Screening for hereditary hemochromatosis: a clinical practice guideline from the American College of Physicians

Testing and Management of Iron Overload After Genetic Screening-Identified Hemochromatosis

Importance

HFE gene-associated hereditary hemochromatosis type 1 (HH1) is underdiagnosed, resulting in missed opportunities for preventing morbidity and mortality.

Objective

To assess whether screening for p.Cys282Tyr homozygosity is associated with recognition and management of asymptomatic iron overload.

Design, Setting, and Participants

This cross-sectional study obtained data from the Geisinger MyCode Community Health Initiative, a biobank of biological samples and linked electronic health record data from a rural, integrated health care system. Participants included those who received a p.Cys282Tyr homozygous result via genomic screening (MyCode identified), had previously diagnosed HH1 (clinically identified), and those negative for p.Cys282Tyr homozygosity between 2017 and 2018. Data were analyzed from April 2020 to August 2023.

Exposure

Disclosure of a p.Cys282Tyr homozygous result.

Main Outcomes and Measures

Postdisclosure management and HFE-associated phenotypes in MyCode-identified participants were analyzed. Rates of HFE-associated phenotypes in MyCode-identified participants were compared with those of clinically identified participants. Relevant laboratory values and rates of laboratory iron overload among participants negative for p.Cys282Tyr homozygosity were compared with those of MyCode-identified participants.

Results

A total of 86 601 participants had available exome sequences at the time of analysis, of whom 52 994 (61.4%) were assigned female at birth, and the median (IQR) age was 62.0 (47.0-73.0) years. HFE p.Cys282Tyr homozygosity was disclosed to 201 participants, of whom 57 (28.4%) had a prior clinical HH1 diagnosis, leaving 144 participants who learned of their status through screening. There were 86 300 individuals negative for p.Cys282Tyr homozygosity. After result disclosure, among MyCode-identified participants, 99 (68.8%) had a recommended laboratory test and 36 (69.2%) with laboratory or liver biopsy evidence of iron overload began phlebotomy or chelation. Fifty-three (36.8%) had iron overload; rates of laboratory iron overload were higher in MyCode-identified participants than participants negative for p.Cys282Tyr homozygosity (females: 34.1% vs 2.1%, P < .001; males: 39.0% vs 2.9%, P < .001). Iron overload (females: 34.1% vs 79.3%, P < .001; males: 40.7% vs 67.9%, P = .02) and some liver-associated phenotypes were observed at lower frequencies in MyCode-identified participants compared with clinically identified individuals.

Conclusions and Relevance

Results of this cross-sectional study showed the ability of genomic screening to identify undiagnosed iron overload and encourage relevant management, suggesting the potential benefit of population screening for HFE p.Cys282Tyr homozygosity. Further studies are needed to examine the implications of genomic screening for health outcomes and cost-effectiveness.

Hereditary Hemochromatosis: A Cardiac Perspective

Hereditary hemochromatosis (HH) is a common genetic metabolic disorder characterized by excessive iron absorption and elevated serum iron levels, which accumulate in various organs, such as the heart, pancreas, gonads, and damage these organs. There are only a few articles and clinical studies describing the characteristics of cardiac involvement in HH along with the significance of early diagnosis and management in preventing complications. In this review article, we have reviewed multiple pieces of literature and gathered available information regarding the subject. We compiled the data to investigate the importance of early detection of symptoms, regular monitoring, and prompt management with strict adherence to reverse or prevent complications. This article has reviewed different aspects of cardiac hemochromatosis, such as pathogenesis, clinical presentation, diagnosis, and management. Recognition of early symptoms, diagnosis of cardiac involvement with various modalities, and implementation of early treatment are essentially the foundation of better outcomes in HH.

Advancement of echocardiography for surveillance of iron overload cardiomyopathy: comparison to cardiac magnetic resonance imaging

The prevalence of iron overload cardiomyopathy (IOC) is increasing. Patients with transfusion-dependent anemias or conditions associated with increased iron absorption over time are at a significant risk for the development of iron-overloaded states such as IOC. Current guidelines regarding the diagnostic evaluation and follow-up of patients at risk for IOC exist, and are composed of multiple components, including such as echocardiography, genetic testing, magnetic resonance imaging of liver, and cardiac magnetic resonance imaging (CMR). While these are considered reliable for the evaluation of patients at risk for an iron-overloaded state, there is an access challenge associated with initial and serial CMR scanning in this patient population. Furthermore, there are other limiting factors, such as patient characteristics that may preclude the use of CMR as a viable diagnostic imaging modality for these patients. On the other hand, recent evidence in the literature suggests that transthoracic echocardiography, which has had significant technological advances, can equal or even outperform CMR to identify cardiac functional abnormalities such as subclinical left ventricular strain and left atrial functional abnormalities in iron overload conditions. Therefore, there is a potential role of more frequent use of echocardiography for surveillance of the development of IOC. Our purpose with this narrative review is to describe recent advances in echocardiography and propose a potential increased use of echocardiography in the surveillance of the development of IOC.

Genetic diagnosis history and osteoarticular phenotype of a non-transfusion secondary hemochromatosis

BACKGROUND

It is not easy to identify the cause of various iron overload diseases because the phenotypes overlap. Therefore, it is important to perform genetic testing to determine the genetic background of patients.

AIM

To investigate the genetic background of a patient with hemochromatosis complicated by psoriasis on both lower extremities.

METHODS

Ten years ago, a 61-year-old male presented with iron overload, jaundice, hemolytic anemia and microcytic hypochromic anemia. Computed tomography of the left knee joint showed enlargement of the tibial medullary cavity and thinned bone cortices. Magnetic resonance imaging showed hepatic hemochromatosis, extensive abnormal signals from bone marrow cavities and nodular lesions in the lateral medullary cavity of the upper left lateral tibia. Single photon emission computed tomography showed radial dots of abnormal concentration in the upper end of the left tibia and radial symmetry of abnormal concentrations in joints of the extremities. The patient showed several hot spot mutations of the HFE and G6PD genes detected by next-generation sequencing, but no responsible gene mutation was found. The thalassemia gene was detected by gap-PCR.

RESULTS

The patient was found to carry the -α^4.2 and --^SEA deletion mutations of the globin gene. These two mutations are common causes of Southeast Asian α-thalassemia, but rarely cause severe widespread non-transfusion secondary hemochromatosis osteoarthropathy. The simultaneous presence of an auxiliary superposition effect of a rare missense mutation of the PIEZO1 gene (NM_001142864, c.C4748T, p.A1583V) was considered. Moreover, several rare mutations of the IFIH1, KRT8, POFUT1, FLG, KRT2, and TGM5 genes may be involved in the pathogenesis of psoriasis.

CONCLUSION

The selection of genetic detection methods for hemochromatosis still needs to be based on an in-depth study of the clinical manifestations of the disease.

A mouse model of subacute liver failure with ascites induced by step-wise increased doses of (-)-epigallocatechin-3-gallate

Acute liver failure is divided into hyperacute, acute and subacute liver failure. Ascites is a common complication of subacute liver failure. Although animal models of acute liver failure have been established, the study of the pathogenesis of subacute liver failure with ascites complication is hampered by the lack of experimental animal model. The present study aimed at providing a mouse model of subacute liver failure with ascites complication. Kunming mice were intraperitoneally injected with (-)-epigallocatechin-3-gallate (EGCG), a redox-active polyphenol from green tea, for 32 consecutive days with step-wise increased dosage. The EGCG treatment resulted in liver failure as evidenced by extensive hepatocyte necrosis observed histologically along with significant elevation of serum alanine aminotransferase, aspartate aminotransferase, total bilirubin and direct bilirubin levels as well as significant reduction of serum albumin. Liver fibrosis was not observed by Masson staining and fibrosis-associated proteins were not increased. The mortality was less than 12% and the survival mice developed noticeable ascites. Hepatic thioredoxin and glutathione systems were activated by the EGCG. These adaptive responses might render most mice tolerable to the EGCG treatment. The EGCG treatment significantly up-regulated renal urea transporter A1 and promoted its trafficking to apical membrane. These alterations, known to increase water reabsorption, may be responsible, at least in part, for the formation of the ascites. Overall, the mice treated with gradually elevated doses of EGCG exhibits some of the features observed in patients with subacute liver failure, especially ascites. This mouse model is a useful tool for investigating the pathogenesis of subacute liver failure with ascites complication.

Biomarkers of Nutrition for Development (BOND)-Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health.The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation.

Iron loading, alcohol and mortality: A prospective study

BACKGROUND & AIMS

The relationship between total body iron and cardiovascular disease remains controversial and information absent in black sub-Saharan Africans in whom alcohol consumption tends to be high. The level of total body iron is tightly regulated, however this regulation is compromised by high alcohol intake causing iron loading. The aim of this study is to investigate total body iron, as represented by serum ferritin, and its interaction with measures of alcohol intake in predicting all-cause and cardiovascular mortality.

METHODS

We followed health outcomes for a median of 9.22 years in 877 randomly selected HIV negative African women (mean age: 50.4 years).

RESULTS

One hundred and five deaths occurred of which 40 were cardiovascular related. Ferritin averaged 84.0 (5th to 95th percentile interval, 7.5-533.3) ng/ml and due to the augmenting effect of inflammation, lowered to 75.3 (6.9-523.2) ng/ml after excluding 271 participants with high-sensitivity C-reactive protein (CRP) levels (above 8 mg/l). CRP increased by quartiles of ferritin in the total group (P trend = 0.002), but this relationship was absent after excluding the 271 participants with high CRP values (P trend = 0.10). Ferritin, gamma-glutamyl transferase and carbohydrate deficient transferrin (all P < 0.0001) were higher in drinkers compared to non-drinkers, but CRP was similar (P = 0.77). In multivariable-adjusted analyses, ferritin predicted both all-cause (hazard ratio, 2.08; 95% confidence interval, 1.62-2.68; P < 0.0001) and cardiovascular (1.94; 1.29-2.92; P = 0.002) mortality. In participants with CRP levels below or equal to 8 mg/l, the significant relationship remained between ferritin and all-cause (2.51; 1.81-3.49; P < 0.0001) and cardiovascular mortality (2.34; 1.45-3.76; P = 0.0005). In fully adjusted models, interactions existed between ferritin and gamma-glutamyl transferase, self-reported alcohol use and carbohydrate deficient transferrin in predicting all-cause (P ≤ 0.012) and cardiovascular mortality (P ≤ 0.003).

CONCLUSIONS

Iron loading in African women predicted all-cause and cardiovascular mortality and the intake of alcohol seems mechanistically implicated.

Management of cardiac hemochromatosis

Iron-overload syndromes may be hereditary or acquired. Patients may be asymptomatic early in the disease. Once heart failure develops, there is rapid deterioration. Cardiac hemochromatosis is characterized by a dilated cardiomyopathy with dilated ventricles, reduced ejection fraction, and reduced fractional shortening. Deposition of iron may occur in the entire cardiac conduction system, especially the atrioventricular node. Cardiac hemochromatosis should be considered in any patient with unexplained heart failure. Screening for systemic iron overload with serum ferritin and transferin saturation should be performed. If these tests are consistent with iron overload, further noninvasive and histologic confirmation is indicated to confirm organ involvement with iron overload. Cardiac magnetic resonance imaging is superior to other diagnostic tests since it can quantitatively assess myocardial iron load. Therapeutic phlebotomy is the therapy of choice in nonanemic patients with cardiac hemochromatosis. Therapeutic phlebotomy should be started in men with serum ferritin levels of 300 μg/l or more and in women with serum ferritin levels of 200 μg/l or more. Therapeutic phlebotomy consists of removing 1 unit of blood (450 to 500 ml) weekly until the serum ferritin level is 10 to 20 μg/l and maintenance of the serum ferritin level at 50 μg/l or lower thereafter by periodic removal of blood. Phlebotomy is not a treatment option in patients with anemia (secondary iron-overload disorders) nor in patients with severe congestive heart failure. In these patients, the treatment of choice is iron chelation therapy.

Clinical penetrance in hereditary hemochromatosis: estimates of the cumulative incidence of severe liver disease among HFE C282Y homozygotes

Iron overload (hemochromatosis) can cause serious, symptomatic disease that is preventable if detected early and managed appropriately. The leading cause of hemochromatosis in populations of predominantly European ancestry is homozygosity of the C282Y variant in the HFE gene. Screening of adults for iron overload or associated genotypes is controversial, largely because of a belief that severe phenotypes are uncommon, although cascade testing of first-degree relatives of patients is widely endorsed. We contend that severe liver disease (cirrhosis or hepatocellular cancer) is not at all uncommon among older males with hereditary hemochromatosis. Our review of the published data from a variety of empirical sources indicates that roughly 1 in 10 male HFE C282Y homozygotes is likely to develop severe liver disease during his lifetime unless iron overload is detected early and treated. New evidence from a randomized controlled trial of treatment allows for evidence-based management of presymptomatic patients. Although population screening for HFE C282Y homozygosity faces multiple barriers, a potentially effective strategy for increasing the early detection and prevention of clinical iron overload and severe disease is to include HFE C282Y homozygosity in lists of medically actionable gene variants when reporting the results of genome or exome sequencing.

Ferritin levels and risk of heart failure-the Atherosclerosis Risk in Communities Study

AIMS

Severe iron overload is associated with cardiac damage, while iron deficiency has been related to worse outcomes in subjects with heart failure (HF). This study investigated the relationship between ferritin, a marker of iron status, and the incidence of HF in a community-based cohort.

METHODS AND RESULTS

We examined 1063 participants who were free of heart failure from the Atherosclerosis Risk in Communities (ARIC) Study in whom ferritin serum levels were measured at baseline (1987-1989). The participants (mean age 52.7 ± 5.5 years, 62% women), were categorized in low (<30 ng/mL; n = 153), normal (30-200 ng/mL in women and 30-300 ng/mL in men; n = 663), and high (>200 ng/mL in women and >300 ng/mL in men; n = 247) ferritin levels. Multivariable Cox proportional hazards models were used to evaluate the relationship between ferritin and incident HF. After 21 ± 4.6 years of follow-up, HF occurred in 144 (13.5%) participants. When compared with participants with normal ferritin levels, participants with low ferritin levels had a higher risk of HF [hazard ratio (HR) = 2.24, 95% confidence interval (CI) 1.15-4.35; P = 0.02] as did those with high ferritin levels (HR = 1.81, 95% CI 1.01-3.25; P = 0.04), after adjusting for potential confounders. Notably, low ferritin levels remained associated with incident HF even after excluding subjects with anaemia (HR = 2.28, 95% CI 1.11-4.68; P = 0.03).

CONCLUSION

Derangements in iron metabolism, either low or high ferritin serum levels, were associated with higher risk of incident HF in a general population, even without concurrent anaemia. These findings suggest that iron imbalance might play a role in the development of HF.

Review and evaluation of the methodological quality of the existing guidelines and recommendations for inherited neurometabolic disorders

Background

Inherited neurometabolic disorders (iNMDs) represent a group of almost seven hundred rare diseases whose common manifestations are clinical neurologic or cognitive symptoms that can appear at any time, in the first months/years of age or even later in adulthood. Early diagnosis and timely treatments are often pivotal for the favorable course of the disease. Thus, the elaboration of new evidence-based recommendations for iNMD diagnosis and management is increasingly requested by health care professionals and patients, even though the methodological quality of existing guidelines is largely unclear. InNerMeD-I-Network is the first European network on iNMDs that was created with the aim of sharing and increasing validated information about diagnosis and management of neurometabolic disorders. One of the goals of the project was to determine the number and the methodological quality of existing guidelines and recommendations for iNMDs.

Methods

We performed a systematic search on PubMed, the National Guideline Clearinghouse (NGC), the Guidelines International Network (G-I-N), the Scottish Intercollegiate Guideline Network (SIGN) and the National Institute for Health and Care Excellence (NICE) to identify all the published guidelines and recommendations for iNMDs from January 2000 to June 2015. The methodological quality of the selected documents was determined using the AGREE II instrument, an appraisal tool composed of 6 domains covering 23 key items.

Results

A total of 55 records met the inclusion criteria, 11 % were about groups of disorders, whereas the majority encompassed only one disorder. Lysosomal disorders, and in particular Fabry, Gaucher disease and mucopolysaccharidoses where the most studied. The overall methodological quality of the recommendation was acceptable and increased over time, with 25 % of the identified guidelines strongly recommended by the appraisers, 64 % recommended, and 11 % not recommended. However, heterogeneity in the obtained scores for each domain was observed among documents covering different groups of disorders and some domains like 'stakeholder involvement' and 'applicability' were generally scarcely addressed.

Conclusions

Greater efforts should be devoted to improve the methodological quality of guidelines and recommendations for iNMDs and AGREE II instrument seems advisable for new guideline development. The elaboration of new guidelines encompassing still uncovered disorders is badly needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-015-0376-9) contains supplementary material, which is available to authorized users.

The Ethical, Legal, and Social Implications Program of the National Human Genome Research Institute: reflections on an ongoing experiment

For more than 20 years, the Ethical, Legal, and Social Implications (ELSI) Program of the National Human Genome Research Institute has supported empirical and conceptual research to anticipate and address the ethical, legal, and social implications of genomics. As a component of the agency that funds much of the underlying science, the program has always been an experiment. The ever-expanding number of issues the program addresses and the relatively low level of commitment on the part of other funding agencies to support such research make setting priorities especially challenging. Program-supported studies have had a significant impact on the conduct of genomics research, the implementation of genomic medicine, and broader public policies. The program's influence is likely to grow as ELSI research, genomics research, and policy development activities become increasingly integrated. Achieving the benefits of increased integration while preserving the autonomy, objectivity, and intellectual independence of ELSI investigators presents ongoing challenges and new opportunities.

Molecular basis of HFE-hemochromatosis

Iron-overload disorders owing to genetic misregulation of iron acquisition are referred to as hereditary hemochromatosis (HH). The most prevalent genetic iron overload disorder in Caucasians is caused by mutations in the HFE gene, an atypical MHC class I molecule. Recent studies classified HFE/Hfe-HH as a liver disease with the primarily failure in the production of the liver iron hormone hepcidin in hepatocytes. Inadequate hepcidin expression signals for excessive iron absorption from the diet and iron deposition in tissues causing multiple organ damage and failure. This review focuses on the molecular actions of the HFE/Hfe and hepcidin in maintaining systemic iron homeostasis and approaches undertaken so far to combat iron overload in HFE/Hfe-HH. In the light of the recent investigations, novel roles of extra-hepatocytic Hfe are discussed raising a question to the relevance of the multipurpose functions of Hfe for the understanding of HH-associated pathologies.

Transferrin saturation and hospital length of stay and mortality in Medicare beneficiaries

OBJECTIVES

To evaluate in a large, nationally representative cohort the association between high serum transferrin saturation (TS) and hospital length of stay and mortality in older adults.

DESIGN

Prospective cohort.

SETTING

Longitudinal analyses of the Third National Health and Nutrition Examination Survey linked to Medicare claims from 1991 through 2006.

PARTICIPANTS

Medicare beneficiaries aged 65 and older at baseline.

MEASUREMENTS

Transferrin saturation collected on each participant at baseline was characterized as <20.0%, 20.0% to 54.9%, and 55.0% and greater. Length of stay in the hospital and death in the hospital were primary outcomes. Analyses were adjusted for age, sex, race and ethnicity, education, and severity of illness.

RESULTS

Individuals hospitalized during the study period (79.4%) with high (odds ratio (OR) = 2.54, 95% confidence interval (CI) = 1.05-6.12) or low (OR = 1.31, 95% CI = 1.07-1.62) TS had a significantly greater risk of death than those with moderate TS. Individuals with high TS had longer average length of stay per hospitalization (11.1 days, (standard error, SE 1.7 days), P = .01) than those with moderate TS (8.4 (0.3) days). Individuals with high TS also had more hospital days per year (8.6 (2.0) days, P = .04) than those with moderate TS (6.7 (0.5) days).

CONCLUSION

High TS is associated with longer length of stay and death in the hospital (unweighted N = 3,847, weighted N = 28,395,464).

Diagnostic value of transferrin

Despite the growing interest in hepcidin and other relatively new biomarkers, guidelines and clinical pathways continue to recommend traditional markers, such as serum transferrin (Tf) and ferritin, as laboratory tests for the diagnostic evaluation of iron-related disorders. In this study, we aimed to critically evaluate the diagnostic role of Tf relying on the highest level of available evidence by a comprehensive literature search. The role of Tf in iron deficiency (ID) and iron overload (IO) syndrome as well as a risk marker was evaluated. The low accuracy of Tf and Tf saturation (TS) in the diagnosis and management of ID conditions does not permit definitively recommending their use, even if recently published guidelines still consider the TS investigation as a complementary test for ferritin. If a tissue IO is suspected, TS is often used, even if it may not be the best test for detecting this condition. Nevertheless, clinical guidelines strongly recommend the use of TS as a first-level test for performing genetic diagnosis of hereditary hemochromatosis. Recently reported data indicating elevated TS as a risk factor for diabetes mellitus, cancer, and total mortality, may provide useful additions to the debate over whether or not to screen for IO using TS.

IRon Overload screeNing tool (IRON): development of a tool to guide screening in primary care

Iron overload is associated with significant morbidity and mortality yet is easily treated. The objective of this study was to create a tool that could be easily adapted to clinical practice that indicates the likelihood of a patient having undetected iron overload. We used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 for US adults aged 20 years and older to build a model (unweighted n=8,779). We chose potential variables for inclusion that could be gathered by self-report or measured without laboratory data and were suggested by past literature on hemochromatosis and iron overload. We computed logistic regressions to create the scores by initially evaluating the variables' relationship with elevated ferritin and elevated transferrin saturation and then using odds ratios to correspond to scores. The resulting score on the IRon Overload ScreeNing Tool (IRON) was then validated with data on 13,844 adults in the NHANES III, 1988-94. Predictors in the final tool were age, gender, previous diagnoses of liver condition, osteoporosis or thyroid disease. The IRON score yielded an area under the curve (AUC) in the NHANES 1999-02 of 0.720 and an AUC of 0.685 in the NHANES III validation sample. The IRON score is a tool to assist in identification of patients with iron overload that has several qualities that make it attractive for use in clinical practice with an undifferentiated patient population including brevity, easily collected information and predictive ability comparable to other tools that help in directing screening.

Evaluating the role of blood collection centers in public health: a status report

Blood centers have a central role in the community through recruitment and donation, and these community interactions enable blood centers to have a critical role in public health. Some public health initiatives are inherent in the blood center, such as providing human immunodeficiency virus educational material, whereas other initiatives have been actively created, such as cardiovascular screening, as a means to increase blood donor rates and increase the blood center's community interaction. These public health initiatives have been inconsistently practiced by blood collection centers over many years. An understanding of the current literature and exploring the potential role of blood centers in public health, while considering cost and value of these programs, are necessary for blood centers to evaluate the value of implementing these programs. The studies do not support a significant improvement in donor health or significant increase in donation rates through these public health initiatives. However, no study published thus far has been comprehensive enough or carried out long enough to adequately evaluate the value of providing health initiatives to donors.

Iron overload and HFE gene mutations in Polish patients with liver cirrhosis

BACKGROUND

Increased liver iron stores may contribute to the progression of liver injury and fibrosis, and are associated with a higher risk of hepatocellular carcinoma development. Pre-transplant symptoms of iron overload in patients with liver cirrhosis are associated with higher risk of infectious and malignant complications in liver transplant recipients. HFE gene mutations may be involved in the pathogenesis of liver iron overload and influence the progression of chronic liver diseases of different origins. This study was designed to determine the prevalence of iron overload in relation to HFE gene mutations among Polish patients with liver cirrhosis.

METHODS

Sixty-one patients with liver cirrhosis included in the study were compared with a control group of 42 consecutive patients subjected to liver biopsy because of chronic liver diseases. Liver function tests and serum iron markers were assessed in both groups. All patients were screened for HFE mutations (C282Y, H63D, S65C). Thirty-six of 61 patients from the study group and all controls had liver biopsy performed with semiquantitative assessment of iron deposits in hepatocytes.

RESULTS

The biochemical markers of iron overload and iron deposits in the liver were detected with a higher frequency (70% and 47% respectively) in patients with liver cirrhosis. There were no differences in the prevalence of all HFE mutations in both groups. In patients with a diagnosis of hepatocellular carcinoma, no significant associations with iron disorders and HFE gene mutations were found.

CONCLUSIONS

Iron disorders were detected in patients with liver cirrhosis frequently but without significant association with HFE gene mutations. Only the homozygous C282Y mutation seems to occur more frequently in the selected population of patients with liver cirrhosis. As elevated biochemical iron indices accompanied liver iron deposits more frequently in liver cirrhosis compared to controls with chronic liver disease, there is a need for more extensive studies searching for the possible influence of non-HFE iron homeostasis regulators and their modulation on the course of chronic liver disease and liver cirrhosis.

Hereditary hemochromatosis: laboratory evaluation

The condition of hereditary hemochromatosis (HH) is caused by gene-dependent protein abnormalities involved in iron absorption, storage, or modulation of iron; these abnormalities result in iron overload. The clinical laboratory plays a significant role in case finding, diagnostic validation, and monitoring HH therapy. Elevated serum iron, transferrin saturation, and ferritin suggest HH, but results can also indicate other forms of hepatocyte injury such as alcoholic or viral hepatitis, or other inflammatory disorders involving the liver. In the context of elevated serum iron, transferrin saturation, and ferritin, and after ruling out secondary causes of iron overload, HFE gene evaluation is the preferred test to confirm the diagnosis of HH. However, 5% to 15% of patients with phenotypic HH do not have HFE gene mutations. In these cases, MRI evaluation or liver biopsy with iron quantification is indicated. The clinical role of hepcidin, the iron modulating protein, is undetermined at this time. Because hepcidin also plays a key role in antimicrobial and inflammatory activities, interpretation of hepcidin serum or urine concentration will require thorough understanding of its complex role in iron regulation.

Iron overload cardiomyopathy: better understanding of an increasing disorder

The prevalence of iron overload cardiomyopathy (IOC) is increasing. The spectrum of symptoms of IOC is varied. Early in the disease process, patients may be asymptomatic, whereas severely overloaded patients can have terminal heart failure complaints that are refractory to treatment. It has been shown that early recognition and intervention may alter outcomes. Biochemical markers and tissue biopsy, which have traditionally been used to diagnose and guide therapy, are not sensitive enough to detect early cardiac iron deposition. Newer diagnostic modalities such as magnetic resonance imaging are noninvasive and can assess quantitative cardiac iron load. Phlebotomy and chelating drugs are suboptimal means of treating IOC; hence, the roles of gene therapy, hepcidin, and calcium channel blockers are being actively investigated. There is a need for the development of clinical guidelines in order to improve the management of this emerging complex disease.

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.

The global burden of iron overload. Hepatol Int. 2009;3:434-444. [PMID: 19669241 DOI: 10.1007/s12072-009-9144-z]

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.

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.

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.

Fragile X syndrome detection in newborns-pilot study

PURPOSE

Fragile X syndrome is the most common form of hereditary intellectual disability. Detection of the fragile X phenotype in the prepubertal period is very difficult, and early detection might assist in early developmental intervention and reproductive counseling. A pilot study was conducted to establish the feasibility of newborn screening for fragile X syndrome.

METHODS

A prospective study was done contacting mothers postdelivery in two hospitals in upstate South Carolina from 2005 to 2006. With their permission, blood samples were obtained from the male infants via heelstick and analyzed.

RESULTS

A total of 1,459 newborns were tested, and 5 abnormal results were obtained. The results included one sex chromosome aneuploidy (47, XXY), two premutations, and two full mutations.

CONCLUSIONS

Our study establishes the potential feasibility of such a screening process. However, more complete studies assessing a larger population and risk-benefit analyses are necessary before any universal application of this test. Our detection rate for fragile X syndrome (1:730) was inexplicably greater than anticipated but likely represents a chance occurrence among the small number of infants tested.

Ferritin for the clinician

Ferritin, a major iron storage protein, is essential to iron homeostasis and is involved in a wide range of physiologic and pathologic processes. In clinical medicine, ferritin is predominantly utilized as a serum marker of total body iron stores. In cases of iron deficiency and overload, serum ferritin serves a critical role in both diagnosis and management. Elevated serum and tissue ferritin are linked to coronary artery disease, malignancy, and poor outcomes following stem cell transplantation. Ferritin is directly implicated in less common but potentially devastating human diseases including sideroblastic anemias, neurodegenerative disorders, and hemophagocytic syndrome. Additionally, recent research describes novel functions of ferritin independent of iron storage.

Hereditary hemochromatosis: pathophysiology, diagnosis, and management

Hereditary hemochromatosis (HH) is an autosomal recessive genetic disease resulting in inappropriate intestinal iron absorption leading to iron overload and end-organ disease. The disease is most prevalent in white individuals of European descent. The C282Y mutation on the HFE gene accounts for most cases of HH; however, other genetic mutations have been identified. End-organ damage results in cirrhosis, diabetes mellitus, and cardiomyopathy. Therapeutic phlebotomy to deplete excessive iron stores is the standard treatment of HH and results in normal longevity if therapy is initiated before end-organ disease occurs.

Screening for haematological and iron-related abnormalities in elite athletes—Analysis of 576 cases

The aim of this prospective, cohort study was to determine the clinical and performance related utility of haematological and iron-related screening in elite athletes. Three hundred and three male and 273 female elite athletes underwent routine medical screening over a three-year period. In association with a standard medical consultation, a full blood count and iron-related variables were measured. Ten male athletes had a serum ferritin less than 30ng/mL and satisfied AIS criteria for iron supplementation. In only one case was a disorder identified which was not expected following the clinical history and examination. Fifty-two female athletes had a serum ferritin less than 30ng/mL and satisfied AIS criteria for iron supplementation. In the females, there were no instances in which a medical condition was identified which was not expected following the clinical history and examination. In both groups, clinically non-significant abnormalities were generally minor or isolated reductions in haemoglobin and/or haematocrit, and alterations in red cell parameters or single measures of iron status.

CONCLUSION

Screening for haematological and iron-related abnormalities in athletes has a low yield. Due to the critical nature of the effects of anaemia and low serum ferritin on some aspects of performance it is reasonable to perform a haemoglobin and a serum ferritin on male and female athletes entering an elite training program. Isolated abnormalities which are close to the limits of their normal ranges and not accompanied by symptoms or signs of illness can almost certainly be ignored.

Genetic discrimination in health insurance: current legal protections and industry practices

Most states have enacted genetic nondiscrimination laws in health insurance, and federal legislation is pending in Congress. Scientists worry fear of discrimination discourages some patients from participating in clinical trials and hampers important medical research. This paper describes a study of medical underwriting practices in the individual health insurance market related to genetic information. Underwriters from 23 companies participated in a survey that asked them to underwrite four pairs of hypothetical applicants for health insurance. One person in each pair had received a positive genetic test result indicating increased risk of a future health condition--breast cancer, hemochromatosis, or heart disease--for a total of 92 underwriting decisions on applications involving genetic information. In seven of these 92 applications, underwriters said they would deny coverage, place a surcharge on premiums,or limit covered benefits based on an applicant's genetic information.

Screening for hemochromatosis by measuring ferritin levels: a more effective approach. Blood. 2008;111:3373-3376. [PMID: 18025154 DOI: 10.1182/blood-2007-07-102673]

Because the penetrance of HFE hemochromatosis is low, traditional population screening measuring the transferrin saturation is unlikely to be cost-effective because the majority of subjects detected neither have clinical disease nor are likely to develop it. Three independent studies show that only patients with serum ferritin concentrations more than 1000 microg/L are at risk for cirrhosis, one of the main morbidities of hemochromatosis. Among 29,699 white subjects participating in the Scripps/Kaiser hemochromatosis study, only 59 had serum ferritin levels more than 1000 microg/L; 24 had homozygous mutant or compound heterozygous mutant HFE genotypes. In all but 5 of the other subjects, the causes of elevated ferritin were excessive alcohol intake, cancer, or liver disease. Screening for hemochromatosis with serum ferritin levels will detect the majority of patients who will be clinically affected and may detect other clinically significant disease in patients who do not have hemochromatosis genotypes. Because the ferritin level of the majority of adult homozygotes for HFE mutations does not rise over long periods of time, excluding subjects with serum ferritin levels less than or equal to 1000 microg/L should not result in missed opportunities for early treatment of patients who could benefit.

Directions for clinical practice improvement in HFE gene mutation testing

OBJECTIVE

To audit the clinical indications for HFE gene mutation testing in a consecutive series of requests.

DESIGN

Retrospective audit of reasons prompting 187 HFE test requests received between June 2003 and June 2005, by examination of the request form, hospital notes (when available) and, when required, information from the referring doctor.

SETTING

A tertiary care public teaching hospital laboratory, Perth, Western Australia.

MAIN OUTCOME MEASURES

Reasons prompting requests for HFE genotype testing and compliance with accepted clinical indications (biochemical evidence of iron overload on repeated samples, or a first-degree relative with either haemochromatosis or a C282Y mutation).

RESULTS

Insufficient clinical details in requests prevented the inclusion of interpretive comments in HFE genotype reports in 70 of 187 cases (37%). Re-evaluation after collation of the missing details for all but seven requests revealed that 103 of the 180 auditable requests (57%) had been prompted for reasons other than biochemical evidence of iron accumulation or family history.

CONCLUSIONS

A substantial proportion of HFE genotype test requests are made for inappropriate reasons. Clinical practice could be improved by educating doctors on the practical utility of this genetic test and by laboratories taking steps to secure the clinical information needed to include appropriate interpretive comments in their reports.

Zinc protoporphyrin, a useful parameter to address hyperferritinemia

Zinc protoporphyrin (ZPP) is produced instead of heme as soon as iron support to erythropoiesis becomes insufficient. In iron deficiency the intra-erythrocytic ZPP concentration is increased. The aim of this study was to investigate whether ZPP is influenced by increased iron levels in hereditary hemochromatosis (HE) and is useful in the clarification of hyperferritinemia. Twenty HE patients and 160 patients with hyperferritinemic caused by anemia of chronic disorders, liver diseases, transfusional iron overload and hematologic or solid malignancies were enrolled. ZPP was measured using the Aviv front-face hematofluorometer (normal <or= 40 micromol/mol heme). In HE, ZPP was significantly lower (median, 20 micromol/mol heme; p = 0.0005) compared to our historical control group. At diagnosis, 15 (75%) HE patients had ZPP values <or=25 micromol/mol heme. After phlebotomy, ZPP remained unchanged (median, 23 micromol/mol heme), although the initially high ferritin concentration decreased to normal. ZPP values in the other hyperferritinemic groups were significantly higher compared to HE and control groups. In contrast to HE, ZPP values <or=25 micromol/mol heme were only observed in 11% of cases with non-transfusional hyperferritinemia. The diagnostic accuracy of a ZPP <or=25 micromol/mol heme to detect HE in non-transfused hyperferritinemic patients was 87%, with a sensitivity of 75% and a specificity of 89%. Showing significantly lower values in HE, ZPP seems to be a useful parameter in distinguishing HE from other hyperferritinemic disorders as those conditions are generally accompanied by an increased ZPP.

The blood centre as a community health resource

Blood centres in the USA encounter over 35,000 blood donors every day, a number that is far exceeded worldwide. This daily encounter of thousands of people with the healthcare system offers an unusual opportunity for blood centres to engage these donors in ways that contribute to individual and community health. In addition, a positive interaction at the blood centre may encourage donors to return more often, thus enhancing the blood supply. The wealth of medical information gathered by blood centres also presents an opportunity for epidemiological studies of health and illness that affect the community at large. Donors receive a 'mini-physical' as part of the donor qualification process. Required procedures include blood pressure measurement and haemoglobin determination. Targeted education, counselling and referral of donors with hypertension and/or low haemoglobin engages them in the care of critical personal health issues. Carbonyl iron supplied to female donors of child-bearing age replaces iron lost in the donation and can retain them as active blood donors. A range of optional screening tests and procedures offer enhanced interactions between the donor and the blood centre. Inexpensive tests, such as cholesterol and random blood glucose determination, can detect abnormalities that may initiate further medical interventions to address cardiovascular and diabetic risks. These enhanced medical interactions with donors must be undertaken with care and appropriate medical supervision. However, the opportunity, indeed the responsibility, to act on important medical information enhances the range of medical support for donors and is an opening for blood centres to expand their involvement in the health of the community.

Screening in liver disease

A disease is suitable for screening if it is common, if the target population can be identified and reached and if both a good screening test and an effective therapy are available. Of the most common liver diseases only viral hepatitis and genetic hemochromatosis partially satisfy these conditions. Hepatitis C is common, the screening test is good and the therapy eliminates the virus in half of the cases, but problems arise in the definition of the target population. In fact generalized population screening is not endorsed by international guidelines, although some recommend screening immigrants from high prevalence countries. Opportunistic screening (case finding) of individuals with classic risk factors, such as transfusion before 1992 and drug addiction, is the most frequently used strategy, but there is disagreement whether prison inmates, individuals with a history of promiscuous or traumatic sex and health care workers should be screened. In a real practice setting the performance of opportunistic screening by general practitioners is low but can be ameliorated by training programs. Screening targeted to segments of the population or mass campaigns are expensive and therefore interventions should be aimed to improve opportunistic screening and the detection skills of general practitioners. Regarding genetic hemochromatosis there is insufficient evidence for population screening, but individual physicians can decide to screen racial groups with a high prevalence of the disease, such as people in early middle age and of northern European origin. In the other cases opportunistic screening of high risk individuals should be performed, with a high level of suspicion in case of unexplained liver disease, diabetes, juvenile artropathy, sexual dysfunction and skin pigmentation.

Prevalence of HFE mutations in California newborns

Advances in molecular diagnostics have led to an increased interest in expanding population-based screening to include genetic diseases that occur outside the newborn period. Hereditary hemochromatosis may be a candidate for large-scale screening in populations with a high prevalence of the common HFE mutations. To determine race-specific frequencies of the HFE mutations, C282Y and H63D, the authors applied an automated, high-throughput genotyping method to dried blood spot samples from a representative population of California newborns. In this sample of 3989 newborns, C282Y and H63D allele frequencies were highest in white (C282Y: 5.5 +/- 0.5%; H63D: 13.4 +/- 0.76%) and Hispanic (C282Y: 1.8 +/- 0.29%; H63D: 11.9 +/- 0.72%) newborns, and lowest in black (C282Y: 1.3 +/- 0.25%; H63D: 3.0 +/- 0.38%) and Asian (C282Y 0.5 +/- 0.16%; H63D 2.9 +/- 0.37%) newborns. The estimated prevalence of C282Y homozygotes in this multiracial population is 1.4/1000. As additional genetic and environmental risk factors for HHC are identified, neonatal screening may become an acceptable strategy to follow susceptible individuals and prevent clinical disease.