Epidemiology of alcoholic liver disease

Ethanol metabolism and its effects on the intestinal epithelial barrier

Ethanol is widely consumed and is associated with an increasing global health burden. Several reviews have addressed the effects of ethanol and its oxidative metabolite, acetaldehyde, on the gastrointestinal (GI) tract, focusing on carcinogenic effects or alcoholic liver disease. However, both the oxidative and the nonoxidative metabolites of ethanol can affect the epithelial barrier of the small and large intestines, thereby contributing to GI and liver diseases. This review outlines the possible mechanisms of ethanol metabolism as well as the effects of ethanol and its metabolites on the intestinal barrier. Limited studies in humans and supporting in vitro data have indicated that ethanol as well as mainly acetaldehyde can increase small intestinal permeability. Limited evidence also points to increased colon permeability following exposure to ethanol or acetaldehyde. In vitro studies have provided several mechanisms for disruption of the epithelial barrier, including activation of different cell-signaling pathways, oxidative stress, and remodeling of the cytoskeleton. Modulation via intestinal microbiota, however, should also be considered. In conclusion, ethanol and its metabolites may act additively or even synergistically in vivo. Therefore, in vivo studies investigating the effects of ethanol and its byproducts on permeability of the small and large intestines are warranted.

Understanding the Global Problem of Drug Addiction is a Challenge for IDARS Scientists

IDARS is an acronym for the International Drug Abuse Research Society. Apart from our scientific and educational purposes, we communicate information to the general and scientific community about substance abuse and addiction science and treatment potential. Members of IDARS are research scientists and clinicians from around the world, with scheduled meetings across the globe. IDARS is developing a vibrant and exciting international mechanism not only for scientific interactions in the domain of addiction between countries but also ultimately as a resource for informing public policy across nations. Nonetheless, a lot more research needs to be done to better understand the neurobiological basis of drug addiction - A challenge for IDARS scientists.

Identifying changes in the synaptic proteome of cirrhotic alcoholic superior frontal gyrus

Hepatic complications are a common side-effect of alcoholism. Without the detoxification capabilities of the liver, alcohol misuse induces changes in gene and protein expression throughout the body. A global proteomics approach was used to identify these protein changes in the brain. We utilised human autopsy tissue from the superior frontal gyrus (SFG) of six cirrhotic alcoholics, six alcoholics without comorbid disease, and six non-alcoholic non-cirrhotic controls. Synaptic proteins were isolated and used in two-dimensional differential in-gel electrophoresis coupled with mass spectrometry. Many expression differences were confined to one or other alcoholic sub-group. Cirrhotic alcoholics showed 99 differences in protein expression levels from controls, of which half also differed from non-comorbid alcoholics. This may reflect differences in disease severity between the sub-groups of alcoholics, or differences in patterns of harmful drinking. Alternatively, the protein profiles may result from differences between cirrhotic and non-comorbid alcoholics in subjects’ responses to alcohol misuse. Ten proteins were identified in at least two spots on the 2D gel; they were involved in basal energy metabolism, synaptic vesicle recycling, and chaperoning. These post-translationally modified isoforms were differentially regulated in cirrhotic alcoholics, indicating a level of epigenetic control not previously observed in this disorder.

Electrically evoked synaptosomal amino acid transmitter release in human brain in alcohol misuse

Severe chronic alcohol misuse leads to neuropathological changes in human brain, with the greatest neuronal loss in the dorsolateral prefrontal cortex. In this region, GABA(A) receptors are selectively upregulated, and show altered subunit expression profiles only in alcoholics without comorbid disease, whereas glutamate(NMDA) subunit expression profiles are selectively downregulated only in alcoholics with comorbid cirrhosis of the liver. To determine whether these outcomes might be conditional on synaptic transmitter levels, evoked release was studied in well-characterized synaptosome suspensions preloaded with L-[(3)H]glutamate and [(14)C]GABA and stimulated electrically (±10 V contiguous square waves, 0.4 ms, 100 Hz, 1.5 min) with and without Ca(2+). Stimulation elicited brief peaks of both radioisotopes that were larger in the presence of Ca(2+) ions (p < 0.01). A repeat stimulus evoked a second, smaller (p < 0.01) peak. Ca(2+)-dependent L-[(3)H]glutamate release, but not [(14)C]GABA release, was higher overall in alcoholics than in controls (p < 0.05). With comorbid cirrhosis, L-[(3)H]glutamate release showed a graded response, whereas [(14)C]GABA release was lowest in noncirrhotic alcoholics. Release patterns did not differ between cortical regions, or between males and females. Neither age nor postmortem interval was a significant confounder. The released transmitters may differentially alter receptor profiles on postsynaptic cells.

Behaviour does not fully explain the high risk of chronic liver disease in less educated men in Hungary

BACKGROUND

Hungary has among the highest mortality rates from chronic liver disease (CLD) and cirrhosis in Europe. Usually, conventional behavioural factors are hypothesized as the cause of the high risk of CLD.

METHODS

A case-control study was performed with 287 cases and 892 controls to study the relationship between socio-economic and behavioural factors and the risk of CLD. Liver disease was verified by physical examination and blood tests. Blood samples were collected for detecting hepatitis B, C and E virus infection. Information on exposure factors was recorded by the participating physicians and by self-administered questionnaire. Simple regression analysis was used to study the relationship between CLD/cirrhosis and potential risk factors as alcohol intake (amount and source), problem drinking, cigarette smoking, physical activity, viral hepatitis infections, socio-economic factors (education, financial and marital status). Multiple regression analysis was used to identify whether the effect of socio-economic factors is fully mediated by health behaviour (smoking, alcohol consumption, physical activity).

RESULTS

The univariate analysis showed that heavy alcohol consumption, problem drinking, former and heavy cigarette smoking, single, separated or divorced marital status, bad or very bad perceived financial status and lower education significantly increased the risk of CLD/cirrhosis. The effect of marital status and of education did not change after adjustment for behavioural factors, but the effect of perceived financial status disappeared.

CONCLUSIONS

The effect of low socio-economic status on the risk of CLD/cirrhosis is only partially explained by conventional behavioural risk factors in Hungary.

Sex differences in NMDA receptor expression in human alcoholics

AIM

The aim of this study was to assess whether chronic alcohol misuse affects N-methyl-d-aspartate (NMDA) receptor subunit concentrations in human cases, and whether male and female subjects respond differently.

METHODS

Real-time RT-PCR normalized to GAPDH was used to assay NR1, NR2A and NR2B subunit mRNA in superior frontal (SFC) and primary motor (PMC) cortex tissue obtained at autopsy from chronic alcoholics with and without comorbid cirrhosis of the liver, and from matched controls.

RESULTS

The expression of all three subunits was significantly lower in both areas of cirrhotic alcoholics than in either controls or alcoholics without comorbid disease, who did not differ significantly. Values were also influenced by the subject's sex and genotype. The mu-opiate receptor C1031G polymorphism selectively modulated NMDA transcript expression in cirrhotic-alcoholic SFC, an effect that was more marked for NR1 and NR2A than for NR2B subunit transcripts. Contrasting 5HT1B genotypes affected NMDA mRNA expression differently in male and female SFC, but not PMC, in cirrhotic alcoholics.

CONCLUSION

NMDA receptor subunit expression may differentially influence male and female cirrhotic alcoholics' susceptibility to brain damage.

Alcoholic liver disease: a clinical series in an Australian private practice

BACKGROUND AND AIM

The published literature on alcoholic liver disease (ALD) in Australia lacks a large clinical series out of private practice as distinct from hospital-based hepatology referral units. This series describes the presentation and clinical features of ALD in a consecutive series out of metropolitan private practice in Australia.

METHODS

A retrospective descriptive study by case-note review found 297 cases of ALD at a Brisbane practice over 20 years. The main outcome measures were: clinical features and stage at presentation, reasons for referral, and the predictive value of aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio.

RESULTS

Most patients (57.9%) had no symptoms of liver disease and 29 patients (9.8%) had neither symptoms nor signs. Cirrhosis was found in 41% of patients and hepatitis-fibrosis was found in 26% of patients. The male to female (M : F) ratio was 4.7:1. The AST/ALT ratio was not reliably predictive of ALD stage. The average reported daily alcohol intake was 131 g. Females drank less on average and presented a more vigorous clinical picture.

CONCLUSIONS

This series presents the spectrum of ALD in a metropolitan Australian private practice. Many patients are asymptomatic on presentation. All heavy drinkers should be targeted for early investigation without waiting for volunteered symptoms or abnormal physical signs. The male to female ratio in ALD is higher than hitherto reported. The AST/ALT ratio is not generally applicable in the staging of ALD. The differences from hospital series data suggest the demography and epidemiology of ALD in Australia are incomplete, and further study is warranted.

Liver transplantation for alcoholic cirrhosis: long term follow-up and impact of disease recurrence

BACKGROUND

Alcoholic liver disease has emerged as a leading indication for hepatic transplantation, although it is a controversial use of resources. We aimed to examine all aspects of liver transplantation associated with alcohol abuse.

METHODS

Retrospective cohort analysis of 123 alcoholic patients with a median of 7 years follow-up at one center.

RESULTS

In addition to alcohol, 43 (35%) patients had another possible factor contributing to cirrhosis. Actuarial patient and graft survival rates were, respectively, 84% and 81% (1 year); 72% and 66% (5 years); and 63% and 59% (7 years). After transplantation, 18 patients (15%) manifested 21 noncutaneous de novo malignancies, which is significantly more than controls (P=0.0001); upper aerodigestive squamous carcinomas were overrepresented (P=0.03). Thirteen patients had definitely relapsed and three others were suspected to have relapsed. Relapse was predicted by daily ethanol consumption (P=0.0314), but not by duration of pretransplant sobriety or explant histology. No patient had alcoholic hepatitis after transplantation and neither late onset acute nor chronic rejection was significantly increased. Multiple regression analyses for predictors of graft failure identified major biliary/vascular complications (P=0.01), chronic bile duct injury on biopsy (P=0.002), and pericellular fibrosis on biopsy (P=0.05); graft viral hepatitis was marginally significant (P=0.07) on univariate analysis.

CONCLUSIONS

Alcoholic liver disease is an excellent indication for liver transplantation in those without coexistent conditions. Recurrent alcoholic liver disease alone is not an important cause of graft pathology or failure. Potential recipients should be heavily screened before transplantation for coexistent conditions (e.g., hepatitis C, metabolic diseases) and other target-organ damage, especially aerodigestive malignancy, which are greater causes of morbidity and mortality than is recurrent alcohol liver disease.

Exploring the combined action of lifetime alcohol intake and chronic hepatotropic virus infections on the risk of symptomatic liver cirrhosis. Collaborative Groups for the Study of Liver Diseases in Italy

Although alcohol intake and hepatitis B and C virus (HBV and HCV) infections are the major determinants of liver cirrhosis (LC) in western countries, the joint effect of these factors on LC risk has not yet been adequately studied. Data from three case-control studies performed in Italy were used. Cases were 462 cirrhotic patients admitted to Hospitals for liver decompensation. Controls were 651 inpatients admitted for acute diseases unrelated to alcohol. Alcohol consumption was expressed as lifetime daily alcohol intake (LDAI). Three approaches were used to explore the interaction structure. The Breslow and Storer parametric family of relative risk functions showed that an intermediate structure of interaction from additive to multiplicative was the most adequate one. The Rothman synergism index showed that the interaction structure between LDAI and viral status differed significantly from the additive model in particular for high levels of alcohol intake. When multiple regression additive and multiplicative models were compared after adjustment for the known confounding variables. a trend of the interaction structure towards the multiplicative model was observed at increasing levels of consumption. Better methods are needed for assessing mixed interaction structures in conditions characterized by multifactorial etiologies like cirrhosis of the liver.

Independent and combined action of hepatitis C virus infection and alcohol consumption on the risk of symptomatic liver cirrhosis

Although alcohol intake and hepatitis C virus (HCV) infection are the major determinants of liver cirrhosis (LC) in Western countries, the joint effect of these two factors on LC risk has not yet been adequately studied. We used data from two hospital-based case-control studies performed in Italy. Cases were 285 cirrhotic patients admitted for the first time to district hospitals for liver decompensation. Controls were 417 patients admitted during the same period, and in the same hospitals as the cases, for acute diseases unrelated to alcohol. Alcohol consumption was expressed as lifetime daily alcohol intake (LDAI). Serum HCV antibodies (anti-HCV) were detected using a second-generation test and recombinant immunoblotting assay. We found a dose-effect relationship between LDAI and the risk of LC in both anti-HCV-negative and -positive subjects. Considering the extreme LDAI categories (LDAI = 0 g, lifetime teetotalers, and LDAI = 175 g), the LC odds ratios increased from 1.0 (reference category) to 15.0 (95% CI, 7.1-31.7) and from 9.2 (95% CI, 2.0-43.2) to 147.2 (95% CI, 42.1-514.3) in anti-HCV-negative and -positive patients respectively. The interaction between LDAI and HCV showed an additive structure for LDAI < 50 g/day and a multiplicative structure for consumption > 125 g/day. Alcohol intake and HCV infection are independent risk factors for symptomatic liver cirrhosis, each being sufficient to induce the disease. In subjects with high alcohol intake, the coexistence of HCV infection multiplies the alcohol-associated risk of cirrhosis. In subjects with low alcohol intake, other factors could be involved.

Alcohol consumption and micronutrient intake as risk factors for liver cirrhosis: a case-control study. The Provincial Group for the study of Chronic Liver Disease

PURPOSE

The purpose of this study was to assess the relationship of alcohol consumption and intake of 15 selected micronutrients with risk of liver cirrhosis.

METHODS

Data from a case-control study performed in 1989-1990 in central Italy involving 115 incident cases and 167 hospital controls were used.

RESULTS

Cases and controls did not differ for mean daily intake of calories, carbohydrates, lipids, and proteins. Significant direct dose-response relationships between the intakes of vitamin A and iron and the risk cirrhosis were observed, while significant protective effects were obtained for the intakes of vitamins B2 (riboflavin) and B12. Different patterns of the joint effect of nutrients and alcohol were also observed. The intakes of vitamin A and iron were significantly associated with the risk of cirrhosis in lifetime teetotalers (odds ratios (OR) and 95% coincidence intervals (CI) of 33.6 (1.2-979.9) and 37.9 (1.8-819.4) for higher intake of vitamin A and iron, respectively) and in consumers of < 50 g/day of alcohol (vitamin A: OR 45.0; 95% CI, (2.6-774.6); iron: OR, 73.6; 95% CI, 4.3-999). The OR associated with intakes of vitamins B2 (riboflavin) and B12 were not significant for the first two categories of alcohol use, while a higher intake of these two vitamins reduced the risk of cirrhosis associated with alcohol consumption above 50 g/day; the ORs (95% CI) were 23.0 (2.7-198.9) and 104.4 (7.2-999), respectively, for higher and lower intakes of riboflavin and 12.8 (1.8-88.1) and 138.4 (14.0-999), respectively, for higher and lower intake of vitamin B12.

CONCLUSION

These findings might explain at least a portion of the individual susceptibility to alcohol-induced liver damage.

Is alcohol a risk factor for liver cirrhosis in HBsAg and anti-HCV negative subjects? Collaborative Groups for the Study of Liver Diseases in Italy

BACKGROUND/AIMS

In order to evaluate the association between alcohol intake and the risk of liver cirrhosis in the absence of B and C hepatitis viruses, we analyzed data from three hospital-based case-control studies performed in various Italian areas.

METHODS

From the case and control series we excluded HBsAg and/or anti-HCV positive patients. Cases were 221 cirrhotic patients admitted for the first time to hospital for liver decompensation. Controls were 614 patients admitted to the same hospitals during the same period as the cases for acute diseases unrelated to alcohol. Alcohol consumption was expressed as lifetime daily alcohol intake (LDAI).

RESULTS

We found a dose-effect relationship between LDAI and the risk of liver cirrhosis (LC). Considering the extreme LDAI categories (LDAI = 0 g: lifetime teetotallers and LDAI > or = 100 g), the LC odds ratio (OR) increased from 1.0 (reference category) to 44.7 (95% confidence interval: 95% CI: 20.0-99.9). An increased risk of LC associated with the female gender independent of alcohol consumption was also observed (OR = 2.9; 95% CI: 1.8-4.6).

CONCLUSIONS

Alcohol intake acts as a risk factor for symptomatic liver cirrhosis also in the absence of HBV and/or HCV infection. Besides alcohol and viruses, some unknown gender-related factors might be involved in the occurrence of the disease.

The case for liver transplantation in end-stage alcoholic liver disease

Liver transplantation is now a routine procedure and is seen as a valid treatment option for end-stage liver disease. Alcoholism has been regarded as a relative or absolute contraindication to liver transplantation in many transplant units. Recent data document a success rate for transplantation in alcoholic patients that equals that in other patient groups. Issues relating to the ethical and scientific arguments surrounding this complex area of treatment are discussed. It is concluded that individual patients should be assessed in their own right for this treatment option. It is argued that patient groups should not be denied access to specific life-saving treatments.

Benzodiazepine binding sites in alcoholic cirrhotics: evidence for gender differences

Synaptic plasma membranes were prepared from superior frontal gyrus and motor cortex obtained at autopsy from 17 chronic alcoholics not differentiated on thiamine status, of whom 8 had pathologically confirmed cirrhosis of the liver, and 10 controls. Three of the cirrhotic alcoholic cases were female, as was one control. Cases were closely matched for age at death and post-mortem delay. The affinity of "central-type" benzodiazepine sites for [3H]diazepam tended to be lower in both brain regions of both groups of alcoholics of cf controls, but the reverse was true for [3H]flunitrazepam, especially in cirrhotic cases. [3H]Diazepam affinity was invariant across all males and the female control, but lower in the female cirrhotic alcoholics. Affinity for [3H]flunitrazepam tended to be the reverse of that for [3H]diazepam. [3H]Diazepam Bmax was markedly lower in female cirrhotic alcoholics, especially in superior frontal gyrus, whereas this region showed a much higher Bmax in the female control case. A small regional difference in [3H]flunitrazepam Bmax was the reverse of that for [3H]diazepam Bmax and was seen in all groups. GABA-mediated neurotransmission may be selectively altered in a pathologically abnormal region of cerebral cortex in cirrhotic alcoholics, and the sexes may show differing susceptibilities to change.