The predictive value of steatosis in hepatitis C virus infection

Association between MTTP genotype (-493G/T) polymorphism and hepatic steatosis in hepatitis C: a systematic review and meta-analysis

BACKGROUND

Hepatitis C has been associated with the development of hepatic steatosis, which increases the risk of liver cancer. The microsomal triglyceride transporter protein (MTTP), is a lipid transport protein that mediates lipid metabolism and CD1d antigen presentation. The study aimed to explore the association between MTTP genotype (-493G/T) polymorphism and hepatic steatosis in hepatitis C.

METHODS

The database "Pubmed, Cochrane library, CNKI, Web of science, Embase and CBM" were retrieved to identify the literature. The quality of the selected literature was evaluated using the "the Newcastle-Ottawa Scale" (NOS). Relevant data was extracted and analyzed using the Stata software. Heterogeneity was expressed by "Cochran's Q and I2", with I2 ≥ 50% or P < 0.05 indicating high heterogeneity. A random-effects model and subgroup analysis were conducted to identify the sources of heterogeneity. We also used "Funnel plots", "Egger's tests" and "Begg's tests" to evaluate biases in the literature.

RESULTS

The study found a significant and positive association between liver steatosis and the HCV genotype 3 with a dominant model of the MTTP genotype (-493G/T) (OR = 11.57, 95%CI: 4.467-29.962, P < 0.001). In contrast, no correlation was found between hepatic steatosis and either the recessive, homozygous or heterozygous models (OR = 1.142, P = 0.5; OR = 1.581, P = 0.081; OR = 1.029, P = 0.86). There was no significant publication biases, as measured by the Funnel plot, and the Egger's and Begg's tests. Finally, sensitivity analysis showed the obtained results are stable.

CONCLUSIONS

Dominant mutations in the T allele of the MTTP genotype (-493G/T) increase susceptibility to hepatic steatosis in patients presenting with the HCV genotype 3.

Effect of MTTP -493G/T, I128T, Q95H and Q244E polymorphisms on hepatic steatosis in patients with chronic hepatitis

BACKGROUND

Chronic hepatitis C is characterized by a progressive deterioration of liver function and is involved in metabolic complications, such as hepatic steatosis.

OBJECTIVE

The aim of this study was to investigate the role of host and viral characteristics associated with -493G/T (rs1800591), I128T (rs3816873), Q95H (rs61733139), and Q244E (rs17599091) Single Nucleotide Polymorphisms (SNPs) in the Microsomal Triglyceride Transfer Protein (MTTP) gene on hepatic steatosis in chronic hepatitis C.

METHODS

SNPs were genotyped by PCR-RFLP and analyzed in combination with host and viral characteristics by multiple logistic regression in different genetic models of inheritance.

RESULTS

The authors analyzed 236 patients with chronic hepatitis C, and 53% had hepatic steatosis. The mutated allele frequencies were > 5%, and the genotypes were in Hardy-Weinberg equilibrium (p ≥ 0.05). It was observed that patients with HCV genotype 3 infection (OR = 2.74, 95% CI 1.24‒6.06, p = 0.013), female sex (OR = 2.28, 95% CI 1.21‒4.28, p = 0.011) and moderate- and high-intensity liver inflammatory activity (A2-A3) (OR = 3.61, 95% CI 1.86‒7.01, p < 0.001) alone exhibited a higher risk of steatosis. The results of multiple logistic regression analysis for interaction showed that for the -493G/T SNP, when the GT/TT genotype (dominant model) and the GT genotype (codominant model) were each combined with HCV genotype 3 infection, an 11.51-fold (95% CI 2.08‒63.59, p = 0.005) and a 15.69-fold (95% CI 2.46‒99.85, p = 0.004) increased risk of steatosis, respectively, was observed. For the I128T SNP, when both the IT/TT genotype (dominant model) and the IT genotype (codominant model) were combined with HCV genotype 3 infection, an 8.51-fold (95% CI 1.59‒45.54, p = 0.012) and an 8.40 fold (95% CI 1.51‒46.91, p = 0.015) increased risk of steatosis, respectively, was observed.

CONCLUSION

The present study showed that the viral genotype combined with the -493G/T and I128T SNPs in the MTTP gene influences hepatic steatosis.

Metabolic and cardiovascular complications after virological cure in hepatitis C: What awaits beyond

The association between chronic hepatitis C (CHC) infection and extrahepatic manifestations (EHMs), particularly cardiometabolic diseases, has been extensively examined. However, there has still been insufficient evaluation for these EHMs after virological cure. Several multidirectional mechanisms have been proposed explaining the ability of hepatitis C virus (HCV) developing EHMs, cardiometabolic ones, as well as the effect of antiviral therapy to resolve these EHMs. Data on these manifestations after achieving sustained virologic response (SVR) are still conflicting. However, current evidence suggests that reversal of hepatic steatosis and its coexistent hypocholesterolemia after successful viral eradication led to unfavorable lipid profile, which increases cardiovascular disease (CVD) risk. Additionally, most observations showed that metabolic alterations, such as insulin resistance and diabetes mellitus (DM), undergo some degree of reduction after viral clearance. These changes seem HCV-genotype dependent. Interferon-based antiviral therapy and direct acting antiviral drugs were shown to minimize incidence of DM. Large epidemiological studies that investigated the effect of SVR on CVD showed great discrepancies in terms of results, with predominant findings indicating that CVD events decreased in patients with SVR compared to non-responders or untreated ones. In this review, we present a summary of the current knowledge regarding extrahepatic sequelae of CHC following SVR, which may have an impact on healthcare providers’ clinical practice.

Chronic hepatitis C infection induces cardiovascular disease and type 2 diabetes: mechanisms and management

Despite the availability of effective treatments, hepatitis C virus (HCV) still remains a threat to public health. HCV is capable to trigger, behind liver damage, extrahepatic manifestations, including cardiovascular disease and type 2 diabetes (T2DM). A close association has been reported between HCV infection and cardiovascular disease due to imbalances in metabolic pathways and chronic inflammation. HCV through both direct and indirect mechanisms causes a higher incidence of ischemic stroke, acute coronary syndrome, heart failure and peripheral arterial disease. In addition, a higher risk of death from cardiovascular events has been showed in HCV patients. Insulin resistance is a hallmark of HCV infection and represents the link between HCV and T2DM, which is one of the most frequent HCV-associated extrahepatic manifestations. The pathological basis of the increased risk of T2DM in HCV infection is provided by the alterations of the molecular mechanisms of IR induced both by the direct effects of the HCV proteins, and by the indirect effects mediated by chronic inflammation, oxidative stress and hepatic steatosis. T2DM increases the risk of compensated and decompensate cirrhosis and hepatocellular carcinoma as well as increases the risk of cardiovascular disease, lower limb amputation and end stage renal disease. Current evidence suggests that HCV eradication reduces the incidence and mortality of cardiovascular disease and T2DM, further underling the importance of public health strategies for eradication the infection. The aim of this review was to update evidence and management of interaction between HCV, cardiovascular disease, and T2DM in the era of DAA treatment.

Hepatitis C, systemic inflammation and oxidative stress: correlations with metabolic diseases

Introduction: Hepatitis C chronic infection has long been correlated with numerous systemic diseases, such as diabetes mellitus and hepatic steatosis. Recent studies have also revealed an association with atherosclerosis.Areas covered: An analysis is presented on the mechanisms through which the hepatitis C viral infection can lead to a systemic increase in pro-inflammatory markers, especially tumor necrosis factor-a and interleukin-6. The immunological imbalance created may, through different mechanisms, act on the metabolic pathways that contribute to the development of insulin resistance, the accumulation of lipids in the liver, and even the formation of atherosclerotic plaques. Moreover, an additional contributing factor to the above-mentioned metabolic derangements is the unopposed oxidative stress observed in chronic hepatitis C viral infection. The virus itself contributes to the formation of oxidative stress, through alterations in the trace metal homeostasis and its effect on pro-inflammatory cytokines, such as tumor necrosis factor-a.Expert opinion: The scope of this review is to emphasize the importance of the metabolic manifestations of hepatitis C viral infection and to elucidate the pathophysiological mechanisms behind their emergence.

Genetic variation in the microsomal triglyceride transfer protein (-493G/T) is associated with hepatic steatosis in patients infected with hepatitis C virus

Background

In chronic hepatitis C, the fibrosis progression rates are extremely variable and can be influenced by factors associated with the host, virus and environment. Among the associated metabolic factors, hepatic steatosis is characterized by an accumulation of triglycerides in hepatocytes. In the host, genetic determinants of hepatic steatosis are observed, such as single-nucleotide polymorphisms (SNPs) in the microsomal triglyceride transfer protein (MTTP) gene. The MTTP -493G/T SNP appears to play an important role in the regulation of gene expression and influences the plasma concentration of circulating low-density lipoprotein (LDL). The present study investigated the influence of this SNP in the development of hepatic steatosis in patients with chronic hepatitis C and evaluated the association of hepatic steatosis with certain characteristics of these patients and the hepatitis C virus (HCV).

Methods

Two hundred thirty-nine patients with chronic hepatitis C were genotyped for the MTTP -493G⁄T SNP by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The association between hepatic steatosis and selected characteristics of the patient and virus was evaluated using bivariate and multivariate analyses.

Results

The most prevalent MTTP -493G/T genotype was GG (46%) followed by GT (43.5%) and TT (10.5%). Multivariate analysis of the total cohort revealed associations between the presence of hepatic steatosis and inflammatory activity of moderate to high intensity (P < 0.001), advanced age (P = 0.010), elevated gamma glutamyl transpeptidase (GGT) levels (P = 0.010) and low LDL levels (P = 0.022). Hepatic steatosis was also associated with the TT/GT genotype of the MTTP -493G⁄T SNP in patients infected with HCV genotype 3 (P < 0.001).

Conclusions

In chronic hepatitis C patients infected with HCV genotype 3 and with the TT/GT genotype of the MTTP -493G/T SNP, a significant increase in hepatic steatosis was observed, which may indicate that this SNP has a significant influence on the accumulation of triglycerides in hepatocytes. Furthermore, associations were observed between hepatic steatosis and inflammatory activity of moderate to high intensity, advanced age, elevated GGT and low LDL levels.

Computational identifying and characterizing circular RNAs and their associated genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is currently still a major factor leading to death, lacking of reliable biomarkers. Therefore, deep understanding the pathogenesis for HCC is of great importance. The emergence of circular RNA (circRNA) provides a new way to study the pathogenesis of human disease. Here, we employed the prediction tool to identify circRNAs based on RNA-seq data. Then, to investigate the biological function of the circRNA, the candidate circRNAs were associated with the protein-coding genes (PCGs) by GREAT. We found significant candidate circRNAs expression alterations between normal and tumor samples. Additionally, the PCGs associated with these candidate circRNAs were also found have discriminative expression patterns between normal and tumor samples. The enrichment analysis illustrated that these PCGs were predominantly enriched for liver/cardiovascular-related diseases such as atherosclerosis, myocardial ischemia and coronary heart disease, and participated in various metabolic processes. Together, a further network analysis indicated that these PCGs play important roles in the regulatory and the PPI network. Finally, we built a classification model to distinguish normal and tumor samples by using candidate circRNAs and their associated genes, respectively. Both of them obtained satisfactory results (~ 0.99 of AUC for circRNA and PCG). Our findings suggested that the circRNA could be a critical factor in HCC, providing a useful resource to explore the pathogenesis of HCC.

Fibrosis in Chronic Hepatitis C: Correlation between Immunohistochemically-Assessed Virus Load with Steatosis and Cellular Iron Content

AIM

We aimed study impact of hepatocytic viral load, steatosis, and iron load on fibrosis in chronic hepatitis C and role of VEGF and VEGFR overexpression in cirrhotic cases in evolving HCC.

MATERIAL AND METHODS

Total of 120 cases were included from TBRI and Beaujon Hospital as chronic hepatitis C (CHC), post-hepatitis C cirrhosis, and HCC. Cases of CHC were stained for Sirius red, Prussian blue and immunohistochemically (IHC) for HCV-NS3/NS4. HCC were stained IHC for VEGF and by FISH.

RESULTS

Stage of fibrosis was significantly correlated with inflammation in CHC (P < 0.01). Noticed iron load did not correlate with fibrosis. Steatosis was associated with higher inflammation and fibrosis. The cellular viral load did not correlate with inflammation, steatosis or fibrosis. VEGF by IHC was significantly higher in cases of HCC when compared to cirrhotic group (P < 0.001). Amplification of VEGFR2 was confirmed in 40% of cases of HCC. Scoring of VEGF by IHC was the good indicator of VEGFR2 amplification by FISH (P < 0.005).

CONCLUSION

Grade of inflammation is the factor affecting fibrosis in CHC. The degree of liver damage is not related to cellular viral load or iron load. Steatosis is associated with higher inflammation and fibrosis. VEGF by IHC is correlated with overexpression of VEGFR2 by FISH.

Retrospective study of the associations between hepatitis C virus infection and metabolic factors

AIM

To evaluate the bidirectional association between metabolic syndrome (MS) components and antiviral treatment response for chronic hepatitis C virus (HCV) infection.

METHODS

This retrospective cohort study included 119 HCV + patients treated with pegylated-interferon-α and ribavirin. Metabolic characteristics and laboratory data were collected from medical records. Differences in baseline clinical and demographic risk factors between responders and non-responders were assessed using independent samples t-tests or χ² tests. The effects of sustained viral response (SVR) to antiviral treatment on de novo impairments in MS components, including impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM), were assessed using univariable and multivariable logistic regression analysis, while the effect of MS components on SVR was assessed using univariable logistic regression analysis.

RESULTS

Of the 119 patients, 80 (67%) developed SVR over the average 54 ± 13 mo follow-up. The cumulative risks for de novo T2DM and IFG were 5.07- (95%CI: 1.261-20.4, P = 0.022) and 3.87-fold higher (95%CI: 1.484-10.15, P = 0.006), respectively for non-responders than responders, when adjusted for the baseline risk factors age, sex, HCV genotype, high viral load, and steatosis. Post-treatment triglyceride levels were significantly lower in non-responders than in responders (OR = 0.27; 95%CI: 0.069-0.962, P = 0.044). Age and HCV genotype 3 were significantly different between responders and non-responders, and MS components were not significantly associated with SVR. Steatosis tended to attenuate SVR (OR = 0.596; 95%CI: 0.331-1.073, P = 0.08).

CONCLUSION

SVR was associated with lower de novo T2DM and IFG incidence and higher triglyceride levels. Patients infected with HCV should undergo T2DM screening and antidiabetic treatment.

Treatment of type 2 diabetes mellitus by viral eradication in chronic hepatitis C: Myth or reality?

Chronic hepatitis C is a systemic disease inducing metabolic alterations leading to extrahepatic consequences. In particular, hepatitis C virus (HCV) infection seems to increase the risk of incident type 2 diabetes mellitus in predisposed individuals, independently of liver disease stage. The mechanisms through which hepatitis C induces T2DM involve direct viral effects, insulin resistance, pro-inflammatory cytokines and other immune-mediated processes. Many studies have reported the clinical consequences of type 2 diabetes mellitus on hepatitis C outcome, but very few studies have addressed the issue of microangiopathic complications among patients with hepatitis C only, who develop type 2 diabetes mellitus. Moreover, clinical trials in HCV-positive patients have reported improvement in glucose metabolism after antiviral treatment; recent studies have suggested that this metabolic amelioration might have a clinical impact on type 2 diabetes mellitus-related complications. These observations raise the question as to whether the HCV eradication may also have an impact on the future morbidity and mortality due to type 2 diabetes mellitus. The scope of this review is to summarise the current evidence linking successful antiviral treatment and the prevention of type 2 diabetes mellitus and its complications in hepatitis C-infected patients.

Atherosclerosis as Extrahepatic Manifestation of Chronic Infection with Hepatitis C Virus

Chronic hepatitis C virus infection is associated with significant morbidity and mortality, as a result of progression towards advanced natural course stages including cirrhosis and hepatocellular carcinoma. On the other hand, the SVR following successful therapy is generally associated with resolution of liver disease in patients without cirrhosis. Patients with cirrhosis remain at risk of life-threatening complications despite the fact that hepatic fibrosis may regress and the risk of complications such as hepatic failure and portal hypertension is reduced. Furthermore, recent data suggest that the risk of HCC and all-cause mortality is significantly reduced, but not eliminated, in cirrhotic patients who clear HCV compared to untreated patients and nonsustained virological responders. Data derived from studies have demonstrated a strong link between HCV infection and the atherogenic process. Subsequently HCV seems to represent a strong, independent risk factor for coronary heart disease, carotid atherosclerosis, stroke, and, ultimately, CVD related mortality. The advent of new direct acting antiviral therapy has dramatically increased the sustained virological response rates of hepatitis C infection. In this scenario, the cardiovascular risk has emerged and represents a major concern after the eradication of the virus which may influence the life expectancy and the quality of patients' life.

High sustained virological response to pegylated interferon and ribavirin for recurrent genotype 3 hepatitis C infection post-liver transplantation

INTRODUCTION

Treatment outcomes of recurrent HCV genotype 3 (GT-3) after liver transplantation (LT) are ill-defined.

AIMS

To determine efficacy, predictors, and long-term survival after treatment of recurrent HCV GT-3 infection, post-LT, with a combination of pegylated interferon (PEG) and ribavirin (RBV).

METHODS

We studied all LT recipients (LTR) in our program treated with PEG and RBV for recurrent HCV GT-3 between Jan 1st 2002 and Dec 31st 2013. Antiviral therapy (AVT) was started if histology showed recurrent HCV with ≥ stage 2 fibrosis. Treatment was intended for 24 or 36 weeks, depending on early virologic response, and/or 24 weeks consolidation. Primary endpoint was sustained virological response (SVR). We also studied predictors of SVR and long-term patient survival.

RESULTS

Among 492 LT for HCV-related cirrhosis and/or hepatocellular carcinoma performed during the study period, 110 (22%) had HCV GT-3 infection. Fifty-two (10.5%) HCV GT-3 patients had indications for AVT. Six were unable to complete the AVT, three because of clinical decompensation and one each because of metastatic disease involving the brain, lung cancer, and ductopenic rejection. Forty-seven (90%) patients achieved early virological response (EVR) and 37 (71%) achieved SVR. Predictors of SVR were EVR (p < 0.001), stage ≤ 3 fibrosis (p = 0.008), and 36 weeks treatment duration (p < 0.001). Less advanced fibrosis ≤ 3 was independent predictor of SVR (OR 0.18, 95% CI 0.05-0.67). SVR patients had actuarial (Kaplan-Meier) 1, 3, and 10 year post-treatment survival of 100, 100, and 95%, compared with 87, 78, and 20% for non-SVR patients (p < 0.001, log rank test).

CONCLUSION

Efficacy of AVT for recurrent HCV GT-3 post-LT is high, and comparable with that for non-transplant patients. Less advanced fibrosis is an independent predictor of SVR. SVR improves long-term survival.

Insulin resistance and liver steatosis in chronic hepatitis C infection genotype 3

Hepatitis C virus (HCV) infection is a common chronic liver disease worldwide. Non-alcoholic fatty liver disease and insulin resistance (IR) are the major determinants of fibrosis progression and response to antiviral therapy. The pathogenetic link between IR and chronic HCV infection is complex, and is associated with HCV genotype. Liver steatosis is the most common in the patients infected with genotype 3 virus, possibly due to direct effects of genotype 3 viral proteins. To the contrary, hepatic steatosis in the patients infected with other genotypes is thought to be mostly due to the changes in host metabolism, involving IR. In HCV genotype 3, liver steatosis correlates with viral load, reverts after reaching the sustained virologic response and reoccurs in the relapsers. A therapeutic strategy to improve IR and liver steatosis and subsequently the response to antiviral treatment in these patients is warranted.

Insulin resistance and steatosis in HBV-HCV co-infected patients: Role of PNPLA3 polymorphisms and impact on liver fibrosis progression

AIM: To evaluate steatosis, insulin resistance (IR) and patatin-like phospholipase domain-containing 3 (PNPLA3) and their relation to disease progression in hepatitis B and C viruses (HCV-HBV) co-infected patients.

METHODS: Three hundred and thirty patients with biopsy proven chronic hepatitis were enrolled: 66 had HBV-HCV, 66 HBV and 198 HCV infection. Prevalence of steatosis, IR and PNPLA3 polymorphisms and their relation to anthropometric, biochemical, virological and histological parameters were evaluated.

RESULTS: Prevalence of steatosis in group HBV-HCV was similar to that in HCV (47.0% vs 49.5%, respectively); group HBV showed the lowest steatosis (33.3%). Group HBV-HCV had a lesser degree of steatosis than HCV (P = 0.016), lower HCV RNA levels (P = 0.025) and lower prevalence and degree of IR (P = 0.01). PNPLA3 polymorphisms were associated with steatosis. Group HBV-HCV showed higher levels of liver fibrosis than group HCV (P = 0.001), but similar to that observed in HBV group. In HBV-HCV group, liver fibrosis was not associated with steatosis, IR or PNPLA3. HBV infection was the independent predictor of advanced liver fibrosis.

CONCLUSION: HBV-HCV co-infected patients have lower degree of hepatic steatosis, IR and HCV RNA than HCV mono-infected; co-infected patients showed a more rapid liver fibrosis progression that seems to be due to the double infection and/or HBV dominance.

Evolution of noninvasive tests of liver fibrosis is associated with prognosis in patients with chronic hepatitis C

No data are available about the prediction of long-term survival using repeated noninvasive tests of liver fibrosis in chronic hepatitis C (CHC). We aimed to assess the prognostic value of 3-year liver stiffness measurement (LSM), aspartate aminotransferase to platelet ratio index (APRI), and fibrosis 4 (FIB-4) evolution in CHC. CHC patients with two LSM (1,000-1,500 days interval) were prospectively included. Blood fibrosis tests APRI and FIB-4 were calculated the day of baseline (bLSM) and follow-up (fLSM) LSM. Evolution of fibrosis tests was expressed as delta: (follow-up-baseline results)/duration. Date and cause of death were recorded during follow-up that started the day of fLSM. In all, 1,025 patients were included. Median follow-up after fLSM was 38.0 months (interquartile range [IQR]: 27.7-46.1) during which 35 patients died (14 liver-related death) and seven had liver transplantation. Prognostic accuracy (Harrell C-index) of multivariate models including baseline and delta results was not significantly different between LSM and FIB-4 (P ≥ 0.24), whereas FIB-4 provided more accurate prognostic models than APRI (P = 0.03). By multivariate analysis including LSM variables, overall survival was independently predicted by bLSM, delta (dLSM), and sustained virological response (SVR). Prognosis was excellent in patients having bLSM <7 kPa, SVR, or no increase (<1 kPa/year) in 7-14 kPa bLSM. Prognosis was significantly impaired in patients with an increase (≥ 1 kPa/year) in 7-14 kPa bLSM, or decrease (≤ 0 kPa/year) in ≥ 14 kPa bLSM (P = 0.949 between these two groups). Patients with an increase (>0 kPa/year) in ≥ 14 kPa bLSM had the worst prognosis. Baseline and delta FIB-4 also identified patient subgroups with significantly different prognosis.

CONCLUSION

Three-year evolution of noninvasive tests of liver fibrosis has a strong prognostic value in CHC patients. These tests should be repeated to monitor patients and predict their outcome.

Chronic hepatitis C virus infection and atherosclerosis: Clinical impact and mechanisms

Hepatitis C virus (HCV) infection represents a major health issue worldwide due to its burden of chronic liver disease and extrahepatic manifestations including cardiovascular diseases, which are associated with excess mortality. Analysis of published studies supports the view that HCV infection should be considered a risk factor for the development of carotid atherosclerosis, heart failure and stroke. In contrast, findings from studies addressing coronary artery disease and HCV have yielded conflicting results. Therefore, meta-analytic reviews and prospective studies are warranted. The pathogenic mechanisms connecting HCV infection, chronic liver disease, and atherogenesis are not completely understood. However, it has been hypothesized that HCV may promote atherogenesis and its complications through several direct and indirect biological mechanisms involving HCV colonization and replication within arterial walls, liver steatosis and fibrosis, enhanced and imbalanced secretion of inflammatory cytokines, oxidative stress, endotoxemia, mixed cryoglobulinemia, perturbed cellular and humoral immunity, hyperhomocysteinemia, hypo-adiponectinaemia, insulin resistance, type 2 diabetes and other components of the metabolic syndrome. Understanding these complex mechanisms is of fundamental importance for the development of novel therapeutic approaches to prevent and to treat vascular complications in patients with chronic HCV infection. Currently, it seems that HCV clearance by interferon and ribavirin treatment significantly reduces non-liver-related mortality; moreover, interferon-based treatment appears to decrease the risk of ischemic stroke.

Non-invasive assessment of hepatic steatosis in patients with NAFLD using controlled attenuation parameter and 1H-MR spectroscopy

Introduction

Non-invasive assessment of steatosis and fibrosis is of growing relevance in non-alcoholic fatty liver disease (NAFLD). ¹H-Magnetic resonance spectroscopy (¹H-MRS) and the ultrasound-based controlled attenuation parameter (CAP) correlate with biopsy proven steatosis, but have not been correlated with each other so far. We therefore performed a head-to-head comparison between both methods.

Methods

Fifty patients with biopsy-proven NAFLD and 15 healthy volunteers were evaluated with ¹H-MRS and transient elastography (TE) including CAP. Steatosis was defined according to the percentage of affected hepatocytes: S1 5-33%, S2 34–66%, S3 ≥67%.

Results

Steatosis grade in patients with NAFLD was S1 36%, S2 40% and S3 24%. CAP and ¹H-MRS significantly correlated with histopathology and showed comparable accuracy for the detection of hepatic steatosis: areas under the receiver-operating characteristics curves were 0.93 vs. 0.88 for steatosis ≥S1 and 0.94 vs. 0.88 for ≥S2, respectively. Boot-strapping analysis revealed a CAP cut-off of 300 dB/m for detection of S2-3 steatosis, while retaining the lower cut-off of 215 dB/m for the definition of healthy individuals. Direct comparison between CAP and ¹H-MRS revealed only modest correlation (total cohort: r = 0.63 [0.44, 0.76]; NAFLD cases: r = 0.56 [0.32, 0.74]). For detection of F2–4 fibrosis TE had sensitivity and specificity of 100% and 98.1% at a cut-off value of 8.85 kPa.

Conclusion

Our data suggest a comparable diagnostic value of CAP and ¹H-MRS for hepatic steatosis quantification. Combined with the simultaneous TE fibrosis assessment, CAP represents an efficient method for non-invasive characterization of NAFLD. Limited correlation between CAP and ¹H-MRS may be explained by different technical aspects, anthropometry, and presence of advanced liver fibrosis.

An insight into the diagnosis and pathogenesis of hepatitis C virus infection

This review focuses on research findings in the area of diagnosis and pathogenesis of hepatitis C virus (HCV) infection over the last few decades. The information based on published literature provides an update on these two aspects of HCV. HCV infection, previously called blood transmitted non-A, non-B infection, is prevalent globally and poses a serious public health problem worldwide. The diagnosis of HCV infection has evolved from serodetection of non-specific and low avidity anti-HCV antibodies to detection of viral nucleic acid in serum using the polymerase chain reaction (PCR) technique. Current PCR assays detect viral nucleic acid with high accuracy and the exact copy number of viral particles. Moreover, multiplex assays using real-time PCR are available for identification of HCV-genotypes and their isotypes. In contrast to previous methods, the newly developed assays are not only fast and economic, but also resolve the problem of the window period as well as differentiate present from past infection. HCV is a non-cytopathic virus, thus, its pathogenesis is regulated by host immunity and metabolic changes including oxidative stress, insulin resistance and hepatic steatosis. Both innate and adaptive immunity play an important role in HCV pathogenesis. Cytotoxic lymphocytes demonstrate crucial activity during viral eradication or viral persistence and are influenced by viral proteins, HCV-quasispecies and several metabolic factors regulating liver metabolism. HCV pathogenesis is a very complex phenomenon and requires further study to determine the other factors involved.