Serum hepcidin levels in chronic liver disease: a systematic review and meta-analysis.

OBJECTIVES: Dysregulation of hepcidin-iron axis is presumed to account for abnormal iron status in patients with chronic liver disease (CLD). Our aim is to determine the effect of specific etiologies of CLD and of cirrhosis on serum hepcidin levels. METHODS: PubMed, Embase, Web of Science were searched for studies comparing serum hepcidin levels in patients with CLD to that in controls using enzyme-linked immunosorbent assay. The study was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Guidelines. Statistical analysis was carried out with STATA using random effects model to calculate the mean difference (MD) between two groups. RESULTS: Hepcidin levels were significantly lower in subjects with hepatitis C virus (16 studies) [MD -1.6 (95 % CI: -2.66 to -0.54), p<0.01] and alcoholic liver disease (3 studies) [MD -0.84 (95 % CI: -1.6 to -0.07), p=0.03] than controls. Serum hepcidin was significantly higher in subjects with non-alcoholic fatty liver disease (12 studies) [MD 0.62 (95 % CI: 0.21 to 1.03), p<0.01], but did not differ in subjects with hepatitis B and controls (eight studies) [MD -0.65 (95 % CI: -1.47 to 0.16), p=0.12]. Hepcidin levels were significantly lower in patients with cirrhosis of any etiology (four studies) [MD -1.02 (CI: -1.59 to -0.45), p<0.01] vs. controls (CI: confidence interval). CONCLUSIONS: Serum hepcidin levels are altered in common forms of CLD albeit not in a consistent direction. Additional study is needed to determine how changes in hepcidin levels are related to dysregulation of iron metabolism in CLD.

Spleen size change after hepatitis C treatment: a simple parameter to predict clinical outcomes.

Portal hypertension contributes to splenomegaly in cirrhotic patients. Reduction in spleen size may represent improvement in portal hypertension. The goal was to determine whether reduction in spleen size following sustained virologic response (SVR) in patients with hepatitis C virus (HCV) cirrhosis is associated with lower risk of liver-related adverse outcomes. A retrospective cohort study was performed regarding HCV-infected patients treated with direct-acting antiviral agents at the Iowa City Veterans Administration Medical Center between 2014 and 2019. Patients with cirrhosis and splenomegaly on baseline ultrasound were included. Spleen size, platelet counts, decompensations, hepatocellular carcinoma (HCC) status, and mortality were recorded through July 31, 2021. Decrease in spleen size ≥1.5 cm was regarded as significant. Intergroup comparisons were performed on SPSS 28. Eighty patients with cirrhosis and splenomegaly before SVR were identified. Spleen sizes decreased significantly after SVR in 31 patients over a median of 1 year (Group A), whereas 49 patients did not meet this endpoint (Group B). Lack of spleen size reduction was associated with the presence of varices before SVR (odds ratio (OR): 5.3, p < 0.01). Group A had significantly greater increases in platelet count after SVR than did Group B. Patients in Group B had greater risk of HCC (OR: 9.7, CI: 1.2-79; p = 0.03) and death (OR: 3.6, CI: 1.1-12; p = 0.04). Reduced spleen size in patients with HCV cirrhosis after SVR is associated with greater increment in platelet count, decreased risk of HCC, and reduced mortality compared to patients whose spleen size does not decrease.

A thorny matter: Spur cell anemia.

Spur cell anemia (SCA) is an acquired form of non-autoimmune hemolytic anemia that occurs in advanced liver disease. It is characterized by the presence of acanthocytes or spur cells, spiculated erythrocytes whose shortened life span causes anemia that is unresponsive to transfusion. SCA has been regarded as a rare condition with an ominous prognosis for which the only known cure is liver transplantation, but recent prospective studies have demonstrated the existence of a milder form of SCA in which there are smaller numbers of acanthocytes, but which is nevertheless associated with hemolysis and poor outcomes. This form of SCA appears to be considerably more common than the severe classical variant. The conventional understanding of the pathogenesis of SCA is that abnormalities of lipid metabolism are the primary event driving the formation of spur cells. However, the studies that underpin this theory are based on small numbers of patients with heterogeneous clinical features and inconsistent use of nomenclature for dysmorphic red blood cells. In this review, we discuss the evolution of the current understanding of SCA and therapeutic strategies that have been employed based on this understanding. Our goal is to raise awareness of this understudied condition that has significant implications for patient outcomes. Furthermore, we highlight the need for rigorous, contemporary research into the underlying cause or causes of SCA in order to develop an effective therapy for this disorder.

Hepcidin and Iron Metabolism in Experimental Liver Injury.

The liver plays a pivotal role in the regulation of iron metabolism through its ability to sense and respond to iron stores by release of the hormone hepcidin. Under physiologic conditions, regulation of hepcidin expression in response to iron status maintains iron homeostasis. In response to tissue injury, hepcidin expression can be modulated by other factors, such as inflammation and oxidative stress. The resulting dysregulation of hepcidin is proposed to account for alterations in iron homeostasis that are sometimes observed in patients with liver disease. This review describes the effects of experimental forms of liver injury on iron metabolism and hepcidin expression. In general, models of acute liver injury demonstrate increases in hepcidin mRNA and hypoferremia, consistent with hepcidin's role as an acute-phase reactant. Conversely, diverse models of chronic liver injury are associated with decreased hepcidin mRNA but with variable effects on iron status. Elucidating the reasons for the disparate impact of different chronic injuries on iron metabolism is an important research priority, as is a deeper understanding of the interplay among various stimuli, both positive and negative, on hepcidin regulation. Future studies should provide a clearer picture of how dysregulation of hepcidin expression and altered iron homeostasis impact the progression of liver diseases and whether they are a cause or consequence of these pathologies.

Effects of long-term ethanol ingestion on hepatic iron metabolism in two mouse strains.

The mechanisms responsible for dysregulation of iron metabolism in response to ethanol ingestion are poorly understood. Relatively brief ethanol exposures in rodents are associated with reduced hepatic hepcidin expression without increases in hepatic iron content. This study evaluated the effects of long-term ethanol treatment on hepatic iron metabolism in two mouse strains. Ethanol was administered in the drinking water to C57BL/6 and BALB/c mice for up to 11 months. Hepatic histology and iron concentrations (HIC) were assessed, along with expression of relevant genes and proteins by real-time RT-PCR and western blot, respectively. The livers of ethanol-consuming mice of both strains showed mild steatosis without inflammation or fibrosis. Stainable hepatocyte iron was modestly increased in both strains ingesting ethanol, although hepatic iron concentrations were significantly higher only in C57BL/6 mice. Long-term ethanol did not affect hepcidin mRNA (Hamp1 or Hamp2) in either strain, nor was the expression of several oxidative stress-responsive genes (glutamate cysteine ligase, gamma-glutamyl transpeptidase, heme oxygenase-1 and growth differentiation factor 15) altered in response to ethanol, suggesting that oxidative stress and suppression of hepcidin expression in short-term ethanol feeding models may be transient phenomena that resolve as mice adapt to ethanol exposure. This murine model of chronic ethanol ingestion demonstrates modest increases in hepatic iron without changes in hepcidin expression, markers of oxidative stress or significant histologic liver injury. Further investigations are needed to characterize the mechanisms of dysregulated iron metabolism resulting from chronic ethanol ingestion.

Clinical Factors Associated with Hepatocellular Iron Deposition in End-stage Liver Disease.

Background and Aims: Hepatocellular iron accumulation in patients with chronic liver disease has been linked to adverse outcomes. The objective of this study was to identify clinical factors associated with hemosiderosis. Methods: A total of 103 consecutive liver transplant recipients were identified, in whom liver biopsy had been performed prior to transplantation. Laboratory and clinical data at biopsy and transplant were abstracted from the medical records and hepatocyte iron was graded in the biopsy and explant. The association of change in iron score from biopsy to transplant, with the time interval between these two events, was examined using linear mixed model analysis for repeated measures. Results: Most subjects had advanced fibrosis (F3-F4) at liver biopsy, which was performed on average about 2.5 years before transplant. Over 80% of patients had no or 1+ hepatocyte iron at biopsy; iron increased between biopsy and transplant in about 40%. The only demographic or clinical feature that correlated with increased iron was the presence of a transjugular intrahepatic portosystemic shunt. Increased iron at transplant was associated with higher serum iron and transferrin saturation at biopsy, and with lower hemoglobin level, greater mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, higher ferritin and model for end-stage liver disease score at transplant. Conclusions: The development of hemosiderosis in end-stage liver disease is associated with lower hemoglobin levels and alterations in red blood cell indices that are suggestive of hemolysis. These observations suggest that extravascular hemolysis may play a role in the development of secondary iron overload.

Renal Iron Accumulation and Oxidative Injury With Aging: Effects of Treatment With an Iron Chelator.

Dysregulation of iron metabolism in the kidney may contribute to age-related increases in renal oxidative stress and dysfunction. This study assessed the effects of short-term iron chelation on markers of iron status, oxidative stress, inflammation, and autophagy in the kidneys of old rats. Old Fischer 344 rats (24 months) were treated with deferoxamine (DFO; 200 mg/kg, twice daily for 4.5 days); saline-treated young (6 months) and old rats served as controls. Renal nonheme iron was significantly higher in the old rats, with iron localized in the renal cortex. Ferritin levels were elevated in the kidneys of old rats, while expression of several antioxidant enzymes and mitochondrial proteins were reduced and protein carbonyls increased compared to young rats. DFO treatment significantly reduced ferritin levels, and increased transferrin receptor-1 protein, but did not affect nonheme iron content or protein carbonyls, nor did it reverse age-related changes in antioxidant enzymes and mitochondrial proteins. Although short-term DFO treatment did not mitigate the age-related increase in iron content and oxidative damage, this work demonstrates that old rats respond appropriately to DFO, suggesting that optimization of iron chelation regimens could be useful in improving renal homeostasis with aging.

Aging results in accumulation of M1 and M2 hepatic macrophages and a differential response to gadolinium chloride.

Macrophages have vital roles in innate immunity by modulating the inflammatory response via their ability to alter their phenotype from pro-inflammatory (M1) to anti-inflammatory (M2). Aging increases activation of the innate immune system, and macrophage numbers increase in the aged liver. Since macrophages also produce free radical molecules, they are a potential source of age-related oxidative injury in the liver. This study evaluated macrophage phenotype in the aged liver and whether the increase in the number of macrophages with aging is associated with enhanced hepatic oxidative stress. Hepatic macrophage phenotype and oxidative stress were evaluated 2 days after a single intraperitoneal injection of saline or gadolinium chloride (GdCl3, 10 mg/kg) in young (6 months) and aged (24 months) Fischer 344 rats. GdCl3 has been shown to decrease the expression of macrophage-specific markers and impair macrophage phagocytosis in the liver. Saline-treated aged rats demonstrated greater numbers of both M1 (HO-1+/iNOS+) and M2 (HO-1+/CD163+) macrophages, without evidence of a phenotypic shift. GdCl3 did not alter levels of dihydroethidium fluorescence or malondialdehyde, suggesting that macrophages are not a major contributor to steady-state levels of oxidative stress. However, GdCl3 decreased M1 and M2 macrophage markers in both age groups, an effect that was attenuated in aged rats. In old animals, GdCl3 decreased iNOS expression to a greater extent than HO-1 or CD163. These results suggest a novel effect of aging on macrophage biology and that GdCl3 shifts hepatic macrophage polarization to the M2 phenotype in aged animals.

ACG Clinical Guideline: Hereditary Hemochromatosis.

Hereditary hemochromatosis (HH) is one of the most common genetic disorders among persons of northern European descent. There have been recent advances in the diagnosis, management, and treatment of HH. The availability of molecular diagnostic testing for HH has made possible confirmation of the diagnosis for most patients. Several genotype-phenotype correlation studies have clarified the differences in clinical features between patients with the C282Y homozygous genotypes and other HFE mutation patterns. The increasing use of noninvasive tests such as MRI T2* has made quantification of hepatic iron deposition easier and eliminated the need for liver biopsy in most patients. Serum ferritin of <1,000 ng/mL at diagnosis remains an important diagnostic test to identify patients with a low risk of advanced hepatic fibrosis and should be used routinely as part of the initial diagnostic evaluation. Genetic testing for other types of HH is available but is expensive and generally not useful in most clinical settings. Serum ferritin may be elevated among patients with nonalcoholic fatty liver disease and in those with alcoholic liver disease. These diagnoses are more common than HH among patients with elevated serum ferritin who are not C282Y homozygotes or C282Y/H63D compound heterozygotes. A secondary cause for liver disease should be excluded among patients with suspected iron overload who are not C282Y homozygotes. Phlebotomy remains the mainstay of therapy, but emerging novel therapies such as new chelating agents may have a role for selected patients.

Iron-Induced Liver Injury: A Critical Reappraisal.

Iron is implicated in the pathogenesis of a number of human liver diseases. Hereditary hemochromatosis is the classical example of a liver disease caused by iron, but iron is commonly believed to contribute to the progression of other forms of chronic liver disease such as hepatitis C infection and nonalcoholic fatty liver disease. In this review, we present data from cell culture experiments, animal models, and clinical studies that address the hepatotoxicity of iron. These data demonstrate that iron overload is only weakly fibrogenic in animal models and rarely causes serious liver damage in humans, calling into question the concept that iron overload is an important cause of hepatotoxicity. In situations where iron is pathogenic, iron-induced liver damage may be potentiated by coexisting inflammation, with the resulting hepatocyte necrosis an important factor driving the fibrogenic response. Based on the foregoing evidence that iron is less hepatotoxic than is generally assumed, claims that assign a causal role to iron in liver injury in either animal models or human liver disease should be carefully evaluated.

Clinical burden of liver disease from hemochromatosis at an academic medical center.

Hereditary hemochromatosis (HH) can cause cirrhosis and hepatocellular carcinoma (HCC), but the frequency of these complications is controversial. To address this question, we reviewed the experience with HH at an academic medical center that is the sole liver transplantation center in a state with a population that is >90% Caucasian. The records of all subjects with International Classification of Diseases, Ninth Revision, code 275, "disorders of iron metabolism" seen at the University of Iowa Hospitals and Clinics between January 1, 2004 and December 31, 2014 were reviewed, and HFE C282Y homozygotes and C282Y/H63D compound heterozygotes were identified. Clinical, pathologic, and laboratory data from these subjects were examined in detail. We identified 118 C282Y homozygotes and 44 compound heterozygotes; 22 of the former and 3 of the latter had advanced hepatic fibrosis (bridging or cirrhosis). Male patients predominated in both groups. Most of the C282Y homozygotes and all compound heterozygotes had causes of chronic liver disease in addition to iron overload. Together, these accounted for 0.42% of cases of cirrhosis seen at the University of Iowa Hospitals and Clinics during this period. Two male patients with cirrhosis attributable solely to iron overload presented with cardiac dysfunction and atrial fibrillation; this classical presentation was rare, representing approximately one per 3,000 cases of cirrhosis. Eight homozygotes were diagnosed with HCC, representing 1.8% of patients with HCC. Conclusion: Despite the expected high prevalence of HH mutations in our state and the referral bias inherent in our study, serious hepatic manifestations of HH were uncommon. These data support claims that the penetrance of frank clinical hemochromatosis is low. (Hepatology Communications 2017;1:453-459).

Strain- and time-dependent alterations in hepatic iron metabolism in a murine model of nonalcoholic steatohepatitis.

Nonalcoholic steatohepatitis is a common liver disease that is often accompanied by dysregulated iron metabolism. The aim of the study was to test the hypothesis that aberrant iron metabolism in nonalcoholic steatohepatitis is modulated by genetic susceptibility to inflammation and oxidative stress. Hepatic histology and iron content were assessed in 3 inbred strains of mice (C57BL/6, BALB/c, and C3H/HeJ) fed an atherogenic diet (AD). Hepatic expression of genes relevant to iron metabolism, inflammation, and oxidative stress were quantitated by real-time reverse transcription-polymerase chain reaction. At 6 weeks on the AD, histologic injury and induction of inflammatory and oxidative stress-associated gene expression were most pronounced in C57BL/6. At 18 weeks on the AD, these parameters were similar in C57BL/6 and BALB/c. Atherogenic diet-fed C3H/HeJ showed milder responses at both time points. The AD was associated with decreased hepatic iron concentrations in all strains at 6 and 18 weeks. The decrease in hepatic iron concentrations did not correlate with changes in hepcidin expression and was not associated with altered expression of iron transporters. These findings are similar to those observed in models of obesity-induced steatosis and indicate that hepatic steatosis can be associated with depletion of iron stores that is not explained by upregulation of hepcidin expression by inflammation. SIGNIFICANCE OF THE STUDY: Nonalcoholic steatohepatitis (NASH) is a common liver disease that often accompanies the metabolic syndrome. The latter condition has been linked to iron deficiency and diminished intestinal iron absorption, likely the result of hepcidin upregulation by chronic inflammation. Paradoxically, some NASH patients accumulate excess hepatic iron, which may increase fibrosis and cancer risk. Iron accumulation has been attributed to suppression of hepcidin by oxidative stress. The objective of this study was to investigate the contributions of inflammation and oxidative stress to altered hepatic iron metabolism in a murine model of NASH using inbred strains of mice with differing susceptibilities to injury.

Mirizzi Syndrome in a Cirrhotic Patient After TIPS Resolved by Technetium99m Mebrofenin Hepatobiliary Scan.

Cholestatic pattern on the hepatic panel is common and can be caused by a broad array of etiologies. Although rare, with a prevalence as low as 0.06%, it is imperative to keep Mirizzi syndrome in the differential diagnosis when evaluating cholestasis. Due to the nonspecific presentation and inconsistent radiologic features, a high index of suspicion is needed to diagnose Mirizzi Syndrome. We present an unusual case of a 51-year-old man with worsening cholestatic laboratory tests and a normal ultrasound and abdominal computerized tomography. A technetium99m mebrofenin hepatobiliary acid scan suggested the diagnosis of Mirizzi syndrome that was later confirmed during an open cholecystectomy.

Tumour promotion versus tumour suppression in chronic hepatic iron overload.

Although iron-catalysed oxidative damage is presumed to be a major mechanism of injury leading to cirrhosis and hepatocellular carcinoma in hemochromatosis, these events have been difficult to recapitulate in an animal model. In this study, we evaluated regulators of hepatocarcinogenesis in a rodent model of chronic iron overload. Sprague-Dawley rats were iron loaded with iron dextran over 6 months. Livers were harvested and analysed for markers of oxidative stress, as well as the following proteins: p53, murine double minute 2, the Shc proteins p66, p52, p46; ß-catenin, CHOP, C/EBPα and Yes-associated protein. In this model, iron loading is associated with hepatocyte proliferation, and indices of oxidative damage are mildly increased in tandem with augmented antioxidant defenses. Alterations potentially favouring carcinogenesis included a modest but significant decrease in p53 levels and increases in p52, p46 and ß-catenin levels compared with control livers. Countering these factors, the iron-loaded livers demonstrated a significant decrease in CHOP, which has recently been implicated in the development of hepatocellular carcinoma, as well as a reciprocal increase in C/EBPα and decrease in Yes-associated protein. Our results suggest that chronic iron overload elicits both tumour suppressive as well as tumour-promoting mechanisms in rodent liver.

Iron overload secondary to cirrhosis: a mimic of hereditary haemochromatosis?

AIMS: Hepatic iron deposition unrelated to hereditary haemochromatosis is common in cirrhosis. The aim of this study was to determine whether hepatic haemosiderosis secondary to cirrhosis is associated with iron deposition in extrahepatic organs. METHODS AND RESULTS: Records of consecutive adult patients with cirrhosis who underwent autopsy were reviewed. Storage iron was assessed by histochemical staining of sections of liver, heart, pancreas and spleen. HFE genotyping was performed on subjects with significant liver, cardiac and/or pancreatic iron. The 104 individuals were predominantly male (63%), with a mean age of 55 years. About half (46%) had stainable hepatocyte iron, 2+ or less in most cases. In six subjects, there was heavy iron deposition (4+) in hepatocytes and biliary epithelium. All six of these cases had pancreatic iron and five also had cardiac iron. None of these subjects had an explanatory HFE genotype. CONCLUSIONS: In this series, heavy hepatocyte iron deposition secondary to cirrhosis was commonly associated with pancreatic and cardiac iron. Although this phenomenon appears to be relatively uncommon, the resulting pattern of iron deposition is similar to haemochromatosis. Patients with marked hepatic haemosiderosis secondary to cirrhosis may be at risk of developing extrahepatic complications of iron overload.

Heat stress stimulates hepcidin mRNA expression and C/EBPα protein expression in aged rodent liver.

Elevations in hepatic iron content occur with aging and physiological stressors, which may promote oxidative injury to the liver. Since dysregulation of the iron regulatory hormone, hepcidin, can cause iron accumulation, our goal was to characterize the regulation of hepcidin in young (6 mo) and old (24 mo) Fischer 344 rats exposed to environmental heat stress. Liver and blood samples were taken in the control condition and after heating. Hepcidin expression did not differ between young and old rats in the control condition, despite higher levels of hepatic iron and IL-6 mRNA in the latter. Following heat stress, pSTAT3 increased in both groups, but C/EBPα and hepcidin mRNA increased only in old rats. Despite this, serum iron decreased in both age groups 2 h after heat stress, suggesting hepcidin-independent hypoferremia in the young rats. The differential regulation of hepcidin between young and old rats after hyperthermia may be due to the enhanced expression of C/EBPα protein in old rats. These data support the concept of "inflammaging" and suggest that repeated exposures to stressors may contribute to the development of anemia in older individuals.

Altered expression of iron regulatory proteins with aging is associated with transient hepatic iron accumulation after environmental heat stress.

An increasing body of evidence suggests that dysregulation of iron metabolism contributes to age-related pathologies. We have previously observed increased hepatic iron with aging, and that environmental heat stress stimulates a further increase in iron and oxidative liver injury in old rats. The purpose of this study was to determine a mechanism for the increase in hepatic iron in old rats after heat stress. Young (6 mo) and old (24 mo) Fischer 344 rats were exposed to two heating bouts separated by 24 h. Livers were harvested after the second heat stress, and protein levels of the iron import protein, transferrin receptor-1 (TFR1), and the iron export protein, ferroportin (Fpn) were determined by immunoblot. In the nonheated condition, old rats had lower TFR1 expression, and higher Fpn expression. After heat stress, TFR1 declined in the old rats, and iron chelation studies demonstrated that this decline was dependent on a hyperthermia-induced increase in iron. TFR1 did not change in the young rats after heat stress. Since TFR1 is inversely regulated by iron, our results suggest that the increase in intracellular iron with aging and heat stress lower TFR1 expression. Fpn expression increased in both age groups after heat stress, but this response was delayed in old rats. This delay in the induction of an iron exporter suggests a mechanism for the increase in hepatic iron and oxidative injury after heat stress in aged organisms.