Sarino Aricò

Detection of antibodies against proteins modified by hydroxyethyl free radicals in patients with alcoholic cirrhosis

BACKGROUND/AIMS We have previously shown that hydroxyethyl free radicals produced during cytochrome P4502E1-mediated oxidation of ethanol covalently bind to microsomal proteins. The present study examined whether alkylation of proteins by hydroxyethyl radicals induces an immunologic response in alcoholic patients. METHODS A microplate enzyme-linked immunosorbent assay was developed using as antigen human serum albumin or bovine fibrinogen reacted with chemically produced hydroxyethyl radicals. RESULTS This assay showed that the sera of alcoholic cirrhotics contained both immunoglobulin (Ig) Gs and IgAs that recognized proteins modified by hydroxyethyl radicals, whereas practically no reaction was observed in the sera of healthy controls or cirrhotics without evidence of alcohol abuse. The reactivity of the sera from alcoholic patients was not influenced by the protein to which hydroxyethyl radicals were bound. The sera of alcoholic cirrhotics also contained antibodies directed against acetaldehyde-modified albumin. However, the reaction of alcoholic sera with hydroxyethyl radical epitopes was not inhibited by increasing concentrations of acetaldehyde-modified albumin produced under either reducing or nonreducing conditions. CONCLUSIONS The results indicate that a new group of antigens that do not cross-react with antibodies against acetaldehyde-derived epitopes is formed by the alkylation of protein by hydroxyethyl radicals and is involved in the development of immunologic reactions in alcoholic patients.

Attributable risk for symptomatic liver cirrhosis in Italy

BACKGROUNDS/AIMS Knowledge of the proportion of liver cirrhosis attributable to the main risk factors is largely based on methodologically questionable clinical reports. METHODS The proportion of newly diagnosed cases of symptomatic liver cirrhosis attributable to known risk factors was estimated by a case-control study performed during 1989-1996 in 23 medical divisions of several hospitals distributed throughout Italy. Cases were 462 inpatients with cirrhosis admitted for the first time for liver decompensation. Controls were 651 patients admitted during the same period and to the same hospitals as the cases, for acute diseases unrelated to alcohol and virus infection. The proportion of symptomatic liver cirrhosis cases due to alcohol intake and hepatitis B and C viruses and the combination of these was expressed as the population attributable risk. RESULTS Attributable risks were 67.9% (95% confidence interval (CI): 53.8-79.4) for alcohol, 40.1% (95% CI: 35.3-45.2) for hepatitis C virus and 4.4% (95% CI: 2.5-7.6) for hepatitis B virus. The three factors together explained 98.1% (95% CI: 81.6-99.6) of cases in men and 67.0% (95% CI: 50.4-85.8) in women. CONCLUSIONS Alcohol is the risk factor with the highest impact on symptomatic liver cirrhosis risk in Italy. From a public health viewpoint, with the elimination of the well-known risk factors (particularly alcohol and hepatitis C virus), liver cirrhosis should become a rare disease.

AMOUNT AND DURATION OF ALCOHOL INTAKE AS RISK FACTORS OF SYMPTOMATIC LIVER CIRRHOSIS: A CASE-CONTROL STUDY

We carried out a hospital based case-control study involving 320 patients with symptomatic liver cirrhosis (LC) and 320 pair-matched control individuals, in order to estimate the dose-response relationship between both the daily amount and the duration of alcohol intake and the risk of LC. Lifetime alcohol consumption was measured by a standardized and reproducible questionnaire, and expressed as lifetime daily alcohol intake (LDAI) and duration of alcohol consumption (DAC). The odds ratio (OR) for LC was estimated by the conditional logistic regression. It increased from 1.0 for lifetime abstainers to 4.2 for LDAI of 225 g or more. Comparing durations of alcohol consumption of < or = 10 and > or = 30 years in the model, the ORs consistently decreased for all the LDAI categories: from 4.1 to 0.6 in the 25-50 g category; from 15.1 to 0.9 in the 75-100 g category; from 67.2 to 1.5 in the 125 g or more category. Our results suggest that the dose-dependent relationship between alcohol and LC may be mediated by the degree of individual susceptibility to the detrimental effect of alcohol to the liver.

Female Sex and the Risk of Liver Cirrhosis

BACKGROUND Evidence on gender-related differences in susceptibility to alcohol-induced liver diseases is questionable with regard to both methodologic and clinical aspects. With the aim to assess the role of gender in the risk of liver cirrhosis, independently and in combination with known risk factors, data from three case-control studies performed in various Italian areas were analysed. METHODS The cases were 462 cirrhotic patients (300 men and 162 women) admitted for the first time to hospital for liver decompensation. Controls were 651 patients (355 men and 296 women) 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. RESULTS A significant and independent associations between alcohol intake, chronic hepatitis B and C virus infections, and the risk of liver cirrhosis was observed. The effect of alcohol intake was multiplicatively increased in women. The odds ratio (OR) increased from 1.0 (reference category: men, lifetime abstainers) to 31.4 (95% confidence interval (CI), 10.3-95.8) in men drinking more than 100 g/day of alcohol, and from 2.2 (95% CI, 1.0-7.1) in abstaining women to 44.8 (95% CI, 8.2-224.0) in women drinking more than 100 g/day of alcohol. An increased risk of liver cirrhosis associated with female gender independently of alcohol consumption and virus infection was also observed. CONCLUSIONS A higher susceptibility to alcohol-induced liver diseases was confirmed for women, and an independent effect of female sex on the risk of cirrhosis was observed. Besides alcohol and viruses, some unknown gender-related factor might then be involved in the occurrence of the disease.

Exploring the combined action of lifetime alcohol intake and chronic hepatotropic virus infections on the risk of symptomatic liver cirrhosis

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.

Is alcohol a risk factor for liver cirrhosis in HBsAg and anti-HCV negative subjects?

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.

Nutrient intakes, nutritional patterns and the risk of liver cirrhosis: an explorative case-control study

Several experimental studies have suggested that specific nutrients might play a role on the risk of liver damage. Nevertheless, few epidemiological studies have evaluated the role of diet on the risk of symptomatic liver cirrhosis, giving contradictory results. To evaluate the role of the intake of nutritional factors and dietary patterns on the risk of symptomatic liver cirrhosis and to examine their combined action with alcohol consumption we used data from the Italian Study on Liver Cirrhosis Determinants project. From 1994 to 1998 all the consecutive cirrhotic inpatients admitted to 19 Italian collaborative hospitals for signs of liver decompensation in whom the diagnosis of liver cirrhosis was made for the first time (259 cases) and one or two gender, age and area of residence matched individuals (416 controls) were recruited. Data on lifetime alcohol intake, usual consumption of 191 food items and on markers of hepatitis B and C viral infection were collected. The analysis of principal components identified a nutritional pattern positively correlated with vegetable and fruit intakes and negatively with animal and no-fruit sugar products. With respect to abstainers, relative risks in consumers of use ≤25 and ≥51g/day of alcohol increased from 0.4 [95% confidence interval 0.0, 5.9] to 9.3 [1.3, 69.0] and from 2.1 [1.1, 4.2] to 18.1 [2.8, 118.3] for the lowest and the highest value of this nutritional pattern, respectively. Diet might therefore modulate the damaging effect of alcohol on the liver.

A strong negative association between alcohol consumption and the risk of hepatocellular carcinoma in cirrhotic patients - A case-control study

We carried out a hospital-based, case-control study to assess the association of both the Hepatitis B Virus (HBV) infection and the lifetime daily alcohol intake with the risk of developing hepatocellular carcinoma (HCC) in patients with liver cirrhosis (LC). Cases were 62 consecutive inpatients of a Gastroenterology Division in whom a first diagnosis of HCC superimposed on LC was made. Two control groups were used: 310 patients without liver disease, matched 1:5 with cases and randomly selected from inpatients of the same hospital, and 97 consecutive asymptomatic inpatients in whom the first diagnosis of LC was made. Alcohol intake was quantified in all subjects by a standardized questionnaire. HBV infection was associated with HCC development in cirrhotics (odds ratio =6.8; 95% confidence interval =1.4−32.3), whereas we observed a trend towards a decreased HCC risk at increased alcohol intake values (odds ratio from 1 for lifetime abstainers to 0.2 for drinkers of 175 g/day or more). Our results suggest that alcohol intake is not a direct determinant of HCC, but its role is mediated by LC. Cirrhotics with high alcohol intake do not usually survive long enough to develop HCC.

Anti-hcv antibodies in patients with chronic liver disease and different amounts of alcohol intake: a multivariate analysis

Objective To investigate the association between the mean daily alcohol intake and positivity for serum anti-hepatitis C virus antibodies in patients with chronic liver disease of varying severity. To test the hypothesis that alcohol intake and hepatitis C virus infection have an independent role in determining chronic liver disease. Design Retrospective study using a multivariate analysis model. Methods In 212 consecutive patients with chronic liver disease, serum anti-hepatitis C virus antibodies were detected using a second-generation test and recombinant immunoblotting assay. The lifetime mean daily alcohol intake was measured by a standardized questionnaire. Patients were subsequently divided according to the histological presence or absence of liver cirrhosis and stratified into progressive categories of alcohol intake. The dose-effect relationship between anti-hepatitis C virus status and mean daily alcohol intake was assessed by a model of unconditional logistic regression, where age, gender, degree of severity of liver disease and chronic hepatitis B virus infection were considered as covariates. Results There was a strong negative association between the mean daily alcohol intake and the presence of anti-hepatitis C virus antibodies, with odds ratio decreasing down to 0.01 for the category of highest alcohol intake; no association was found for the other variables considered. Conclusion Our data support the hypothesis that alcohol intake and infection with hepatitis viruses are independent determinants of chronic liver disease.