Causal relationship of hepatic fat with liver damage and insulin resistance in nonalcoholic fatty liver

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease is epidemiologically associated with hepatic and metabolic disorders. The aim of this study was to examine whether hepatic fat accumulation has a causal role in determining liver damage and insulin resistance.

METHODS

We performed a Mendelian randomization analysis using risk alleles in PNPLA3, TM6SF2, GCKR and MBOAT7, and a polygenic risk score for hepatic fat, as instruments. We evaluated complementary cohorts of at-risk individuals and individuals from the general population: 1515 from the liver biopsy cohort (LBC), 3329 from the Swedish Obese Subjects Study (SOS) and 4570 from the population-based Dallas Heart Study (DHS).

RESULTS

Hepatic fat was epidemiologically associated with liver damage, insulin resistance, dyslipidemia and hypertension. The impact of genetic variants on liver damage was proportional to their effect on hepatic fat accumulation. Genetically determined hepatic fat was associated with aminotransferases, and with inflammation, ballooning and fibrosis in the LBC. Furthermore, in the LBC, the causal association between hepatic fat and fibrosis was independent of disease activity, suggesting that a causal effect of long-term liver fat accumulation on liver disease is independent of inflammation. Genetically determined hepatic steatosis was associated with insulin resistance in the LBC and SOS. However, this association was dependent on liver damage severity. Genetically determined hepatic steatosis was associated with liver fibrosis/cirrhosis and with a small increase in risk of type 2 diabetes in publicly available databases.

CONCLUSION

These data suggest that long-term hepatic fat accumulation plays a causal role in the development of chronic liver disease.

Acquired hepatocerebral degeneration (AHD): a peculiar neurological impairment in advanced chronic liver disease

We discuss the case of a rare and often unrecognized neurologic syndrome, called Acquired Hepatocerebral Degeneration (AHD), observed in patients with advanced liver disease and portosystemic shunts. The clinical manifestations can be very heterogeneous and in our case included a combination of cerebellar and extrapyramidal signs, arisen in a period of few days. Brain Magnetic Resonance Imaging (MRI) showed, in T1-weighted images, diffuse bilateral hyper intensities in basal ganglia and biemispheric brain and cerebellar cortices, resembling paramagnetic deposits. No other neurological impairments, like stroke, infection or neoplasia, were found. It was excluded an episode of acute hepatic encephalopathy. We also ruled out Wilsonian degeneration, iron overload and autoimmune encephalitis and we lastly found high manganese levels as the possible cause of the brain paramagnetic deposits. Even though either serum Mn determination or its accumulation in the brain are not specific for AHD, however the chronic and progressively worsening of the neurological manifestations advocated a degenerative condition, possibly AHD. We finally opted for the early restoration of liver function by OLT, and we observed complete clinical symptoms' resolution and partial MRI reversal after a follow up of 6 months.

Alcohol Dehydrogenase: An Autoantibody Target in Patients with Alcoholic Liver Disease

The link between alcohol consumption and liver disease is not direct and several factors including autoimmunity to hepatocyte components have been implicated. We have previously identified alcohol dehydrogenase (ADH) as an autoantigen in autoimmune liver disease and in a proportion of patients with alcoholic liver disease. The aim of the present study is to investigate the association between the presence of anti-ADH antibodies, alcohol consumption and severity of liver damage in alcoholic patients. The presence of antibodies to human ADH β2 and horse ADH was investigated in 108 patients with documented history of alcohol consumption and alcohol related liver disease, 86 being active alcohol abusers and 22 on sustained alcohol withdrawal, 39 with non-alcohol related disease and 22 normal subjects.

Antibodies to either ADH form were more frequently detected in active alcohol abusers (55/86, 64%) than in patients on sustained alcohol withdrawal longer than 6 months (1/8, 13%, p<0.005), HBV infection (2/8, 25%, P=0.03), non-alcohol related disease (9/29, 23%, p<0.0001) and in normal controls (3/22, 14%, p<0.0001); were more frequent in patients with cirrhosis than in those with steatosis (26/34, 76% vs 34/64, 53%, P=0.02); and were associated with elevated levels of ALT (anti-ADH β2, p<0.05), immunoglobulin A (p<0.05) and γ-glutamyl transpeptidase (P=0.01). Anti-ADH antibody positive serum samples were able to inhibit the enzymatic activity of ADH. These findings suggest that anti-ADH antibodies may be triggered by alcohol consumption and act as a disease activity marker in alcoholic liver disease.

Elafibranor, an Agonist of the Peroxisome Proliferator-Activated Receptor-α and -δ, Induces Resolution of Nonalcoholic Steatohepatitis Without Fibrosis Worsening

BACKGROUND & AIMS

Elafibranor is an agonist of the peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-δ. Elafibranor improves insulin sensitivity, glucose homeostasis, and lipid metabolism and reduces inflammation. We assessed the safety and efficacy of elafibranor in an international, randomized, double-blind placebo-controlled trial of patients with nonalcoholic steatohepatitis (NASH).

METHODS

Patients with NASH without cirrhosis were randomly assigned to groups given elafibranor 80 mg (n = 93), elafibranor 120 mg (n = 91), or placebo (n = 92) each day for 52 weeks at sites in Europe and the United States. Clinical and laboratory evaluations were performed every 2 months during this 1-year period. Liver biopsies were then collected and patients were assessed 3 months later. The primary outcome was resolution of NASH without fibrosis worsening, using protocol-defined and modified definitions. Data from the groups given the different doses of elafibranor were compared with those from the placebo group using step-down logistic regression, adjusting for baseline nonalcoholic fatty liver disease activity score.

RESULTS

In intention-to-treat analysis, there was no significant difference between the elafibranor and placebo groups in the protocol-defined primary outcome. However, NASH resolved without fibrosis worsening in a higher proportion of patients in the 120-mg elafibranor group vs the placebo group (19% vs 12%; odds ratio = 2.31; 95% confidence interval: 1.02-5.24; P = .045), based on a post-hoc analysis for the modified definition. In post-hoc analyses of patients with nonalcoholic fatty liver disease activity score ≥4 (n = 234), elafibranor 120 mg resolved NASH in larger proportions of patients than placebo based on the protocol definition (20% vs 11%; odds ratio = 3.16; 95% confidence interval: 1.22-8.13; P = .018) and the modified definitions (19% vs 9%; odds ratio = 3.52; 95% confidence interval: 1.32-9.40; P = .013). Patients with NASH resolution after receiving elafibranor 120 mg had reduced liver fibrosis stages compared with those without NASH resolution (mean reduction of 0.65 ± 0.61 in responders for the primary outcome vs an increase of 0.10 ± 0.98 in nonresponders; P < .001). Liver enzymes, lipids, glucose profiles, and markers of systemic inflammation were significantly reduced in the elafibranor 120-mg group vs the placebo group. Elafibranor was well tolerated and did not cause weight gain or cardiac events, but did produce a mild, reversible increase in serum creatinine (effect size vs placebo: increase of 4.31 ± 1.19 μmol/L; P < .001).

CONCLUSIONS

A post-hoc analysis of data from trial of patients with NASH showed that elafibranor (120 mg/d for 1 year) resolved NASH without fibrosis worsening, based on a modified definition, in the intention-to-treat analysis and in patients with moderate or severe NASH. However, the predefined end point was not met in the intention to treat population. Elafibranor was well tolerated and improved patients' cardiometabolic risk profile. ClinicalTrials.gov number: NCT01694849.

Subclinical atherosclerosis is associated with Epicardial Fat Thickness and hepatic steatosis in the general population

BACKGROUND AND AIMS

Abdominal obesity and hepatic steatosis are ectopic fat depots associated with Metabolic Syndrome (MetS). Epicardial Fat Thickness (EFT) is a newly discovered one, increasing with obesity, insulin resistance and MetS. Therefore we studied whether different ectopic fat markers, and EFT in particular, are associated with MetS and markers of subclinical cardiovascular disease.

METHODS AND RESULTS

868 subjects from the PLIC Study were included, EFT, aortic calcifications, carotid Intima-Media Thickness (c-IMT) and echocardiographic parameters were determined by ultrasound; extra-cardiac atherosclerotic lesions were defined in presence of plaques at both carotid and aortic levels. Hepatic steatosis degrees were defined according to a scoring system. Abdominal adiposity was determined using Dual X-ray Absorbimetry (DEXA). Independently from age, women showed higher EFT versus men (4.5 (0.20-9.00) mm vs 4.00 (0.10-8.00) mm, p = 0.013); EFT was thicker in post-menopausal women (independently from hormone-replacement therapy). EFT, liver steatosis and abdominal adiposity increased with MetS (p < 0.001). EFT was the only ectopic fat marker associated with cardiac dysfunction (OR = 1.340 [1.088-1.651 95% C.I., p = 0.006); liver steatosis and EFT were associated with extra-cardiac plaques (OR = 2.529 [1.328-4.819] 95% C.I., p < 0.001 and OR = 1.195 [1.008-1.299] 95% C.I., p = 0.042; respectively). On top of cardiovascular risk factors, only EFT improved the discrimination of subjects with cardiac dysfunction and atherosclerotic plaques.

CONCLUSIONS

EFT is associated with left ventricular dysfunction and subclinical atherosclerosis. Our data suggest that EFT may represent an additional tool for the stratification of cardiovascular risk.

Particulate matter phagocytosis induces tissue factor in differentiating macrophages

Airborne exposure to particulate matter with diameter < 10 mcM (PM10) has been linked to an increased risk of thromboembolic events, but the mechanisms are not completely understood. The aim of this study was to evaluate the effect of PM10 phagocytosis on the release of procoagulant molecules in human differentiating macrophages, and that of PM10 inhalation in an experimental model in rats. Human monocytes were separated from the peripheral blood by the lymphoprep method, differentiated in vitro and treated with standard PM10 or vehicle. Sprague-Dawley rats were instilled intratracheally with PM10 or vehicle alone. The outcome was expression of proinflammatory genes and of tissue factor (TF). In human differentiating macrophages, PM10 exposure upregulated inflammatory genes, but most consistently induced TF mRNA and protein levels, but not TF protein inhibitor, resulting in increased TF membrane expression and a procoagulant phenotype. Differentiation towards the anti-inflammatory M2 phenotype inhibited PM10 -mediated TF expression. TF induction required phagocytosis of PM10 , whereas phagocytosis of inert particles was less effective. PM10 phagocytosis was associated with a gene expression profile consistent with intracellular retention of iron, inducing oxidative stress. Both PM10 and iron activated the stress kinases ERK1/2 pathway, involved in the induction of TF expression. In rats, alveolar exposure to PM10 was associated with pulmonary recruitment of inflammatory cells and resulted in local, but not systemic, induction of TF expression, which was sufficient to increase circulating TF levels. In conclusion, TF induction by differentiating lung macrophages, activated following phagocytosis, contributes to the increased risk of thromboembolic complications associated with PM10 exposure.

Implications of PNPLA3 polymorphism in chronic hepatitis C patients receiving peginterferon plus ribavirin

BACKGROUND

Homozygosity for the PNPLA3 p.I148M polymorphism influences steatosis and fibrogenesis in chronic hepatitis C (CHC).

AIM

To evaluate the effect of p.148M/M on sustained virological response (SVR) and viral kinetics in patients who underwent antiviral therapy with peg-interferon and ribavirin, stratified according to viral genotype and fibrosis severity, and secondarily, the interaction with interleukin-28B ( IL28B ) genotype on liver damage.

METHODS

In this observational study, we considered 602 treatment-naïve consecutive patients from tertiary referral centres in Milan and Vienna [61% genotype 1 (G1), 30% advanced fibrosis, 33% IL28B rs12979860 CC].

RESULTS

The p.148M/M genotype, detected in 8% of patients, did not influence SVR in the overall series (P = 0.29), but it was associated with SVR (3/17, 17% vs. 56/121, 46%; P = 0.034) and complete early viral response (4/17, 23% vs. 68/121, 56%; P = 0.018) in G1/4 patients with advanced fibrosis. After adjustment for age, viral load, IL28B CC genotype, treatment dose, and steatosis, p.148M/M remained a predictor of SVR in G1/4 patients with advanced fibrosis (OR 0.23, 95% CI 0.04-0.87). The p.148M/M genotype was associated with more advanced fibrosis in the overall series (P = 0.049), whereas the rs12979860 IL28B CC genotype only in patients negative for p.148M/M (P = 0.017), independently of age, BMI and alanine transaminase levels (OR 1.51, 95% CI 1.01-2.27).

CONCLUSIONS

PNPLA3 p.148M/M genotype was negatively associated with SVR and early viral kinetics independently of steatosis, albeit only in difficult-to-cure G1/4 patients with advanced fibrosis, whereas stratification for the p.148M/M PNPLA3 genotype unmasked an association between IL28B CC genotype and more severe liver fibrosis.

A tetra-primer amplification refractory mutation system polymerase chain reaction for the evaluation of rs12979860 IL28B genotype

Recently, genome-wide association studies in patients affected by HCV infection have identified a strong association between sustained virological response to peg-interferon/ribavirin and spontaneous viral clearance and common single nucleotide polymorphisms (SNPs) near the IL28B gene, encoding for interferon-lambda-3. Thus, it is anticipated that IL28B genotype determination will be integrated in clinical practice to guide treatment decisions. Here, we describe a simple tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) for the evaluation of the rs12979860 C>T IL28B SNP, for which strong evidence of association with clinical outcomes has been collected in subjects of European descent. Valid genotypic data were obtained for over 99% of subjects analysed, and T-ARMS-PCR procedures were validated by the analysis of DNA samples of 164 patients with chronic HCV infection. In conclusion, this method allows rapid, reproducible, inexpensive and accurate detection of rs12979860 polymorphism without need of any special equipment and is also suitable for evaluation of a low number of samples on a routine basis.

Serum ferritin levels are associated with vascular damage in patients with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Increased ferritin and body iron stores are frequently observed in nonalcoholic fatty liver disease (NAFLD), associated with heightened susceptibility to vascular damage. Conflicting data have been reported on the role of iron in atherosclerosis, with recent data suggesting that excess iron induces vascular damage by increasing levels of the hormone hepcidin, which would determine iron trapping into macrophages, oxidative stress, and promotion of transformation into foam cells. Aim of this study was to investigate the relationship between iron status and cardiovascular damage in NAFLD.

METHODS AND RESULTS

Vascular damage was evaluated by common carotid arteries intima-media thickness (CC-IMT) measurement and plaque detection by ecocolor-doppler ultrasonography in 506 patients with clinical and ultrasonographic diagnosis of NAFLD, hemochromatosis gene (HFE) mutations by restriction analysis in 342 patients. Serum hepcidin-25 was measured by time-of-flight mass spectrometry in 143 patients. At multivariate analysis CC-IMT was associated with systolic blood pressure, glucose, LDL cholesterol, abdominal circumference, age, and ferritin (p=0.048). Carotid plaques were independently associated with age, ferritin, glucose, and hypertension. Ferritin reflected iron stores and metabolic syndrome components, but not inflammation or liver damage. Hyperferritinemia was associated with increased vascular damage only in patients with HFE genotypes associated with hepcidin upregulation by iron stores (p<0.0001), and serum hepcidin-25 was independently associated with carotid plaques (p=0.05).

CONCLUSION

Ferritin levels, reflecting iron stores, are independent predictors of vascular damage in NAFLD. The mechanism may involve upregulation of hepcidin by increased iron stores in patients not carrying HFE mutations, and iron compartmentalization into macrophages.

Venesection for non-alcoholic fatty liver disease unresponsive to lifestyle counselling--a propensity score-adjusted observational study

BACKGROUND/AIM

To test the short-term clinical usefulness of venesection associated with lifestyle counselling as against counselling alone on insulin resistance and liver enzymes in subjects with non-alcoholic fatty liver disease (NAFLD), using a propensity score approach.

METHODS

We carried out a 6- to 8-month observational analysis of 198 NAFLD patients in three Italian referral centres (79 venesection and 119 counselling alone). Insulin resistance was measured by the homeostasis model assessment (HOMA) method. Logistic regression was used to identify factors associated with normal HOMA and normal alanine aminotransferase (ALT) at the end of observation. The results were adjusted for the propensity score to be enrolled in the venesection programme, based on clinical and laboratory data, including common HFE polymorphisms and liver biopsy (available in 161 cases).

RESULTS

After adjustment for propensity and changes in BMI, venesection was significantly associated with normal HOMA [all cases: odds ratio (OR) 3.00; 95% confidence interval (CI) 1.51-5.97; cases with histology: OR 2.29; 95% CI 1.08-4.87] and ALT within normal limits (all cases: OR 2.56; 95% CI 1.29-5.10; cases with histology: OR 2.81; 95% CI 1.20-5.24). The results were confirmed in an analysis of 57 pairs matched for propensity, where venesection similarly increased the probability of normal HOMA (OR 3.27; 95% CI 1.16-7.84) and normal ALT (OR 5.60; 95% CI 2.09-15.00). Similar data were obtained in the subset of cases with normal basal ferritin (<350 ng/ml).

CONCLUSION

Iron depletion by venesection favours the normalization of insulin resistance and raised liver enzymes in non-haemochromatosis patients with NAFLD.

A promoter polymorphism in the liver-specific fatty acid transport protein 5 is associated with features of the metabolic syndrome and steatosis

The fatty acid transport protein 5 (FATP5) is exclusively expressed in the liver and is involved in hepatic lipid and bile metabolism. We investigated whether a variation in the FATP5 promoter (rs56225452) is associated with hepatic steatosis and further features of the metabolic syndrome. A total of 716 male subjects from the Metabolic Intervention Cohort Kiel (MICK) and 103 male subjects with histologically proved nonalcoholic fatty liver disease (NAFLD) were genotyped for this FATP5 polymorphism rs56225452 and phenotyped for features of the metabolic syndrome. In the MICK cohort, ALT activities, postprandial insulin, and triglyceride concentrations were higher in subjects carrying the rare A-allele compared to GG homozygotes. Accordingly, the insulin sensitivity index determined after a mixed meal and standardized glucose load was lower in A-allele carriers. NAFLD cases carrying allele A were presented with also higher ALT activities. In NAFLD subjects, the association of BMI with the degree of steatosis and glucose concentration differed across FATP5 promoter polymorphism. The FATP5 promoter polymorphism rs56225452 is associated with higher ALT activity, insulin resistance, and dyslipidemia in the general population. The impact of the BMI on the severity of steatosis in NAFLD cases seems to depend on the FATP5 polymorphism.

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.

Genetic polymorphisms in non-alcoholic fatty liver disease: interleukin-6-174G/C polymorphism is associated with non-alcoholic steatohepatitis

BACKGROUND

Environmental and genetic factors play a role in the pathogenesis and natural history of non-alcoholic fatty liver disease (NAFLD).

METHODS

In 114 subjects with NAFLD we report the prevalence and correlation with clinical parameters of three polymorphisms: interleukin-6 (-174G/C), plasma cell differentiation antigen (K121Q) and microsomal transfer protein (-493G/T). In 59 biopsied patients with NAFLD the polymorphisms were also related to histological features.

RESULTS

IL-6 -174C variant was more prevalent (p<0.01) in NAFLD compared to controls. In the NAFLD group, C carriers had higher HOMA-IR and fasting insulin than G carriers (p<0.05). The prevalence of IL-6/C variant was higher (83%) in biopsied than in not biopsied subjects (66%) (p<0.05). In biopsied subjects, C carriers had higher HOMA and fasting insulin (p<0.05) compared than those with G allele. The prevalence of IL-6 -174G/C polymorphism was significantly higher in NASH than in NAFLD (p=0.048). At logistic regression analysis IL-6 -174C was an independent predictor of both NAFLD (OR 4.116, C.I. 1.126-15.048) and NASH (OR 7.035, C.I. 1.167-42.394). Conversely, the distribution of PC-1 and MTP polymorphisms was not significantly different compared to the control group, nor associated with clinical or histological characteristics.

CONCLUSIONS

Our data suggest that IL-6 -174C genetic polymorphisms, involved in inflammation and insulin resistance, are associated with NASH. These data may contribute to the understanding of the genetic susceptibility to NAFLD.

Ferroportin-1 in the recurrence of hepatic iron overload after liver transplantation

Hepatic siderosis is frequent in patients with Hepatitis C virus (HCV) chronic hepatitis and considered secondary to advanced liver disease when detected in the explanted liver of cirrhotic patients submitted to transplantation. Here, we document the early recurrence of hepatic iron overload starting from host Kupffer cells and later involving hepatocytes in an Italian male submitted to liver transplantation for HCV-related cirrhosis, whose hemosiderosis was interpreted as related to a primary defect of iron handling by monocytic cells due to decreased Ferroportin-1 expression. He was negative for HFE mutations, had normal liver function, did not drink alcohol and had no erythropoietic defect. He was positive for the (CGG)(8/9) and the IVS1 -24 G>C Ferroportin-1 polymorphisms, associated with non-parenchymal iron overload, and had decreased Ferroportin-1 expression in monocytes. In conclusion, this case report documents the recurrence of progressive liver siderosis, which recalls Ferroportin disease, associated with decreased Ferroportin-1 expression in host monocytes repopulating the donor liver.

Association between iron overload and osteoporosis in patients with hereditary hemochromatosis

SUMMARY

In 87 patients with hereditary hemochromatosis, osteoporosis was detected in 25%, and osteopenia in 41%. Bone mineral density was independently associated with BMI, ALP levels, hypogonadism/menopause, and the amount of iron removed to reach depletion, but not with cirrhosis. Osteoporosis is influenced by iron overload in hemochromatosis.

INTRODUCTION

To analyze prevalence, clinical characteristics and genetic background associated with osteoporosis in a retrospective study in Italian patients with hereditary hemochromatosis (HHC).

METHODS

In 87 consecutive patients with HHC, bone mineral density was systematically evaluated by dual energy x-ray absorptiometry of the lumbar spine (n = 87) and femoral neck (n = 66).

RESULTS

Osteoporosis was detected in 22 (25.3%), and osteopenia in 36 (41.4%) patients. Mean Z scores were -0.92 +/- 1.42 at lumbar spine and -0.35 +/- 1.41 at femoral neck. Lumbar spine T-score was independently associated with total ALP (p = 0.002), hypogonadism/menopause (p = 0.026), and iron overload (p = 0.033 for ferritin and p = 0.017 for iron removed). We observed a borderline significance for BMI (p = 0.069) and smoking status (p = 0.086). Lumbar spine osteoporosis was independently associated with lower BMI (OR 0.73, 95% CI 0.54-0.94), total ALP (OR 1.17, 95% CI 1-1.39 per 10 unit increase) and the amount of iron removed (OR 1.53, 95% CI 1-2.5 per 5 g increase). HFE genotypes did not differ between patients with and without osteoporosis.

CONCLUSIONS

Osteoporosis is observed in a quarter of unselected patients with HHC, independently of the genetic background, and is associated with ALP, hypogonadism, body weight, and severity of iron overload.

Consensus recommendations for managing asymptomatic persistent non-virus non-alcohol related elevation of aminotransferase levels: suggestions for diagnostic procedures and monitoring

A persistent increase in non-virus non-alcohol related aminotransferase levels can have multiple causes, which differ in terms of prevalence and clinical importance. In the general population, the most frequent cause is non-alcoholic hepatic steatosis, which can evolve into steato-hepatitis and cirrhosis. The treatment for steatosis and non-alcoholic steato-hepatitis consists of modifying lifestyles, whereas the effectiveness of drug treatment remains to be determined. Other much less frequent (yet not rare) causes of persistent non-virus non-alcohol related elevations in aminotransferase levels are celiac disease and hemochromatosis, whereas autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, and alpha-1-anti-trypsin deficit are rare. Given that some of these conditions are susceptible to treatment, early diagnosis is important. No epidemiological data are available for evaluating the prevalence of elevated aminotransferase levels correlated with the toxicity of drugs or other xenobiotics, including herbal products. The present document, created by a panel of experts based on a systematic review of scientific evidence, is mainly geared towards physicians working in General Medicine and Transfusion Centres, who generally represent the first contact of persons with elevated aminotransferase levels. The document includes suggestions for diagnosing causes of persistent non-virus non-alcohol related increases in aminotransferase levels, considering the frequency and response to treatment. The conditions requiring specialized visits are also indicated.

Iron and insulin resistance

BACKGROUND

Preliminary clinical and experimental results suggest that iron can modify hepatocytes' insulin sensitivity by interfering with insulin receptor and intracellular insulin signalling.

AIM

To evaluate in vivo the influence of iron on insulin resistance and insulin release in patients with non-alcoholic fatty liver disease and in vitro the interaction between iron and insulin sensitivity by analysing the effect of iron manipulation on insulin receptor expression in hepatoblastoma HepG2 cell line.

RESULTS

Insulin resistance evaluated by homeostatis model assessment (HOMA)-insulin resistance significantly decreased after diet, and a further reduction was observed after phlebotomies. Iron depletion by desferrioxamine increased by twofold the 125I-insulin-specific binding, whereas iron addition reduced insulin binding, similarly to cells exposed to high glucose concentration.

CONCLUSION

Iron status affects insulin sensitivity by modulating the transcription and membrane expression/affinity of insulin receptor expression in hepatocytes and influencing insulin-dependent gene expression suggesting that increased insulin clearance and decreased insulin resistance may contribute to the positive effect of iron depletion in patients with non-alcoholic fatty liver disease.

The mitochondrial superoxide dismutase A16V polymorphism in the cardiomyopathy associated with hereditary haemochromatosis

The A16V mitochondrial targeting sequence polymorphism influences the antioxidant activity of MnSOD, an enzyme involved in neutralising iron induced oxidative stress. Patients with hereditary haemochromatosis develop parenchymal iron overload, which may lead to cirrhosis, diabetes, hypogonadism, and heart disease. The objective of this study was to determine in patients with haemochromatosis whether the presence of the Val MnSOD allele, associated with reduced enzymatic activity, affects tissue damage, and in particular heart disease, as MnSOD knockout mice develop lethal cardiomyopathy. We studied 217 consecutive unrelated probands with haemochromatosis, and 212 healthy controls. MnSOD polymorphism was evaluated by restriction analysis. The frequency distribution of the polymorphism did not differ between patients and controls. Patients carrying the Val allele had higher prevalence of cardiomyopathy (A/A 4%, A/V 11%, V/V 30%, p = 0.0006) but not of cirrhosis, diabetes, or hypogonadism, independently of age, sex, alcohol misuse, diabetes, and iron overload (odds ratio 10.1 for V/V, p = 0.006). The frequency of the Val allele was higher in patients with cardiomyopathy (0.67 v 0.45, p = 0.003). The association was significant in both C282Y+/+ (p = 0.02), and in non-C282Y+/+ patients (p = 0.003), and for both dilated (p = 0.01) and non-dilated stage (p = 0.04) cardiomyopathy, but not for ischaemic heart disease. In patients with hereditary haemochromatosis, the MnSOD genotype affects the risk of cardiomyopathy related to iron overload and possibly to other known and unknown risk factors and could represent an iron toxicity modifier gene.

The mitochondrial superoxide dismutase A16V polymorphism in the cardiomyopathy associated with hereditary haemochromatosis

The A16V mitochondrial targeting sequence polymorphism influences the antioxidant activity of MnSOD, an enzyme involved in neutralising iron induced oxidative stress. Patients with hereditary haemochromatosis develop parenchymal iron overload, which may lead to cirrhosis, diabetes, hypogonadism, and heart disease. The objective of this study was to determine in patients with haemochromatosis whether the presence of the Val MnSOD allele, associated with reduced enzymatic activity, affects tissue damage, and in particular heart disease, as MnSOD knockout mice develop lethal cardiomyopathy. We studied 217 consecutive unrelated probands with haemochromatosis, and 212 healthy controls. MnSOD polymorphism was evaluated by restriction analysis. The frequency distribution of the polymorphism did not differ between patients and controls. Patients carrying the Val allele had higher prevalence of cardiomyopathy (A/A 4%, A/V 11%, V/V 30%, p = 0.0006) but not of cirrhosis, diabetes, or hypogonadism, independently of age, sex, alcohol misuse, diabetes, and iron overload (odds ratio 10.1 for V/V, p = 0.006). The frequency of the Val allele was higher in patients with cardiomyopathy (0.67 v 0.45, p = 0.003). The association was significant in both C282Y+/+ (p = 0.02), and in non-C282Y+/+ patients (p = 0.003), and for both dilated (p = 0.01) and non-dilated stage (p = 0.04) cardiomyopathy, but not for ischaemic heart disease. In patients with hereditary haemochromatosis, the MnSOD genotype affects the risk of cardiomyopathy related to iron overload and possibly to other known and unknown risk factors and could represent an iron toxicity modifier gene.

Searching for coeliac disease in patients with non-alcoholic fatty liver disease

BACKGROUND

A non-negligible percentage of patients with non-alcoholic fatty liver disease, a leading cause of hepatic progressive disorder related to insulin resistance, have no metabolic risk factors, and abnormal intestinal permeability has been suggested to be involved in the pathogenesis of the liver damage. Coeliac disease, a curable disorder characterised by inflammatory mucosal damage, may show hepatic histological features similar to steatohepatitis. Conflicting data have been reported on the prevalence of coeliac disease in non-alcoholic steatohepatitis.

AIM

To search for coeliac disease in a series of patients with non-alcoholic fatty liver disease by screening with anti-tissue transglutaminase and anti-endomysium antibodies.

PATIENTS AND METHODS

Fifty-nine consecutive patients with hypertransaminasemia and non-alcoholic fatty liver disease, 38 (64%) with steatohepatitis. Anti-endomysium antibodies were assayed by indirect immunofluorescence, IgA anti-tissue transglutaminase by ELISA. Patients who tested positive underwent HLA DQ typing and endoscopy.

RESULTS

Tissue transglutaminase antibodies were positive in six (10%) patients and anti-endomysium in two (3.4%); only two (3.4%), positive for both anti-endomysium positive and anti-transglutaminase, resulted to have coeliac disease based on histological findings. After 6 months of gluten-free diet, liver enzymes normalised.

CONCLUSIONS

The prevalence of silent coeliac disease is 3.4% in patients with non-alcoholic fatty liver. The inclusion of anti-endomysium antibodies test in studying patients with non-alcoholic fatty liver and persistent biochemical abnormalities has to be taken into account, since positivity for tissue transglutaminase antibodies, in the absence of confirmatory anti-endomysium antibodies, is not sufficient to perform diagnostic endoscopy.

What is the contribution of differences in three measures of tumor necrosis factor-alpha activity to insulin resistance in healthy volunteers?

To address the potential role that tumor necrosis factor-alpha (TNF-alpha) might play in modulation of insulin resistance in healthy, nondiabetic individuals, we compared plasma TNF-alpha and soluble TNF-alpha receptor 2 (sTNF-R2) concentrations, as well as TNF-alpha polymorphisms, in 94 healthy individuals, stratified into insulin-resistant (IR) and insulin-sensitive (IS) groups based on their plasma insulin concentrations 120 minutes after oral glucose on 2 occasions (1993 and 2000). The IR group (n = 50; 29 men and 21 women) was in the upper quartile and the IS group (n = 44; 24 men and 20 women) in the lowest quartile of the distribution of post-glucose challenge insulin concentrations in a large unselected population (>50 v <23 microU/mL). The IR group had significantly higher values for body mass index, waist-to-hip girth, fasting and post-glucose challenge insulin concentrations, and fasting triglyceride concentrations, and lower high-density lipoprotein cholesterol concentrations as compared to the IS group. Despite the fact that they were relatively more obese, and insulin-resistant, plasma concentrations of TNF-alpha were similar in the IR (1.6 +/- 0.6 pg/mL) and IS (1.7 +/- 0.6 pg/mL) groups, as were the concentrations (5.4 +/- 1.4 v 5.8 +/- 2.0 pg/mL) of sTNF-R2. Furthermore, TNF-alpha polymorphisms (detected by polymerase chain reaction [PCR]) were similar in the 2 groups, with essentially identical allelic frequencies of the 238 (10.3% v 9.4%) and 308 polymorphisms (17.9% v 18.7%). In conclusion, plasma TNF-alpha and sTNF-R2 concentrations, as well as TNF-alpha gene polymorphisms, were not different in healthy volunteers stratified into IR and IS groups on the basis of their plasma insulin response to an oral glucose challenge. Given these data, it does not appear that differences in TNF-alpha activity contribute to the marked variations in insulin action that occur in healthy individuals.

Increased susceptibility to nonalcoholic fatty liver disease in heterozygotes for the mutation responsible for hereditary hemochromatosis

BACKGROUND

Insulin resistance is a key feature of nonalcoholic fatty liver disease. Patients with hereditary hemochromatosis, a disease characterized by progressive iron overload due, in most cases, to homozygosity for C282Y mutation in the HFE gene, have often decreased insulin sensitivity and release.

AIMS

To determine whether increased iron parameters/heterozygosity for the mutations of the HFE gene confer susceptibility to nonalcoholic fatty liver disease.

PATIENTS

One hundred and thirty-four consecutive Italian patients with clinical and ultrasonographic diagnosis of nonalcoholic fatty liver disease (82 with hyperferritinemia), half confirmed by liver biopsy.

METHODS

Insulin was determined by radioimmunoassay. HFE gene mutations were determined by polymerase chain reaction and restriction fragment length polymorphism analysis.

RESULTS

(1) Prevalence of C282Y HFE mutation was significantly higher in patients with nonalcoholic fatty liver disease compared to controls, the difference being more striking in patients with hyperferritinemia than in those without. (2) The presence of mild iron overload was associated with a lower insulin release. (3) Carriers of C282Y mutation developed nonalcoholic fatty liver disease despite lower body mass index and triglycerides.

CONCLUSION

The mild iron overload associated with heterozygosity for C282Y HFE mutation confers susceptibility to nonalcoholic fatty liver disease, causing relative insulin deficiency.

Red blood cell antioxidant and iron status in alcoholic and nonalcoholic cirrhosis

BACKGROUND

Iron overload has been reported in alcoholic liver cirrhosis but it remains to be established whether iron is involved in inducing oxidative damage to erythrocytes in alcoholic cirrhosis. The aim of this study was to assess oxidative damage and red cell indicators of antioxidant defences in alcoholics with mild-to-severe liver cirrhosis, taking into account the iron status.

MATERIALS AND METHODS

Twenty-nine patients with alcoholic liver cirrhosis (AC) and 27 with nonalcoholic cirrhosis (NAC) were studied. Serum lipid peroxides (LPO) were assayed by a colourimetric method. Serum-free malonyldialdehyde (MDA) was assayed by selected ion monitoring in positive chemical ionization; serum 4-hydroxy-2(E)-nonenal (4-HNE) was determined by a colorimetric method. Reduced (GSH) and oxidized glutathione (GSSG), adenine and pyridine cofactors were assayed in whole blood extracts by HPLC. Hexose-monophosphate shunt (HMPS), glycolytic pathway (EMP) and antioxidant enzyme activities were determined by standard methods. Iron status was evaluated by standard clinical chemistry and by histological grading of liver iron. Nontransferrin-bound iron (NTBI) was measured in serum by HPLC.

RESULTS

GSH progressively decreased with increasing severity of liver involvement in AC and NAC. MDA, 4-HNE and NTBI were significantly higher in AC serum. Stimulation of red cell HMPS and reducing potential, in terms of NADPH production, were more pronounced in AC.

CONCLUSIONS

These results suggest that NTBI is more important than the decrease of antioxidant defences in inducing lipid peroxidation. NTBI may play a catalytic role in free radical reactions in the presence of cellular reductants such as NADPH.

Non-transferrin-bound iron in alcohol abusers

BACKGROUND

Non-transferrin-bound iron, a low-molecular-weight iron complex capable of initiating free radical formation and lipid peroxidation, has been detected in the serum of animals experimentally fed with alcohol, but no data have been reported in alcohol abusers. The purpose of this study was to evaluate whether non-transferrin-bound iron is present in chronic alcohol abusers with liver involvement and whether alcohol plays any part in its appearance.

METHODS

We measured non-transferrin-bound iron in a cohort of chronic alcohol abusers with and without liver cirrhosis at presentation, when 43 were active abusers and 33 were abstainers, and in a smaller group during a follow-up period.

RESULTS

At presentation, non-transferrin-bound iron was detectable in 83.7% of active abusers but only in 21.2% of abstainers, and within the group of abusers, patients with cirrhosis had significantly higher non-transferrin-bound iron than patients without. Non-transferrin-bound iron was present not only in patients with transferrin saturation >45% but also in those with transferrin saturation < or =45%. Multiple regression analyses revealed that only alcohol intake and total bilirubin were associated independently with non-transferrin-bound iron values. Longitudinal study confirmed the data of the cross-sectional study.

CONCLUSIONS

Non-transferrin-bound iron could have a role in initiating or promoting alcohol-induced liver damage.

Contrast-enhanced Doppler ultrasonography in the diagnosis of hepatocellular carcinoma and premalignant lesions in patients with cirrhosis

Hepatocellular carcinogenesis in cirrhosis is a multistage process that includes large regenerative nodules, dysplastic nodules, and hepatocarcinoma. The aim of this study was to establish whether contrast-enhanced Doppler ultrasonography (US) is able to distinguish between early hepatocellular carcinoma (HCC) and small nonmalignant nodules in cirrhosis. Between January 1998 and December 1999, 500 cirrhotic patients with no previous history of HCC or evidence of hepatic focal lesions were enrolled and prospectively followed-up with US every 6 months until December 2000. Sixty-one patients developed focal lesions, 12 multifocal, and 49 monofocal. Biopsy of focal lesions, contrast-enhanced Doppler US, and spiral computed tomography (CT) were performed in 41 consecutive patients with small (<3 cm) monofocal lesions. Twenty nodules were diagnosed as HCC and 21 as nonmalignant (14 large regenerative nodules, 3 low-grade, and 4 high-grade dysplastic nodules) by liver biopsy. Intratumoral arterial blood flow was detected in 19 of 20 (95%) HCC and 6 of 21 (28%) nonmalignant nodules by contrast-enhanced Doppler US (P<.0001). The mean peak resistance and pulsatility indices were 0.82 +/- 0.09 and 1.56 +/- 0.2 in HCC and 0.62 +/- 0.08 and 0.82 +/- 0.08 in dysplastic lesions (P =.002 and.0001), respectively. Spiral CT revealed arterial perfusion in 19 of 20 HCC and in 4 of 21 nonmalignant nodules (high-grade dysplastic nodules). Four of the apparently false-positive nodules at enhanced Doppler US were high-grade dysplastic nodules and 2 evolved to HCC during follow-up. In conclusion, contrast-enhanced Doppler US is a noninvasive, very sensitive technique in differentiating malignant and premalignant lesions from nonmalignant focal lesions in the liver.

Non-transferrin-bound iron in alcohol abusers

BACKGROUND

Non-transferrin-bound iron, a low-molecular-weight iron complex capable of initiating free radical formation and lipid peroxidation, has been detected in the serum of animals experimentally fed with alcohol, but no data have been reported in alcohol abusers. The purpose of this study was to evaluate whether non-transferrin-bound iron is present in chronic alcohol abusers with liver involvement and whether alcohol plays any part in its appearance.

METHODS

We measured non-transferrin-bound iron in a cohort of chronic alcohol abusers with and without liver cirrhosis at presentation, when 43 were active abusers and 33 were abstainers, and in a smaller group during a follow-up period.

RESULTS

At presentation, non-transferrin-bound iron was detectable in 83.7% of active abusers but only in 21.2% of abstainers, and within the group of abusers, patients with cirrhosis had significantly higher non-transferrin-bound iron than patients without. Non-transferrin-bound iron was present not only in patients with transferrin saturation >45% but also in those with transferrin saturation < or =45%. Multiple regression analyses revealed that only alcohol intake and total bilirubin were associated independently with non-transferrin-bound iron values. Longitudinal study confirmed the data of the cross-sectional study.

CONCLUSIONS

Non-transferrin-bound iron could have a role in initiating or promoting alcohol-induced liver damage.

Autoantibodies to human cytosol: a marker of sporadic porphyria cutanea tarda

The enzymes potentially involved in the pathogenesis of sporadic porphyria cutanea tarda (PCT) reside in liver cytosoles and microsomes. PCT is frequently associated with hepatitis C virus (HCV) infection, which is in turn associated with autoimmune manifestations. To investigate whether autoimmune reactions, possibly triggered by HCV, are involved in the pathogenesis of PCT, we measured by immunoblot autoantibodies to human cytosolic and microsomal liver fractions in 82 patients with PCT (77% with HCV infection), 105 with other liver disorders and 40 healthy subjects. Anti-liver cytosolic antibodies were more frequent in PCT patients (38/82, 46%) than in pathological controls (P < 0.05-P < 0.001) or in healthy subjects (3/40, 8%, P < 0.001). Among PCT patients, anticytosolic antibodies were more frequent in HCV positive (36/63, 57%) than in HCV negative (2/19, 11%, P < 0.05) cases. Reactivity to a 40-kDa cytosolic polypeptide was present in 20 PCT patients (19 HCV positive), being more frequent than in all pathological controls (P < 0.01-P < 0.0001). Histological activity index (P = 0.04) and antibodies to HCV (P = 0.027) - but not HCV RNA - were associated independently with anticytosolic antibodies as assessed by multivariate analysis. In contrast, frequency of antiliver microsomal antibodies was similar in PCT patients (24/82, 29%) and pathological controls (8-26%), being higher in the autoimmune hepatitis control group (23/23, 100%, P < 0.0001). In conclusion, anticytosolic antibodies, particularly to a 40-kDa polypeptide, are frequent in PCT and associated with HCV infection and severity of liver damage.

Liver cancer risk is increased in patients with porphyria cutanea tarda in comparison to matched control patients with chronic liver disease

BACKGROUND/AIMS

Patients with porphyria and chronic liver disease could be at high risk of developing hepatocellular carcinoma. To define the incidence of primary liver cancer and identify variables associated with the risk of cancer in patients with porphyria cutanea tarda in comparison to control patients.

METHODS

Fifty-three patients with porphyria cutanea tarda were enrolled in a prospective study (median follow-up 72 +/- 54.1 months; range 12-216) and matched individually to a control case according to age (+/-5 years), sex, duration of follow up (+/- 5 years), severity of liver disease, and hepatitis C virus infection.

RESULTS

During follow-up hepatocellular carcinoma developed in 18 patients with porphyria and in four control patients. Incidence of primary liver cancer was 4.8 and 1.3 x 100 patients/year in the overall series of patients and of controls, respectively. The cumulative probability of being tumor free was significantly lower in porphyria cutanea tarda than in matched controls (75 vs 95%). Variables independently associated with the risk of liver cancer were the presence of porphyria and cirrhosis at enrollment (Odds ratios: 5.3, 95% CI 1.4-19.3 and 3.0, 95% CI 1.2-7.6, respectively).

CONCLUSIONS

Patients with porphyria are at higher risk of developing liver cancer than matched control patients.

Hyperferritinemia, iron overload, and multiple metabolic alterations identify patients at risk for nonalcoholic steatohepatitis

OBJECTIVE

The aim of this study was to define in patients with hyperferritinemia and normal transferrin saturation the relationships among hyperferritinemia, iron overload, HFE gene mutations, the presence of metabolic alterations, and nonalcoholic steatohepatitis (NASH).

METHODS

Forty patients with increased serum ferritin, resistant to dietary restriction and normal transferrin saturation, 90 with ultrasonographic evidence of hepatic steatosis, and 60 obligate heterozygotes for hemochromatosis, all negative for alcohol abuse, hepatitis virus infections, and inflammation were studied. Transferrin saturation, serum ferritin, uric acid, lipids, glucose tolerance, insulin resistance, HFE gene mutations, liver histology, and hepatic iron concentration were analyzed.

RESULTS

Of the 40 patients with hyperferritinemia, 29 (72%) had biochemical metabolic abnormalities, 18 of the 26 examined (69%) had insulin resistance, 26 (65%) had the presence of one of the two HFE gene mutations (normal controls, 33 of 128 [26%], p < 0.0001), and all had increased liver iron concentration. Thirty-one patients (77%) had histology compatible with NASH. At univariate analysis, NASH was significantly associated with the presence of metabolic alterations, the C282Y mutation, and severity of fibrosis. At multivariate analysis, NASH was associated with the coexistence of multiple metabolic alterations (odds ratio = 5.2, 95% CI = 0.95-28.7). The risk of having NASH augmented in the presence of higher values of ferritin and liver iron concentration. Among the 90 patients with ultrasonographic evidence of hepatic steatosis, 24 (27%) had increased serum ferritin with normal transferrin saturation, but only six remained hyperferritinemic after dietary restriction.

CONCLUSION

Increased ferritin with normal transferrin saturation is frequently found in patients with hepatic steatosis, but it reflects iron overload only in those patients in whom it persists despite an appropriate diet. The simultaneous disorder of iron and glucose and/or lipid metabolism, in most of the cases associated with insulin resistance, is responsible for persistent hyperferritinemia and identifies patients at risk for NASH.

Tumor necrosis factor alpha promoter polymorphisms influence the phenotypic expression of hereditary hemochromatosis

Severe iron overload usually develops in patients with hereditary hemochromatosis (HHC), but variability in the phenotypic expression of the disease has been reported. This study assessed whether tumor necrosis factor alpha (TNF-alpha) plays a role in phenotypic expression of HHC. Sixty-four patients with HHC and 172 healthy volunteers (controls) were studied. Release of TNF-alpha from stimulated peripheral blood monocytes was measured by enzyme-linked immunosorbent assay, and 308 and 238 TNF-alpha polymorphisms were detected with polymerase chain reaction and restriction fragment-length polymorphism analysis. The relation between TNF-alpha polymorphisms and clinical expression of HHC was evaluated. Patients with HHC released less TNF-alpha than controls, but the difference was significant only in homozygotes for the C282Y mutation. The prevalence of the 308 TNF-alpha polymorphism was similar in patients and controls, whereas the prevalence of the 238 polymorphic allele was significantly lower in patients (3% versus 16%; P =.002). A lower prevalence of cirrhosis was observed in patients with TNF-alpha polymorphism than in those without it (4 of 15 [27%] versus 28 of 49 [57%]), but the difference was not significant (P =.07). In nonhomozygotes for the C282Y mutation, severe liver siderosis was less prevalent in patients with the 308 polymorphism than in those without it (P =.05). Alanine aminotransferase (ALT) values were significantly lower in patients with TNF-alpha polymorphism (P =.006), even when patients with other hepatotoxic factors were excluded. Multivariate analysis showed that TNF-alpha polymorphism was independently associated with ALT values (P =.0008 and P =.045, respectively, in homozygotes and nonhomozygotes for the C282Y mutation) and siderosis in nonhomozygotes (P =.047). Thus, TNF-alpha appears to play a role in HHC by modulating the severity of liver damage. (Blood. 2001;97:3707-3712)

Seven novel point mutations in the uroporphyrinogen decarboxylase (UROD) gene in patients with familial porphyria cutanea tarda (f-PCT)

In this work, we describe seven novel molecular defects in the uroporphyrinogen decarboxylase gene responsible for familial porphyria cutanea tarda in Italian subjects with reduced erythrocyte URO-D activity. Four of these molecular abnormalities (R142Q, L161Q, S219F, P235S) are missense mutations, one (Q206X) is a nonsense mutation, one (IVS8-1 G>C) is a splicing defect causing the exon 9 deletion and one (1107 G>A) is located in the 3' untranslated region of UROD gene. All the amino acid substitutions fall in conserved regions in several organisms suggesting an important role in catalysis or in the protein structure stabilization. Three of these mutations have been detected in more than one subject. These results suggest a molecular heterogeneity at the UROD locus in Italian PCT patients although recurrent mutations have been identified.

Mutations in the HFE gene and their interaction with exogenous risk factors in hepatocellular carcinoma

The possible role of iron in facilitating the development of liver cancer is still debated. The aims of this study were to define the prevalence of the mutations 845G --> A and 187C --> G (C282Y and H63D) in the HFE gene associated with hereditary hemochromatosis in Italian patients with hepatocellular carcinoma occurring in cirrhosis and to analyze the interaction between these mutations and other established risk factors for hepatocellular carcinoma. The HFE gene mutations, performed by polymerase chain reaction, were analyzed in 81 patients (63 males, 18 females) with hepatocellular carcinoma. None of the patients had a phenotype compatible with homozygous hereditary hemochromatosis. Interaction between HFE mutations and exogenous risk factors was analyzed by collecting information on alcohol consumption, hepatitis B and C virus infections, and iron status at the time of diagnosis of chronic liver disease. This analysis was performed only in males to rule out gender influence on patients' iron status by using the case-only approach specifically designed to estimate departure from multiplicative risk ratios under the assumption of independence between genotype and environmental exposure. The prevalence of the C282Y mutation was significantly higher in patients with hepatocellular carcinoma than in normal controls (8.6% vs 1.6%, P < 0.03). At univariate analysis, iron overload was significantly associated with both HFE mutations (P < 0.0001), whereas ongoing hepatitis B virus infection was associated with the C282Y mutation (P < 0.05). By multivariate analysis, a trend for an increased risk of being positive for hepatitis virus markers (OR 2.9, CI 95% 0.9-9.5) and of having been alcohol abusers (OR 3, CI 95% 0.7-14) was observed in patients heterozygous for the HFE mutations. These data indicate that the prevalence of the main mutation associated with hereditary hemochromatosis is significantly higher in cirrhotic Italian patients with hepatocellular carcinoma compared to a normal population and suggest that heterozygotes for HFE mutations exposed to hepatitis virus infections or who had been alcohol abusers could have an increased risk of developing cirrhosis and later liver cancer than people without the mutations exposed to the same risk factors.

Increased cancer risk in a cohort of 230 patients with hereditary hemochromatosis in comparison to matched control patients with non-iron-related chronic liver disease

It has been suggested that excess iron may facilitate the occurrence of cancer. Patients with hereditary hemochromatosis (HH) are at high risk of developing liver cancer, and studies of limited series reported a high frequency of nonhepatic cancers. To verify whether patients with HH are at higher risk of liver cancer and other malignancies as compared with patients with non-iron-related chronic liver disease (CLD), we analyzed the occurrence of neoplasms in 230 patients with HH and 230 with non-iron-related CLD. The patients were matched by sex, age, duration of follow-up (+/-5 years), and severity of liver disease. On enrollment, the following variables were considered: hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, alcohol abuse, smoking, and a family history of cancer (first-degree relatives). The diagnosis of primary cancers was confirmed by histology. During the follow-up, hepatocellular carcinoma (HCC) developed in 49 and 29 patients (all cirrhotic patients) with HH and non-iron-related CLD, respectively, with a relative risk of 1.8 (95% confidence interval [CI] 1.1-2.9); nonhepatic cancers occurred in 20 and 11 patients, respectively, with a relative risk of 1.8 (95% CI 0.8-4). Four patients with HH and 1 with non-iron-related CLD developed 2 different primary cancers during follow-up. The risk of cancer after adjustment for alcohol abuse, smoking, and family history of cancer was 1.9 (95% CI 1.1-3.1) in the patients with HH. In conclusion, patients with HH are at high risk of both liver cancer and other malignancies, which should be carefully sought during follow-up.

Haemochromatosis in patients with beta-thalassaemia trait

Severe iron overload has been reported in patients with the beta-thalassaemia trait. Studies performed before the discovery of the haemochromatosis gene (HFE) have yielded conflicting results: some suggest that iron overload might arise from the interaction of the beta-thalassaemia trait with heterozygosity for haemochromatosis, some with homozygosity for haemochromatosis and others that it was unrelated to haemochromatosis. We have studied the clinical phenotype, iron indices and HFE genotypes of 22 unrelated patients with the beta-thalassaemia trait and haemochromatosis, the inheritance of chromosome 6p and 1q haplotypes in families of non-homozygous C282Y probands and serum measures of iron status in relatives heterozygous for C282Y with or without the beta-thalassaemia trait. We demonstrate that the beta-thalassaemia trait aggravates the clinical picture of C282Y homozygotes, favouring higher rates of iron accumulation and the development of severe iron-related complications. We suggest that the coexistence of the beta-thalassaemia trait might also increase the risk of iron overload in patients with HFE genotypes at a mild risk of haemochromatosis. Our findings do not support the hypothesis that the association of the beta-thalassaemia trait with a single C282Y or H63D allele might lead to iron overload and suggest that other non-HFE-related inherited factors are present in haemochromatosis patients with incomplete HFE genotypes.

TT virus infection in adult beta-thalassemia major patients

BACKGROUND AND OBJECTIVES

Patients with thalassemia-major are at risk of blood-borne viral infections. TT virus (TTV), a single stranded, circular DNA virus, has recently been found to be associated with acute and chronic hepatitis. The aims of this study were to assess the prevalence of TTV infection in adult patients with transfusion-dependent thalassemia, and to evaluate the clinical significance of TTV.

DESIGN AND METHODS

We studied 68 adult patients with thalassemia major, 97% of whom were hepatitis C virus (HCV) antibody positive. TTV DNA was amplified from serum by heminested polymerase chain reaction (PCR). Direct sequencing of PCR products was used to establish TTV genotypes.

RESULTS

TTV DNA was detected in 47 patients (69.1%). Sequence analysis of PCR products identified TTV genotype 1b as the most common viral genotype in this group. Patients co-infected by HCV and TTV had a significantly higher histologic grade score than patients with isolated HCV infection (5.1+/-2.7 vs. 2.8+/-1.7, p=0.02) while the stage score was not significantly different.

INTERPRETATION AND CONCLUSIONS

TTV is highly prevalent among Italian multiply transfused patients. In these patients TTV viremia appears to affect the necro-inflammatory activity of hepatitis C, though no evidence of an effect on the evolution of fibrosis was found.

Hereditary hemochromatosis in a patient with congenital dyserythropoietic anemia

Herein is described the case of a young woman presenting with iron overload and macrocytosis. The initial diagnosis was hereditary hemochromatosis. Severe anemia developed after a few phlebotomies, and she was also found to have congenital dyserythropoietic anemia that, though not completely typical, resembled type II. Only genetic testing allowed the definition of the coexistence of the 2 diseases, both responsible for the iron overload. This report points out the need to consider congenital dyserythropoietic anemia in patients with hemochromatosis and unexplained macrocytosis and, conversely, to check for the presence of hereditary hemochromatosis in patients with congenital dyserythropoietic anemia and severe iron overload. To the authors' knowledge, this is the first report of homozygosity for the C282Y mutation of the HFE gene in a patient affected by congenital dyserythropoietic anemia.

Iron and liver diseases

A mild to moderate iron excess is found in patients with liver diseases apparently unrelated to genetic hemochromatosis. Iron appears to affect the natural history of hepatitis C virus-related chronic liver diseases, alcoholic liver disease and nonalcoholic steatohepatitis by leading to a more severe fibrosis and thus aiding the evolution to cirrhosis. A higher frequency of mutations of the HFE gene, the gene responsible for hereditary hemochromatosis, is found in patients with liver diseases and increased liver iron than in normal patients. Patients with excess iron are potentially at a higher risk of developing hepatocellular carcinoma. Iron depletion therapy could interfere with fibrosis development and possibly reduce the risk of liver cancer occurrence.

Can large cell change and high proliferative activity predict hepatocellular carcinoma in patients with hereditary hemochromatosis?

OBJECTIVE

Patients with hereditary hemochromatosis are at high risk of developing hepatocellular carcinoma. This study was undertaken to define whether large cell change and nucleolar organizer regions proliferative index (marker of high proliferative activity) predict hepatocellular carcinoma development in hereditary hemochromatosis.

METHODS

Histological staining for large cell change and high proliferative activity were done on baseline liver biopsies of 74 patients with hereditary hemochromatosis (52 with and 22 without cirrhosis), prospectively followed-up for 83 +/- 53 months (range, 1-230 months).

RESULTS

Large cell change and high proliferative activity were found only in cirrhotic patients; 16 of 52 patients (31%) had either the large cell change or high proliferative activity. Large cell change was more frequent in patients with hepatitis B surface antigen than in those positive for hepatitis C virus (57% vs 14%, p = 0.04). Hepatocellular carcinoma developed in 7 of 16 (44%) and in 6 of 36 patients (16%) of the patients positive or negative for these morphological variables. The probability of developing hepatocellular carcinoma at 7 yr of follow-up was significantly higher in patients with large cell change or high proliferative activity than in those without. The length of follow-up from baseline histology to hepatocellular carcinoma occurrence was shorter in patients with large cell change or high proliferative activity than in those without these changes (46 +/- 36 and 109 +/- 34 months, p = 0.01). A multivariate analysis indicated that in patients with cirrhosis, large cell change or high proliferative activity (considered as a single variable), and age >55 yr were the only independent variables significantly associated with the risk of developing hepatocellular carcinoma, with a risk ratio of 4.8 (confidence interval 1.2-18.2) and 4.0 (confidence interval 1.1-15.6), respectively.

CONCLUSIONS

In hereditary hemochromatosis, the presence of large cell change or high proliferative activity in patients older than 55 yr with cirrhosis should be considered a strong predictor of hepatocellular carcinoma development, especially if hepatitis B virus infection coexists.

Relationship between TNF-alpha and iron metabolism in differentiating human monocytic THP-1 cells

The human monocytic cell line THP-1 differentiates along the macrophage line after phorbol-12-myristate-13-acetate (PMA) supplementation and can be stimulated to secrete tumour necrosis factor alpha (TNF-alpha) by interferon gamma (IFN-gamma) addition. We found that, in the early stage of differentiation (1-48 h), PMA induction elicited an upregulation of intracellular H ferritin and H ferritin binding sites and a downregulation of transferrin receptor. In addition, we found that iron administration to PMA-differentiating cells induced the expression of TNF-alpha mRNA and TNF-alpha secretion to levels even higher than those induced by IFN-gamma alone. The iron chelator desferrioxamine showed the opposite effect and reduced TNF-alpha release. In contrast, preincubation of the cells with iron before PMA induction resulted in a decrease of the TNF-alpha secretion induced by IFN-gamma, whereas the opposite was true after preincubation with desferrioxamine. The data support a co-ordinate interaction between iron and TNF-alpha in monocyte macrophages, with an iron-mediated upregulation of TNF-alpha in the early phase of differentiation and an iron-mediated inhibition at later stages. This complex relationship has to be considered in evaluating the effects of iron on inflammation.

Molecular analysis of the hydroxymethylbilane synthase (HMBS) gene in Italian patients with acute intermittent porphyria: report of four novel mutations

Acute intermittent porphyria (AIP) is an autosomal disorder caused by molecular abnormalities in the hydroxymethylbilane synthase (HMBS) gene coding for the third enzyme in the heme biosynthetic pathway. So far, more than 160 different mutations responsible for AIP have been identified in this gene. We have now identified seven mutations in eight unrelated Italian patients with AIP: two splicing defects (IVS7+2T-->C, 612G-->T), three small deletions (308-309delTG, 730-731delCT, 182delA) and two missense mutations (134C-->A, 541C-->T). The splicing defects were responsible for activation of splicing cryptic sites respectively within intron 7 (15 bp insertion) and exon 10 (9 bp deletion). The small deletions resulted in frameshifts leading to the formation of premature stop codons. The 134C-->A and 541C-->T mutations caused the formation of stop codons likely to be responsible for drastic disruption of the HMBS structure (Ser45Ter, Gln181Ter). This is the first molecular study in AIP patients of Italian origin leading to the identification of four new mutations and three molecular defects that have already been described.

Immunohistochemistry of HFE in the duodenum of C282Y homozygotes with antisera for recombinant HFE protein

BACKGROUND AND OBJECTIVE

HFE is a class-I MHC related protein which carries the C282Y mutation in most patients with hereditary hemochromatosis, an iron overload disease. HFE protein is expected to have a relevant role in the regulation of duodenal iron absorption, and HFE protein was immunohistochemically identified in the crypt cells. The aim of the work was to analyze whether the C282Y mutation affects HFE accumulation in the duodenum.

DESIGN AND METHODS

We developed antisera for the extracellular portion of recombinant human HFE protein expressed in E. coli. The antisera were specific for HFE protein and the C282Y mutant in immunoblotting, immunoprecipitation and immunocytochemistry experiments of transfected cells, and they did not cross react with HLA antigens in various analyses. The antisera gave positive results in the staining of paraffin-fixed sections of duodenal slices of subjects with hemochromatosis.

RESULTS

The antisera stained evident supranuclear granules in all enterocytes of 7 C282Y homozygous subjects, and a dark area in the same region in 3 other C282Y homozygotes. Granular bodies were absent from the duodenal sections of 8 C282Y negative subjects, from 2 C282Y heterozygotes and 3 C282Y homozygotes, with or without hemochromatosis.

INTERPRETATION AND CONCLUSIONS

The detection of HFE-protein in granular bodies in the enterocytes of the large majority (77%) of C282Y homozygotes and not in other subjects suggests that the mutation facilitates protein accumulation in the duodenum.

Inherited HFE-unrelated hemochromatosis in Italian families

Hemochromatosis (HH) is usually caused by the homozygous state for C282Y mutation in the HFE gene. A minority of iron loaded patients have no mutations in this gene. An infrequent subset shows an early-onset aggressive disorder, denoted juvenile hemochromatosis (JH), which has no linkage to 6p. In this report we describe six patients from three unrelated Italian families, four men and two women, aged 21 to 44 with the typical hemochromatosis phenotype, who are homozygous for the wild type allele at the HFE gene. In two families the disorder is unlinked to 6p; in one family some features of the juvenile form are seen, but linkage to 6p is not excluded. Our results point to genetic forms of hemochromatosis not associated with HFE and raise the problem of whether non-HFE hemochromatosis in Italy is related to the "juvenile" form. They also emphasize the importance of phenotypic as well as genetic diagnosis of HH.