Adverse physical effects of alcohol misuse

This article outlines the majority of the adverse physical effects that have been described secondary to the consumption of alcohol at levels above recommended sensible limits. These conditions are cited according to the organ system they belong to. Only brief descriptions are provided because of the vastness of this topic. The underlying pathophysiology of tolerance and withdrawal is touched upon as this is of relevance to the psychiatrist. Definitions of the terms used describing alcohol misuse, and sensible upper limits of alcohol consumption are also mentioned.

Carriage of the PNPLA3 rs738409 C >G polymorphism confers an increased risk of non-alcoholic fatty liver disease associated hepatocellular carcinoma

BACKGROUND & AIMS

Subtle inter-patient genetic variation and environmental factors combine to determine disease progression in non-alcoholic fatty liver disease (NAFLD). Carriage of the PNPLA3 rs738409 c.444C >G minor allele (encoding the I148M variant) has been robustly associated with advanced NAFLD. Although most hepatocellular carcinoma (HCC) is related to chronic viral hepatitis or alcoholic liver disease, the incidence of NAFLD-related HCC is increasing. We examined whether rs738409 C >G was associated with HCC-risk in patients with NAFLD.

METHODS

PNPLA3 rs738409 genotype was determined by allelic discrimination in 100 European Caucasians with NAFLD-related HCC and 275 controls with histologically characterised NAFLD.

RESULTS

Genotype frequencies were significantly different between NAFLD-HCC cases (CC=28, CG=43, GG=29) and NAFLD-controls (CC=125, CG=117, GG=33) (p=0.0001). In multivariate analysis adjusted for age, gender, diabetes, BMI, and presence of cirrhosis, carriage of each copy of the rs738409 minor (G) allele conferred an additive risk for HCC (adjusted OR 2.26 [95% CI 1.23-4.14], p=0.0082), with GG homozygotes exhibiting a 5-fold [1.47-17.29], p=0.01 increased risk over CC. When compared to the UK general population (1958 British Birth Cohort, n=1476), the risk-effect was more pronounced (GC vs. CC: unadjusted OR 2.52 [1.55-4.10], p=0.0002; GG vs. CC: OR 12.19 [6.89-21.58], p<0.0001).

CONCLUSIONS

Carriage of the PNPLA3 rs738409 C >G polymorphism is not only associated with greater risk of progressive steatohepatitis and fibrosis but also of HCC. If validated, these findings suggest that PNPLA3 genotyping has the potential to contribute to multi-factorial patient-risk stratification, identifying those to whom HCC surveillance may be targeted.

Genetic variants regulating insulin receptor signalling are associated with the severity of liver damage in patients with non-alcoholic fatty liver disease

BACKGROUND/AIMS

The aim of this study was to assess the effect of functional ENPP1(ectoenzyme nucleotide pyrophosphate phosphodiesterase 1)/PC-1 (plasma cell antigen-1) and IRS-1 (insulin receptor substrate-1) polymorphisms influencing insulin receptor activity on liver damage in non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, whose progression is associated with the severity of insulin resistance.

PATIENTS AND METHODS

702 patients with biopsy-proven NAFLD from Italy and the UK, and 310 healthy controls. The Lys121Gln ENPP1/PC-1 and the Gly972Arg IRS-1 polymorphisms were evaluated by restriction analysis. Fibrosis was evaluated according to Kleiner. Insulin signalling activity was evaluated by measuring phosphoAKT levels by western blotting in a subset of obese non-diabetic patients.

RESULTS

The ENPP1 121Gln and IRS-1 972Arg polymorphisms were detected in 28.7% and 18.1% of patients and associated with increased body weight/dyslipidaemia and diabetes risk, respectively. The ENPP1 121Gln allele was significantly associated with increased prevalence of fibrosis stage >1 and >2, which was higher in subjects also positive for the 972Arg IRS-1 polymorphism. At multivariate analysis, the presence of the ENPP1 121Gln and IRS-1 972Arg polymorphisms was independently associated with fibrosis >1 (OR 1.55, 95% CI 1.24 to 1.97; and OR 1.57, 95% CI 1.12 to 2.23, respectively). Both polymorphisms were associated with a marked reduction of approximately 70% of AKT activation status, reflecting insulin resistance and disease severity, in obese patients with NAFLD.

CONCLUSIONS

The ENPP1 121Gln and IRS-1 972Arg polymorphisms affecting insulin receptor activity predispose to liver damage and decrease hepatic insulin signalling in patients with NAFLD. Defective insulin signalling may play a causal role in the progression of liver damage in NAFLD.

Abnormal serum alanine aminotransferase levels are associated with impaired insulin sensitivity in young women with polycystic ovary syndrome

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS) are both associated with insulin resistance.We assessed whether NAFLD is associated with impaired insulin sensitivity in PCOS women independently of age and total adiposity.

SUBJECTS AND METHODS

We enrolled 14 young PCOS women with NAFLD, 14 women with PCOS alone and 14 healthy controls, who were matched for age, body mass index, and total body fat (by bio-impedance analyzer). NAFLD was diagnosed by the surrogate measure of abnormal serum alanine aminotransferase (ALT) concentrations (defined as ALT>19 U/l) after excluding other secondary causes of liver disease (alcohol, virus, and medications). Insulin sensitivity was measured by euglycemic hyperinsulinemic clamp.

RESULTS

Insulin sensitivity was markedly decreased (p<0.001) in PCOS women with abnormal ALT levels, whereas it was similar between PCOS women with normal ALT levels andmatched healthy controls (8.3+/-2.5 vs 12.1+/-1.7 vs 13.2+/-1.8 mg/min x kg of fat-free mass, respectively). PCOS women with abnormal ALT levels also had higher plasma triglycerides and lower HDLcholesterol concentrations than those with PCOS alone. There was a strong inverse association between serum ALT levels and insulin sensitivity in the whole group of PCOS women (r=-0.59, p=0.0013).

CONCLUSIONS

Abnormal serum ALT levels, as surrogate measure of NAFLD, are closely associated with impaired insulin sensitivity in young PCOS women in a manner that is independent from the contribution of age and total adiposity. Early recognition of NAFLD by radiological imaging tests in this group of young patients is warranted.

Abnormal serum alanine aminotransferase levels are associated with impaired insulin sensitivity in young women with polycystic ovary syndrome

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS) are both associated with insulin resistance.We assessed whether NAFLD is associated with impaired insulin sensitivity in PCOS women independently of age and total adiposity.

SUBJECTS AND METHODS

We enrolled 14 young PCOS women with NAFLD, 14 women with PCOS alone and 14 healthy controls, who were matched for age, body mass index, and total body fat (by bio-impedance analyzer). NAFLD was diagnosed by the surrogate measure of abnormal serum alanine aminotransferase (ALT) concentrations (defined as ALT>19 U/l) after excluding other secondary causes of liver disease (alcohol, virus, and medications). Insulin sensitivity was measured by euglycemic hyperinsulinemic clamp.

RESULTS

Insulin sensitivity was markedly decreased (p<0.001) in PCOS women with abnormal ALT levels, whereas it was similar between PCOS women with normal ALT levels andmatched healthy controls (8.3+/-2.5 vs 12.1+/-1.7 vs 13.2+/-1.8 mg/min x kg of fat-free mass, respectively). PCOS women with abnormal ALT levels also had higher plasma triglycerides and lower HDLcholesterol concentrations than those with PCOS alone. There was a strong inverse association between serum ALT levels and insulin sensitivity in the whole group of PCOS women (r=-0.59, p=0.0013).

CONCLUSIONS

Abnormal serum ALT levels, as surrogate measure of NAFLD, are closely associated with impaired insulin sensitivity in young PCOS women in a manner that is independent from the contribution of age and total adiposity. Early recognition of NAFLD by radiological imaging tests in this group of young patients is warranted.

Fatigue in non-alcoholic fatty liver disease (NAFLD) is significant and associates with inactivity and excessive daytime sleepiness but not with liver disease severity or insulin resistance

OBJECTIVE

To quantify fatigue in non-alcoholic fatty liver disease (NAFLD), to determine whether perceived fatigue reflects impairment of physical function and to explore potential causes.

PATIENTS AND METHODS

A cohort study was carried out on 156 consecutive patients with histologically proven NAFLD studied in two cohorts. Phase 1 determined the perceived fatigue experienced by NAFLD patients (assessed using the Fatigue Impact Scale (FIS)) in comparison with normal and liver disease controls, and the relationship to physical function (actigraphy). In phase 2, biological associations of fatigue in NAFLD were explored.

RESULTS

Fatigue was markedly higher in NAFLD patients than in controls (mean (SD) FIS 51 (38) vs 8 (12), p<0.001). NAFLD patients showed significantly lower physical activity over 6 days (7089 (2909) mean steps/day vs 8676 (2894), p = 0.02). A significant inverse correlation was seen between FIS and physical activity (r = 0.1, p = 0.02). Fatigue experienced by NAFLD patients was similar to that in primary biliary cirrhosis (n = 36) (FIS 64 (9) vs 61 (2), p = NS). No association was seen between FIS and biochemical and histological markers of liver disease severity or insulin resistance (homeostasis model assessment (HOMA)) (r < 0.005). Significant association was seen between fatigue severity and daytime somnolence (Epworth Sleepiness Scale) (r = 0.2, p < 0.001).

CONCLUSION

Fatigue is a significant problem in NAFLD, is similar in degree to that in primary biliary cirrhosis patients and is associated with impairment in physical function. Fatigue in NAFLD appears to be unrelated to either severity of underlying liver disease or insulin resistance, but is associated with significant daytime somnolence.

The Glasgow alcoholic hepatitis score identifies patients who may benefit from corticosteroids

INTRODUCTION

There is no consensus on the pharmacological treatment of alcoholic hepatitis. The Glasgow alcoholic hepatitis score (GAHS) has been shown to be more accurate than the modified Maddrey's discriminant function (mDF) in the prediction of outcome from alcoholic hepatitis. This study aimed to determine whether the GAHS was able to identify those patients who would benefit from corticosteroids.

METHODS

225 patients with an mDF greater than or equal to 32 from five hospital centres in the United Kingdom were reviewed. Patient survival relative to the GAHS and the use of corticosteroids was recorded.

RESULTS

144 patients with an mDF greater than or equal to 32 (64%) also had a GAHS greater than or equal to 9. There was no difference in survival between untreated or corticosteroid-treated patients for those with a GAHS less than 9. For patients with a GAHS greater than or equal to 9 the 28-day survival for untreated and corticosteroid-treated patients was 52% and 78% (p = 0.002), and 84-day survival was 38% and 59% (p = 0.02), respectively.

CONCLUSIONS

Among patients with an mDF greater than or equal to 32, there was no appreciable benefit from treatment with corticosteroids in patients with a GAHS less than 9. Patients with a GAHS greater than or equal to 9 have an extremely poor prognosis if they are not treated with corticosteroids, or if such treatment is contraindicated.

Non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease: an open question

AIMS

To review available data concerning the basic science and epidemiological-clinical evidence for an association of NAFLD and cardiovascular disease.

DATA SYNTHESIS

Non-alcoholic fatty liver disease (NAFLD) defines alcohol-like hepatic histological lesions seen in the non-alcoholic, insulin resistant patient representing the hepatic counterpart of the metabolic syndrome. Along with insulin resistance, additional genetic, endocrine and vascular changes together with environmental stimuli--which are also involved in the pathogenesis of atherosclerosis--play a prominent role in the development and progression of NAFLD. Clinical and epidemiological studies seem to indicate that NAFLD is associated with an increased risk for cardiovascular disease but further studies are needed to confirm the available data. The mainstay of NAFLD treatment is based on the correction of the same metabolic changes that predispose to atherosclerosis.

CONCLUSIONS

Non-invasive evaluation of risk for cardiovascular events is recommended in all individuals presenting with NAFLD and conversely, the presence of NAFLD should always be looked for in subjects with features belonging to the metabolic syndrome. Further studies are needed on the mechanisms linking fatty liver and vascular diseases.

Genes or environment to determine alcoholic liver disease and non-alcoholic fatty liver disease

While the vast majority of heavy drinkers and individuals with obesity, insulin resistance, and the metabolic syndrome will have steatosis, only a minority will ever develop steatohepatitis, fibrosis, and cirrhosis. Genetic and environmental risk factors for advanced alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) seem likely to include factors that influence the severity of steatosis and oxidative stress, the cytokine milieu, the magnitude of the immune response, and/or the severity of fibrosis. For ALD, the dose and pattern of alcohol intake, along with obesity are the most important environmental factors determining disease risk. For NAFLD, dietary saturated fat and antioxidant intake and small bowel bacterial overgrowth may play a role. Family studies and interethnic variations in susceptibility suggest that genetic factors are important in determining disease risk. For ALD, functional polymorphisms in the alcohol dehydrogenases and aldehyde dehydrogenase alcohol metabolising genes play a role in determining susceptibility in Oriental populations. No genetic associations with advanced NAFLD have been replicated in large studies. Preliminary data suggest that polymorphisms in the genes encoding microsomal triglyceride transfer protein, superoxide dismutase 2, the CD14 endotoxin receptor, TNF-alpha, transforming growth factor-beta, and angiotensinogen may be associated with steatohepatitis and/or fibrosis.

Spontaneous rupture of the hepatic artery in a patient with type 1 neurofibromatosis treated by embolization: a case report

We report the case of a 48-year-old man with neurofibromatosis presenting with sudden-onset abdominal pain, profound hypotension, and a drop in hemoglobin. CT scan demonstrated a massive hematoma within the right lobe of the liver with rupture into the peritoneal cavity. Angiography demonstrated diffuse abnormalities of the hepatic circulation with fusifom, ectatic, and stenotic segments. Acute extravasation from a peripheral branch of the right hepatic artery was identified and successfully embolized with subsequent hemodynamic stabilization of the patient. To the best of our knowledge this is the first case report of this kind in a patient with type I neurofibromatosis.

Popliteal artery branching patterns—an angiographic study

AIM

To analyse the variations in branching patterns of the popliteal artery and infrapopliteal vessels using angiography.

MATERIALS AND METHODS

Femoral angiograms of 1037 lower limbs in 568 patients were examined to assess the popliteal artery branching pattern. Variations of the infrapopliteal vessels supplying the foot were assessed in 662 limbs from the same cohort of patients.

RESULTS

Nine hundred and forty-one (90.7%) limbs had the usual branching pattern with anterior tibial artery (AT) arising first followed by the tibial-peroneal trunk (TPT), which then gives rise to the posterior tibial (PT) and peroneal (PR) arteries. Variations in popliteal branching pattern were seen in 96 (9.3%) limbs. The commonest variation is high origin of the AT in 47 (4.5%) limbs or trifurcation of the popliteal artery in 33 (3.2%) limbs with AT, PT and PR arising together with no true TPT. The course of AT with high origin either anterior or posterior to popliteus was almost equal [25 (2.4%) or 22 (2.1%) limbs, respectively]. Eleven limbs (1.1%) had high origin of PT and two (0.2%) had a high origin of the PR. Six hundred and fifty-five (99%) limbs had normal infrapopliteal vessels. Seven (1%) had hypoplasia-aplasia of the infrapopliteal vessels. Five (0.8%) limbs had a hypoplastic PT with the remaining 2 (0.2%) having either a hypoplastic-aplastic AT or hypoplasia-aplasia of both AT and PT.

CONCLUSION

Variations in the branching of the popliteal artery occur in about 10% of patients. Knowledge of these variations is important because of the potential consequences for the management of peripheral vascular disease.

Polymorphisms in the T cell regulatory gene cytotoxic T lymphocyte antigen 4 influence the rate of acute rejection after liver transplantation

BACKGROUND

The cytotoxic T lymphocyte antigen 4 (CTLA-4) gene encodes for a membrane bound (mCTLA-4) and a soluble (sCTLA-4) isoform, which are both involved in regulation of T cell function. The CTLA-4 +49A/G single nucleotide polymorphism (SNP) influences expression of mCTLA-4; +6230G/A SNP affects the production of sCTLA-4.

AIM

To examine whether these functional SNPs influence the rate of rejection after liver transplantation.

PATIENTS AND METHODS

Liver graft recipients (n = 483) were genotyped for both SNPs, and haplotypes were reconstructed. Association with rejection was tested by the log rank test using the Kaplan-Meier method with time to the first acute rejection episode as outcome. Multiple analysis of SNPs together with demographic factors was performed by Cox regression.

RESULTS

Three haplotypes were observed in the cohort: +49A/+6230A, +49A/+6230G, and +49G/+6230G. The +49A/+6230G haplotype was significantly and dose dependently associated with acute rejection (p = 0.01). Of the demographic factors tested, only underlying liver disease was significantly associated with rejection. Adjusted for underlying liver disease, each additional +49A/+6230G haplotype allele resulted in a significantly higher risk of acute rejection (risk ratio 1.34 (95% confidence interval 1.04-1.72); p = 0.02). Patients who lacked this haplotype had the lowest, carriers an intermediate, and homozygotes the highest risk of acute rejection.

CONCLUSION

The CTLA-4 +49A/+6230G haplotype, which encodes for normal mCTLA-4 expression but reduced sCTLA-4 production, is a co-dominant risk allele for acute rejection after clinical liver transplantation. This implies that even under immunosuppression, CTLA-4 is critically involved in the regulation of the human immune response to allogeneic grafts.

Relationship between the inhibition of phosphatidic acid phosphohydrolase-1 by oleate and oleoyl-CoA ester and its apparent translocation

Phosphatidic acid phosphohydrolase-1 (PAP-1) activity is reversibly inhibited by fatty acids and their acyl-CoA esters and it appears paradoxical that these effectors have been reported to increase the liver's esterification capacity by translocating the rate-limiting enzyme PAP-1 from cytosol to the endoplasmic reticulum. Therefore, we have examined the effect of oleate, oleoyl-CoA, and spermine on the activation and translocation of PAP-1 of rat liver. PAP-1 activity is directly inhibited by oleic acid and oleoyl-CoA ester in an allosteric manner, resulting in the formation of inactive PAP-1-fatty acid (or -acyl-CoA) complex, even in the absence of any subcellular structures. Such association/aggregation of PAP-1 can be easily collected by centrifugation and may explain the apparent translocation phenomenon of this enzyme to a particular structure in the presence of fatty acids or acyl-CoA esters as reported in many works. Indeed, incubation of cytosol fraction alone with oleate or oleoyl-CoA at 37 degrees C, followed by centrifugation, induces a significant increase (sevenfold) in PAP-1 activity in the pellet fraction. This displacement is accompanied by an increase in the specific activity of PAP-1 in the pellet fraction. Spermine is less effective than oleate in inducing the displacement of PAP-1 activity from cytosol to the pellet fraction in the absence of any membrane structures. This apparent translocation of PAP-1 is also promoted when homogenate fraction was incubated with oleate prior to the preparation of cytosol and microsomal fraction. Thus, many of the announced factors, including fatty acids, would promote the in vitro association/aggregation of PAP-1 enzyme rather than its translocation, and therefore, re-evaluation of the reported effects on PAP-1 translocation phenomenon is required. It is proposed that fatty acids and their esters would favour beta-oxidation over esterification by promoting the forming of inactive associated PAP-1 in situations such as starvation and metabolic stress in which there is an increased supply of fatty acids to the liver.

Analysis of factors predictive of mortality in alcoholic hepatitis and derivation and validation of the Glasgow alcoholic hepatitis score

INTRODUCTION

Alcoholic hepatitis is associated with a high short term mortality. We aimed to identify those factors associated with mortality and define a simple score which would predict outcome in our population.

METHODS

We identified 241 patients with alcoholic hepatitis. Clinical and laboratory data were recorded on the day of admission (day 1) and on days 6-9. Stepwise logistic regression was used to identify variables related to outcome at 28 days and 84 days after admission. These variables were included in the Glasgow alcoholic hepatitis score (GAHS) and its ability to predict outcome assessed. The GAHS was validated in a separate dataset of 195 patients.

RESULTS

The GAHS was derived from five variables independently associated with outcome: age (p = 0.001) and, from day 1 results, serum bilirubin (p<0.001), blood urea (p = 0.019) and, from day 6-9 results, serum bilirubin (p<0.001), prothrombin time (p = 0.002), and peripheral blood white blood cell count (p = 0.001). The GAHS on day 1 had an overall accuracy of 81% when predicting 28 day outcome. In contrast, the modified discriminant function had an overall accuracy of 49%. Similar results were found using information at 6-9 days and when predicting 84 day outcome. The accuracy of the GAHS was confirmed by the validation study of 195 patients The GAHS was equally accurate irrespective of the use of the international normalised ratio or prothrombin time ratio, or if the diagnosis of alcoholic hepatitis was biopsy proven or on the basis of clinical assessment.

CONCLUSIONS

Using variables associated with mortality we have derived and validated an accurate scoring system to assess outcome in alcoholic hepatitis. This score was able to identify patients at greatest risk of death throughout their admission.

Immune response towards lipid peroxidation products as a predictor of progression of non-alcoholic fatty liver disease to advanced fibrosis

AIMS

Factors responsible for the progression of non-alcoholic fatty liver disease (NAFLD) to more severe liver injury are poorly understood. In the present study, we investigated the association between immune reactions triggered by oxidative stress and stage of NAFLD.

METHODS

Titres of IgG against human serum albumin adducted with malondialdehyde (MDA-HSA) or arachidonic acid hydroperoxide (AAHP) and against oxidised cardiolipin (Ox-CL) were measured in 167 NAFLD patients with steatosis only (n = 79), steatohepatitis (n = 74), or steatosis plus cirrhosis (n = 14), and in 59 age and sex matched controls.

RESULTS

Circulating IgG against lipid peroxidation products was significantly higher (p<0.001) in NAFLD patients than in controls. Oxidative stress dependent immune responses were not associated with obesity, type 2 diabetes, or with serum cholesterol, ferritin, or aminotransferase levels. Titres of lipid peroxidation related antibodies were also independent of the extent of steatosis and were similarly distributed in patients with and without necroinflammation. In contrast, the same antibodies were significantly increased in patients with advanced fibrosis or cirrhosis. Logistic regression analysis confirmed that anti-MDA antibodies were independently associated with progression of NALFD and that NAFLD patients with titres of anti-MDA-HSA antibodies above the control threshold value had a threefold (relative risk 2.82 (95% confidence interval 1.35-5.90); p = 0.007) higher risk of having advanced fibrosis/cirrhosis than patients whose antibody titres were within the control range.

CONCLUSIONS

These results indicate that the presence of immune reactions triggered by oxidative stress can be an independent predictor of progression of NAFLD to advanced fibrosis.

The potential role of genes in nonalcoholic fatty liver disease

Although most people with obesity and type 2 diabetes will have steatosis, only a minority will ever develop nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Family studies suggest that genetic factors are important in disease progression, although dissecting genetic factors playing a role in NASH and fibrosis from those influencing the development established risk factors is difficult. Several approaches can be used to look for genetic factors playing a role in nonalcoholic fatty liver disease (NAFLD). In the future, genome-wide single nucleotide polymorphism (SNP) scanning of cases and controls may become feasible. To date, however,studies have relied on candidate gene, case control, allele association methodology. Recent, and as yet preliminary, studies have reported associations between steatosis severity, NASH, and fibrosis with genes whose products are involved in lipid metabolism,oxidative stress, and endotoxin-cytokine interactions. If confirmed,these associations will enhance understanding of disease pathogenesis,and accordingly, the ability to design effective therapies.

Pathogenesis of steatohepatitis

Understanding the pathogenesis of non-alcoholic steatohepatitis has recently assumed great importance with the recognition that it has the potential to progress to fibrosis and cirrhosis. The 'two-hit' model of pathogenesis was proposed in 1998, with the first 'hit' - steatosis - increasing the sensitivity of the liver to the second 'hits' mediating liver injury. The main aim of this chapter is to review this model in the light of studies that have been published over the subsequent 4 years. Particular attention will be focused on the role of insulin resistance and recent advances in our understanding of the basic cellular mechanisms linking obesity and insulin resistance. Based on this information I will propose a modification of the two-hit model that places more emphasis on the role of free fatty acids. This model will provide the basis for further research and enable the rational design of treatment strategies.

Non-alcoholic steatohepatitis (NASH): where are we now and where are we going?

Although non-alcoholic steatohepatitis (NASH) was considered relatively uncommon prior to the middle of the last decade, over the past three years there has been an explosion of studies on various aspects of NASH with one study reporting that after hepatitis C, NASH was the most common diagnosis in patients presenting largely with persistent abnormalities of liver function tests. The field of NASH has come a long way in a relatively short space of time. This article considers advances in knowledge that have arisen as a result of these studies and highlights areas for further work.

Candidate gene case-control association studies: advantages and potential pitfalls

There is increasing information on the importance of genetic polymorphisms in human genes. Polymorphisms occur on average once every 500-1000 base pairs in the human genome and are useful in the identification of genes involved in human disease. Some genetic polymorphisms have functionally significant effects on the gene product and are the most useful type of polymorphism in disease association studies while others are simply useful markers. There are two main approaches using polymorphisms in the identification of genes involved in polygenic diseases. The first involves examining inheritance patterns for genetic polymorphisms in family studies and the second case-control studies which compare genotype frequencies for candidate disease genes in unrelated individuals with the disease and healthy controls. Use of family studies is generally the preferred approach but this is only feasible if the genetic component of the disease is relatively strong, DNA samples are available from other family members and the disease is relatively easy to diagnose and is not stigmatized. Population case-control studies are useful both as an alternative and an adjunct to family studies. When performing case-control studies factors such as study design, methods for recruitment of cases and controls, functional significance of polymorphisms chosen for study and statistical analysis of data require close attention to ensure that only genuine associations are detected. To illustrate some potential problems in the design and interpretation of association studies, some specific examples of association studies on drug response and on disease susceptibility involving receptor genes, cytochrome P450 and other xenobiotic metabolizing enzyme genes and immune system genes including TNF-alpha, IL-10 and the IL-4 receptor are discussed.

Alcoholic liver disease: new insights into mechanisms and preventative strategies

Alcoholic liver disease has a known aetiology but a complex pathogenesis. It is an extremely common disease with a high mortality, but the reason why only a relatively small proportion of heavy drinkers progress to advanced disease remains elusive. Accumulating evidence points towards an elaborate interplay between metabolism, inflammation and immunity in the development of steatosis, hepatitis and fibrosis. These complex pathways leading to liver injury offer many potential susceptibility loci, as well as sites for potential therapeutic intervention.

Role of polymorphisms in the interleukin-10 gene in determining disease susceptibility and phenotype in inflamatory bowel disease

Interleukin-10 (IL-10) has a key role in regulating mucosal inflammation. The role of functional polymorphisms at positions -627 and -1117 in the IL-10 gene as candidate susceptibility loci in inflammatory bowel disease and their importance in determining disease extent were evaluated in 159 patients with ulcerative colitis (83 left-sided; 76 extensive), 90 patients with Crohn's disease (22 small bowel; 29 large bowel; 39 both), and 227 controls. Genotyping was performed either by PCR-RFLP assays (-627 site) or SSCP analysis (-1117 site). An excess of -627A allele was observed in patients with left-sided colitis (52%) compared with controls (33%; P = 0.004) suggesting that IL-10 may influence the extent of the disease. These results were not replicated in a newly recruited group (N = 100) of patients with UC. We conclude that polymorphisms at -627 and -1117 sites in the IL-10 gene do not contribute to the susceptibility to IBD or determining the extent of the disease in our population.

Association of the tumour necrosis factor alpha -308 but not the interleukin 10 -627 promoter polymorphism with genetic susceptibility to primary sclerosing cholangitis

BACKGROUND AND AIMS

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology. Abnormalities in immune regulation and genetic associations suggest that PSC is an immune mediated disease. Several polymorphisms within the tumour necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10) promoter genes have been described which influence expression of these cytokines. This study examines the possible association between polymorphisms at the -308 and -627 positions in the TNF-alpha and IL-10 promoter genes, respectively, and susceptibility to PSC.

METHODS

TNF-alpha -308 genotypes were studied by polymerase chain reaction (PCR) in 160 PSC patients from Norway and the UK compared with 145 ethnically matched controls. IL-10 -627 genotypes were studied by PCR in 90 PSC patients compared with 84 ethnically matched controls.

RESULTS

A total of 16% of Norwegian PSC patients and 12% of British PSC patients were homozygous for the TNF2 allele compared with 3% and 6% of respective controls. The TNF2 allele was present in 60% of PSC patients versus 30% of controls (OR(combined data)=3.2 (95% confidence intervals (CI) 1.8--4.5); p(corr)=10(-5)). The association between the TNF2 allele and susceptibility to PSC was independent of the presence of concurrent inflammatory bowel disease (IBD) in the PSC patients; 61% of PSC patients without IBD had TNF2 compared with 30% of controls (OR(combined data)=3.2 (95% CI 1.2--9.0); p(corr)=0.006 ). There was no difference in the -627 IL-10 polymorphism distributions between patients and controls in either population. The increase in TNF2 allele in PSC patients only occurs in the presence of DRB1*0301 (DR3) and B8. In the combined population data, DRB1*0301 showed a stronger association with susceptibility to PSC than both the TNF2 and B8 alleles (OR(combined data)=3.8, p(corr)=10(-6) v OR(combined data)=3.2, p(corr)=10(-5) v OR(combined data )=3.41, p(corr)=10(-4), respectively).

CONCLUSIONS

This study identified a significant association between possession of the TNF2 allele, a G-->A substitution at position -308 in the TNF-alpha promoter, and susceptibility to PSC. This association was secondary to the association of PSC with the A1-B8-DRB1*0301-DQA1*0501-DQB1*0201 haplotype. No association was found between the IL-10 -627 promoter polymorphism and PSC.

Role of polymorphisms in the interleukin-10 gene in determining disease susceptibility and phenotype in inflamatory bowel disease

Interleukin-10 (IL-10) has a key role in regulating mucosal inflammation. The role of functional polymorphisms at positions -627 and -1117 in the IL-10 gene as candidate susceptibility loci in inflammatory bowel disease and their importance in determining disease extent were evaluated in 159 patients with ulcerative colitis (83 left-sided; 76 extensive), 90 patients with Crohn's disease (22 small bowel; 29 large bowel; 39 both), and 227 controls. Genotyping was performed either by PCR-RFLP assays (-627 site) or SSCP analysis (-1117 site). An excess of -627A allele was observed in patients with left-sided colitis (52%) compared with controls (33%; P = 0.004) suggesting that IL-10 may influence the extent of the disease. These results were not replicated in a newly recruited group (N = 100) of patients with UC. We conclude that polymorphisms at -627 and -1117 sites in the IL-10 gene do not contribute to the susceptibility to IBD or determining the extent of the disease in our population.

Mycophenolate mofetil monotherapy in liver transplantation

Chronic renal failure is a major cause of morbidity and mortality after orthotopic liver transplantation. We did a randomised controlled trial of mycophenolate mofetil monotherapy in liver transplant patients who developed renal failure associated with calcineurin-inhibitor (ciclosporin or tacrolimus) immunosuppressive therapy. Although renal failure improved when the calcineurin-inhibitor dose was reduced and ultimately stopped, the trial was stopped when three of five patients on monotherapy developed organ rejection requiring a second transplantation.

Association of single nucleotide polymorphisms in the interleukin-4 gene and interleukin-4 receptor gene with Crohn's disease in a British population

Interleukin-4 (IL-4) is an important cytokine in mucosal immunity and plays a critical role in the development of colitis in T-alpha cell receptor mutant mice. Functionally significant polymorphisms have been described in the genes encoding IL-4 and IL-4 receptor. To examine the role of these polymorphisms in disease susceptibility 98 patients with ulcerative colitis, 86 patients with Crohn's disease and 321 healthy controls were genotyped for polymorphisms at position -34 in the IL-4 gene and codon 576 in the IL-4 receptor gene. Thirty-two percent of patients with Crohn's disease carried one or two copies of the variant allele for IL-4 compared with 16% of the controls (P = 0.002). Forty-one percent of patients with Crohn's disease carried one or two copies of the variant IL-4 receptor allele compared with 31% of the controls (P = 0.09). Fifteen percent of patients with Crohn's disease carried combination of both (IL-4 and IL-4 receptor) variant alleles compared with 4% of the controls (P = 0.005). Association with alleles resulting in high IL-4 transcription and enhanced signalling activity suggests that IL-4 may have a role in the pathogenesis of Crohn's disease.

Clinical diagnostic scale: a useful tool in the evaluation of suspected hepatotoxic adverse drug reactions

BACKGROUND/AIM

Due to an absence of specific markers, the diagnosis of drug-induced hepatotoxicity is necessarily based on circumstantial evidence and is often inaccurate. We have evaluated the use of the clinical diagnostic scale (CDS) in the causality assessment of hepatotoxic adverse drug reaction (ADR) reports.

METHODS

135 hepatic adverse ADRs reported to the Committee on Safety of Medicines in North East England 1992-6 were evaluated. Initially, "International Consensus Criteria" were used to classify reactions as "drug-related", "drug-unrelated" and "indeterminate". Using the CDS, each ADR was then categorised as either definite drug hepatotoxicity (score >17), probable (14-17), possible (10-13), unlikely (6-9), or drug hepatotoxicity excluded (<6).

RESULTS

49 ADRs were considered drug-related, 65 unrelated and 21 indeterminate. Reports classified as drug-related by consensus criteria scored higher on the CDS, with a median score of 12, range: 8-15, than either the indeterminate (8; [3-12]) or drug-unrelated reports (5; [2-11]) (p<0.0001). A CDS score of >9, identified 88% of the cases classified as drug-related hepatotoxicity by consensus criteria and excluded 98% of those unrelated to the drugs.

CONCLUSIONS

CDS scoring correlates well with the international consensus classification and may be a useful tool in the routine evaluation of suspected hepatotoxic drug reactions.

Who gets alcoholic liver disease: nature or nurture?

The factors determining why fewer than 10% of drinkers develop advanced alcoholic liver disease remain largely unknown. There is a weak relationship between disease risk and the dose and pattern of alcohol consumed. Obesity increases the risk of all stages of alcoholic liver disease, probably reflecting the role of steatosis in the pathogenesis of more advanced disease. Women develop disease at a lower intake than men due, in part, to their lower volume of distribution for alcohol, but also potentially to increased gut permeability to endotoxin. Recent studies suggest a non-gender-linked genetic component to disease susceptibility and recent case-control studies have suggested that polymorphisms of genes encoding cytokines and other immunoregulatory molecules may exert a significant effect. The pattern of polymorphisms associated with risk suggests that antibody-mediated mechanisms play a role in disease pathogenesis. This has implications for treatment and for identifying high risk individuals at an early stage.

Relationship of polymorphism in CYP2C9 to genetic susceptibility to diclofenac-induced hepatitis

The mechanism by which diclofenac-induced hepatotoxicity occurs is unclear, even though covalent modification of proteins by diclofenac metabolites appears to be important in pathogenesis, either by altering protein function or by eliciting an immune response. Adduct formation may be due to metabolism of diclofenac via an alternative pathway rather than via its major 4'-hydroxylation pathway mediated by the cytochrome P450 CYP2C9. We hypothesized that possession of variant CYP2C9 alleles might be a risk factor for diclofenac-induced hepatotoxicity, since the allelic variants CYP2C9*2 and CYP2C9*3 may be associated with impaired metabolism compared to the wild-type (CYP2C9*1). To investigate in more detail the effects of the polymorphisms on diclofenac metabolism in human liver, the kinetics of diclofenac 4-hydroxylation by human liver microsomes of known CYP2C9 >genotype were examined. An overall difference in Vmax and Vmax/Km between samples homozygous for CYP2C9*1 and heterozygous for CYP2C9*2 or CYP2C9*3 was detected (P = 0.044). However, on subgroup analysis, there was no significant difference between samples homozygous for CYP2C9*1 and heterozygous for CYP2C9*2, although there was a borderline difference between the samples homozygous for CYP2C9*1 and those heterozygous for CYP2C9*3 (P = 0.057). The relationship between CYP2C9 genotype and susceptibility to diclofenac-induced hepatotoxicity was further examined by genotyping 24 patients with diclofenac-induced hepatotoxicity together with 100 healthy controls for the CYP2C9*2 and CYP2C9*3 alleles. CYP2C9 genotype frequencies for CYP2C9*2 and CYP2C9*3 were similar in patients and controls. To assess whether diclofenac-induced hepatotoxicity was due to rare CYP2C9 mutations, the upstream sequence (-1 to -1000) and all exons and exon-intron boundaries of CYP2C9 from four subjects who had suffered severe hepatotoxicity was determined. However, no new polymorphisms were detected. We therefore found no evidence that polymorphism in CYP2C9 is a determinant of diclofenac-induced hepatotoxicity.

Interleukin 10 promoter region polymorphisms and susceptibility to advanced alcoholic liver disease

BACKGROUND

The factors determining why less than 10% of heavy drinkers develop advanced alcoholic liver disease (ALD) remain elusive, although genetic factors may be important. Interleukin 10 (IL-10) is an important cytokine with anti-inflammatory, anti-immune, and antifibrotic functions. Several polymorphisms have been identified in the IL-10 promoter and recent evidence suggests that some of these may have functional effects on IL-10 secretion.

AIMS

To test the hypothesis that IL-10 promoter region polymorphisms are associated with susceptibility to ALD.

METHODS

The allele frequencies for the two single base pair substitutions at positions -627 (C-->A) and -1117 (A-->G) in the IL-10 promoter were determined in 287 heavy drinkers with biopsy proved advanced ALD, 107 heavy drinkers with no evidence of liver disease or steatosis only on biopsy, and 227 local healthy volunteers.

RESULTS

At position -627, 50% of patients with advanced ALD had a least one A allele compared with 33% of controls (p<0.0001) and 34% of drinkers with no or mild disease (p=0.017). At position -1117, the slight excess of the A allele in drinkers with advanced disease was because of linkage disequilibrium between the A alleles at the two sites.

CONCLUSIONS

Among heavy drinkers, possession of the A allele at position -627 in the IL-10 promoter is associated with an increased risk of advanced liver disease. This is consistent with recent functional data that the -627*A allele is associated with low IL-10 expression which will favour inflammatory, immune mediated, and profibrotic mechanisms of alcohol related liver injury.

Stress-activated protein kinases in the activation of rat hepatic stellate cells in culture

BACKGROUND/AIMS

The signal cascades involved in the activation of hepatic stellate cells (HSC) are largely unknown. Factors initiating activation include tumour necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, endothelin, and oxidative stress. In other cell types some of these have been reported to stimulate p38 mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK). We have therefore investigated the role of these kinases in HSC activation.

METHODS

HSC were isolated from male Wistar rats. Quiescent experiments were performed on day 2 HSC and transformed experiments on day 15 passage 1 HSC. Kinase activities were determined by immunoprecipitation and phosphorylation of specific substrate proteins and alpha-smooth muscle actin (SMA) expression by immunoblotting.

RESULTS

The constitutive activity of p38 MAP kinase was higher in transformed versus quiescent cells. In quiescent cells TNFalpha stimulated p38 MAP kinase and JNK activities 12- and 4-fold respectively and this was halved by 2-mercaptoethanol, an indirect antioxidant. Endothelin-1 activated both kinases in quiescent cells via the endothelin-B receptor, while TGFbeta had no effect. Both 2-mercaptoethanol and a p38 inhibitor (SB202190) inhibited alpha-SMA expression by day 5 cells.

CONCLUSIONS

The activation of p38 MAP kinase and JNK by TNFalpha and endothelin, together with the inhibition of this activation by 2-mercaptoethanol, provides indirect evidence supporting their role in HSC transformation. Direct evidence for a role for p38 MAP kinase is provided by the observations that its constitutive activity is higher in transformed versus quiescent cells and that its inhibitor reduces HSC activation in culture as assessed by alpha-SMA expression.

The role of phosphatidic acid in platelet-derived growth factor-induced proliferation of rat hepatic stellate cells

Platelet-derived growth factor (PDGF) is the most potent mitogen for hepatic stellate cells (HSCs) in vitro. The aim of this study was to investigate the role of the lipid-derived second messenger phosphatidic acid (PA) in mediating this effect and, in particular, to determine its interaction with the extracellular signal-regulated kinase (ERK) cascade. HSCs were isolated from rat livers. PA production was determined by lipid extraction and thin-layer chromatography (TLC) after prelabeling cells with [(3)H]myristate. ERK activity was measured by an in vitro kinase assay after immunoprecipitation. Mitogenic concentrations of PDGF, but not those of the relatively less potent mitogen, transforming growth factor alpha (TGF-alpha), stimulated the sustained production of PA from HSCs. Exogenous PA stimulated HSC proliferation and a sustained increase in ERK activity, and proliferation was completely blocked by the inhibition of ERK activation with PD98059. The stimulation of ERK by PDGF was of a similar magnitude but more sustained than that caused by TGF-alpha. These results suggest that the potent mitogenic effect of PDGF in HSCs may be caused, in part, by the generation of PA and subsequently by a more sustained activation of ERK than occurs with less potent mitogens that do not induce the production of this lipid second messenger.

Inhibition of rat hepatocyte proliferation by transforming growth factor beta and glucagon is associated with inhibition of ERK2 and p70 S6 kinase

Stimulation of hepatocyte proliferation by epidermal growth factor (EGF) and insulin is inhibited by transforming growth factor beta (TGF-beta) and by glucagon. It is also suppressed by inhibitors of various protein kinases, including rapamycin, which blocks activation of p70 S6 kinase (p70(S6k)), PD98059, which inhibits the activation of extracellular-regulated kinase (ERK), and SB 203580, an inhibitor of the p38 mitogen-activated protein kinase (p38 MAPK). In this study, we investigated whether the inhibition of proliferation by TGF-beta involves these protein kinase cascades. Culture of hepatocytes with TGF-beta for 16 hours decreased the stimulation by EGF of ERK2 and p70(S6k) (by 50% and 35%, respectively), but did not affect the stimulation of either p38 MAPK, c-jun NH2-terminal kinase (JNK), or protein kinase B (PKB). Culture of hepatocytes with glucagon for 16 hours also inhibited the stimulation by EGF of activation of ERK2 and p70(S6k) (by approximately 50%). The inhibitory effects of glucagon were observed when the hormone was added either 10 minutes or 60 minutes before EGF addition, whereas no effects of TGF-beta were observed after 10-minute or 60-minute incubation. These results suggest that the inhibition of hepatocyte proliferation by TGF-beta may be in part mediated by inhibition of ERK2 and p70(S6k), but does not involve PKB, JNK, or p38 MAPK. Unlike glucagon, the effects of TGF-beta are not elicited in response to short-term treatment.

The natural history of histologically proved drug induced liver disease

BACKGROUND

The long term outcome of drug related liver disease is unknown.

AIMS

To study the natural history of histologically proved drug induced hepatotoxicity.

METHODS

110 patients with liver biopsies coded either as drug induced liver disease or hepatitis/cholestasis of unknown aetiology were identified from hospital records 1978-1996. Review of case notes and histology identified 44 patients with definite drug induced hepatotoxicity. Forty surviving patients were invited to attend a follow up clinic. History, examination, full liver screen, and isotope and ultrasound liver scans were repeated in all patients. Repeat liver biopsies were offered to patients with abnormal liver tests.

RESULTS

Presentation at index biopsy was jaundice in 24 patients, abnormal liver tests in 17, and hepatic failure in three. Antibiotics (n=13) and non-steroidal anti-inflammatory drugs (n=11) were the most common drugs implicated. Initial histology showed acute hepatitis in six, chronic hepatitis in 20, and cholestasis in 18. At 1-19 years (median 5 years) follow up, 13/33 (39%) patients had persistent significant abnormalities in their liver blood tests and/or scans. Three of the five repeat liver biopsies performed showed significant abnormalities. Factors predicting persistence or development of chronic liver disease were fibrosis and continued exposure to the drug.

CONCLUSIONS

Drugs should be considered in the differential diagnosis of abnormal liver function and/or histology, as failure to withdraw the offending drug is associated with a high risk of persistent liver damage.

Association of polymorphisms in the cytochrome P450 CYP2C9 with warfarin dose requirement and risk of bleeding complications

BACKGROUND

The cytochrome P450 CYP2C9 is responsible for the metabolism of S-warfarin. Two known allelic variants CYP2C9*2 and CYP2C9*3 differ from the wild type CYP2C9*1 by a single aminoacid substitution in each case. The allelic variants are associated with impaired hydroxylation of S-warfarin in in-vitro expression systems. We have studied the effect of CYP2C9 polymorphism on the in-vivo warfarin dose requirement.

METHODS

Patients with a daily warfarin dose requirement of 1.5 mg or less (low-dose group, n=36), randomly selected patients with a wide range of dose requirements from an anticoagulant clinic in north-east England (clinic control group, n=52), and 100 healthy controls from the community in the same region were studied. Genotyping for the CYP2C9*2 and CYP2C9*3 alleles was done by PCR analysis. Case notes were reviewed to assess the difficulties encountered during the induction of warfarin therapy and bleeding complications in the low-dose and clinic control groups.

FINDINGS

The odds ratio for individuals with a low warfarin dose requirement having one or more CYP2C9 variant alleles compared with the normal population was 6.21 (95% CI 2.48-15.6). Patients in the low-dose group were more likely to have difficulties at the time of induction of warfarin therapy (5.97 [2.26-15.82]) and have increased risk of major bleeding complications (rate ratio 3.68 [1.43-9.50]) when compared with randomly selected clinic controls.

INTERPRETATION

We have shown that there is a strong association between CYP2C9 variant alleles and low warfarin dose requirement. CYP2C9 genotyping may identify a subgroup of patients who have difficulty at induction of warfarin therapy and are potentially at a higher risk of bleeding complications.

Tumour necrosis factor-alpha promoter polymorphisms in primary biliary cirrhosis

BACKGROUND/AIMS

The incidence of primary biliary cirrhosis (PBC) is increased in the close relatives of patients, suggesting that genetic factors play a role in disease susceptibility. Decreased in vitro production of tumour necrosis factor (TNF)-alpha has been reported in PBC patients, suggesting a potential aetiological role for this cytokine. The aim of this study was to examine two biallelic polymorphisms in the promoter region of the TNF-alpha gene, which may play a role in the control of TNF-alpha secretion, as candidate susceptibility loci in PBC.

METHODS

The polymorphisms at positions -238 and -308 in the TNF-alpha promoter region were analysed by polymerase chain reaction in 168 unrelated PBC patients and 145 local unrelated, geographically matched normal individuals. All PBC subjects were also genotyped for HLA DR8, a previously identified susceptibility locus in PBC.

RESULTS

The -308 TNF1/TNF1 genotype was seen in a similar proportion of PBC patients (66%) and controls (60%). However, this genotype was found significantly more frequently in the 95 PBC patients with more advanced disease (histological stage III/IV) (77%) than in either controls (p<0.01, OR = 2.2 [1.2-4.0]) or the PBC patients with earlier disease (38/73 (52%), p = 0.001 OR 3.1 [1.6-5.9]). Linkage between TNF -308 and HLA DR8 was not seen. No association was found between PBC and the biallelic -238 TNF-alpha polymorphism, either in the whole PBC population or the histological Stage III/IV subgroup.

CONCLUSIONS

Our study provides no evidence for involvement of the TNF-alpha -308 or -238 promoter polymorphisms in genetic predisposition to PBC. However, the significantly increased frequency of the -308 TNF1/TNF1 genotype seen in 95 patients with more advanced disease raises the possibility that this allele may be linked to disease progression rather than susceptibility. The finding of different allele frequencies in PBC patients in different disease subgroups emphasises the importance of clinical phenotype/casemix in the design of disease association studies.

Detection and characterization of novel polymorphisms in the CYP2E1 gene

To investigate whether interindividual variation in CYP2E1 levels can be explained by genetic polymorphism, we analysed DNA samples from 40 healthy individuals by single-strand conformational polymorphism analysis for polymorphisms in the CYP2E1 coding sequence and promoter region. DNA sequencing of samples showing mobility shifts on single-strand conformational polymorphism detected polymorphisms at positions -316 (A to G), -297 (T to A), -35 (G to T), 1107 (G to C; intron 1), 4804 (G to A Val179Ile; exon 4) and 10157 (C to T; exon 8). All individuals positive for either A(-316)G, G(-35)T, G(4804)A or the previously described RsaI polymorphism at -1019 were also positive for T(-297)A, which had the highest allele frequency of the observed polymorphisms (0.20). A(-316)G, G(-35)T and G(4804)A were detected at allele frequencies of 0.022, 0.052 and 0.013, respectively. The functional significance of the upstream polymorphisms was examined by preparing constructs of positions -549 to +3 of CYP2E1 containing the observed combinations of the polymorphisms fused to luciferase reporter genes and transfecting HepG2 cells. For the G(-35)T/T(-297)A construct, a 1.8-fold increase in luciferase activity compared with the wild-type sequence (P = 0.06) and 2.5-fold compared with T(-297)A only (P = 0.025) was observed. No significant difference in activity was observed between the other constructs. The significance of the predicted Val179Ile base change from G(4804)A was determined by expression of the wild-type and mutated full length cDNAs in lymphoblastoid cells. No significant difference in kinetic constants for chlorzoxazone hydroxylation between mutant and wild-type was observed. In summary, this study demonstrated six novel CYP2E1 polymorphisms, including three upstream of the promoter, but with the possible exception of G(-35)T, none appeared to be of functional significance.

Diagnosis and interpretation of steatosis and steatohepatitis

Steatosis--accumulation of triacylglycerol in hepatocytes--is a common finding in liver biopsy specimens. The commonest form is macrovesicular change, which occurs in response to a wide range of insults. In the absence of other features, the pathologist cannot ascertain the likely cause on morphological features alone but can give an indication of the severity of steatosis. Close clinicopathological correlation is required to establish the cause. In most instances, macrovesicular steatosis is at least potentially reversible. Although it may be thought of as a benign condition, it may be associated with the development of necroinflammation and fibrosis--so-called steatohepatitis. The classic example of this is alcoholic hepatitis, but there is increasing awareness of steatohepatitis occurring in nonalcoholics: NASH. Distinction between alcoholic hepatitis and NASH on purely histological grounds may be impossible; careful clinicopathological discussion is mandatory. Microvesicular steatosis is generally a more severe disease than the macrovesicular form and is seen in a variety of conditions in which there is either an inherited or an acquired defect in beta-oxidation of fatty acids; the former includes mitochondrial cytopathies and disorders of ureagenesis, and the latter includes acute fatty liver of pregnancy and Reye's syndrome. This review describes the morphological features of steatosis and steatohepatitis, considers their pathogenesis, and outlines the clinical significance of the different patterns of injury.

Intravenous bisphosphonate prevents symptomatic osteoporotic vertebral collapse in patients after liver transplantation

Osteoporosis is common in patients with chronic cholestatic liver disease, and atraumatic spinal fracture is a recognized complication after orthotopic liver transplantation. Bisphosphonates are potent inhibitors of osteoclast bone resorption and have been successfully used to treat postmenopausal osteoporosis. We examined whether preoperative bone mineral density can predict the risk of fracture after orthotopic liver transplantation and whether intravenous bisphosphonate can prevent fractures in high-risk patients. Beginning in February 1993, standard bone mineral density measurements of the lumbar spine were performed as part of routine pretransplantation assessment. On the basis of a preliminary analysis from January 1995, patients with a lumbar spine bone mineral density of <0.84 g/cm2, or <84% of the predicted value (age/sex), were treated with intravenous bisphosphonate (pamidronate disodium) every 3 months before and for 9 months after liver transplantation. Bone mineral density measurements were available in 90 of 136 consecutive first transplants performed in our unit from February 1993 to September 1996. Before the use of pamidronate, 7 patients sustained symptomatic vertebral fractures. Their mean spine bone mineral density was lower than in the 38 patients with no clinical evidence of fracture (81.8% +/- 12.3% v 94.2% +/- 10.2%; P = .006). Since the introduction of pamidronate, no symptomatic vertebral fractures have occurred. Of 29 surviving patients with bone mineral density <0.84 g/cm2 before transplantation, 38% who did not receive treatment with pamidronate suffered spontaneous fracture, whereas 0 of 13 who received treatment suffered such a complication. A low lumbar spine bone mineral density is associated with a high risk of symptomatic vertebral fracture after liver transplantation. These results suggest that this risk is considerably reduced by the administration of intravenous bisphosphonate before and after transplantation.

Heterozygotes for HFE mutations have no increased risk of advanced alcoholic liver disease

BACKGROUND

Iron overload is common in the livers of alcoholics and may play a role in disease pathogenesis. An MHC like gene, HFE, has recently been identified that is mutated in most patients with hereditary haemochromatosis (C282Y in 90% and H63D in 45% of the remainder).

AIM

To examine the hypothesis that these mutations determine hepatic iron status in alcoholics and play a role in pre-disposition to advanced alcoholic liver disease.

METHODS

The HFE gene was genotyped in 257 patients with alcoholic liver disease and 117 locally matched healthy volunteers. In addition, iron staining was scored (0-4) on biopsy specimens from fibrotic/cirrhotic patients with and without HFE mutations matched for age and sex.

RESULTS

Some 15.7% of fibrotic/cirrhotic patients were C282Y heterozygotes compared with 13.7% of controls (p = 0.77). One control and three patients were C282Y homozygotes. Of chromosomes without the C282Y mutation, 68/442 (15.4%) of patients' chromosomes carried the H63D mutation compared with 36/216 (16.6%) of control chromosomes (p = 0.91). Significant (> grade 1) hepatocyte iron staining was seen in 6/23 C282Y heterozygotes and 4/26 H63D heterozygotes compared with 4/23 controls.

CONCLUSIONS

Possession of a single copy of either of the two HFE mutations influences neither liver iron content nor the risk of fibrotic disease in alcoholics.

The RsaI polymorphism of CYP2E1 and susceptibility to alcoholic liver disease in Caucasians: effect on age of presentation and dependence on alcohol dehydrogenase genotype

Twin studies in Caucasians suggest that susceptibility to alcoholic liver disease is, in part, genetically determined. Because most of the deleterious effects of alcohol are caused by its metabolism, attention has focused upon genes encoding ethanol metabolizing enzymes. Caucasians are polymorphic at only two of these gene loci--cytochrome P450 2E1 (CYP2E1) and alcohol dehydrogenase 3 (ADH3). We examined the frequency of the RsaI polymorphism of CYP2E1 and ADH3 genotype in 264 patients with alcoholic liver disease and 121 local control individuals. There was a non-significant excess of the rare c2 CYP2E1 allele in patients with advanced liver disease compared with control individuals/patients with steatosis only (0.029 versus 0.017/0.00). However, patients with the c2 allele presented at a younger age compared with those with the wild type c1 allele only (42.3 +/- 1.6 years versus 49.0 +/- 0.6 years; P = 0.001) with at least as advanced histology (93% cirrhotic versus 74%). Male patients had a higher frequency of the ADH3*2/*2 genotype (which encodes the less active gamma2 subunit) than control individuals [odds ratio (OR) 2.04 (1.11-3.76)], however, ADH3 genotype did not differ with histological stage or with age of presentation. Patients with advanced disease possessing the c2 allele had a significantly higher frequency of the ADH3*2/*2 genotype compared with c1 homozygotes [OR 3.71 (1.24-11.09)]. This study demonstrates that, although rare in Caucasians, possession of the mutant c2 allele of CYP2E1 increases the risk of alcoholic liver disease at a given level of cumulative alcohol consumption. This risk appears to be particularly manifest in individuals carrying the ADH3*2 allele, presumably reflecting increased metabolism of ethanol by CYP2E1. In the absence of the c2 allele, ADH3 genotype does not influence the risk of advanced alcoholic liver disease but, in males at least, may influence the risk of alcoholism.