Alcohol, hepatotropic viruses, and hepatocellular carcinoma

Oxidative stress and antioxidants in hepatic pathogenesis

Long term hepatitis B virus (HBV) infection is a major risk factor in pathogenesis of chronic liver diseases, including hepatocellular carcinoma (HCC). The HBV encoded proteins, hepatitis B virus X protein and preS, appear to contribute importantly to the pathogenesis of HCC. Both are associated with oxidative stress, which can damage cellular molecules like lipids, proteins, and DNA during chronic infection. Chronic alcohol use is another important factor that contributes to oxidative stress in the liver. Previous studies reported that treatment with antioxidants, such as curcumin, silymarin, green tea, and vitamins C and E, can protect DNA from damage and regulate liver pathogenesis-related cascades by reducing reactive oxygen species. This review summarizes some of the relationships between oxidative stress and liver pathogenesis, focusing upon HBV and alcohol, and suggests antioxidant therapeutic approaches.

Psychiatric and substance use disorders in individuals with hepatitis C: epidemiology and management

Hepatitis C virus (HCV) infection is a major health concern in the US as well as in other countries worldwide. Treatment issues and disease management strategies are complicated by the extremely high rate of psychiatric and substance use disorders in those who have HCV. The majority of new and existing cases of HCV are related to injection drug use and, in this population, the prevalence of psychiatric comorbidity is high. Optimally, all patients with HCV should be screened for psychiatric and substance use disorders before initiation of antiviral therapy. If a patient screens positive, he or she should be referred to a mental healthcare provider or addiction specialist, assessed for the presence of a psychiatric or substance use disorder, and appropriately treated prior to initiation of antiviral (i.e. interferon) therapy. Although interferon-based therapies can lead to severe neuropsychiatric adverse effects, including in rare instances suicide, evidence suggests that many patients with comorbid psychiatric and substance use diagnoses can be treated safely and effectively using comanagement strategies. However, most patients with HCV are not treated with antiviral therapy. Therefore, we must expand our definition of HCV 'treatment' to include treatment of the comorbid psychiatric and substance use disorders that accompany HCV infection and precede antiviral therapy. This paper reviews the epidemiology and management of psychiatric and substance use disorders in patients with HCV, the issue of psychiatric and substance use disorders as contraindications for antiviral therapy, and current treatment strategies for HCV patients with these comorbid conditions.

Early molecular and genetic determinants of primary liver malignancy

Although the overview above provides a partial molecular picture of the early stages of stepwise hepatocarcinogenesis. it should be emphasized that tumor and nontumor liver contain multiple changes, and that there is variability in their profile among different patients even within single studies. Variability in the number and types of genetic changes has also been observed geographically, and may be dependent upon the etiology of the tumor (viral, chemical or both). Interestingly, HBxAg inactivates tumor suppressors (such as p53 [by direct binding] and Rb [by stimulating its phosphorylation]) early in carcinogenesis that are mutated later during tumor progression. HBxAg also constitutively activates signal transduction pathways, such as those involving c-jun and ras, and activates oncogenes,such as c-nloc, that are otherwise activated by 3-catenin mutations. These findings suggest common molecular targets in hepatocarcinogenesis, despite different mechanisms of activation or inactivation. These observations need to be exploited in future drug discovery and in the development of new therapeutics. Heterogeneity in the mechanisms of tumor development, evidenced by the differences in the up- and down regulated genes reported in micro array analyses, as well as in the genetic loci that undergo mutation or LOH indifferent reports, has now been well documented. This suggests that there are multiple pathways to HCC, and that there is redundancy in the pathways that regulate cell growth and survival. These findings also reflect that,although hepatocarcinogenesis is multistep, the molecular changes that underpin histopathological changes in tumor development are likely to be different or only partially overlapping in individual tumors. Overall, the consequences of these changes suggest that the pathogenesis of HCC is accompanied by a progressive loss of differentiation, loss of normal cell adhesion, loss of the ECM, and constitutive activation of selected signal transduction pathways that promote cell growth and survival. Although mechanisms are important, attention also has to be paid to the target genes whose altered expression actually mediate the neoplastic phenotype. Other key avenues of work need to be explored. For example, it will be important to try to identify germline mutations in HBV-infected patients that are passed on to their children, resulting in the development of HCC in childhood. Clinical materials will also be important for the validation of new markers with diagnostic or prognostic potential. In this context, there is an urgent need to establish simple and low-cost tests based upon molecular changes that are hallmarks of HCC development. Identification of patients with early HCC will also significantly increase survival through its impact upon treatment. The discovery and validation of HCC markers may permit accurate staging of lesions, determine the proximity of such lesions to malignancy, and determine whether lesions with a particular genetic profile are still capable of remodeling through appropriate therapeutic intervention. The efficient reintroduction of the relevant tumor suppressors, or the inhibition of oncogene expression by siRNA, provide just some of the additional opportunities that will ultimately be useful in patient treatment. Together, these approaches will go far in reducing the very high morbidity and mortality associated with HCC.

Hepatitis C and alcohol: interactions, outcomes, and implications

BACKGROUND

Alcoholism and chronic hepatitis C (HCV) infection are common causes of liver disease worldwide. Hepatitis C virus and alcohol use frequently coexist, and together lead to more rapid progression of liver disease.

GOALS

To critically review the literature pertaining to the combined effects of alcohol and HCV, focusing primarily on how alcohol influences the natural history, pathogenesis, and treatment of HCV liver disease.

STUDY

A thorough review of the English literature was conducted, using a MEDLINE-based computerized literature search and review of cited references.

RESULTS

Hepatitis C virus is prevalent in unselected alcoholic populations (14-36%) and in alcoholic individuals with liver disease (< or =51%). Hepatitis C virus-infected individuals who drink alcohol in excess have more severe histologic injury, more rapid disease progression, and a higher frequency of cirrhosis and hepatocellular carcinoma. Alcohol use also appears to decrease response rates to interferon therapy. The mechanisms of interaction between alcohol and HCV are not fully understood, but they likely include the effects of alcohol on the host immune system and the virus and on other factors possibly related to HCV liver disease and hepatic carcinogenesis.

CONCLUSIONS

Alcohol use and HCV infection frequently coexist. Although there is ample evidence that alcohol use adversely affects the natural history of HCV liver disease, how the two interact is not well understood. Patients with chronic HCV should be encouraged to avoid alcohol; however, the threshold above which alcohol results in accelerated liver disease remains to be determined.

Mortality from hepatocellular and biliary cancers: changing epidemiological trends

OBJECTIVES

The incidence of hepatocellular carcinoma may be rising in the United States. The aim of this study was to determine the epidemiological trends in mortality from hepatocellular carcinoma (HCC) and biliary cancers (BCs) in Maryland during the last 3 decades.

METHODS

The number of deaths due to HCC and BCs from 1970 to 1997 were obtained from the Maryland State Department of Health & Hygiene vital statistics database. Malignant neoplasms of the gallbladder and intrahepatic and extrahepatic bile ducts were grouped together as biliary cancers. To determine the trend in mortality, the total time period was divided into seven 4-yr periods.

RESULTS

Mortality from HCC increased from 0.94 to 1.84 per 100,000 population (rate ratio = 1.94, CI = 1.87-2.03) and that from BCs increased from 1.28 to 1.7 per 100,000 population (rate ratio = 1.31, CI = 1.26-1.36) over the study period. Although mortality due to HCC doubled in men (1.34 to 2.7 per 100,000) during this period, only a modest increase was observed among women (0.59 to 1.06 per 100,000). Because of a marked increase in the number of deaths among white Americans, the difference in HCC-related mortality between white Americans and African Americans decreased considerably during this period. Mean age at death increased steadily for BCs from 67 to 73 yr, whereas there was no real trend for HCC. Among African Americans, the death from HCC remained stable, but there was a 2-fold increase in BC-related death.

CONCLUSIONS

There was a marked increase in deaths from HCC over the past 3 decades in Maryland. This increase was more evident among men and white Americans. Deaths due to BCs increased modestly during the same period of observation. The marked rise in BC-related deaths among African Americans remains unexplained.

Hepatocellular carcinoma

Hepatocellular carcinoma (HCC) for most patients is a terminal complication of chronic inflammatory and fibrotic liver disease. With regrettably few exceptions, treatment is largely palliative, and long-term survival is rare. However, the major causes of HCC worldwide are known and preventable. Hepatitis B and C exist only in man; the viruses have no known non-human reservoirs. Transmission of the viruses can be interrupted by vaccination against hepatitis B virus infection and improvements in medical techniques for hepatitis C, for which no vaccine has yet been developed.

Efficacy of a high and accelerated dose of hepatitis B vaccine in alcoholic patients: a randomized clinical trial

PURPOSE

A randomized, double-blind trial was conducted to compare the efficacy of a high-dose versus standard-dose hepatitis B vaccine in alcoholic patients.

PATIENTS AND METHODS

One hundred ten alcoholic patients were randomized to either receive the standard dose (20 micrograms at 0.1, and 6 months) or a high dose (40 micrograms at 0, 1, 2, and 6 months) of recombinant hepatitis B vaccine (Engerix-B). Patients were monitored for relapse of drinking using self-report, serial serum carbohydrate deficient transferrin, and collateral verification. The final titer of antibody to hepatitis B surface antigen (anti-HBs) was obtained 12 months after the first vaccine dose; a seroconversion was defined as a titer greater than 10 mlU/ml.

RESULTS

One hundred subjects completed the study; 10 of these had clinical or pathological evidence of cirrhosis. Thirty-six out of 48 (75%) of patients administered the high-dose regimen seroconverted compared with 24 of 52 (46%) in the standard dose group (P < 0.005). The mean anti-HBs titer of the high dose group was significantly greater than of the standard dose group (76.4 versus 39.4 mlU/ml, P < 0.01). Logistic regression demonstrated a significant effect on seroconversion for the vaccine dose (P < 0.005) and serum albumin (P = 0.05) but not for the other variables such as race, age, drinking during the study, serum creatinine, arm muscle circumference, and cirrhosis.

CONCLUSIONS

A high- and accelerated-dose regimen of hepatitis B improves the serological response in alcoholic patients. This regimen (currently recommended for hemodialysis patients) should now also be considered for patients with a history of alcoholism.

Effect of ethanol on mouse hepatitis virus-induced cytotoxicity

The effect of ethanol on cells infected with mouse hepatitis virus (MHV) was investigated. After MHV infection of competent cells, NCTC1469, ethanol was added to the culture at various concentrations, and the viability of cells was measured using 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide. To examine the possible involvement of the ethanol metabolite, acetaldehyde, alcohol dehydrogenase activity was measured in NCTC1469 cells. Ethanol alone did not show cytotoxicity against NCTC1469 cells at concentrations from 0.125% to 2%. After infection with MHV, the viability of cells decreased, and this decrease was further enhanced, dose-dependently, by the addition of ethanol. The activity of alcohol dehydrogenase in the cells was below the detectable level. The same phenomena were also demonstrated in cells infected with influenza virus and Herpes simplex virus. These results demonstrate that ethanol enhances MHV-mediated cytotoxicity; this exacerbation of cytotoxicity by ethanol is suggested to be an effect common to cytopathic virus-infected cells.