Reversibility of hepatic fibrosis in treated genetic hemochromatosis: a study of 36 cases

Reversal of hepatic fibrosis: pathophysiological basis of antifibrotic therapies

Chronic liver injuries of different etiologies eventually lead to fibrosis, a scarring process associated with increased and altered deposition of extracellular matrix in the liver. Progression of fibrosis has a major worldwide clinical impact due to the high number of patients affected by chronic liver disease which can lead to severe complications, expensive treatment, a possible need for liver transplantation, and death. Liver fibrogenesis is characterized by activation of hepatic stellate cells and other extracellular matrix producing cells. Liver fibrosis may regress following specific therapeutic interventions. Other than removing agents causing chronic liver damage, no antifibrotic drug is currently available in clinical practice. The extent of liver fibrosis is variable between individuals, even after controlling for exogenous factors. Thus, host genetic factors are considered to play an important role in the process of liver scarring. Until recently it was believed that this process was irreversible. However, emerging experimental and clinical evidence is starting to show that even cirrhosis in its early stages is potentially reversible.

A comparison of self-reported and record-linked blood donation history in an Australian cohort

BACKGROUND

Questionnaire-based studies investigating blood donation history rely on the accurate recall of information from participants for results to be valid. This study aimed to retrieve electronic records from a national blood donation service and link them to self-reported history of donation to assess agreement between the two sources.

STUDY DESIGN AND METHODS

Between 2004 and 2006, a sample of participants of northern European descent was selected from the Melbourne Collaborative Cohort Study (n = 31,192) to participate in the "HealthIron" study (n = 1438). A total of 1052 participants completed questionnaires that included questions about blood donation history. In 2009, consenting participants' records were linked to the Australian Red Cross Blood Service (ARCBS) to provide information on blood donations made between 1980 and follow-up (2004-2006). Those who commenced blood donation before 1980 were excluded.

RESULTS

A total of 718 participants were available for analysis. Of these, 394 (55%) provided signed consent, including 182 (82%) of the 227 participants who self-reported ever donating blood. The two data sources were concordant for 331 (87%) of participants, with a κ statistic of 0.74 (SE, 0.05) indicating a high level of agreement. Participants tended to overstate by a factor of 2.0 (95% confidence interval, 1.7-2.2) the number of donations they had made when compared with ARCBS records.

CONCLUSION

Participants in studies assessing self-reported blood donation history are likely to correctly indicate whether or not they have ever donated blood. Quantitative estimates are potentially inaccurate and could benefit from validating a sample of records to quantify the bias.

Diagnosis and management of chronic liver disease in older people

Chronic liver disease is increasingly prevalent and, as the population ages, geriatricians will see an increasing burden. We present an overview of the investigation and management of older adults with chronic parenchymal liver disease and highlight the potential roles of transjugular intrahepatic portosytemic shunts and orthotopic liver transplantation.

Antifibrotic therapies: will we ever get there?

Progressive hepatic fibrosis is the final common pathway for most chronic liver injuries, leading to cirrhosis with risk of liver failure and hepatocellular carcinoma. It is now recognized that fibrosis is a dynamic process, and may be reversible prior to the establishment of advanced architectural changes to the liver. The most effective antifibrotic strategy is to cure the underlying disease process before advanced fibrosis has developed. Unfortunately, this is often not possible, and specific antifibrotic therapies are needed. Advances in the understanding of the pathogenesis of liver fibrosis have identified several potential novel therapeutic targets, but unfortunately clinical development has been disappointing. One major limitation has been the often prolonged natural history of fibrosis compared to experimental models, and difficulties in accurate noninvasive fibrosis assessment, thus making clinical trial design difficult. In this review, we highlight the most promising current antifibrotic strategies.

Non-invasive methods for liver fibrosis prediction in hemochromatosis: One step beyond

Advances in recent years in the understanding of, and the genetic diagnosis of hereditary hemochromatosis (HH) have changed the approach to iron overload hereditary diseases. The ability to use a radiologic tool (MRI) that accurately provides liver iron concentration determination, and the presence of non-invasive serologic markers for fibrosis prediction (serum ferritin, platelet count, transaminases, etc), have diminished the need for liver biopsy for diagnosis and prognosis of this disease. Consequently, the role of liver biopsy in iron metabolism disorders is changing. Furthermore, the irruption of transient elastography to assess liver stiffness, and, more recently, the ability to determine liver fibrosis by means of MRI elastography will change this role even more, with a potential drastic decline in hepatic biopsies in years to come. This review will provide a brief summary of the different non-invasive methods available nowadays for diagnosis and prognosis in HH, and point out potential new techniques that could come about in the next years for fibrosis prediction, thus avoiding the need for liver biopsy in a greater number of patients. It is possible that liver biopsy will remain useful for the diagnosis of associated diseases, where other non-invasive means are not possible, or for those rare cases displaying discrepancies between radiological and biochemical markers.

How I treat hemochromatosis

Hemochromatosis is a common genetic disorder in which iron may progressively accumulate in the liver, heart, and other organs. The primary goal of therapy is iron depletion to normalize body iron stores and to prevent or decrease organ dysfunction. The primary therapy to normalize iron stores is phlebotomy. In this opinion article, we discuss the indications for and monitoring of phlebotomy therapy to achieve iron depletion, maintenance therapy, dietary and pharmacologic maneuvers that could reduce iron absorption, and the role of voluntary blood donation.

Impact of gene patents and licensing practices on access to genetic testing for hereditary hemochromatosis

Hereditary hemochromatosis is an iron metabolism disorder that leads to excess iron buildup, especially in the heart, liver, and pancreas. Mutations in the HFE gene are the single most common cause of hereditary hemochromatosis, which can be treated effectively if diagnosed early. Patents cover the HFE gene, related proteins, screening methods, and testing kits. Most initial testing for hereditary hemochromatosis is biochemical, but HFE deoxyribonucleic acid testing or genotyping is used to confirm a diagnosis of inherited hemochromatosis. Concerns over patents covering HFE testing emerged in 2002, when scholars argued that exclusive licensing and the patent-enabled sole provider model then in place led to high prices and limited access. Critics of the sole provider model noted that the test was available at multiple laboratories before the enforcement of patents. By 2007, however, Bio-Rad Limited, acquired the key intellectual property and sublicensed it widely. In part because of broad, nonexclusive licensing, there are now multiple providers and testing technologies, and research continues. This case study illustrates how both changes in intellectual property ownership and evolving clinical utility of HFE genetic testing in the last decade have effected the licensing of patents and availability of genetic testing.

EASL clinical practice guidelines for HFE hemochromatosis

Iron overload in humans is associated with a variety of genetic and acquired conditions. Of these, HFE hemochromatosis (HFE-HC) is by far the most frequent and most well-defined inherited cause when considering epidemiological aspects and risks for iron-related morbidity and mortality. The majority of patients with HFE-HC are homozygotes for the C282Y polymorphism [1]. Without therapeutic intervention, there is a risk that iron overload will occur, with the potential for tissue damage and disease. While a specific genetic test now allows for the diagnosis of HFE-HC, the uncertainty in defining cases and disease burden, as well as the low phenotypic penetrance of C282Y homozygosity poses a number of clinical problems in the management of patients with HC. This Clinical Practice Guideline will therefore, focus on HFE-HC, while rarer forms of genetic iron overload recently attributed to pathogenic mutations of transferrin receptor 2, (TFR2), hepcidin (HAMP), hemojuvelin (HJV), or to a sub-type of ferroportin (FPN) mutations, on which limited and sparse clinical and epidemiologic data are available, will not be discussed. We have developed recommendations for the screening, diagnosis, and management of HFE-HC.

Hemochromatosis

Hemochromatosis is an iron metabolism disorder in which the intestines absorb excessive amounts of iron, which is eventually deposited into soft tissues. Hereditary hemochromatosis is the most common single-gene disorder in the US white population. Typically, adults do not begin to exhibit manifestations of the disease until the age of 40, after years of iron accumulation. Neonatal hemochromatosis is a very rare and serious disorder with no known etiology. It is unrelated to the hereditary mutation of the HFE gene and is thought of as a variety of fulminant hepatic failure. Neonatal hemochromatosis is associated with extremely poor outcomes, and liver transplant is the only reliable treatment. This literature review aims to describe hereditary and neonatal hemochromatosis as well as the sonographic characteristics and treatment.

Screening for iron overload: lessons from the hemochromatosis and iron overload screening (HEIRS) study

BACKGROUND

The HEmochromatosis and IRon Overload Screening (HEIRS) Study provided data on a racially, ethnically and geographically diverse cohort of participants in North America screened from primary care populations.

METHODS

A total of 101,168 participants were screened by testing for HFE C282Y and H63D mutations, and measuring serum ferritin concentration and transferrin saturation. In the present review, lessons from the HEIRS Study are highlighted in the context of the principles of screening for a medical disease as previously outlined by the World Health Organization.

RESULTS

Genetic testing is well accepted, with minimal risk of discrimination. Transferrin saturation has high biological variability and relatively low sensitivity to detect HFE C282Y homozygotes, which limits its role as a screening test. Symptoms attributable to HFE C282Y homozygosity are no more common in individuals identified by population screening than in control subjects.

CONCLUSIONS

Generalized population screening in a primary care population as performed in the HEIRS Study is not recommended. There may be a role for focused screening in Caucasian men, with some debate regarding genotyping followed by phenotyping, or phenotyping followed by genotyping.

Reversibility of liver fibrosis

Liver cirrhosis is a major cause of morbidity and mortality worldwide and has very limited therapeutic options. Regardless of the aetiology, hepatic fibrosis is a characteristic feature of chronic liver disease. Our knowledge regarding the pathogenesis of this scarring has grown exponentially in the past 25 years. It has now clear that this is a highly dynamic process and the long-held dogma that it is irreversible and relentlessly progressive is now being challenged. In this review, we will summarise the key pathogenic mechanisms at play and will focus on the evidence demonstrating that liver fibrosis is reversible in humans and animal models. In particular, we will examine the role of hepatic stellate cells, MMPs, TIMPs and macrophages in this process. Finally, we will discuss some of the studies aimed to therapeutically target the resolution of fibrosis and their potential for translation into a badly-needed treatment modality in the clinical setting.

Hepatic iron overload and risk of hepatocellular carcinoma in cirrhosis

Iron accumulation in the liver is considered to be a co-factor for progression of liver disease. Iron overload can enhance the effects of oxidative stress and influence the natural history of patients with cirrhosis, exposing them to a higher risk of hepatocellular carcinoma. The results of clinical studies designed to assess the impact of liver iron content on the risk of tumor development have remained controversial for some time. It is known that common factors can affect both liver iron overload and the risk of cancer, necessitating multivariate analyses of these features in large cohorts of cirrhotic patients. Furthermore, the causes and consequences of hepatic iron overload appear to depend on the cause of the underlying liver disease. Thus, the only solid evidence of a relationship between liver iron overload and event occurrence has come from longitudinal studies conducted in homogeneous cohorts of patients with cirrhosis. So far, the available data suggest that iron accumulation in the liver is an independent risk factor for hepatocellular carcinoma in patients with alcoholic cirrhosis and/or nonalcoholic hepatosteatosis, but not in those with viral hepatitis C cirrhosis.

The global burden of iron overload

There have been major developments in the field of iron metabolism in the past decade following the identification of the HFE gene and the mutation responsible for the C282Y substitution in the HFE protein. While HFE-associated hemochromatosis occurs predominantly in people of northern European extraction, other less-common mutations can lead to the same clinical syndrome and these may occur in other populations in the Asian-Pacific region. The most common of these is the mutation that leads to changes in the ferroportin molecule, the protein responsible for the transport of iron across the basolateral membrane of the enterocyte and from macrophages. Recent research has unraveled the molecular processes of iron transport and regulation of how these are disturbed in hemochromatosis and other iron-loading disorders. At the same time, at least one new oral iron chelating agent has been developed that shows promise in the therapy of hemochromatosis as well as thalassemia and other secondary causes of iron overload. It is pertinent therefore to examine the developments in the global field of iron overload that have provided insights into the pathogenesis, disease penetrance, comorbid factors, and management.

Coinheritance of hereditary spherocytosis and reversibility of cirrhosis in a young female patient with hereditary hemochromatosis

Here we report a 33-years-old woman with hereditary spherocytosis and hemochromatosis due to homozygosity for the C282Y mutation of the HFE gene. The coinheritance of both conditions led to severe iron overload and liver cirrhosis at young age. The patient was treated by repeated phlebotomy, and reversibility of cirrhosis was documented by transient elastography. This report discusses the pathophysiology of iron accumulation in patients with hemolytic anemia combined with HFE C282Y homozygosity. The case indicates that patients with hematological disorders characterized by increased erythropoetic activity should be screened for HFE mutations.

[Quality and quantity in hepatopathology. Diagnostic and clinically relevant grading for non-tumourous liver diseases]

This article describes the grading and staging systems used in the clinical context for non-neoplastic liver diseases (chronic and autoimmune hepatitis, fatty liver and steatohepatitis, medicinal toxic liver damage, iron storage disease and gall duct diseases). Fibrotic parenchymal alterations can also be assessed as well as livers planned for transplantation, with respect to possible rejection reactions. The basis for the histopathological diagnostic procedure is the liver biopsy. The consistent and correct use of the histological scores is obligatory in the diagnostic assessment of non-neoplastic liver diseases. Different scores are available for the various liver diseases. These are qualitative and quantitative scores based on empiricism and the practical relevance has been effectively proven. Grading describes the inflammatory activity and staging the extent of fibrosis or structural disorders up to liver cirrhosis. In many instances staging is the histopathological criteria for the prognosis assessment and is, therefore, decisive for therapy indications and therapy initiation.

Hereditary haemochromatosis

Haemochromatosis should currently refer to hereditary iron overload disorders presenting with a definite and common phenotype characterised by normal erythropoiesis, increased transferrin saturation and ferritin and primarily parenchymal iron deposition related to innate low (but normally regulated) production of the hepatic peptide hormone hepcidin. Since the discovery of the haemochromatosis gene (HFE) in 1996, several novel gene defects have been detected, explaining the mechanism and diversity of iron overload diseases. Overall, at least four main types of hereditary haemochromatosis (HH) have been identified. This review describes the systematic diagnostic and therapeutic strategy and pitfalls for patients suspected for HH and their relatives.

Systematic review: hepatic fibrosis - regression with therapy

BACKGROUND

Hepatic fibrosis occurs in response to chronic liver injury, regardless of the cause. An impressive amount of knowledge concerning the pathogenesis and treatment of liver fibrosis has emerged over the past few years. The hallmark of this event is the activation of the hepatic stellate cell. The latter event causes accumulation of extracellular matrix and formation of scar, leading to deterioration in hepatic function.

AIM

To assess chronic liver injury, many invasive and non-invasive methods have been suggested.

METHODS

Although transient elastography, image analysis of fractal geometry and fibrotest with actitest have been used in clinical practice, liver biopsy remains the recommended choice, especially when histological staging of fibrosis or response to treatment is needed.

CONCLUSIONS

The recent advances in anti-viral therapy have resulted in many reports on fibrosis and even on cirrhosis regression, especially early and in young people. A number of new agents have been suggested for the treatment of fibrosis, with promising results in animals; however, their efficacy in humans remains to be elucidated. The investigation of heterogeneity and plasticity of hepatic stellate cells is a topic of scientific interest and may result in improvements in patient management.

Fibrosis and cirrhosis reversibility - molecular mechanisms

The concept that liver fibrosis is a dynamic process with potential for regression as well as progression has emerged in parallel with clinical evidence for remodeling of fibrotic extracellular matrix in patients who can be effectively treated for their underlying cause of liver disease. This article reviews recent discoveries relating to the cellular and molecular mechanisms that regulate fibrosis regression, with emphasis on studies that have used experimental in vivo models of liver disease. Apoptosis of hepatic myofibroblasts is discussed. The functions played by transcription factors, receptor-ligand interactions, and cell-matrix interactions as regulators of the lifespan of hepatic myofibroblasts are considered, as are the therapeutic opportunities for modulating these functions. Growth factors, proteolytic enzymes, and their inhibitors are discussed in detail.

Clinical manifestations of hemochromatosis in HFE C282Y homozygotes identified by screening

BACKGROUND

Patients with hemochromatosis may suffer organ damage from iron overload, often with serious clinical consequences.

OBJECTIVE

To assess prevalences of self-reported symptoms and clinical signs and conditions in persons homozygous for the hemochromatosis gene (HFE) mutation (C282Y) identified by screening.

METHODS

Participants were adults 25 years of age or older enrolled in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. C282Y homozygotes (n=282) were compared with control participants without the HFE C282Y or H63D alleles (ie, wild type/wild type; n=364).

RESULTS

Previously diagnosed C282Y homozygotes and newly diagnosed homozygotes with elevated serum ferritin levels had higher prevalences of certain symptoms such as chronic fatigue (OR 2.8; 95% CI 1.34 to 5.95, and OR 2.0; 95% CI 1.07 to 3.75, respectively), and had more hyperpigmentation on physical examination (OR 4.7; 95% CI 1.50 to 15.06, and OR 3.7; 95% CI 1.10 to 12.16, respectively) and swelling or tenderness of the second and third metacarpophalangeal joints (OR 4.2; 95% CI 1.37 to 13.03, and OR 3.3; 95% CI 1.17 to 9.49, respectively) than control subjects. Joint stiffness was also more common among newly diagnosed C282Y homozygotes with elevated serum ferritin than among control subjects (OR 2.7; 95% CI 1.38 to 5.30). However, the sex- and age-adjusted prevalences of self-reported symptoms and signs of liver disease, heart disease, diabetes and most other major clinical manifestations of hemochromatosis were similar in C282Y homozygotes and control subjects.

CONCLUSIONS

Some symptoms and conditions associated with hemochromatosis were more prevalent among C282Y homozygotes identified by screening than among control subjects, but prevalences of most outcomes were similar in C282Y homozygotes and controls in this primary care-based study.

[Genetic iron overloads and hepatic insulin-resistance iron overload syndrome: an update]

Hepcidin inhibits intestinal absorption of iron through internalisation of ferroportin. Its discovery helps to better understand the genetic iron overloads. The insulin resistance-hepatic iron overload (IR-HIO)--also coined as the dysmetabolic iron overload syndrome--is a common cause or iron overload. This article is a review about genetic iron overloads and IR-HIO. Type 1 haemochromatosis C282Y +/+ accounts for 95% of the haemochromatosis. Hepatic fibrosis may develop if serum ferritin is higher than 1000 microg/l but can be partially reversible with phlebotomies. Juvenile haemochromatosis (type 2) and type 3 haemochromatosis (mutation of the transferrin receptor 2) are very uncommon. Several mutations of the ferroportin gene can cause usually mild iron overload of autosomal dominant inheritance. Aceruleoplasminemia is an uncommon disorder involving cerebral iron overload. The causes and consequences of the IR-HIO are unknown. Treatment of IR-HIO is focused on metabolic syndrome and phlebotomies are questionable because the overload is moderate and intestinal absorption of iron seems to be low. MRI (or other non invasive methods) is needed to truly assess iron overload because serum ferritin overestimates it in metabolic syndrome. Several points have to be elucidated: how HFE interferes with hepcidin in type 1 haemochromatosis; the causes of variability of iron overload; the benefits of populations screening; the advantage of phlebotomies in IR-HIO; the use of new oral iron chelators.

Iron and the liver: update 2008

The cross-talk which has taken place in recent years between clinicians and scientists has resulted in a greater understanding of iron metabolism with the discovery of new iron-related genes including the hepcidin gene which plays a critical role in regulating systemic iron homeostasis. Consequently, the distinction between (a) genetic iron-overload disorders including haemochromatosis related to mutations in the HFE, hemojuvelin, transferrin receptor 2 and hepcidin genes and (b) non-haemochromatotic conditions related to mutations in the ferroportin, ceruloplasmin, transferrin and di-metal transporter 1 genes, and (c) acquired iron-overload syndromes has become easier. However, major challenges still remain which include our understanding of the regulation of hepcidin production, the identification of environmental and genetic modifiers of iron burden and organ damage in iron-overload syndromes, especially HFE haemochromatosis, indications regarding the new oral chelator, deferasirox, and the development of new therapeutic tools interacting with the regulation of iron metabolism.

Iron-overload-related disease in HFE hereditary hemochromatosis

BACKGROUND

Most persons who are homozygous for C282Y, the HFE allele most commonly asssociated with hereditary hemochromatosis, have elevated levels of serum ferritin and transferrin saturation. Diseases related to iron overload develop in some C282Y homozygotes, but the extent of the risk is controversial.

METHODS

We assessed HFE mutations in 31,192 persons of northern European descent between the ages of 40 and 69 years who participated in the Melbourne Collaborative Cohort Study and were followed for an average of 12 years. In a random sample of 1438 subjects stratified according to HFE genotype, including all 203 C282Y homozygotes (of whom 108 were women and 95 were men), we obtained clinical and biochemical data, including two sets of iron measurements performed 12 years apart. Disease related to iron overload was defined as documented iron overload and one or more of the following conditions: cirrhosis, liver fibrosis, hepatocellular carcinoma, elevated aminotransferase levels, physician-diagnosed symptomatic hemochromatosis, and arthropathy of the second and third metacarpophalangeal joints.

RESULTS

The proportion of C282Y homozygotes with documented iron-overload-related disease was 28.4% (95% confidence interval [CI], 18.8 to 40.2) for men and 1.2% (95% CI, 0.03 to 6.5) for women. Only one non-C282Y homozygote (a compound heterozygote) had documented iron-overload-related disease. Male C282Y homozygotes with a serum ferritin level of 1000 mug per liter or more were more likely to report fatigue, use of arthritis medicine, and a history of liver disease than were men who had the wild-type gene.

CONCLUSIONS

In persons who are homozygous for the C282Y mutation, iron-overload-related disease developed in a substantial proportion of men but in a small proportion of women.

Haemochromatosis

Since the discovery of the haemochromatosis gene (HFE; chromosome 6p21.3) associated with haemochromatosis in 1996, many studies about diverse aspects of this common genetic disorder have been done. Some patients present with cirrhosis and show high mortality, whereas many asymptomatic homozygotes for the C282Y mutation in the haemochromatosis gene identified in population screening studies, who have been followed up for many years, do not develop iron overload. Studies described the usefulness of transferrin saturation and serum ferritin tests, and the acceptability of genetic testing for haemochromatosis. Phlebotomy therapy improves hepatic fibrosis. Here, we summarise some new findings in haemochromatosis, a disorder first described in 1865.

Role of iron in hepatic fibrosis: One piece in the puzzle

Iron is an essential element involved in various biological pathways. When present in excess within the cell, iron can be toxic due to its ability to catalyse the formation of damaging radicals, which promote cellular injury and cell death. Within the liver, iron related oxidative stress can lead to fibrosis and ultimately to cirrhosis. Here we review the role of excessive iron in the pathologies associated with various chronic diseases of the liver. We also describe the molecular mechanism by which iron contributes to the development of hepatic fibrosis.

Iron storage disease: facts, fiction and progress

There are many forms of iron storage disease, some hereditary and some acquired. The most common of the hereditary forms is HFE-associated hemochromatosis, and it is this disorder that is the main focus of this presentation. The body iron content is regulated by controlling absorption, and studies in the past decade have clarified, in part, how this regulation functions. A 25-amino-acid peptide hepcidin is up-regulated by iron and by inflammation, and it inhibits iron absorption and traps iron in macrophages by binding to and causing degradation of the iron transport protein ferroportin. Most forms of hemochromatosis results from dysregulation of hepcidin or defects of hepcidin or ferroportin themselves. Hereditary hemochromatosis was once considered to be very rare, but in the 1970s and 1980s, with the introduction of better diagnostic tests, it was considered the most common disease among Europeans. Controlled epidemiologic studies carried out in the last decade have shown, however, the disease itself actually is rare, and only its genotype and associated biochemical changes that are common. We do not understand why only a few homozygotes develop severe disease. It now seems unlikely that there are important modifying genes, and although alcohol is known to have some effect, excess drinking probably plays only a modest role in determining the hemochromatosis phenotype. Hereditary hemochromatosis is readily treated by phlebotomy. Secondary forms of the disease require chelation therapy, and the recent introduction of effective oral chelating agents is an important step forward in treating patients with disorders in which iron overload often proves to be fatal, such as thalassemia, myelodysplastic anemias, and dyserythropoietic anemias. While much has been learned about the regulation of iron homeostasis in the past decade, many mysteries remain and represent challenges that will keep us occupied for years to come.

Review article: the genetic basis of haemochromatosis

BACKGROUND

Since the seminal discovery of the HFE gene a decade ago, considerable further progress in unravelling the genetic basis of haemochromatosis has been made. Novel genes and iron overload phenotypes have been described with potential insights into the molecular pathophysiology of human iron metabolism.

AIM

To review recent key advances in the field of inherited iron overload and assess their impact on clinical practice and on our understanding of iron regulation.

METHODS

A PubMed search was undertaken predominantly using 'haemochromatosis', 'HFE', 'hepcidin' and 'ferroportin'. Illustrative cases were sought.

RESULTS

The impact of HFE mutation analysis on the management of haemochromatosis is significant and allows early accurate diagnosis. HFE is also implicated in the siderosis associated with other liver pathologies. Non-HFE genes underpinning other forms of haemochromatosis are now recognized and genotype-phenotype interactions result in a spectrum of disease. These novel gene products interact with HFE in a common pathway for iron homeostasis.

CONCLUSIONS

Further identification of non-HFE genes associated with iron homeostasis will enhance our diagnostic certainty of primary haemochromatosis and may explain the variable expression seen in HFE-related disease. Improving our understanding of the mechanisms of iron regulation may lead to novel therapeutic strategies for the management of iron overload.

[Cardiac involvement in hemochromatosis]

Cardiac involvement in hemochromatosis affects mainly the myocardium: iron overload of the myocytes reduces left ventricular distensibility. Heart failure is the most frequent manifestation of cardiac involvement. Diagnosis of cardiac involvement depends essentially on Doppler echocardiography showing abnormal left ventricular filling and, later, ventricular dilatation with left ventricular systolic dysfunction. Magnetic resonance imaging can quantify intrahepatic and intramyocardial iron levels. Age at onset of symptoms and specific organ involvement in hemochromatosis depend on the type of mutation. The two principal means of treatment by iron depletion are phlebotomy in primary hemochromatosis and excretion of iron by chemical chelation in secondary hemochromatosis. Early diagnosis and iron depletion improve survival by reducing organ iron overload, especially in the liver and the myocardium. Recent guidelines issued by Anaes (national agency for health evaluation) make it possible to identify risk factors for complications early, to determine disease stage, and to provide appropriate management as a function of disease severity.

Chelation therapy for iron overload

Iron overload is characterized by excessive iron deposition and consequent injury and dysfunction of the heart, liver, anterior pituitary, pancreas, and joints. Because physiologic mechanisms to excrete iron are very limited, patients with iron overload and its complications need safe, effective therapy that is compatible with their coexisting medical conditions. The availability of three licensed iron chelation drugs (one parenteral, two oral) and the development and clinical investigation of other oral chelators represent new opportunities to prevent or manage iron overload in patients with heritable types of severe anemia, such as beta-thalassemia major and sickle cell disease, and for the formulation of alternatives to phlebotomy therapy for patients with iron overload associated with the HFE gene and other adult age-of-onset types of hemochromatosis, African iron overload, and African-American iron overload.

Hepatobiliary pathology

PURPOSE OF REVIEW

Recent papers on disorders of the liver and biliary tract which clarify their pathogenesis and attendant morphologic changes are highlighted.

RECENT FINDINGS

The concept of 'bystander hepatitis' was cited in studies showing hepatic infiltration of CD8-positive T cells in the setting of extrahepatic infections such as influenza virus and severe acute respiratory syndrome. Diabetic liver lesions include glycogenic hepatopathy (in which poor diabetic control leads to swollen, glycogen-filled hepatocytes without fat, steatohepatitis or fibrosis) and diabetic hepatosclerosis in which there is diffuse perisinusoidal fibrosis (type IV collagen) without zonal predilection. Ground-glass hepatocellular inclusions (positive with periodic acid-Schiff stain for glycogen) were reported in three separate series of patients who were hepatitis B virus-negative, often transplant recipients, immunosuppressed and on multiple medications. A Banff consensus paper expertly compared and contrasted the histologic features which characterize the various causes of late liver allograft dysfunction.

SUMMARY

Informative papers emerged this past year concerning collateral damage to the liver in extrahepatic infections, diabetic lesions and causes of liver dysfunction after transplantation, among other topics.

Current Approaches to the Management of Hemochromatosis

The term hemochromatosis encompasses at least four types of genetic iron overload conditions, most of them recently distinguished from one another as a result of the identification of a series of genes related to iron metabolism. At least three of these entities (HFE hemochromatosis, juvenile hemochromatosis and transferrin receptor 2 hemochromatosis) involve systemic hepcidin deficiency as a key pathogenetic factor. Major advances in the management of hemochromatosis influence the diagnostic approach to the disease, with the development of an overall non invasive strategy, mainly based on clinical, biological (iron parameters and genetic testing), and imaging (especially magnetic resonance imaging) data. Therapeutic management remains, on the curative side, dominated by phlebotomy (venesection), practical aspects of which have been recently revisited by the Guidelines Department of the French “Haute Autorité de Santé.” However, innovative treatment approaches, based on the improved pathophysiological understanding of these diseases and the progress in iron chelation therapy, are emerging. Preventive therapy, focused on family screening, remains a key part of the management of hemochromatosis.

Current Approaches to the Management of Hemochromatosis

The term hemochromatosis encompasses at least four types of genetic iron overload conditions, most of them recently distinguished from one another as a result of the identification of a series of genes related to iron metabolism. At least three of these entities (HFE hemochromatosis, juvenile hemochromatosis and transferrin receptor 2 hemochromatosis) involve systemic hepcidin deficiency as a key pathogenetic factor. Major advances in the management of hemochromatosis influence the diagnostic approach to the disease, with the development of an overall non invasive strategy, mainly based on clinical, biological (iron parameters and genetic testing), and imaging (especially magnetic resonance imaging) data. Therapeutic management remains, on the curative side, dominated by phlebotomy (venesection), practical aspects of which have been recently revisited by the Guidelines Department of the French “Haute Autorité de Santé.” However, innovative treatment approaches, based on the improved pathophysiological understanding of these diseases and the progress in iron chelation therapy, are emerging. Preventive therapy, focused on family screening, remains a key part of the management of hemochromatosis.