Increased hepatic iron and cirrhosis: no evidence for an adverse effect on patient outcome following liver transplantation

Xanthohumol ameliorates drug-induced hepatic ferroptosis via activating Nrf2/xCT/GPX4 signaling pathway

BACKGROUND

As a canonical iron-dependent form of regulated cell death (RCD), ferroptosis plays a crucial role in chemical-induced liver injuries. Previous studies have demonstrated that xanthohumol (Xh), a natural prenylflavonoid isolated from hops, exhibits anti-inflammatory, anti-antioxidative and hepatoprotective properties. However, the regulatory effects of Xh on hepatic ferroptosis and the underlying mechanism have not yet been fully elucidated.

PURPOSE

To investigate the hepatoprotective effects of Xh against drug-induced liver injury (DILI) and the regulatory effects of Xh on hepatic ferroptosis, as well as to reveal the underlying molecular mechanisms.

METHODS/STUDY DESIGN

The hepatoprotective benefits of Xh were investigated in APAP-induced liver injury (AILI) mice and HepaRG cells. Xh was administered intraperitoneally to assess its in vivo effects. Histological and biochemical studies were carried out to evaluate liver damage. A series of ferroptosis-related markers, including intracellular Fe2+ levels, ROS and GSH levels, the levels of MDA, LPO and 4-HNE, as well as the expression levels of ferroptosis-related proteins and modulators were quantified both in vivo and in vitro. The modified peptides of Keap1 by Xh were characterized utilizing nano LC-MS/MS.

RESULTS

Xh remarkably suppresses hepatic ferroptosis and ameliorates AILI both in vitro and in vivo, via suppressing Fe2+ accumulation, ROS formation, MDA generation and GSH depletion, these observations could be considerably mitigated by the ferroptosis inhibitor ferrostatin-1 (Fer-1). Mechanistically, Xh could significantly activate the Nrf2/xCT/GPX4 signaling pathway to counteract AILI-induced hepatocyte ferroptosis. Further investigations showed that Xh could covalently modify three functional cysteine residues (cys151, 273, 288) of Keap1, which in turn, reduced the ubiquitination rates of Nrf2 and prolonged its degradation half-life.

CONCLUSIONS

Xh evidently suppresses hepatic ferroptosis and ameliorates AILI via covalent modifying three key cysteines of Keap1 and activating Nrf2/xCT/GPX4 signaling pathway.

Association of iron overload with infectious complications in liver transplant recipients: a systematic review and meta-analysis

OBJECTIVE

This study was performed to examine the possible association of iron overload with infectious complications and survival among liver transplant recipients.

METHODS

We conducted a systematic review and meta-analysis of studies published in the PubMed, Embase, Web of Science, and Cochrane Library databases up to September 2022. Hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted to estimate the association of iron overload with infectious outcomes and overall survival after liver transplantation.

RESULTS

Eight studies involving 2817 recipients met the inclusion criteria. Iron overload was strongly associated with an increased risk of infection after liver transplantation (HR, 1.66; 95% CI, 1.03-2.68). An increase in the serum ferritin level was associated with an increased risk of infection after liver transplantation (HR, 1.44; 95% CI, 1.09-1.91). Iron overload was a significant predictor of worse overall survival (HR, 1.35; 95% CI, 1.11-1.64). In addition, a high serum ferritin level was significantly associated with an increased risk of death (HR, 1.34; 95% CI, 1.10-1.64).

CONCLUSION

Iron overload may be associated with a higher risk of infectious complications and a worse prognosis among liver transplant recipients.

(+)-Clausenamide protects against drug-induced liver injury by inhibiting hepatocyte ferroptosis

Drug-induced liver injury is the major cause of acute liver failure. However, the underlying mechanisms seem to be multifaceted and remain poorly understood, resulting in few effective therapies. Here, we report a novel mechanism that contributes to acetaminophen-induced hepatotoxicity through the induction of ferroptosis, a distinctive form of programmed cell death. We subsequently identified therapies protective against acetaminophen-induced liver damage and found that (+)-clausenamide ((+)-CLA), an active alkaloid isolated from the leaves of Clausena lansium (Lour.) Skeels, inhibited acetaminophen-induced hepatocyte ferroptosis both in vivo and in vitro. Consistently, (+)-CLA significantly alleviated acetaminophen-induced or erastin-induced hepatic pathological damages, hepatic dysfunctions and excessive production of lipid peroxidation both in cultured hepatic cell lines and mouse liver. Furthermore, treatment with (+)-CLA reduced the mRNA level of prostaglandin endoperoxide synthase 2 while it increased the protein level of glutathione peroxidase 4 in hepatocytes and mouse liver, confirming that the inhibition of ferroptosis contributes to the protective effect of (+)-CLA on drug-induced liver damage. We further revealed that (+)-CLA specifically reacted with the Cys-151 residue of Keap1, which blocked Nrf2 ubiquitylation and resulted in an increased Nrf2 stability, thereby leading to the activation of the Keap1–Nrf2 pathway to prevent drug-induced hepatocyte ferroptosis. Our studies illustrate the innovative mechanisms of acetaminophen-induced liver damage and present a novel intervention strategy to treat drug overdose by using (+)-CLA.

Iron metabolism imbalance at the time of listing increases overall and infectious mortality after liver transplantation

BACKGROUND

Liver transplantation (LT) is the best treatment for patients with liver cancer or end stage cirrhosis, but it is still associated with a significant mortality. Therefore identifying factors associated with mortality could help improve patient management. The impact of iron metabolism, which could be a relevant therapeutic target, yield discrepant results in this setting. Previous studies suggest that increased serum ferritin is associated with higher mortality. Surprisingly iron deficiency which is a well described risk factor in critically ill patients has not been considered.

AIM

To assess the impact of pre-transplant iron metabolism parameters on post-transplant survival.

METHODS

From 2001 to 2011, 553 patients who underwent LT with iron metabolism parameters available at LT evaluation were included. Data were prospectively recorded at the time of evaluation and at the time of LT regarding donor and recipient. Serum ferritin (SF) and transferrin saturation (TS) were studied as continuous and categorical variable. Cox regression analysis was used to determine mortality risks factors. Follow-up data were obtained from the local and national database regarding causes of death.

RESULTS

At the end of a 95-mo median follow-up, 196 patients were dead, 38 of them because of infections. In multivariate analysis, overall mortality was significantly associated with TS > 75% [HR: 1.73 (1.14; 2.63)], SF < 100 µg/L [HR: 1.62 (1.12; 2.35)], hepatocellular carcinoma [HR: 1.58 (1.15; 2.26)], estimated glomerular filtration rate (CKD EPI Cystatin C) [HR: 0.99 (0.98; 0.99)], and packed red blood cell transfusion [HR: 1.05 (1.03; 1.08)]. Kaplan Meier curves show that patients with low SF (< 100 µg/L) or high SF (> 400 µg/L) have lower survival rates at 36 mo than patients with normal SF (P = 0.008 and P = 0.016 respectively). Patients with TS higher than 75% had higher mortality at 12 mo (91.4% ± 1.4% vs 84.6% ± 3.1%, P = 0.039). TS > 75% was significantly associated with infection related death [HR: 3.06 (1.13; 8.23)].

CONCLUSION

Our results show that iron metabolism imbalance (either deficiency or overload) is associated with post-transplant overall and infectious mortality. Impact of iron supplementation or depletion should be assessed in prospective study.

Combination curcumin and vitamin E treatment attenuates diet-induced steatosis in Hfe-/- mice

AIM

To investigate the synergistic hepato-protective properties of curcumin and vitamin E in an Hfe^-/- high calorie diet model of steatohepatitis.

METHODS

Hfe^-/- C57BL/6J mice were fed either a high calorie diet or a high calorie diet with 1 mg/g curcumin; 1.5 mg/g vitamin E; or combination of 1 mg/g curcumin + 1.5 mg/g vitamin E for 20 wk. Serum and liver tissue were collected at the completion of the experiment. Liver histology was graded by a pathologist for steatosis, inflammation and fibrosis. RNA and protein was extracted from liver tissue to examine gene and protein expression associated with fatty acid oxidation, mitochondrial biogenesis and oxidative stress pathways.

RESULTS

Hfe^-/- mice fed the high calorie diet developed steatohepatitis and pericentral fibrosis. Combination treatment with curcumin and vitamin E resulted in a greater reduction of percent steatosis than either vitamin E or curcumin therapy alone. Serum alanine aminotransferase and non-alcoholic fatty liver disease (NAFLD) activity score were decreased following combination therapy with curcumin and vitamin E compared with high calorie diet alone. No changes were observed in inflammatory or fibrosis markers following treatment. Epididymal fat pad weights were significantly reduced following combination therapy, however total body weight and liver weight were unchanged. Combination therapy increased the mRNA expression of AdipoR2, Ppar-α, Cpt1a, Nrf-1 and Tfb2m suggesting enhanced fatty acid oxidation and mitochondrial biogenesis. In addition, combination treatment resulted in increased catalase activity in Hfe^-/- mice.

CONCLUSION

Combination curcumin and vitamin E treatment decreases liver injury in this steatohepatitis model, indicating that combination therapy may be of value in NAFLD.

Decreased hepatic iron in response to alcohol may contribute to alcohol-induced suppression of hepcidin

Hepatic Fe overload has often been reported in patients with advanced alcoholic liver disease. However, it is not known clearly whether it is the effect of alcohol that is responsible for such overload. To address this lacuna, a time-course study was carried out in mice in order to determine the effect of alcohol on Fe homoeostasis. Male Swiss albino mice were pair-fed Lieber-DeCarli alcohol diet (20 % of total energy provided as alcohol) for 2, 4, 8 or 12 weeks. Expression levels of duodenal and hepatic Fe-related proteins were determined by quantitative PCR and Western blotting, as were Fe levels and parameters of oxidative stress in the liver. Alcohol induced cytochrome P4502E1 and oxidative stress in the liver. Hepatic Fe levels and ferritin protein expression dropped to significantly lower levels after 12 weeks of alcohol feeding, with no significant effects at earlier time points. This was associated, at 12 weeks, with significantly decreased liver hepcidin expression and serum hepcidin levels. Protein expressions of duodenal ferroportin (at 8 and 12 weeks) and divalent metal transporter 1 (at 8 weeks) were increased. Serum Fe levels rose progressively to significantly higher levels at 12 weeks. Histopathological examination of the liver showed mild steatosis, but no stainable Fe in mice fed alcohol for up to 12 weeks. In summary, alcohol ingestion by mice in this study affected several Fe-related parameters, but produced no hepatic Fe accumulation. On the contrary, alcohol-induced decreases in hepatic Fe levels were seen and may contribute to alcohol-induced suppression of hepcidin.

A Single Center Study Comparing the Stainable Iron Depositions in 1000 Explanted Cirrhotic Livers of Different Causes

BACKGROUND

There have been very few studies evaluating the close association between excess iron and cirrhosis; however, cirrhosis could be regarded as an iron-loading disorder.

OBJECTIVES

In this study, the goal was to show the levels of the iron content in the liver tissue in certain types of cirrhosis.

PATIENTS AND METHODS

In this 7 year study (2008 - 2014), in 1000 explanted livers, the amount of iron was scored and compared according to the cause of the cirrhosis. The amount of iron in the liver was determined via the histochemical staining of the liver tissue, using Prussian-blue staining. Additionally, in each patient, the serum iron was determined and compared according to the cause of cirrhosis.

RESULTS

The highest content of iron has been found in cirrhosis caused by chronic hepatitis (i.e. hepatitis B, C, and autoimmune hepatitis), as well as in alcoholic cirrhosis. The least amount of stainable iron has been shown in biliary cirrhosis.

CONCLUSIONS

The presence of high stainable iron in patients with cirrhosis, secondary to chronic viral hepatitis, autoimmune hepatitis, and alcoholic hepatitis, should not be considered indicative of the presence of hereditary hemochromatosis; however, in those patients with biliary cirrhosis, a high iron content is rare, and can be a sign of the presence of the high iron Fe (HFE) gene mutation, or another type of hereditary hemochromatosis.

Serum Ferritin in Patients With Cirrhosis is Associated With Markers of Liver Insufficiency and Circulatory Dysfunction, but Not of Portal Hypertension

BACKGROUND/AIMS

Iron overload is an increasingly recognized phenomenon in nonhemochromatosis cirrhosis. To evaluate the relationship between iron overload and liver insufficiency and portal hypertension.

PATIENTS AND METHODS

Cirrhotics with hepatic hemodynamic and ferritin measurement (within 30 d) were included. Exclusion criteria were malignancy (except hepatocellular carcinoma Milan-in), severe chronic obstructive pulmonary disease, acute events in the previous 2 weeks, immunosuppression, transjugular intrahepatic portosystemic shunt or portal vein thrombosis, and end-stage renal disease. Patients were followed-up until death or liver transplant. Univariate and multivariate analysis were used.

RESULTS

Fifty-one patients were included (male 61%; median age 57 y; interquartile range, 47 to 66 y); Child-Pugh A 11/B 25/C 15). A positive correlation was observed between ferritin and markers of inflammation (C-reactive protein: r=0.273, P=0.06 and aspartate aminotransferase: r=0.302, P=0.035). No correlation between ferritin and hepatic venous pressure gradient was seen. Negative correlations were observed between ferritin and circulatory dysfunction (mean arterial pressure: r=-0.360, P=0.014 and serum sodium: r=-0.419, P=0.002). In contrast, associations to markers of liver failure such as international normalized ratio (r=0.333, P=0.005), bilirubin (r=0.378, P=0.007), albumin (r=-0.265, P=0.082), model for end-stage liver disease (r=0.293, P=0.041), and Child-Pugh score (r=0.392, P=0.009) were observed. No differences in survival according to ferritin was detected.

CONCLUSIONS

In patients with cirrhosis, serum ferritin levels are associated with markers of liver insufficiency, inflammation, and circulatory dysfunction but not portal hypertension.

Recurrence of nonviral liver diseases after liver transplantation

Many nonviral diseases that cause liver failure may recur after liver transplantation. Although most studies have shown that a recurrent disease does not negatively affect patient and graft survival in the intermediate postoperative course, there is growing evidence that, especially in patients with primary sclerosing cholangitis and in patients with recurrent abusive alcohol drinking, disease recurrence is a significant risk factor for graft dysfunction and graft loss. Therefore, the recurrence of nonviral diseases has become a clinically important and prognostically relevant issue in the long-term management of recipients of liver transplantation.

Excess iron modulates endoplasmic reticulum stress-associated pathways in a mouse model of alcohol and high-fat diet-induced liver injury

Endoplasmic reticulum (ER) stress is an important pathogenic mechanism for alcoholic (ALD) and nonalcoholic fatty liver disease (NAFLD). Iron overload is an important cofactor for liver injury in ALD and NAFLD, but its role in ER stress and associated stress signaling pathways is unclear. To investigate this, we developed a murine model of combined liver injury by co-feeding the mildly iron overloaded, the hemochromatosis gene-null (Hfe(-/)) mouse ad libitum with ethanol and a high-fat diet (HFD) for 8 weeks. This co-feeding led to profound steatohepatitis, significant fibrosis, and increased apoptosis in the Hfe(-/-) mice as compared with wild-type (WT) controls. Iron overload also led to induction of unfolded protein response (XBP1 splicing, activation of IRE-1α and PERK, as well as sequestration of GRP78) and ER stress (increased CHOP protein expression) following HFD and ethanol. This is associated with a muted autophagic response including reduced LC3-I expression and impaired conjugation to LC3-II, reduced beclin-1 protein, and failure of induction of autophagy-related proteins (Atg) 3, 5, 7, and 12. As a result of the impaired autophagy, levels of the sequestosome protein p62 were most elevated in the Hfe(-/-) group co-fed ethanol and HFD. Iron overload reduces the activation of adenosine monophosphate protein kinase associated with ethanol and HFD feeding. We conclude that iron toxicity may modulate hepatic stress signaling pathways by impairing adaptive cellular compensatory mechanisms in alcohol- and obesity-induced liver injury.

Monogenic diseases that can be cured by liver transplantation

While the prevalence of most diseases caused by single-gene mutations is low and defines them as rare conditions, all together, monogenic diseases account for approximately 10 in every 1000 births according to the World Health Organisation. Orthotopic liver transplantation (LT) could offer a therapeutic option in monogenic diseases in two ways: by substituting for an injured liver or by supplying a tissue that can replace a mutant protein. In this respect, LT may be regarded as the correction of a disease at the level of the dysfunctional protein. Monogenic diseases that involve the liver represent a heterogeneous group of disorders. In conditions associated with predominant liver parenchymal damage (i.e., genetic cholestatic disorders, Wilson's disease, hereditary hemochromatosis, tyrosinemia, α1 antitrypsin deficiency), hepatic complications are the major source of morbidity and LT not only replaces a dysfunctional liver but also corrects the genetic defect and effectively cures the disease. A second group includes liver-based genetic disorders characterised by an architecturally near-normal liver (urea cycle disorders, Crigler-Najjar syndrome, familial amyloid polyneuropathy, primary hyperoxaluria type 1, atypical haemolytic uremic syndrome-1). In these defects, extrahepatic complications are the main source of morbidity and mortality while liver function is relatively preserved. Combined transplantation of other organs may be required, and other surgical techniques, such as domino and auxiliary liver transplantation, have been attempted. In a third group of monogenic diseases, the underlying genetic defect is expressed at a systemic level and liver involvement is just one of the clinical manifestations. In these conditions, LT might only be partially curative since the abnormal phenotype is maintained by extrahepatic synthesis of the toxic metabolites (i.e., methylmalonic acidemia, propionic acidemia). This review focuses on principles of diagnosis, management and LT results in both paediatric and adult populations of selected liver-based monogenic diseases, which represent examples of different transplantation strategies, driven by the understanding of the expression of the underlying genetic defect.

A corn oil-based diet protects against combined ethanol and iron-induced liver injury in a mouse model of hemochromatosis

BACKGROUND

Combined iron overload and alcohol may promote synergistic chronic liver injury and toxicity. The role of specific dietary fats in influencing the development of co-toxic alcoholic liver disease needs further evaluation and is investigated in this study.

METHODS

Wild-type (WT) and the iron-loaded Hfe-null (Hfe(-/-) ) mice were fed chow (CC), a AIN-93G standard control (SC), or a corn oil-modified, AIN-93G-based (CO) diet with or without the addition of 20% ethanol (EtOH) in the drinking water for 8 weeks and assessed for liver injury.

RESULTS

WT mice on CC, SC, and CO diets had no liver injury, although mild steatosis developed in the SC and CO groups. The addition of EtOH resulted in mild steatohepatitis in WT mice fed SC but not those on a CO diet. EtOH administration in Hfe(-/-) animals on the CC and SC diets caused marked oxidative stress, inflammatory activity, and subsinusoidal and portal-portal tract linkage fibrosis with significant up-regulation of genes involved in cellular stress signaling and fibrogenic pathways. These effects were abrogated in the CO-fed mice, despite elevated serum EtOH levels and hepatic iron concentrations, reduced hepatic glutathione and mitochondrial superoxide dismutase activities. Feeding with the CO diet led to increased hepatic glutathione peroxidase and catalase activities and attenuated alcohol-induced hepatic steatosis in the Hfe(-/-) animals. Iron and EtOH feeding markedly reduced p-STAT3 and p-AMPK protein levels, but this effect was significantly attenuated when a CO diet was consumed.

CONCLUSIONS

A CO-based diet is protective against combined EtOH- and iron-induced liver toxicity, likely via attenuation of hepatic steatosis and oxidative stress and may have a role in the prevention of fibrosis development in chronic liver disease.

Serum ferritin concentration and transferrin saturation before liver transplantation predict decreased long-term recipient survival

Serum ferritin (SF) concentration is a widely available parameter used to assess iron homeostasis. It has been described as a marker to identify high-risk patients awaiting liver transplantation (LT) but is also elevated in systemic immune-mediated diseases, metabolic syndrome, and in hemodialysis where it is associated with an inferior prognosis. This study analyzed whether SF is not only a predictor of liver-related mortality prior to LT but also an independent marker of survival following LT. In a dual-center, retrospective study, a cohort of 328 consecutive first-LT patients from Hannover Medical School, Germany (2003-2008, follow-up 1260 days), and 82 consecutive LT patients from Regensburg University Hospital, Germany (2003-2007, follow-up 1355 days) as validation cohort were analyzed. In patients exhibiting SF ≥365 μg/L versus <365 μg/L prior to LT, 1-, 3-, and 5-year post-LT survival was 73.3% versus 81.1%, 64.4% versus 77.3%, and 61.1% versus 74.4%, respectively (overall survival P = 0.0097), which was confirmed in the validation cohort (overall survival of 55% versus 83.3%, P = 0.005). Multivariate analyses identified SF ≥365 μg/L combined with transferrin saturation (TFS) <55%, hepatocellular carcinoma, and the survival after LT (SALT) score as independent risk factors for death. In patients with SF concentrations ≥365 μg/L and TFS <55%, overall survival was 54% versus 74.8% in the remaining group (P = 0.003). In the validation cohort, it was 28.6% versus 72% (P = 0.017), respectively.

CONCLUSION

SF concentration ≥365 μg/L in combination with TFS <55% before LT is an independent risk factor for mortality following LT. Lower TFS combined with elevated SF concentrations indicate that acute phase mechanisms beyond iron overload may play a prognostic role. SF concentration therefore not only predicts pre-LT mortality but also death following LT.

Altered lipid metabolism in Hfe-knockout mice promotes severe NAFLD and early fibrosis

The HFE protein plays a crucial role in the control of cellular iron homeostasis. Steatosis is commonly observed in HFE-related iron-overload disorders, and current evidence suggests a causal link between iron and steatosis. Here, we investigated the potential contribution of HFE mutations to hepatic lipid metabolism and its role in the pathogenesis of nonalcoholic fatty liver disease. Wild-type (WT) and Hfe knockout mice (Hfe(-/-)) were fed either standard chow, a monounsaturated low fat, or a high-fat, high-carbohydrate diet (HFD) and assessed for liver injury, body iron status, and markers of lipid metabolism. Despite hepatic iron concentrations and body weights similar to WT controls, Hfe(-/-) mice fed the HFD developed severe hypoxia-related steatohepatitis, Tnf-α activation, and mitochondrial respiratory complex and antioxidant dysfunction with early fibrogenesis. These features were associated with an upregulation in the expression of genes involved in intracellular lipid synthesis and trafficking, while transcripts for mitochondrial fatty acid β-oxidation and adiponectin signaling-related genes were significantly attenuated. In contrast, HFD-fed WT mice developed bland steatosis only, with no inflammation or fibrosis and no upregulation of lipogenesis-related genes. A HFD led to reduced hepatic iron in Hfe(-/-) mice compared with chow-fed mice, despite higher serum iron, decreased hepcidin expression, and increased duodenal ferroportin mRNA. In conclusion, our results demonstrate that Hfe(-/-) mice show defective hepatic-intestinal iron and lipid signaling, which predispose them toward diet-induced hepatic lipotoxicity, accompanied by an accelerated progression of injury to fibrosis.

Effect of epigallocatechin-3-gallate on iron overload in mice with alcoholic liver disease

Iron has long been related to the pathological process of alcoholic liver disease (ALD). Liver iron overload is known to accelerate the development of ALD. In the present study we aimed to examine the effect of epigallocatechin-3-gallate (EGCG) on iron overload of ALD and to explore the potential mechanisms involved in its protection against ALD in mice. Male C57BL/6J mice were given alcohol by intragastric administration for 12 weeks. At the end of 8th week, ALD mice were treated for 4 weeks for 10, 20 and 30 mg kg(-1) EGCG by intraperitoneal injection. Liver injuries were assessed by histopathologic examination and Serum Alanine Aminotransferase (ALT) levels. Serum iron content, hepatic iron concentration and liver malondialdehyde (MDA) contents were examined. In addition, hepcidin mRNA levels and transferrin (Tf) and transferrin receptor 1 (TfR1) protein levels of liver tissue were also evaluated. Compared with model group, treatment of ALD mice with EGCG ameliorated liver injuries, decreased serum iron level, hepatic iron levels and liver MDA contents, increased hepcidin mRNA level and decreased Tf and TfR1 protein expression in the liver. The results of our study explain a new point of view that the protective effect of EGCG on ALD is associated with its iron-chelating property. The possible mechanisms are that EGCG affects hepatic iron uptake and inhibits iron absorption in the small intestinal.

Serum ferritin concentration predicts mortality in patients awaiting liver transplantation

Additional markers are required to identify patients on the orthotopic liver transplant (OLT) waiting list at increased risk of death and adverse clinical events. Serum ferritin concentration is a marker of varied pathophysiological events and is elevated with increased liver iron concentration, hepatic necroinflammation, and systemic illness, all of which may cause a deterioration in liver function and clinical status. The aim of this study was to determine whether serum ferritin concentration is an independent prognostic factor in subjects awaiting OLT. This is a dual-center retrospective study. The study cohort consisted of 191 consecutive adults with cirrhosis accepted by the Queensland (Australia) Liver Transplant Service between January 2000 and June 2006 and a validation cohort of 131 patients from University of California Los Angeles (UCLA) Transplant Center. In the study cohort, baseline serum ferritin greater than 200 microg/L was an independent factor predicting increased 180-day and 1-year waiting list mortality. This effect was independent of model for end-stage liver disease (MELD), hepatocellular carcinoma, age, and sex. Subjects with higher serum ferritin had increased frequency of liver-related clinical events. The relationship between serum ferritin and waiting list mortality was confirmed in the UCLA cohort; all deceased patients had serum ferritin greater than 400 microg/L. Serum ferritin greater than 500 microg/L and MELD were independent risk factors for death.

CONCLUSION

Serum ferritin concentration is an independent predictor of mortality-related and liver-related clinical events. Baseline serum ferritin identifies a group of "higher-risk" patients awaiting OLT and should be investigated as an adjunct to MELD in organ allocation.

Survival of liver transplant recipients with hemochromatosis in the United States

BACKGROUND AND AIMS

Earlier studies have suggested that patients with hemochromatosis have poor post-transplantation survival. We aimed to compare patients with hemochromatosis to those with other causes of liver disease with regard to post-transplantation survival.

METHODS

We compared the post-transplant survival of patients with and without hemochromatosis using data provided by the United Network for Organ Sharing on 50,306 adult, cadaveric liver transplantations performed in the United States between January 1, 1990, and July 18, 2006.

RESULTS

During 1990-1996, the post-transplantation survival of patients with hemochromatosis (n = 177) at 1 year (79.1%), 3 years (71.8%), and 5 years (64.6%) was lower than the average 1-year (86.4%), 3-year (79.5%), and 5-year (73.8%) survival of all other transplant recipients (hazard ratio for death, 1.38; 95% confidence interval [CI], 1.12-1.71). In contrast, during 1997-2006, patients with hemochromatosis (n = 217) had excellent 1-year (86.1%), 3-year (80.8%), and 5-year (77.3%) post-transplantation survival, which was not different from the 1-year (88.4%), 3-year (80.3%), and 5-year (74.0%) post-transplantation survival of all other transplant recipients (hazard ratio for death, 0.89; 95% CI, 0.65-1.22). Adjustment for donor and recipient characteristics did not substantially change these results. Compared with recipients without hemochromatosis, those with hemochromatosis were more likely to die of cardiovascular diseases and less likely to die as a result of graft failure.

CONCLUSIONS

The post-transplantation survival of patients with hemochromatosis, which was previously reported to be poor, has been excellent in the United States during the past 10 years.

Association of hepatic iron overload with invasive fungal infection in liver transplant recipients

Invasive fungal infection is a serious complication of orthotopic liver transplantation, but its risk factors remain incompletely defined. Iron overload has already been associated with increased risk of fungal infections, but it has not yet been assessed as a risk factor in liver transplantation. We retrospectively studied a cohort of 153 consecutive patients who underwent their first liver transplantation at a single center and who survived at least 7 days after transplantation. The association between various pretransplant patient characteristics, including hepatic explant iron and risk of invasive fungal infections, was analyzed by univariate and multivariate models. Iron in the hepatic explant was assessed by Perl's Prussian blue stain by a pathologist blinded to clinical outcome. During the first year after transplantation, 28 of 153 patients developed a total of 31 invasive fungal infections, of which 21 (68%) were caused by Candida, 7 (23%) by Aspergillus, 2 (6%) by Cryptococcus, and 1 (3%) by Saccharomyces. Stainable iron in the hepatic explant was found in 48 patients (31%). Stainable iron in the hepatic explant was found to be strongly and independently associated with posttransplantation fungal infections in multivariate analysis (hazard ratio 3.09; 95% confidence interval 1.45-6.56; P = 0.003). Hepatic iron overload is strongly and independently associated with posttransplantation invasive fungal infections. Studies to confirm this finding in other centers and define the mechanism are warranted.

Hepcidin is down-regulated in alcoholic liver injury: implications for the pathogenesis of alcoholic liver disease

BACKGROUND

Alcoholic liver disease is known to be associated with abnormal iron homeostasis, and iron metabolism itself is regulated by the liver-derived peptide hepcidin. Both CCAAT enhancer binding protein alpha (C/EBPalpha) and interleukin 6 (IL-6) have been shown to regulate hepcidin gene transcription.

AIM

To investigate mechanisms underlying alcohol-induced disturbances in iron homeostasis by measuring the expression of hepcidin and C/EBPalpha mRNA using in vivo and in vitro models of alcoholic liver injury.

METHODS

Male rats were pair-fed an alcoholic liquid diet for 12 weeks. RT-PCR was performed on liver tissue using specific primers for hepcidin and C/EBPalpha. The effect of alcohol on hepcidin and C/EBPalpha gene expression was also determined in isolated hepatocytes, HuH-7 cells and HepG2 cells treated with 50 mM ethanol, 200 microM acetaldehyde, and/or 20 ng/ml IL-6.

RESULTS

Hepcidin and C/EBPalpha mRNA expression were significantly decreased in alcohol-fed rats compared with pair-fed controls (6-fold p < 0.001 and 2.2-fold p < 0.0002 reduction, respectively) and hepatic lipid peroxidation was increased by 32.5% (p < 0.05) in alcohol-fed rats compared with controls. Hepcidin gene expression was not altered significantly in cells cultured in the presence of 50 mM ethanol. Following 24 hour stimulation by IL-6, there was a 4-fold increase in hepcidin expression in hepatocytes and a 9-fold increase in HuH-7 cells. Ethanol (50 mM) attenuated the IL-6-induced increase in hepcidin expression in HuH-7 cells (9-fold to a 4-fold increase) but not in hepatocytes. Acetaldehyde had no effect on hepcidin gene expression in cells in culture.

CONCLUSION

The down-regulation of hepcidin and C/EBPalpha gene expression shown in vivo implies disturbed iron sensing contributing to the hepatosiderosis seen in alcoholic liver disease, possibly by mechanisms involving the IL-6 signaling cascade.

Survival after liver transplantation in patients with hepatic iron overload: the national hemochromatosis transplant registry

BACKGROUND & AIMS

Previous uncontrolled studies have suggested that patients with hepatic iron overload have a poor outcome after liver transplantation. We examined the effect of HFE mutations on posttransplantation survival in patients with hepatic iron overload.

METHODS

Two hundred sixty patients with end-stage liver disease and hepatic iron overload were enrolled from 12 liver transplantation centers. Hepatic iron concentration (HIC), hepatic iron index (HII), HFE mutation status, and survival after liver transplantation were recorded.

RESULTS

HFE-associated hemochromatosis (HH) defined as homozygosity for the C282Y (n = 14, 7.2%) mutation or compound heterozygosity for the C282Y/H63D (n = 11, 5.6%) mutation was identified in 12.8% of patients. Survival postliver transplantation was significantly lower among patients with HH (1-, 3-, and 5-year survival rates of 64%, 48%, 34%, respectively) compared with simple heterozygotes (C282Y/wt or H63D/wt) or wild-type patients. Patients with HH had a hazard ratio for death of 2.6 (P = .002) after adjustment for age, United Network for Organ Sharing status, year of transplantation, and either elevated HII or HIC. Non-HH patients with hepatic iron overload also had significantly decreased survival when compared with the overall population undergoing liver transplantation (OR = 1.4, 95% CI: 1.15-1.61, P < .001).

CONCLUSIONS

One- and 5-year survivals after liver transplantation are significantly lower among patients with HFE-associated HH. Our data also suggest that hepatic iron overload may be associated with decreased survival after liver transplantation, even in patients without HH. Early diagnosis of hepatic iron overload using HFE gene testing and iron depletion prior to liver transplantation may improve posttransplantation survival, particularly among patients with HH.

Hepatic iron overload in alcoholic end-stage liver disease is associated with iron deposition in other organs in the absence of HFE-1 hemochromatosis

BACKGROUND

End-stage cirrhosis in the absence of hereditary hemochromatosis (HHC) can be associated with moderate to marked hepatic iron overload, especially in liver disease as a result of alcohol and/or hepatitis C. However, no published studies have addressed extrahepatic iron deposition in this setting.

METHOD

A retrospective case series from three autopsied patients who died from end-stage cirrhosis associated with significant hepatic iron overload. Histology of vital organs was performed to detect extrahepatic iron deposition. HFE genotyping for the C282Y and H63D mutations was determined from archival tissue. Hepatic iron index and hepatic iron concentration (HIC) were quantified from formalin-fixed, paraffin-embedded tissue. Medical records were reviewed for possible causes of iron overload.

RESULTS

Two patients were H63D heterozygous (H63D +/-) and one was wild type (C282Y -/-, H63D -/-). Histology revealed evidence of stainable iron in the heart and pancreas of all three subjects. Additionally, stainable iron was seen in the stomach in one subject and in the thyroid, pituitary, choroid plexus and testes in another subject. HIC ranged from 4354 to 6834 microg/g dry weight and HII from 1.8 to 2.2 (micromol/g/years).

CONCLUSION

Iron overload secondary to end-stage liver disease can be associated with iron deposition in other organs in the absence of HFE-1 HHC.

Patient and graft survival after liver transplantation for hereditary hemochromatosis: Implications for pathogenesis

The clinical outcome of patients who have undergone liver transplantation for hereditary hemochromatosis (HH) or who have received iron-loaded donor grafts is unclear. We reviewed 3,600 adult primary orthotopic liver transplants and assessed the outcomes in 22 patients with HH. We also evaluated graft function and iron mobilization in 12 recipients of iron-loaded donor grafts. All 22 subjects who received liver transplants for HH were male; 13 had other risk factors for liver disease. HH patients had comparatively poor outcomes following transplantation: survival at 1, 3, and 5 years posttransplantation were 72%, 62%, and 55%, respectively. Recurrent hepatocellular cancer was the most common cause of death. There was no convincing evidence of reaccumulation of iron in the grafted liver in HH; however, 1 subject demonstrated increased serum ferritin concentration and grade 2 hepatic siderosis. Liver iron stores were slow to mobilize in 7 of the 12 recipients of iron-loaded grafts. These recipients had appropriate early graft function, but 2 patients with heavy iron loading and increased hepatic iron developed hepatic fibrosis. In conclusion, (1) HH is an uncommon indication for liver transplantation, and the majority of patients requiring transplantation had other risk factors for chronic liver disease; (2) reaccumulation of liver iron in HH patients is very unusual, but increased iron stores may be slow to mobilize in normal recipients of iron-loaded grafts, potentially compromising late graft function; (3) post-liver transplant survival is reduced in HH, and affected patients require careful clinical evaluation of perioperative and postoperative risk factors. Our data suggest that iron excess in HH does not wholly depend on intestinal iron absorption but is also influenced by liver factors that moderate iron metabolism.

Increased duodenal expression of divalent metal transporter 1 and iron-regulated gene 1 in cirrhosis

Hepatic hemosiderosis and increased iron absorption are common findings in cirrhosis. It has been proposed that a positive relation exists between intestinal iron absorption and the development of hepatic hemosiderosis. The current study investigated the duodenal expression of the iron transport molecules divalent metal transporter 1 (DMT1 [IRE]), iron-regulated gene 1 (Ireg1 [ferroportin]), hephaestin, and duodenal cytochrome b (Dyctb) in 46 patients with cirrhosis and 20 control subjects. Total RNA samples were extracted from duodenal biopsy samples and the expression of the iron transport genes was assessed by ribonuclease protection assays. Expression of DMT1 and Ireg1 was increased 1.5 to 3-fold in subjects with cirrhosis compared with iron-replete control subjects. The presence of cirrhosis per se and serum ferritin (SF) concentration were independent factors that influenced the expression of DMT1. However, only SF concentration was independently associated with Ireg1 expression. In cirrhosis, the expression of DMT1 and Ireg1 was not related to the severity of liver disease or cirrhosis type. There was no correlation between the duodenal expression of DMT1 and Ireg1 and the degree of hepatic siderosis. In conclusion, the presence of cirrhosis is an independent factor associated with increased expression of DMT1 but not Ireg1. The mechanism by which cirrhosis mediates this change in DMT1 expression has yet to be determined. Increased expression of DMT1 may play an important role in the pathogenesis of cirrhosis-associated hepatic iron overload.

Effect of alcohol on iron storage diseases of the liver

The consumption of excess alcohol in patients with liver iron storage diseases, in particular the iron-overload disease hereditary haemochromatosis (HH), has important clinical consequences. HH, a common genetic disorder amongst people of European descent, results in a slow, progressive accumulation of excess hepatic iron. If left untreated, the condition may lead to fibrosis, cirrhosis and primary hepatocellular carcinoma. The consumption of excess alcohol remains an important cause of hepatic cirrhosis and alcohol consumption itself may lead to altered iron homeostasis. Both alcohol and iron independently have been shown to result in increased oxidative stress causing lipid peroxidation and tissue damage. Therefore, the added effects of both toxins may exacerbate the pathogenesis of disease and impose an increased risk of cirrhosis. This review discusses the concomitant effects of alcohol and iron on the pathogenesis of liver disease. We also discuss the implications of co-existent alcohol and iron in end-stage liver disease.

Hemochromatosis and alcoholic liver disease

The close association of excessive alcohol consumption and clinical expression of hemochromatosis has been of widespread interest for many years. In most populations of northern European extraction, more than 90% of patients with overt hemochromatosis are homozygous for the C282Y mutation in the HFE gene. Nevertheless, the strong association of heavy alcohol intake with the clinical expression of hemochromatosis remains. We (individually or in association with colleagues from our laboratories) have performed three relevant studies in which this association was explored. In the first, performed in 1975 before the cloning of the HFE gene, the frequency of clinical symptoms and signs was compared in patients with classical hemochromatosis who consumed 100 g or more of alcohol per day versus in nondrinkers or moderate drinkers who consumed less than 100 g of alcohol per day. The results showed no difference between the two groups except for features of complications of alcoholism in the first group, especially jaundice, peripheral neuritis, and hepatic failure. Twenty-five percent of those with heavy alcohol consumption showed histologic features of alcoholic liver disease (including cirrhosis) together with heavy iron overload. It was concluded that these patients had the genetic disease complicated by alcoholic liver disease. In the second study (2002), 206 subjects with classical HFE-associated hemochromatosis in whom liver biopsy had been performed were evaluated to quantify the contribution of excess alcohol consumption to the development of cirrhosis in hemochromatosis. Cirrhosis was approximately nine times more likely to develop in subjects with hemochromatosis who consumed more than 60 g of alcohol per day than in those who drank less than this amount. In the third study (2002), 371 C282Y-homozygous relatives of patients with HFE-associated hemochromatosis were assessed. Eleven subjects had cirrhosis on liver biopsy and four of these drank 60 g or more of alcohol per day. The reason why heavy alcohol consumption accentuates the clinical expression of hemochromatosis is unclear. Increased dietary iron or increased iron absorption is unlikely. The most likely explanation would seem to be the added co-factor effect of iron and alcohol, both of which cause oxidative stress, hepatic stellate cell activation, and hepatic fibrogenesis. In addition, the cumulative effects of other forms of liver injury may result when iron and alcohol are present concurrently. Clearly, the addition of dietary iron in subjects homozygous for hemochromatosis would be unwise.

Review article: haemochromatosis

Hereditary haemochromatosis is the prototype disease for primary iron overload. The disorder is very common, especially amongst subjects of Northern European extraction. It is characterized by an autosomal recessive mode of inheritance, and most cases are homozygous for the C282Y mutation in the HFE gene. Haemochromatosis is now recognized to be a complex genetic disease with probable significant environmental and genetic modifying factors. The early diagnosis of individuals at risk for the development of haemochromatosis is important, because survival and morbidity are improved if phlebotomy therapy is instituted before the development of cirrhosis. The cost-effectiveness and utility of large-scale screening for haemochromatosis have been questioned given that many individuals with the homozygous C282Y mutation do not have iron overload or end-organ damage. However, the use of phenotypic tests, such as serum transferrin-iron saturation, for initial screening avoids the problem of the identification of non-expressing homozygotes. Liver biopsy remains important in management to determine the presence or absence of cirrhosis, particularly amongst patients with serum ferritin levels greater than 1000 ng/mL or elevated liver enzymes. Those with non-HFE haemochromatosis who cannot be identified on genotypic testing should have a liver biopsy to establish diagnosis. Patients with end-stage liver disease may develop liver failure or primary liver cancer, and liver transplantation may be required. Liver transplantation for haemochromatosis is associated with a poorer outcome compared with other indications because of infections and cardiac complications.

Liver allograft iron accumulation in patients with and without pretransplantation hepatic hemosiderosis

There is a paucity of data regarding hepatic allograft iron accumulation in patients undergoing orthotopic liver transplantation (OLT) in whom severe iron overload was present in the native explanted liver. Our aim is to evaluate the frequency and cellular distribution of stainable iron in early and late post-OLT hepatic allograft biopsy specimens from patients undergoing their first OLT who had excess iron in their native explanted liver. We compared iron-staining patterns in hepatic allograft biopsy specimens at approximately 1 month (early) and 1 to 2 years (late) post OLT in 41 patients with hepatic iron indices greater than 1.9 in the explanted liver (cases) with a selected group of matched controls without explant hemosiderosis. Our cases included 6 patients with a pre-OLT diagnosis of hereditary hemochromatosis and 35 patients with cirrhosis and secondary iron overload. Early iron deposition was mild in most cases, commonly affected Kupffer's cells, and was seen with similar frequency in cases and controls (41% v 27%; P =.29). Stainable iron was observed in 20 donor livers (12 cases, 8 controls), and all 20 subjects showed stainable iron in 1-month hepatic allograft biopsy specimens. Liver samples from 35 matched pairs were studied for late iron deposition. Iron deposition was observed in 43% of cases versus 17% of controls (P =.06). In conclusion, the frequency of stainable iron in early hepatic allograft biopsy specimens was not different between patients with versus without pre-OLT hepatic hemosiderosis. There was a suggestion that patients with severe pre-OLT hemosiderosis had a greater frequency of iron accumulation in late hepatic biopsy specimens.