be outlined integrate the biological science underlying modern genetics and the population science underpinning mainstream epidemiology. In keeping with the broad readership of The Lancet and the diverse background of today's genetic epidemiologists, we provide introductory sections to equip readers with basic concepts and vocabulary. We anticipate that, depending on their professional background and specialist knowledge, some readers will wish to skip some of this article.
Steatosis is a frequent histologic finding in chronic hepatitis C (CHC), but it is unclear whether steatosis is an independent predictor for liver fibrosis. We evaluated the association between steatosis and fibrosis and their common correlates in persons with CHC and in subgroup analyses according to hepatitis C virus (HCV) genotype and body mass index.
We conducted a meta-analysis on individual data from 3068 patients with histologically confirmed CHC recruited from 10 clinical centers in Italy, Switzerland, France, Australia, and the United States.
Steatosis was present in 1561 patients (50.9%) and fibrosis in 2688 (87.6%). HCV genotype was 1 in 1694 cases (55.2%), 2 in 563 (18.4%), 3 in 669 (21.8%), and 4 in 142 (4.6%). By stepwise logistic regression, steatosis was associated independently with genotype 3, the presence of fibrosis, diabetes, hepatic inflammation, ongoing alcohol abuse, higher body mass index, and older age. Fibrosis was associated independently with inflammatory activity, steatosis, male sex, and older age, whereas HCV genotype 2 was associated with reduced fibrosis. In the subgroup analyses, the association between steatosis and fibrosis invariably was dependent on a simultaneous association between steatosis and hepatic inflammation.
In this large and geographically different group of CHC patients, steatosis is confirmed as significantly and independently associated with fibrosis in CHC. Hepatic inflammation may mediate fibrogenesis in patients with liver steatosis. Control of metabolic factors (such as overweight, via lifestyle adjustments) appears important in the management of CHC.
HCV (hepatitis C virus) has a high propensity to persist and to cause chronic hepatitis C, eventually leading to cirrhosis. Since HCV itself is not cytopathic, liver damage in chronic hepatitis C is commonly attributed to immune-mediated mechanisms. HCV proteins interact with several pathways in the host's immune response and disrupt pathogen-associated pattern recognition pathways, interfere with cellular immunoregulation via CD81 binding and subvert the activity of NK (natural killer) cells as well as CD4(+) and CD8(+) T-cells. Finally, HCV-specific T-cells become increasingly unresponsive and apparently disappear, owing to several possible mechanisms, such as escape mutations in critical viral epitopes, lack of sufficient help, clonal anergy or expansion of regulatory T-cells. The role of neutralizing antibodies remains uncertain, although it is still possible that humoral immunity contributes to bystander damage of virally coated cells via antibody-dependent cellular cytotoxicity. Cytotoxic lymphocytes kill HCV-infected cells via the perforin/granzyme pathway, but also release Fas ligand and inflammatory cytokines such as IFNgamma (interferon gamma). Release of soluble effector molecules helps to control HCV infection, but may also destroy uninfected liver cells and can attract further lymphocytes without HCV specificity to invade the liver. Bystander damage of these non-specific inflammatory cells will expand the tissue damage triggered by HCV infection and ultimately activate fibrogenesis. A clear understanding of these processes will eventually help to develop novel treatment strategies for HCV liver disease, independent from direct inhibition of HCV replication.
Liver disease is more progressive in HIV/hepatitis C virus (HCV) co-infection than in HCV infection alone. This accelerated pathogenesis is probably influenced by differences in the composition of infiltrating inflammatory cells and the local release of inflammatory and profibrogenic cytokines.
Using quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) we studied intrahepatic messenger RNA levels of cytokines and cellular markers defining distinct subsets of inflammatory cells in liver biopsies from 33 HCV-mono-infected and 40 HIV/HCV-co-infected patients.
Despite their well preserved peripheral blood CD4 cell counts (median 598 cells/microl), HIV/HCV-co-infected patients displayed significantly lower CD4 mRNA levels than HCV-mono-infected patients, whereas increased mRNA levels of CD3epsilon, TCRalpha, CD8alpha and CD8beta suggested intrahepatic enrichment of CD8 T cells in HIV co-infection. Intrahepatic mRNA levels of the inflammatory cytokines interferon gamma (IFN-gamma), regulated upon activation, normal T-cell expressed and secreted (RANTES, CCL5), macrophage inflammatory protein 1 alpha (CCL3) and interferon-inducible protein 10 (CXCL10) were significantly higher in HIV-positive than in HIV-negative patients, whereas mRNA levels of the profibrogenic cytokines macrophage chemoattractant protein 1 (CCL2), secondary lymphochemokine (CCL21) and stroma-derived factor 1 (CXCL12) did not differ between the two groups. All changes were less pronounced in the subgroup of HIV-positive patients receiving antiretroviral treatment (HAART) than in untreated HIV-positive patients.
The accelerated liver disease observed in HIV/HCV-co-infected patients might reflect enhanced intrahepatic inflammatory responses rather than increased local transcription of directly profibrogenic cytokines.