A comparison of the molecular clock of hepatitis C virus in the United States and Japan predicts that hepatocellular carcinoma incidence in the United States will increase over the next two decades

Future of molecular profiling of human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a fatal disease occurring worldwide and developing mainly in chronic liver diseased patients. Despite routine screening of individuals at high risk, most of the patients are diagnosed at late stages of HCC. In addition, the recurrence rate after surgical resection of small tumors is high. Molecular profiling, including expression analysis, comparative genomics and proteomics, provides powerful tools to gain insight into the molecular mechanisms underlying carcinogenesis. Advances in bioinformatics have also allowed for the evaluation of large data sets. Therefore, molecular profiling of HCC using a Biological Expression Network Discovery (BLEND) strategy that integrates global molecular profiling data, including mRNA, miRNA, DNA methylation and DNA copy numbers from both the tumor and the surrounding microenvironment, along with mechanistic studies, may improve the diagnosis, treatment and prognosis of HCC patients. Such an approach will provide mechanistic insight into the pathogenesis of HCC, potentially leading to personalized medicine and the identification of new therapeutic targets.

Screening for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) currently has the fifth highest incidence rate among tumors worldwide, a rate expected to continue to increase over the next several decades. The majority of patients with HCC have cirrhosis of the liver, with chronic hepatitis B and C as the major agents of etiology. Despite advances in technology, the prognosis of patients with HCC has shown little improvement over time, most likely because most patients are diagnosed at advanced stages. HCC meets the criteria established by the World Health Organization for performing surveillance in those at risk for developing this tumor (ie, patients with cirrhosis of the liver). The objective of surveillance is to use a relatively simple and inexpensive examination in a large number of individuals to determine whether or not they are likely to develop cancer, with the overall goal of reducing morbidity and mortality from the cancer. In this article, we evaluate the criteria for performing surveillance for HCC and review the data on the efficacy of current surveillance programs.

Epidemiological and clinical evaluation of hepatitis B, hepatitis C, and delta hepatitis viruses in Tajikistan

The implication of genotypes is recognized increasingly in the clinical course of hepatitis B virus (HBV) and in response to anti-viral drugs of hepatitis C virus (HCV). Genotypic prevalence of both etiological agents varies geographically and no data are available for Tajikistan. To investigate the epidemiology and clinical significance of HBV and HCV genotypes in chronic hepatitis (group 1) and liver cirrhosis/hepatocellular carcinoma (HCC) (group 2) patients in Tajikistan, 124 patients with chronic liver disease (group 1 = 84 and group 2 = 40) were enrolled. Genotypes of HBV, HCV, and delta hepatitis virus (HDV) were determined by sequencing. The overall prevalence of anti-HCV, HCV core antigen (HCVcAg) and HBsAg was 46% (57/124) and 41.1% (51/124), respectively. Coinfection of HCV/HBV, HBV/HDV, and HCV/HBV/HDV was found in 4.8% (6/124), 11.2% (12/124), and 0.8% (1/124) of cases, respectively. HDV genotype 1 was found in 19.6% (10/51) of HBsAg-positive patients. The HBV/HDV coinfection was relatively high in group 2 compared to group 1 (15% vs. 7.1%). HCV/1b detected in 84.6% (44/52) of HCV RNA-positive patients, followed by 3a (7.6%), 2a (5.7%), and 2c (1.9%). HBV/D was detected in 94.1% (48/51) of HBsAg-positive patients, followed by HBV/A [5.8% (3/51)]. T1762/A1764 double mutation was associated with liver cirrhosis/HCC in HBV-infected patients (P = 0.0004). This is the first study on the molecular epidemiology of hepatitis viruses among chronic liver diseases patients in Tajikistan. Among HBV-infected patients, the T1762/A1764 mutation was associated with liver cirrhosis/HCC.

PPARalpha activation is essential for HCV core protein-induced hepatic steatosis and hepatocellular carcinoma in mice

Transgenic mice expressing HCV core protein develop hepatic steatosis and hepatocellular carcinoma (HCC), but the mechanism underlying this process remains unclear. Because PPARalpha is a central regulator of triglyceride homeostasis and mediates hepatocarcinogenesis in rodents, we determined whether PPARalpha contributes to HCV core protein-induced diseases. We generated PPARalpha-homozygous, -heterozygous, and -null mice with liver-specific transgenic expression of the core protein gene (Ppara(+/+):HCVcpTg, Ppara(+/-):HCVcpTg, and Ppara(-/-):HCVcpTg mice. Severe steatosis was unexpectedly observed only in Ppara(+/+):HCVcpTg mice, which resulted from enhanced fatty acid uptake and decreased mitochondrial beta-oxidation due to breakdown of mitochondrial outer membranes. Interestingly, HCC developed in approximately 35% of 24-month-old Ppara(+/+):HCVcpTg mice, but tumors were not observed in the other genotypes. These phenomena were found to be closely associated with sustained PPARalpha activation. In Ppara(+/-):HCVcpTg mice, PPARalpha activation and the related changes did not occur despite the presence of a functional Ppara allele. However, long-term treatment of these mice with clofibrate, a PPARalpha activator, induced HCC with mitochondrial abnormalities and hepatic steatosis. Thus, our results indicate that persistent activation of PPARalpha is essential for the pathogenesis of hepatic steatosis and HCC induced by HCV infection.

Hepatitis C virus core protein induces spontaneous and persistent activation of peroxisome proliferator-activated receptor alpha in transgenic mice: implications for HCV-associated hepatocarcinogenesis

Persistent infection of hepatitis C virus (HCV) can lead to a high risk for hepatocellular carcinoma (HCC). HCV core protein plays important roles in HCV-related hepatocarcinogenesis, because mice carrying the core protein exhibit multicentric HCCs without hepatic inflammation and fibrosis. However, the precise mechanism of hepatocarcinogenesis in these transgenic mice remains unclear. To evaluate whether the core protein modulates hepatocyte proliferation and apoptosis in vivo, we examined these parameters in 9- and 22-month-old transgenic mice. Although the numbers of apoptotic hepatocytes and hepatic caspase 3 activities were similar between transgenic and nontransgenic mice, the numbers of proliferating hepatocytes and the levels of numerous proteins such as cyclin D1, cyclin-dependent kinase 4 and c-Myc, were markedly increased in an age-dependent manner in the transgenic mice. This increase was correlated with the activation of peroxisome proliferator-activated receptor alpha (PPARalpha). In these transgenic mice, spontaneous and persistent PPARalpha activation occurred heterogeneously, which was different from that observed in mice treated with clofibrate, a potent peroxisome proliferator. We further demonstrated that stabilization of PPARalpha through a possible interaction with HCV core protein and an increase in nonesterified fatty acids, which may serve as endogenous PPARalpha ligands, in hepatocyte nuclei contributed to the core protein-specific PPARalpha activation. In conclusion, these results offer the first suggestion that HCV core protein induces spontaneous, persistent, age-dependent and heterogeneous activation of PPARalpha in transgenic mice, which may contribute to the age-dependent and multicentric hepatocarcinogenesis mediated by the core protein.

Incidence, risk factors and consequences of portal vein and systemic thromboses in hepatocellular carcinoma

INTRODUCTION

Hemostatic activation may be important for tumor biology. Hepatocellular carcinoma (HCC) is commonly associated with portal vein thrombosis (PVT). Little is known about factors predictive for PVT in patients with HCC or its correlation with systemic venous thromboembolism (VTE).

METHODS

We conducted a retrospective chart review of 194 consecutive patients diagnosed with HCC at the University of Rochester between 1998 and 2004 to identify the frequency and risk factors for PVT and its correlation with VTE and survival.

RESULTS

Sixty patients (31%) had PVT with a higher rate in the non-transplant group compared to transplanted patients (34% vs. 24%; p=0.15). In multivariate analysis, Child Turcotte Pugh (CTP) class, stage, major vessel involvement, serum albumin, and serum AFP were independently associated with PVT (p<0.05 for each). The presence of PVT was associated with reduced survival (median survival 2.3 months for those with PVT versus 17.6 months for those without PVT, HR 2.05, p=0.004). The incidence of systemic VTE in the total population was 6.7%, and patients with PVT had a higher rate of systemic VTE compared to patients without PVT (11.5% vs. 4.4%; p=0.04).

CONCLUSION

PVT is common in patients with HCC, indicates advanced disease, is associated with worse survival and correlates with systemic VTE, suggesting a common mechanism of hemostatic activation. Advanced stage, higher CTP class, major vessel involvement, low serum albumin, and high AFP levels are predictive of PVT in patients with HCC.

Review article: vaccination and viral hepatitis - current status and future prospects

BACKGROUND

Viral hepatitis is the most common cause of liver disease in the world. In the past 25 years, vaccines have become available for two of the five hepatitis viruses, and, where implemented, vaccination has become a key component of hepatitis prevention.

AIMS

To provide an update on recent advances in the use of current hepatitis vaccines and to examine progress in the development of vaccines for the remaining hepatitis viruses.

METHODS

A Medline search was undertaken to identify the recent relevant literature. Search terms included hepatitis vaccines, hepatitis vaccination and hepatitis A-E vaccines.

RESULTS

Dramatic vaccine-induced declines in the incidence of both hepatitis A and B have occurred in the USA. Strategies to integrate hepatitis A vaccine into universal childhood immunization are being adopted. Similarly, strategies with the goal of eliminating transmission of hepatitis B have been promulgated. A vaccine for hepatitis E has been reported to be effective and safe, but progress in the development of vaccines for hepatitis C and D has been limited.

CONCLUSION

During the next few decades, the goals of eliminating hepatitis A and B virus transmission may be reached in the USA and elsewhere.

Genetically distinct and clinically relevant classification of hepatocellular carcinoma: putative therapeutic targets

BACKGROUND & AIMS

The biological aggressiveness of hepatocellular carcinoma (HCC) and the lack of optimal therapeutic strategies have rendered the disease a major challenge. Highly heterogeneous genetic alteration profiles of HCC have made it difficult to identify effective tailor-made molecular therapeutic targets. Therefore, classification of HCC into genetically homogeneous subclasses would be of great worth to develop novel therapeutic strategies.

METHODS

We clarified genome-scale chromosomal copy number alteration profiles and mutational statuses of p53 and beta-catenin in 87 HCC tumors. We investigated the possibility that HCC might be classifiable into a number of homogeneous subclasses based solely on their genetic alteration profiles. We also explored putative molecular therapeutic targets specific for each HCC subgroup.

RESULTS

Unsupervised hierarchical cluster analysis based on chromosomal alteration profiles suggested that HCCs with heterogeneous genetic backgrounds are divisible into homogeneous subclasses that are highly associated with a range of clinicopathologic features of the tumors and moreover with clinical outcomes of the patients (P < .05). These genetically homogeneous subclasses could be characterized distinctively by pathognomonic chromosomal amplifications (eg, c-Myc-induced HCC, 6p/1q-amplified HCC, and 17q-amplified HCC). An in vitro experiment raised a possibility that Rapamycin would significantly inhibit the proliferative activities of HCCs with 17q amplification.

CONCLUSIONS

HCC is composed of several genetically homogeneous subclasses, each of which harbors characteristic genetic alterations that can be putative tailor-made molecular therapeutic targets for HCCs with specific genetic backgrounds. Our results offer an opportunity for developing novel individualized therapeutic modalities for distinctive genome types of HCC.

The interferon-alpha responsive gene TMEM7 suppresses cell proliferation and is downregulated in human hepatocellular carcinoma

Multiple regions on the chromosome arm 3p are frequently affected by loss of heterozygosity in human cancers. A candidate tumor suppressor gene is TMEM7, at 3p21.3, which encodes a transmembrane protein. TMEM7 is expressed specifically in the liver, and the encoded protein shares substantial sequence homology with human and mouse 28-kDa interferon-alpha (IFN-alpha) responsive protein. In investigation of the possible role of TMEM7 in development of hepatocellular carcinoma (HCC), we examined TMEM7 expression in 20 primary HCC and 18 HCC cell lines and found recurrent functional alterations. Although TMEM7 mRNA was expressed in normal hepatic cells, downregulation or inactivation of the gene was detected in 85% of primary HCC and 33% of HCC cell lines. To identify the mechanisms responsible, we examined genomic deletion and mutation, and also the effect of inhibitors of DNA methyltransferase and histone deacetylase on cells with low or no endogenous TMEM7 expression. Homozygous deletion of TMEM7 was not detected in 17 pairs of human HCC and corresponding noncancerous liver tissues, nor in any of the 18 HCC cell lines. TMEM7 mutation was not detected in the 18 HCC cell lines (low or normal TMEM7 expression). Treatment of two of six cell lines exhibiting downregulation or loss of TMEM7 with 5-aza-2'-deoxycytidine and trichostatin A yielded additive increase in TMEM7 expression, implicating aberrant DNA methylation and histone deacetylation in transcriptional silencing of this gene. Ectopic expression of TMEM7 in two TMEM7-deficient HCC lines suppressed cell proliferation, colony formation, and cell migration in vitro and reduced tumor formation in nude mice. Treatment of two highly invasive HCC cell lines with IFN-alpha for 7 days significantly increased TMEM7 expression and inhibited cell migration. These findings implicate loss of TMEM7 expression in hepatocarcinogenesis and suggest that modification of TMEM7 expression by IFN-alpha may have therapeutic relevance in a subset of HCC.

Risk factors for intrahepatic and extrahepatic cholangiocarcinoma in the United States: a population-based case-control study

BACKGROUND & AIMS

Intrahepatic and extrahepatic cholangiocarcinomas are rare and highly malignant cancers of the bile duct. Although the incidence of extrahepatic cholangiocarcinoma (ECC) has remained constant, the incidence of intrahepatic cholangiocarcinoma (ICC) has increased in the United States. Because the etiology of both tumors is poorly understood, a population-based case-control study was conducted to examine the association of ECC and ICC with preexisting medical conditions.

METHODS

Medical conditions among 535 ICC patients, 549 ECC patients (diagnosed 1993-1999), and 102,782 cancer-free controls were identified by using the Surveillance, Epidemiology and End Results-Medicare databases. Logistic regression analysis was used to calculate adjusted odds ratios.

RESULTS

In addition to established risk factors (choledochal cysts, cholangitis, inflammatory bowel disease), several other conditions were significantly associated with ECC and ICC: biliary cirrhosis (ECC, ICC: P < .001), cholelithiasis (ECC, ICC: P < .001), alcoholic liver disease (ECC, P < .001; ICC, P = .01), nonspecific cirrhosis (ECC, ICC: P < .001), diabetes (ECC, ICC: P < .001), thyrotoxicosis (ECC, P = .006; ICC, P = .04), and chronic pancreatitis (ECC, ICC: P < .001). Conditions only associated with ICC were obesity (ECC, P = .71; ICC, P = .01), chronic nonalcoholic liver disease (ECC, P = .08; ICC, P = .02), HCV infection (ECC, P = .67; ICC, P = .01), and smoking (ECC, P = .07; ICC, P = .04).

CONCLUSIONS

Several novel associations with ECC and ICC were identified. HCV infection, chronic nonalcoholic liver disease, and obesity, all of which are increasing in incidence, and smoking were associated only with ICC, suggesting that these conditions might explain the divergent incidence trends of the tumors.

Tracing hepatitis C and Delta viruses to estimate their contribution in HCC rates in Mongolia

An estimated incidence of hepatocellular carcinoma (HCC) in Mongolia is currently one of the highest in the world. According to previous reports, the sero-prevalence of hepatitis B (HBV) and hepatitis C (HCV) viruses in general population of the country is very high (HBV, 10% and HCV, 15%, respectively). Moreover, the majority (75-100%) of the HBV-infected individuals have co-infection with hepatitis Delta virus (HDV). Despite reported observations that HBV + HDV/HCV co-infection have significantly stronger association with HCC when compared with HCV-monoinfection, the later is still frequently observed among Mongolian HCC patients (39%). In this study, an approach based on principles of population genetics and mathematical epidemiology was used to trace an epidemic history of HCV and HDV. In agreement with the sero-epidemiological and social-historical background of the country, the results have demonstrated that the viruses had different epidemic dynamics in Mongolia; HCV was characterized by earlier epidemic expansion, whereas HDV spread with approximately 50 years lag. This may explain the comparable contribution of the HCV-monoinfection and HBV + HDV co-infection in current HCC rate despite different levels of risk of carcinogenesis. Used approach is useful in evaluation of current and prospective disease burden.

Increasing genetic diversity of hepatitis C virus in haemophiliacs with human immunodeficiency virus coinfection

Patients with inherited bleeding disorders who received clotting factor concentrates before 1987 have high rates of hepatitis C virus (HCV) or HCV/human immunodeficiency virus (HIV) infection. To determine whether the persistent nature of HIV affects the genetic diversity of HCV by less selective pressure through the immunosuppression of HIV/HCV-coinfected patients, both the change of genetic diversity and selective pressure were examined in the HCV envelope genes (E1 and E2) of 325 genotype 1a subclones from eight HIV-positive and five HIV-negative patients with two time points (more than 6 years apart). To infer the genetic diversity of HCV in each patient, we used two approaches. One method was to estimate the difference of total evolutionary distances in the phylogenetic tree between the two time points, and another was to estimate the changes of genetic diversity along the time based on the coalescence theory. The two results indicate that the HIV-positive group has significantly more diverse population structure than the HIV-negative group. A comparative analysis of the synonymous and non-synonymous substitutions found that the HIV-positive group was subject to less selective pressure than the HIV-negative group. In conclusion, HIV-positive patients would have a more diversified HCV population than HIV-negative patients due to less selective pressure from the immune system.

Recent advances in the diagnosis of hepatocellular carcinoma

In the last decade, new imaging techniques have become available, offering the possibility of investigating contrast perfusion of liver nodules in cirrhosis. It is now accepted that a non-invasive diagnosis of hepatocellular carcinoma (HCC) can be established based on the vascular pattern, obtained with pure blood pool contrast agents. The diagnostic pattern includes: hypervascularity in the arterial phase (15-35 s after contrast injection), consisting in a contrast signal in the nodule greater than in the surrounding parenchyma, followed by contrast wash out, which leads the nodule to show the same, or, more specifically, a lower contrast signal, than the surrounding parenchyma in the portal and late phases (>40 s after injection). Such a pattern can be obtained not only by computed tomography or magnetic resonance imaging, but also by contrast-enhanced ultrasonography, most simply with real-time low mechanical index harmonic imaging ultrasound equipment with second-generation ultrasound contrast agents. The risk of false-positive diagnosis of malignancy isnearly abolished when the functional vascular pattern is not the only feature, but is superimposed on a nodule visible also without contrast. One single contrast imaging technique may suffice to make a diagnosis of HCC if the nodule is >1 cm in diameter and has developed during a surveillance program. Other types of contrast agents, such as those taken up by the reticular-endothelial system cells, may offer additional diagnostic clues, but definitive evidence of their efficacy is still to be produced. In conclusion, contrast-enhanced imaging techniques now offer the possibility of a non-invasive diagnosis of HCC in a large number of cases, reducing the need of invasive investigations, such as ultrasound-guided biopsy or angiography.

The epidemiology of hepatitis C infection in the United States

BACKGROUND

The prevalence of hepatitis C virus (HCV) infection in the United States has remained constant from 1988 through 2002, although the peak age of infection has increased. While the number of new HCV cases is declining, the rates of HCV-associated morbidity and mortality are increasing. We reviewed the risk factors for HCV infection, the laboratory methods used to diagnose it, the dynamics of disease progression, and the natural history of HCV infection.

METHODS

Medline searches were performed using the key word HCV, together with incidence, risk factors, demographics, diagnostic methods, disease progression, natural history, normal alanine aminotransferase (ALT), fibrosis, and hepatocellular carcinoma (HCC).

RESULTS

Three characteristics-abnormal serum ALT, history of injection drug use, and blood transfusion before 1992-identified 85% of HCV-positive individuals 20-59 years old. About 75%-85% of acutely infected individuals progress to chronic infection, with up to 20% developing liver cirrhosis over 20-25 years, putting them at increased risk for end-stage liver disease and/or HCC. HCV-associated cirrhosis is the leading cause of liver transplantation in the United States. Rates of infection are higher in non-Hispanic blacks than in non-Hispanic whites and Mexican Americans and higher in men than in women. In the United States, over 70% of HCV-infected individuals are infected with genotype 1.

CONCLUSIONS

HCV infection is more prevalent than human immunodeficiency virus or hepatitis B virus infection and is particularly common among certain demographic groups. Individual rates of fibrosis progression vary, but identification of host and viral characteristics associated with disease progression may reveal the mechanisms of HCV-associated hepatic fibrosis/cirrhosis.

Recent epidemic of acute hepatitis C virus in HIV-positive men who have sex with men linked to high-risk sexual behaviours

OBJECTIVE

To characterize the mode of hepatitis C virus (HCV) transmission in a recent epidemic of acute HCV in HIV-infected individuals using linked molecular and clinical epidemiological studies.

DESIGN

Individuals diagnosed with acute HCV between 1999 and 2005 at three urban HIV units in the UK were enrolled into a phylogenetic and case-control study. Phylogenetic trees were constructed from the amplified sequences of the E1/E2 region of the HCV genome and were used to compare cases with unrelated sequences. A questionnaire-based, case-control study using matched controls recruited from each HIV unit identified putative transmission factors.

RESULTS

One hundred and eleven HIV-positive men who have sex with men with acute HCV (genotype 1: 84%) were enrolled. Phylogenetic analysis of 93 E1/E2 sequences revealed seven monophyletic clusters signifying multiple independent HCV lineages co-circulating in the HIV-positive population. Permucosal rather than percutaneous transmission factors were associated with case/control status. Cases (n = 60) had more sexual partners, increased levels of high-risk sexual behaviour and were more likely to have shared drugs via a nasal or anal route in the preceding year in comparison with controls (n = 130). Sex in a group of more than two people was the strongest predictor of case/control status; odds ratios associated with participation in two or at least three types of high-risk sexual behaviour in a group were 9.16 (95% confidence interval, 3.51-23.90) and 23.50 (95% confidence interval, 9.47-58.33), respectively.

CONCLUSION

The identified co-circulating HCV lineages belong to different subtypes and genotypes, implying that rather than viral change, the epidemic is due to permucosal transmission factors that should be the focus of public health interventions.

Identification and phylogenetic analysis of hepatitis C virus in forensic blood samples obtained from injecting drug users

Injecting drug users (IDUs) are a high-risk group for contracting hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections. In Japan, data on the prevalence of those blood-borne viruses among IDUs are very limited. Blood samples were obtained from 12 cadavers of IDUs sent to Nagoya City University for the purpose of judicious autopsy and two alive IDUs with hepatitis C referred to a local hospital at the same period. The viruses were detected by polymerase chain reaction and phylogenetic analysis was performed. Two (16.6%) of the 12 autopsy cases were positive for HCV, but no case was positive for either HBV or HIV. Phylogenetic analysis of the two HCV isolates revealed that one was classified into genotype 1b and another was genotype 2b. Furthermore, nucleotide sequences of two isolates recovered from IDUs with hepatitis C were identical, that indicated the transmission of HCV between them, and those HCV were phylogenetically classified into genotype 2a. The prevalence of HCV infection among IDUs in Japan, despite the case of judicious autopsy, seems to be high, but HIV infection seems to be rare. The transmission of HCV between IDUs was demonstrated, and this indicates that phylogenetic analysis would applicable to also forensic analysis. HCV isolates identified in this study did not phylogenetically segregate, thus multiple transmission route of HCV among IDUs seems be exist in Japan.

Advancements in hepatocellular carcinoma

PURPOSE OF REVIEW

This review primarily focuses on new developments in the prevention and treatment of hepatocellular carcinoma.

RECENT FINDINGS

Molecular markers for tumor biology are still in development, but advances thus far are promising. The Barcelona Clinic Liver Cancer (BCLC) staging system offers the best prognostic information in patients with hepatocellular carcinoma. While surgery remains the gold standard for the treatment of hepatocellular carcinoma, new methods are emerging with greater potential response, lower risk and lower cost. Percutaneous local ablative therapy has proved very effective. Chemoemobolization therapy in hepatocellular carcinoma has been effective in selected patients with improved survival reported in a large cohort.

SUMMARY

New methods for the management of hepatocellular carcinoma need to continue to evolve. This includes more focused therapies to reduce tumor development or more effective adjuvants to promote positive pre and posttransplant response. With the advent of better treatment options due to a clearer understanding of the pathogenesis of hepatocellular carcinoma, there is hope that the seemingly insurmountable burden of this disease will come under better control.

Hepatitis B virus-related hepatocellular carcinoma: epidemiology and pathogenic role of viral factors

Chronic hepatitis B virus (HBV) infection is the primary risk factor for the development of hepatocellular carcinoma worldwide. After decades of chronic hepatitis, about 30-40% of patients progress into liver cirrhosis, and of them, around 1-5% subsequently develop hepatocellular carcinoma (HCC) annually. Since the carcinogenic process involves the interplay between the hepatitis virus and the host hepatocytes, both genomes contribute to the final pathogenic outcome, either individually or synergistically. Studying the genetic factors predisposing hepatocarcinogenesis in both host and viral genomes will help illuminate the critical carcinogenic mechanisms, and create molecular targets for future therapy. In this article, we thus review the epidemiology of HBV-related HCC and viral factors involved in hepatocarcinogenesis.

Rising costs and hospital admissions for hepatocellular carcinoma in Portugal (1993-2005)

AIM: To determine, for hepatocellular carcinoma (HCC), the patient demographic profile and costs of their admissions to the hospitals of the Portuguese National Health System from 1993 to 2005.

METHODS: The National Registry (ICD-9CM, Inter-national Classification of Diseases, 155.0) provided data from the 97 Hospitals in Portugal.

RESULTS: We studied 7932 admissions that progres-sively rose from 292 in 1993 to 834 in 2005, having a male predominance of 78% (6130/7932). The global rate of hospital admissions for HCC rose from 3.1/10⁵ in 1993 to 8.3/10⁵ in 2005. The average length of stay decreased from 17.5 ± 17.9 d in 1993 to 9.3 ± 10.4 d in 2005, P < 0.001. The average hospital mortality for HCC remained high over these years, 22.3% in 1993 and 26.7% in 2005. Nationally, hospital costs (in Euros - €) rose in all variables studied: overall costs from €533 000 in 1993, to €4 629 000 in 2005, cost per day of stay from €105 in 1993, to €597 in 2005, average cost of each admission from €1828 in 1993, to €5550 in 2005. In 2005, 1.8% (15/834) of hospital admissions for HCC were related to liver transplant, and responsible for a cost of about €1.5 million, corresponding to one third of the overall costs for HCC admissions in that same year.

CONCLUSION: From 1993 to 2005 hospital admissions in Portugal for HCC tripled. Overall costs for these admissions increased 9 times, with all variables related to cost analysis rising accordingly. Liver transplant, indicated in a small group of patients, showed a disproportionate increase in costs.

Hepatocellular cancer: a guide for the internist

Hepatocellular cancer is the third leading cause of cancer-related deaths worldwide. Its incidence has increased dramatically in the United States because of the spread of hepatitis C virus infection and is expected to increase for the next 2 decades. Hepatitis B virus, hepatitis C virus, and chronic heavy alcohol use leading to cirrhosis of the liver remain the most important causes. The diagnosis of hepatocellular cancer rests on a combination of radiologic, serologic, and histopathologic criteria. Liver transplantation is the only definitive treatment. Resection of the tumor and other percutaneous therapies are more commonly used in practice, because most hepatocellular cancers are detected at an advanced stage. Patients who are at high risk for the development of hepatocellular cancer should be screened with an ultrasound of the liver every 6 months. The prognosis is dependent on both the underlying liver function and the stage at which the tumor is diagnosed. The aim of this review is to familiarize internists in screening, diagnosis, and referral of patients with hepatocellular cancer in an appropriate and timely fashion.

Estimating the future health burden of chronic hepatitis C and human immunodeficiency virus infections in the United States

The aim of this work was to estimate the future disease burden of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections in the United States until the year 2030. Two back-calculation models of the HIV and the HCV epidemic were developed. They were based on US epidemiological data regarding prevalence, age and gender of incident cases, AIDS, hepatocellular carcinoma (HCC) mortality and general population mortality from the Centers for Disease Control and WHO. Based on the HCV back-calculation model, HCV incidence peaked in 1984 at 350,000 new infections and then fell to about 77,000 in 1998. Based on the HIV back-calculation model, HIV incidence reached its maximum in 1989 at 142,000 new infections and then declined to 79,000 in 1998. Mortality related to HCV (death from liver failure or HCC) rose from about 3,700 in 1998 and is expected to peak at about 13,000 in 2030. Predicted HCV mortality would fall only if increased access to or more effective antiviral therapy occurs. For comparison, observed HIV-related mortality was 14,400 in 1998 and projected to be 4,200 for 2030. With the availability of effective highly active antiretroviral therapy for HIV infection, mortality from HIV appears to have declined substantially, whereas HCV-related deaths as a result of pre-1999 infections will likely continue to increase over the next 25 years.

Epidemic dynamics of two coexisting hepatitis C virus subtypes

Hepatitis C virus (HCV) infection affects about 3% of the human population. Phylogenetic analyses have grouped its variants into six major genotypes, which have a star-like distribution and several minor subtypes. The most abundant genotype in Europe is the so-called genotype 1, with two prevalent subtypes, 1a and 1b. In order to explain the higher prevalence of subtype 1b over 1a, a large-scale sequence analysis (100 virus clones) has been carried out over 25 patients of both subtypes in two regions of the HCV genome: one comprising hypervariable region 1 and another including the interferon sensitivity-determining region. Neither polymorphism analysis nor molecular variance analysis (attending to intra- and intersubtype differences, age, sex and previous history of antiviral treatment) was able to show any particular difference between subtypes that might account for their different prevalence. Only the demographic history of the populations carrying both subtypes and analysis of molecular variance (AMOVA) for risk practice suggested that the route of transmission may be the most important factor to explain the observed difference.

Treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world and the third cause of cancer-related death. Despite therapeutic advances, the overall survival of patients with HCC has not significantly improved in the last two decades. In the majority of the cases there is underlying cirrhosis, so the prognosis of HCC depends on not only tumor stage but also liver function. There is not a widely accepted HCC staging system. In our group we have developed a new staging classification that stratifies HCC patients into four major categories and simultaneously links staging with treatment. Patients at an early stage are those who present with an asymptomatic single HCC with a maximum diameter of 5cm or up to three nodules each less than 3cm. They will benefit from curative therapies, including resection, liver transplantation (LT), and percutaneous ablation. Patients exceeding these limits, but who are free of cancer-related symptoms and vascular invasion or extrahepatic spread fit into the intermediate stage and may benefit from palliation with chemoembolization. The patients with mild cancer-related symptoms and/or vascular invasion or extrahepatic spread are included in the advanced stage. In this stage there is not effective therapy, and these patients may profit from new therapies in the setting of randomized controlled trials (RCTs). Finally, the patients with severe cancer-related symptoms or great tumor burden belong to the terminal stage and only benefit from symptomatic treatment.

Molecular evolution of hepatitis B virus over 25 years

Determining the longitudinal molecular evolution of hepatitis B virus (HBV) is difficult due to HBV's genomic complexity and the need to study paired samples collected over long periods of time. In this study, serial samples were collected from eight hepatitis B virus e antigen-negative asymptomatic carriers of HBV genotype B in 1979 and 2004, thus providing a 25-year period to document the long-term molecular evolution of HBV. The rate, nature, and distribution of mutations that emerged over 25 years were determined by phylogenetic and linear regression analysis of full-length HBV genome sequences. Nucleotide hypervariability was observed within the polymerase and pre-S/S overlap region and within the core gene. The calculated mean number of nucleotide substitutions/site/year (7.9 x 10(-5)) was slightly higher than published estimates (1.5 x 10(-5) to 5 x 10(-5)). Nucleotide changes in the quasispecies population did not significantly alter the molecular evolutionary rate, based on linear regression analysis of evolutionary distances among serial clone pre-S region sequences. Therefore, the directly amplified or dominant sequence was sufficient to estimate the putative molecular evolutionary rate for these long-term serial samples. On average, the ratio of synonymous (dS) to nonsynonymous (dN) substitutions was highest for the polymerase-coding region and lowest for the core-coding region. The low dS/dN ratios observed within the core suggest that selection occurs within this gene region, possibly as an immune evasion strategy. The results of this study suggest that HBV sequence divergence may occur more rapidly than previously estimated, in a host immune phase-dependent manner.

Epigenetic instability and chromosomal instability in hepatocellular carcinoma

The aim of this study was to clarify the association between the epigenetic instability phenotype and the chromosomal instability phenotype in primary hepatocellular carcinoma (HCC). Sixty primary HCC tumors were examined. Methylation status for nine CpG islands (the p16, COX2, GSTP1, RASSF1A, E-cadherin, and APC gene promoters, and the MINT 1, 25, and 31 clones) was evaluated by methylation-specific polymerase chain reaction. Chromosomal structural alterations of these 60 HCC tumors were characterized in our previous study by using whole genomic array-based comparative genomic hybridization. We found that the epigenetic instability phenotype and the chromosomal instability phenotype are not mutually exclusive in hepatocarcinogenesis and that they do not show a simple cause-and-effect relationship. Hepatitis virus infection in the background liver was significantly associated with these instability phenotypes. Furthermore, we identified an epigenetic instability-dependent HCC that shows frequent epigenetic aberrations without chromosomal instability. It was noteworthy that epigenetic instability-positive and -negative HCCs displayed distinctive combinations of chromosomal structural alterations. In summary, by combined analyses of genetic and epigenetic aberration profiles in HCC, we obtained a comprehensive view of genomic alterations in hepatocarcinogenesis. Our results have clinical relevance because epigenetic instability-dependent HCCs may respond well to methylation inhibitory therapies.

Investigating the origin and spread of hepatitis C virus genotype 5a

Epidemiological and phylogenetic studies of hepatitis C virus (HCV) have identified six major HCV genotypes and have attempted to characterize their origin and spread worldwide. Putative regions of endemic infection have been identified for all HCV genotypes except HCV genotype 5a. Although HCV genotype 5a was previously thought to be largely restricted to the northern part of South Africa, this study reports an unexpected cluster of the genotype in West Flanders Province in Belgium. To investigate the molecular epidemiology of this cluster and of HCV genotype 5a in general, a rigorous phylogenetic analysis of Belgian and South African HCV genotype 5a samples was performed. Remarkably, the Belgian and South African strains form two distinct clusters of similar diversity. We used a Bayesian coalescent method to estimate the rate of virus spread through time for HCV genotype 5a in both regions. Our results indicate that HCV genotype 5a strains have been spreading independently in Belgium and South Africa for more than 100 years, with a rate of spread characteristic of an epidemic genotype. These findings have major implications for tracing the origin of HCV genotype 5a. Here, we speculate about the possible origins of these clusters.

Hepatocellular carcinoma

PURPOSE OF REVIEW

Our aim is to review the latest information regarding the risk factors, markers for early detection, diagnosis, and therapy for this tumor type.

RECENT FINDINGS

Alcohol, tobacco, and obesity interact together to increase the risk of hepatocellular carcinoma, which may allow us to identify a high-risk group for hepatocellular carcinoma among patients with cirrhosis. For the first time, a randomized controlled trial of surveillance for hepatocellular carcinoma showed improved survival for those patients who underwent surveillance compared with no surveillance. Another study showed that washout of contrast of an arterially enhancing lesion is sensitive and specific for hepatocellular carcinoma. The Barcelona Clinic Liver Cancer staging classification is the best at stratifying prognosis and treatment strategy for patients with hepatocellular carcinoma. Three randomized trials showed that radiofrequency ablation improves survival when compared to percutaneous ethanol injection for early hepatocellular carcinoma.

SUMMARY

Not all patients with cirrhosis have an equal risk for developing hepatocellular carcinoma. Further studies should stratify the risk of hepatocellular carcinoma so surveillance is tailored to those at the highest risk. Washout of contrast of arterially enhancing mass is regarded as the typical appearance of hepatocellular carcinoma in triple-phase imaging. Radiofrequency ablation is the best ablative technique for the treatment of small hepatocellular carcinoma.

Molecular tracing of Japan-indigenous hepatitis E viruses

The ancestor(s) of apparently Japan-indigenous strains of Hepatitis E virus (HEV) was probably of foreign origin, but it remains unclear when and from where it made inroads. In this study, 24 genotype 3 and 24 genotype 4 HEV strains recovered in Japan each showed a significant cluster, clearly distinct from those of foreign strains, in the phylogenetic tree constructed from an 821 nt RNA polymerase gene fragment. The evolutionary rate, approximately 0.8 x 10(-3) nucleotide substitutions per site per year, enabled tracing of the demographic history of HEV and suggested that the ancestors of Japan-indigenous HEV had made inroads around 1900, when several kinds of Yorkshire pig were imported from the UK to Japan. Interestingly, the evolutionary growth of genotype 3 in Japan has been slow since the 1920s, whereas genotype 4 has spread rapidly since the 1980s. In conclusion, these data suggest that the indigenization and spread of HEV in Japan were associated with the popularization of eating pork.

Hepatitis viruses, alcohol, and tobacco in the etiology of hepatocellular carcinoma in Italy

Mortality rates of hepatocellular carcinoma (HCC) are high in Italy compared with other Western countries. To elucidate further the role of hepatitis B virus (HBV), hepatitis C virus (HCV), alcohol drinking, and tobacco smoking in the etiology of HCC, we carried out a hospital-based case-control study in two areas of Italy: the province of Pordenone in the Northeast and the town of Naples in the South. A total of 229 HCC cases (median age, 66 years) and 431 controls (median age, 65 years) answered a questionnaire and provided blood samples between 1999 and 2002. Odds ratios (OR), percent attributable risks, and corresponding 95% confidence intervals were computed using unconditional multiple logistic regression. ORs for hepatitis B surface antigen (HBsAg) positive versus HBsAg negative and for anti-HCV antibody positive versus anti-HCV antibody negative were 20.2 and 15.6, respectively. Positivity for both markers was associated with an OR of 51.6. Sensitive molecular techniques applied to sera in a subset of HCC cases disclosed a very small number of occult hepatites. Maximal lifetime alcohol intake of > or =35 versus <7 drinks/wk was associated with an HBV/HCV adjusted OR of 5.9. Tobacco smoking was unrelated to HCC risk overall but seemed to enhance HCC risk among virus carriers. Overall, 61% of HCC were attributable to HCV, 13% to HBV, and 18% to heavy alcohol drinking. In conclusion, our study confirms the importance of HCV in HCC etiology in Italy where the widespread dissemination of the virus dates back four or five decades.

Population genetic history of hepatitis C virus 1b infection in China

Subtype 1b is the most common strain of Hepatitis C virus (HCV) in China. Here, the molecular epidemiology and epidemic history of this strain were investigated by conducting phylogenetic and population genetic analyses of E1 and NS5B gene sequences sampled from nine Chinese cities. The phylogenetic analysis indicated the presence of two clusters of Chinese strains that did not include reference strains from other countries, suggesting that these clusters represent two independent chains of HCV transmission within China. The remaining Chinese isolates were more closely related to reference strains from other countries. The date of origin and past population dynamics of the two groups were investigated using a new population genetic method, the Bayesian skyline plot. The estimated dates of origin of both groups coincide with the period of the Chinese 'Cultural Revolution' during the years 1966-1976. Both groups grew at a rapid exponential rate between approximately 1970 and approximately 1990, after which transmission slowed considerably. Possible explanations for the groups' fast spread and subsequent slowdown are discussed, including parenteral transmission by unsafe injection, iatrogenic transmission by infected blood or blood products and improvements in blood safety since 1990. These results shed light on HCV transmission in China and may help to predict the future burden of HCV-related disease in the country.

Molecular tracing of the global hepatitis C virus epidemic predicts regional patterns of hepatocellular carcinoma mortality

BACKGROUND & AIMS

Molecular evolutionary analysis based on coalescent theory can provide important insights into epidemiologic processes worldwide. This approach was combined with analyses of the hepatitis C virus (HCV) epidemiologic-historical background and HCV-related hepatocellular carcinoma (HCC) in different countries.

METHODS

The HCV gene sequences of 131 genotype 1b (HCV-1b) strains from Japan, 38 HCV-1a strains from the United States, 33 HCV-1b strains from Spain, 27 HCV-3a strains from the former Soviet Union (FSU), 47 HCV-4a strains from Egypt, 25 HCV-5a strains from South Africa, and 24 HCV-6a strains from Hong Kong isolated in this study and previous studies were analyzed.

RESULTS

The coalescent analysis indicated that a transition from constant size to rapid exponential growth (spread time) occurred in Japan in the 1920s (HCV-1b), but not until the 1940s for the same genotype in Spain and other European countries. The spread time of HCV-1a in the United States was estimated to be in the 1960s; HCV-3a in the FSU, HCV-5a in South Africa, and HCV-6a in Hong Kong in the 1960s, mid-1950s, and late 1970s, respectively. Three different linear progression curves were determined by analysis of the relationship between HCV seroprevalence and HCC mortality in different geographic regions; a steep ascent indicated the greatest progression to HCC in Japan, a near horizontal line indicated the least progression in the United States and the FSU, and an intermediate slope was observed in Europe.

CONCLUSIONS

These findings strongly suggest that the initial spread time of HCV is associated with the progression dynamics of HCC in each area, irrespective of genotype.

Hepatitis C: cost of illness and considerations for the economic evaluation of antiviral therapies

Chronic hepatitis C virus (HCV) infection affects 170 million individuals worldwide. As it is detected incidentally through the evaluation of liver function tests or at the time of blood donor testing, it is usually clinically silent until the advanced stages of liver disease have occurred, when treatment is less effective and shortages of donor liver organs limit the therapeutic options. Combination therapy with ribavirin and pegylated interferon has resulted in sustained viral negative response rates of 54-61%. Because treatment is expensive and not uniformly effective, and because not all chronically infected patients will develop complications, concerns have arisen regarding the cost effectiveness of combination therapy. This paper reviews the public health and individual implications of HCV infections. Because of the latency of infection, numerous country-specific population analyses suggest that HCV will cause an increasing number of liver-related deaths over the next 10 years, despite the dramatic drop in incidence over the past 10-15 years. These deaths will be related to prevalent HCV infection from transfusion and injection drug use prior to identification of the virus and availability of screening tests in the late 1980s and early 1990s. HCV can reduce life expectancy and impair quality of life, yet not all patients will develop progressive liver disease, and antiviral treatment may have associated adverse effects. Finally, to assess the value of antiviral drugs for HCV infection, this paper reviews studies examining the costs of antiviral drugs and of the disease itself along with response to antiviral therapy and the cost effectiveness of antiviral therapy. Although antiviral therapy appears to be expensive, when also considering the likelihood of sustained viral response to therapy, and the cost savings, quality-of-life improvement and prolongation of life expectancy from the prevention of HCV complications, antiviral treatment for HCV appears to be cost effective when compared with other well accepted medical interventions.

Limitation of combination therapy of interferon and ribavirin for older patients with chronic hepatitis C

In contrast to the United States, Japanese patients with chronic hepatitis C currently treated with interferon are generally 10 to 15 years older. Older patients, however, tend to experience more frequent adverse events. This study was conducted to clarify the effect of patient age on the efficacy and safety of combination therapy. We consecutively enrolled 208 patients with naïve chronic hepatitis C. Patients were classified into three groups according to age: younger than 50 years of age (n = 52); 50 to 59 years old (n = 83); and 60 years of age or older (n = 73). Interferon alpha-2b therapy was administered daily for 2 weeks, followed by 3 times per week for 22 weeks, while ribavirin was administered daily. Of the 208 study patients, discontinuation of therapy or dose reduction was required in 116 (56%) and was more frequent in older patient groups: 38%, 48%, and 77% for the < 50, 50-59, and > or = 60-year-old patient groups, respectively (P < .001). Multivariate analysis showed patient age to be independently associated with adherence to therapy. A sustained virological response was achieved in 77 (37%) patients, with genotype, viral load, and adherence to therapy associated with this achievement. A tendency toward a lower sustained virological response rate was seen in the older patients. In conclusion, patient age is an important factor contributing to the safety of combination therapy. Thus, treatment schedule should be modified, or other therapeutic modalities should be considered for older patients with chronic hepatitis C.

Spread times of hepatitis C virus estimated by the molecular clock differ among Japan, the United States and Egypt in reflection of their distinct socioeconomic backgrounds

Infection with hepatitis C virus (HCV) is taking an ever increasing role in the development of hepatocellular carcinoma (HCC) over the world. Dynamics of HCV infection were determined by the molecular clock, estimating the dissemination time when HCV entered the country and the "spread time" when it started to grow exponentially on a national scale. A comparison of HCV dynamics in Japan, the United States and Egypt has disclosed different dissemination and spread times among the three countries. Furthermore, they faithfully mirror socioeconomic as well as medical and paramedical events inherent to each country responsible for the wide spread of HCV infection during the past. Epidemic histories of HCV would enable us to predict what is going to happen in the future for HCV infection, in special reference to HCC associated with it. Population dynamics of HCV need to be determined in other countries where HCV prevails and compared with those in the three countries described. These studies should help foresee what will happen in the near future for HCV infection in a given country, time the future development of HCC and take measures for preventing it.

Expression of intestinal trefoil factor (TFF-3) in hepatocellular carcinoma

BACKGROUND

Trefoil peptides (TFF-1, 2, 3) are a family of protease-resistant regulatory factors that play a role in mucosal restitution, angiogenesis, apoptosis, and tumor progression. Intestinal trefoil peptide (TFF-3) expression has been demonstrated in benign hepatobiliary diseases, but there are limited data regarding its expression in HCC.

METHODS

Thirty consecutive cases of HCC from 1998 to 2003 were studied. Immunohistochemistry was performed on formalin-fixed paraffin-embedded blocks of HCC using polyclonal antibody to TFF-3. TFF-3 expression was classified as strong, moderate, weak, focal, and negative. Clinical data were obtained per an IRB-approved protocol.

RESULTS

Median age was 69 yr (range: 39-83 yr). Twenty- three patients were males and 7 were females. Treatments included hepatic resection (n = 16), chemo-embolization (n = 4), combined modality therapy (n = 5) and no treatment (n = 4). HCC was well differentiated in 12 (40%), moderately differentiated in 13 (43%), and poorly differentiated in 5 (17%) patients. TFF-3 expression was detected in 28/30 (93.3%) patient samples. Sixteen patients (53%) had moderate and 1 (3%) patient had strong TFF-3 expression. Tumor/ normal tissue interface was assessable in 21 cases; 11 cases expressed TFF-3 at the interface. There was a strong correlation between tumor grade and TFF-3 expression, wherein poorly differentiated tumors had moderate/strong TFF-3 expression (p = 0.008). There was no correlation between TFF-3 expression and survival (p = 0.77). Furthermore, there was no correlation among age, disease stage, and survival.

CONCLUSION

TFF-3 is commonly expressed in HCC and its expression correlates with tumor grade.

GP73, a resident Golgi glycoprotein, is a novel serum marker for hepatocellular carcinoma

BACKGROUND/AIMS

Golgi protein-73 (GP73) is up-regulated in hepatocellular carcinoma (HCC). The aims of this study were to determine if GP73 is detected in the serum, and to establish the sensitivity and specificity of serum GP73 for diagnosing HCC.

METHODS

Serum GP73 was detected by immunoblots and quantified by densitometric analysis.

RESULTS

A total of 352 patients were studied. Serum GP73 levels were significantly higher in patients with HCC compared to those with cirrhosis (P < 0.001). GP73 had a sensitivity of 69% and a specificity of 75% at the optimal cutoff point of 10 relative units, with an area under the receiver operating curve of 0.79 vs. 0.61 for AFP (P = 0.001). GP73 levels had significantly higher sensitivity (62%) than AFP (25%) for diagnosing early HCC (P < 0.0001). Moreover, GP73 levels were elevated in the serum of 57% (32/56) of individuals with HCC who had serum AFP levels less than 20ng/ml.

CONCLUSIONS

Higher levels of GP73 can be found in the serum of patients with HCC than of those without. GP73 was better than AFP for the diagnosis of early HCC. Further validation studies are needed to confirm the role of GP73 in the early detection of HCC.

Evolution over a 10 year period of the epidemiological profile of 1,726 newly diagnosed HCV patients in Belgium

In order to evaluate the future burden of hepatitis C, there is a need to quantify the evolution with time of some crucial parameters such as disease frequency and age, modes of infection and infecting genotypes of patients presenting for the first time at consultation. The yearly evolution of these parameters was analyzed retrospectively in a cohort of 1,726 patients living in Belgium, who were diagnosed as hepatitis C virus (HCV) carriers by polymerase chain reaction (PCR) between 1992 and 2002. The epidemiological profile of HCV patients showed significant changes during this period. The number of new patients increased with time. The proportion of patients under 50 increased linearly at a rate of 3% per year. The rate of newly presenting patients infected by transfusion before 1990 decreased, but only by 2.7% per year. The proportion of intravenous (IV) drug users increased by 2.5% per year. Patients presenting "undefined" risk factors increased by 2.1% per year. Nosocomial acquisition of HCV infection exhibited a disturbing relative stability in time whereas dialysis tended to disappear as a cause of infection. There was a significant linear annual decrease of 2.3% in the frequency of genotype 1b, which was counterbalanced by a significant increase of 0.7% for genotype 1a and 1.1% for genotype 4. Genotypes 2 and 3 did not vary significantly with time. Such figures are useful for evaluating the epidemiological changes of C virus infection and for anticipating the future economical cost of hepatitis C treatment in the next few years.

Viral load change and sequential evolution of entire hepatitis C virus genome in Irish recipients of single source-contaminated anti-D immunoglobulin*

In hepatitis C virus (HCV) infection, serum viral load is important in the prediction of therapeutic efficacy. However, factors that affect the viral load remain poorly understood. To identify viral genomic elements responsible for the viral load, we investigated samples from a population of Irish women who were iatrogenically infected from a single HCV source by administration of HCV 1b-contaminated anti-D immune globulin between 1977 and 1978 (Kenny-Walsh, N Engl J Med 1999; 340: 1228). About 15 patients were divided into two groups, viral load increasing group (11 patients) and decreasing group (4 patients). Pairs of sera were collected from each patient at interval between 1.1 and 5.8 years. Full-length sequences of HCV genome were determined, and analyzed for changes in each patient. Sliding window analysis showed that the decreasing group had significantly higher mutation rates in a short segment of NS5B region that may affect the activity of RNA-dependent RNA polymerase. By comparing each coding regions, significantly higher mutation numbers were accumulated in NS5A region in the increasing group than the decreasing group (0.92 vs 0.16 nucleotides/site/year, P = 0.021). The mutation in certain positions of the HCV genome may be determinant factors of the viral load in a relatively homogeneous patient population.

Different seroprevalence and molecular epidemiology patterns of hepatitis C virus infection in Italy

The epidemiological picture of hepatitis C virus (HCV) infection in the general population is largely unknown, even in developed countries. The aim of this study was to estimate the prevalence and genotype distribution of HCV amongst a large sample of the Italian general population. A total of 3,577 serum samples were collected and screened for anti-HCV antibodies. ELISA and RIBA tests were used to assess the presence of anti-HCV. NS5b region sequencing was performed for molecular characterization. Of 3,577 tested sera, 95 (2.7%) were anti-HCV positive and a genome was detected and sequenced in 50 sera. The age-adjusted prevalence was 4.4%. Seroprevalence increased with age, following a North-South gradient, and increased steeply between the 15 and 30 and 31-45 age groups. Subtype 1b showed the highest prevalence in all geographical areas and age groups, followed by subtypes 2c (detected mainly in the elderly population in Southern Italy), 4a/d, and 3a (detected exclusively in adults) and 1a. These findings confirm that Central and Southern Italy are hyperendemic areas. The high prevalence observed in adults over age 30 is mainly attributable to an increase in 1b-prevalence but also to subtypes 2c- and 3/4-infections. Age-specific prevalence data and molecular characterization of the virus suggest that two transmission patterns co-exist in Italy: one characterized by subtype 1b and 2c infections, mainly in adults older than 60 years, and the other by subtype 3 and 4 infections, mainly in the 31-60 year age group, and consistent with intravenous drug use and immigration.

Hepatocellular carcinoma as a complex polygenic disease. Interpretive analysis of recent developments on genetic predisposition

The different frequency of hepatocellular carcinoma (HCC) in humans at risk suggests a polygenic predisposition. However, detection of genetic variants is difficult in genetically heterogeneous human population. Studies on mouse and rat models identified 7 hepatocarcinogenesis susceptibility (Hcs) and 2 resistance (Hcr) loci in mice, and 7 Hcs and 9 Hcr loci in rats, controlling multiplicity and size of neoplastic liver lesions. Six liver neoplastic nodule remodeling (Lnnr) loci control number and volume of re-differentiating lesions in rat. A Hcs locus, with high phenotypic effects, and various epistatic gene-gene interactions were identified in rats, suggesting a genetic model of predisposition to hepatocarcinogenesis with different subset of low-penetrance genes, at play in different subsets of population, and a major locus. This model is in keeping with human HCC epidemiology. Several putative modifier genes in rodents, deregulated in HCC, are located in chromosomal segments syntenic to sites of chromosomal aberrations in humans, suggesting possible location of predisposing loci. Resistance to HCC is associated with lower genomic instability and downregulation of cell cycle key genes in preneoplastic and neoplastic lesions. p16(INK4A) upregulation occurs in susceptible and resistant rat lesions. p16(INK4A)-induced growth restraint was circumvented by Hsp90/Cdc37 chaperons and E2f4 nuclear export by Crm1 in susceptible, but not in resistant rats and human HCCs with better prognosis. Thus, protective mechanisms seem to be modulated by HCC modifiers, and differences in their efficiency influence the susceptibility to hepatocarcinogenesis and probably the prognosis of human HCC.

Glypican-3 promotes the growth of hepatocellular carcinoma by stimulating canonical Wnt signaling

Glypican-3 (GPC3) is a heparan sulfate proteoglycan that is bound to the cell membrane by a glycosyl-phosphatidylinositol anchor. GPC3 is expressed by most hepatocellular carcinomas but not by normal hepatocytes and benign liver lesions. We report here that GPC3 stimulates the in vitro and in vivo growth of hepatocellular carcinoma cells by increasing autocrine/paracrine canonical Wnt signaling. Co-immunoprecipitation experiments showed that GPC3 is able to form complexes with Wnts, and cell-binding assays indicated that GPC3-expressing cells have an increased capacity to bind Wnt. Collectively, these results suggest that GPC3 stimulates Wnt activity by facilitating the interaction of this polypeptide with its signaling receptors. Surprisingly, in contrast to the current model that proposes that Wnt-glypican binding is mediated by the heparan sulfate chains, we found that the nonglycanated GPC3 core protein can form complexes with Wnts. Furthermore, we showed that the glycosaminoglycan chains are not required for the stimulatory effect on Wnt signaling and hepatocellular carcinoma growth.

Glypican-3 and alphafetoprotein as diagnostic tests for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor. It is usually asymptomatic in the early stages and tends to be intravascularly and intrabiliary invasive. Therefore, most patients present with incurable disease at the time of detection and early diagnosis of HCC is critical for a good prognosis. The imaging-based diagnosis of small tumors is relatively inaccurate, as cirrhotic and dysplastic nodules mimic HCC radiologically. The availability of a suitable serological marker to distinguish between HCC and benign liver lesions would, therefore, be very useful for early diagnosis. The only serological marker currently widely used for the diagnosis of HCC is alphafetoprotein (AFP). However, the sensitivity of this marker is limited (41-65%). Given the high heterogeneity of HCC, it is currently thought that an optimal serological test for HCC will be based on the simultaneous measurement of two or three highly specific serological markers.Several laboratories have recently reported that glypican-3 (GPC3), a membrane-bound proteoglycan, is expressed by a large proportion of HCCs, but is undetectable in normal hepatocytes and non-malignant liver disease. Furthermore, various studies demonstrated that GPC3 could be used as a serological test for the diagnosis of patients with HCC. Although the specificity of the test was very high in the context of a population with chronic liver disease, the sensitivity was limited (within the same range as AFP). Interestingly, in most cases, elevated GPC3 values did not correlate with elevated AFP values. As a consequence, the serological level of at least one of the two markers was elevated in a large majority of HCC patients. These results suggest that the sensitivity of the diagnostic test can be significantly improved without compromising specificity with the simultaneous measurement of both GPC3 and AFP.

Glypican-3 and alphafetoprotein as diagnostic tests for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor. It is usually asymptomatic in the early stages and tends to be intravascularly and intrabiliary invasive. Therefore, most patients present with incurable disease at the time of detection and early diagnosis of HCC is critical for a good prognosis. The imaging-based diagnosis of small tumors is relatively inaccurate, as cirrhotic and dysplastic nodules mimic HCC radiologically. The availability of a suitable serological marker to distinguish between HCC and benign liver lesions would, therefore, be very useful for early diagnosis. The only serological marker currently widely used for the diagnosis of HCC is alphafetoprotein (AFP). However, the sensitivity of this marker is limited (41-65%). Given the high heterogeneity of HCC, it is currently thought that an optimal serological test for HCC will be based on the simultaneous measurement of two or three highly specific serological markers.Several laboratories have recently reported that glypican-3 (GPC3), a membrane-bound proteoglycan, is expressed by a large proportion of HCCs, but is undetectable in normal hepatocytes and non-malignant liver disease. Furthermore, various studies demonstrated that GPC3 could be used as a serological test for the diagnosis of patients with HCC. Although the specificity of the test was very high in the context of a population with chronic liver disease, the sensitivity was limited (within the same range as AFP). Interestingly, in most cases, elevated GPC3 values did not correlate with elevated AFP values. As a consequence, the serological level of at least one of the two markers was elevated in a large majority of HCC patients. These results suggest that the sensitivity of the diagnostic test can be significantly improved without compromising specificity with the simultaneous measurement of both GPC3 and AFP.

Role of interleukin-18 and its receptor in hepatocellular carcinoma associated with hepatitis C virus infection

Interleukin (IL)-18 is a proinflammatory cytokine that is up-regulated in patients with hepatitis C virus (HCV) infection, which is the most common underlying disease in hepatocellular carcinoma (HCC). The purpose of our study was to investigate the role of IL-18 in HCC associated with HCV infection. Sixty-five patients with HCC and HCV infections who received curative surgical resections were examined in our study. The expression of the IL-18 receptor was investigated in HCC tissues obtained from these patients and in 2 HCC cell lines. Nuclear factor (NF)-kappaB activity and the expression of Bcl-xL and xIAP mRNA were tested in the cell lines using recombinant human (rh) IL-18. The IL-18 receptor was expressed in both the HCC tissues and the cell lines. NF-kappaB activation and the expression of Bcl-xL and xIAP mRNA were increased by rhIL-18. Moreover, rhIL-18 suppressed the apoptosis of HCC cells which was induced by etoposide in vitro. The overall survival rate (55.4%) was significantly worse in the IL-18 receptor-positive patients than in the IL-18 receptor-negative patients (p = 0.015). In a Cox multivariate analysis, the expression of the IL-18 receptor was found to be a significant predictor of a poor outcome in HCC patients. The expression of the IL-18 receptor and an antiapoptotic mechanism involving NF-kappaB activation in HCC cells may be implicated in a poor patient outcome.