A retinoic acid receptor agonist tamibarotene suppresses iron accumulation in the liver

OBJECTIVE

Hepatic iron overload (HIO) and iron-induced oxidative stress have recently emerged as an important factor for the development and progression of insulin resistance. The aim of this study was to evaluate the effect of tamibarotene, a selective retinoic acid receptor α/β agonist, on hepatic iron metabolism, based on our previous findings that retinoids suppress hepatic iron accumulation by increasing hepatic iron efflux through the regulation of hemojuvelin and ferroportin expression.

DESIGN AND METHODS

We quantitated the non-heme iron content and iron metabolism-related gene expression in the liver, and serum lipid and blood glucose levels in KK-A(y) mice after dietary administration of tamibarotene.

RESULTS

It was demonstrated that tamibarotene significantly reduced blood glucose and hepatic iron, but not serum lipids, and that hemojuvelin expression significantly decreased while ferroportin increased, as observed previously.

CONCLUSIONS

These results suggest that tamibarotene is a promising alternative for the treatment of insulin resistance associated with HIO.

Hereditary haemochromatosis - diagnosis and management

BACKGROUND

Hereditary haemochromatosis is a common inherited disorder in which excessive iron is absorbed and which, over time, may cause organ damage. Genetic predisposition leads to disease in some but not all cases.

OBJECTIVE

This article discusses the presentation, testing, treatment and management of hereditary haemochromatosis.

DISCUSSION

Hereditary haemochromatosis is autosomal recessive and is more common in people of Celtic or northern European descent. Although more than 90% of cases of hereditary haemochromatosis are due to C282Y homozygosity (carrying two copies of the C282Y gene) not all C282Y homozygous individuals will progress through all stages of disease development. Clinical disease is less common in females due to physiological blood loss from menstruation and pregnancy. Most importantly, early diagnosis and treatment of hereditary haemochromatosis prevents complications and results in a normal life expectancy. Venesection is a simple and effective way to both prevent and manage the potential sequelae of iron overload, which include severe fatigue, arthritis, impotence, raised alanine aminotransferase/aspartate aminotransferase, fibrosis or cirrhosis, diabetes, and cardiomyopathy.

Diagnosis and current treatments for primary iron overload

Primary iron overload encompasses a variety of genetic iron overload syndromes, dominated in frequency by HFE-related, or Type 1 hemochromatosis, for which French diagnostic and therapeutic guidelines have been recently proposed. Differential diagnosis of Type 1 hemochromatosis can be made from both clinical data and genetic studies. Venesection therapy and family screening remain the basis for the curative and preventive management of most genetic iron overload diseases.

A genome-wide linkage scan for iron phenotype quantitative trait loci: the HEIRS Family Study

Iron overload phenotypes in persons with and without hemochromatosis are variable. To investigate this further, probands with hemochromatosis or evidence of elevated iron stores and their family members were recruited for a genome-wide linkage scan to identify potential quantitative trait loci (QTL) that contribute to variation in transferrin saturation (TS), unsaturated iron-binding capacity (UIBC), and serum ferritin (SF). Genotyping utilized 402 microsatellite markers with average spacing of 9 cM. A total of 943 individuals, 64% Caucasian, were evaluated from 174 families. After adjusting for age, gender, and race/ethnicity, there was evidence for linkage of UIBC to chromosome 4q logarithm of the odds (LOD) = 2.08, p = 0.001) and of UIBC (LOD = 9.52), TS (LOD = 4.78), and SF (LOD = 2.75) to the chromosome 6p region containing HFE (each p < 0.0001). After adjustments for HFE genotype and other covariates, there was evidence of linkage of SF to chromosome 16p (LOD = 2.63, p = 0.0007) and of UIBC to chromosome 5q (LOD = 2.12, p = 0.002) and to chromosome 17q (LOD = 2.19, p = 0.002). We conclude that these regions should be considered for fine mapping studies to identify QTL that contribute to variation in SF and UIBC.

Traitement par immunoglobulines pendant la grossesse chez deux patientes à risque de récurrence d'hémochromatose néonatale

Two patients, with prior affected children with Neonatal Haemochromatosis [NH], benefited from intravenous immunoglobulin treatment during their following pregnancy in order to prevent recurrent NH. Whereas NH is a severe disease with high risk of recurrence and high mortality rate (about 80%), a recent treatment was suggested in the USA, which seems to completely modify the prognosis of this pathology. We proposed this treatment for two patients with indeed apparent benefit, giving birth to two healthy babies.

[Hereditary haemochromatosis: novel genes, novel diseases and hepcidin]

Since the discovery of the HFE gene of hereditary haemochromatosis in 1996 several new genetic defects have been identified, enabling explanation of the cause and variety of this disease. To date, at least 5 major types of hereditary haemochromatosis have been recognised. All these genes encode for proteins that are involved in metabolic pathways relevant to hepcidin synthesis in the liver. Hepcidin is a small protein that regulates the activity of the iron exporting protein ferroportin in the basolateral membrane of duodenal cells and the cell membrane of macrophages and thereby controls serum iron concentration. Plasma hepcidin concentration is elevated in body iron excess and by inflammatory stimuli, and is lowered in erythroid iron demand, hypoxia and most types of hereditary haemochromatosis. It is the clinician's task to diagnose hereditary haemochromatosis before irreversible tissue damage arises and at the same time to differentiate between ongoing iron accumulation and increasingly prevalent disorders with elevated serum ferritin such as the metabolic syndrome.

Ca2+ channel blockers reverse iron overload by a new mechanism via divalent metal transporter-1

Hereditary hemochromatosis and transfusional iron overload are frequent clinical conditions associated with progressive iron accumulation in parenchymal tissues, leading to eventual organ failure. We have discovered a new mechanism to reverse iron overload-pharmacological modulation of the divalent metal transporter-1 (DMT-1). DMT-1 mediates intracellular iron transport during the transferrin cycle and apical iron absorption in the duodenum. Its additional functions in iron handling in the kidney and liver are less well understood. We show that the L-type calcium channel blocker nifedipine increases DMT-1-mediated cellular iron transport 10- to 100-fold at concentrations between 1 and 100 microM. Mechanistically, nifedipine causes this effect by prolonging the iron-transporting activity of DMT-1. We show that nifedipine mobilizes iron from the liver of mice with primary and secondary iron overload and enhances urinary iron excretion. Modulation of DMT-1 function by L-type calcium channel blockers emerges as a new pharmacological therapy for the treatment of iron overload disorders.

Tumor necrosis factor-alpha -308G>A allelic variant modulates iron accumulation in patients with hereditary hemochromatosis

BACKGROUND

In vitro and animal studies suggest that tumor necrosis factor alpha (TNF-alpha) modulates intestinal iron transport. We hypothesized that the effect of TNF-alpha might be particularly relevant if iron absorption is not effectively controlled by the HFE gene.

METHODS

In patients with homozygous C282Y hemochromatosis, we investigated the influence of TNF-alpha -308G>A allelic variant on total body iron overload, determined in all patients by measuring iron removed during depletion therapy, and hepatic iron index and need for phlebotomy to prevent iron reaccumulation, measured in patient subgroups.

RESULTS

Of 86 patients with hereditary hemochromatosis, 16 (19%) were heterozygous carriers and 1 (1%) was a homozygous carrier of the TNF-alpha promoter -308A allele. Mean (SD) total body iron overload was increased 2-fold in TNF-alpha -308A allele carriers [10.9 (7.6) g] compared with homozygous carriers of the G allele [5.6 (5.0) g, P<0.001]. Hepatic iron index differed markedly between TNF-alpha -308A allele carriers [5.6 (3.5) micromol/g/year] and homozygous G allele carriers [3.1 (2.2) micromol/g/year, P=0.040, n=30]. After iron depletion, the need for phlebotomy to prevent iron reaccumulation (maintenance therapy) was substantially higher in TNF-alpha -308A allele carriers than in homozygous G allele carriers (P=0.014, n=73). We used multiple regression analyses to exclude possible confounding effects of sex, age, family screening, body-mass index, and meat or alcohol intake.

CONCLUSION

TNF-alpha -308G>A allelic variant modulates iron accumulation in patients with hereditary (homozygous C282Y) hemochromatosis, but the effect of the TNF-alpha -308A allele on clinical manifestations of hemochromatosis was less accentuated than expected from the increased iron load associated with this allele.

High-dose immunoglobulin during pregnancy for recurrent neonatal haemochromatosis

BACKGROUND

Neonatal haemochromatosis is a rare disease of gestation that results in severe fetal liver injury. We hypothesised an alloimmune aetiology for the disorder on the basis of its high recurrence rate in sibships. In this study, we assessed the effectiveness in preventing or changing the severity of recurrent neonatal haemochromatosis of administering during pregnancy high-dose intravenous immunoglobulin (IVIG) derived from pooled serum of multiple donors.

METHODS

Women whose most recent pregnancy ended in documented neonatal haemochromatosis were treated with IVIG, 1 g/kg bodyweight, weekly from the 18th week until the end of gestation in their subsequent pregnancy. The outcomes of treated pregnancies were compared with those of randomly selected previous affected pregnancies for each woman, which were used as historical controls.

FINDINGS

15 women were treated through 16 pregnancies. All pregnancies progressed uneventfully and resulted in live babies with normal physical examinations and birthweights that were appropriate for gestational age. 12 babies had evidence of liver involvement with neonatal haemochromatosis: 11 had higher than normal concentrations of serum alpha-fetoprotein and ferritin or serum alpha-fetoprotein alone, including four with coagulopathy (international normalised ratio >1.5), and one had coagulopathy alone. All babies survived with medical or no treatment and were healthy at follow-up within the past 6 months. In analysis on a per-mother basis comparing outcomes of treated gestations with those of randomly selected previous affected gestations, gestational IVIG therapy was associated with better infant survival (15 good outcomes vs two in previous pregnancies; p=0.0009).

INTERPRETATION

Treatment with high-dose IVIG during gestation appears to have modified recurrent neonatal haemochromatosis so that it was not lethal to the fetus or neonate. These results further support an alloimmune mechanism for recurrent neonatal haemochromatosis.

Review article: targeted screening for hereditary haemochromatosis in high-risk groups

Patients with hereditary haemochromatosis are at risk for significant morbidity from iron overload as well as reduced life-expectancy once cirrhosis is established. Although inexpensive, sensitive screening tests and effective therapy are available, there is continued debate regarding the utility of screening for this condition because of recent data suggesting that the homozygous haemochromatosis mutation (C282Y) is associated with low penetrance and mild expressivity when identified in population screening studies. In this review, we examine the published data related to general population screening for haemochromatosis, as well as the evidence for screening selected 'high-risk' populations. We also suggest possible screening strategies based on the available evidence.

Hereditary haemochromatosis and hepatocellular carcinoma in males: a strategy for estimating the potential for primary prevention

OBJECTIVES

Homozygosity for the C282Y mutation of the HFE gene is the main cause of iron overload in hereditary haemochromatosis. This study calculated the number of hepatocellular carcinoma cases among a cohort of white males that could be attributed to C282Y homozygosity. A better understanding of the extent of potentially preventable mortality arising from this cancer might help with decision making about the feasibility of population screening.

METHODS

We combined information from published life tables, age-specific cancer rates and DNA studies of archived liver biopsy specimens to calculate the number of cases of hepatocellular carcinoma that might occur during the lifetime of a cohort of 1,000,000 men, including a subgroup of 5000 C282Y homozygotes.

RESULTS

Hepatocellular carcinoma was estimated to occur in 2673 men in the cohort (1:374); 267 of these cases were in the subgroup of 5000 C282Y homozygotes (1:17). If these 267 cases were prevented, the remaining lifetime risk among all males would be 1:416. The relative risk for this cancer in C282Y homozygotes is 23.

CONCLUSIONS

There continues to be uncertainty about the efficacy of screening for haemochromatosis. Hepatocellular carcinoma is the most readily quantifiable serious health problem attributable to this source. Further confirmatory DNA (C282Y) studies would be helpful in larger, unbiased sets of archived biopsy specimens, as a way to confirm the present estimate. Any strategy designed to prevent attributable liver cancer is likely to prevent other serious problems from haemochromatasis as well.

[Composition of commercial feeds for mynah birds with particular attention to the iron content]

The composition of 12 commercial feeds for mynah birds was analysed, with special attention being paid to the iron content. To prevent iron overload, the iron content of such diets should be maximally 5 mg/MJ, which is equivalent to 100 mg iron/kg if the commercial diet is the sole food source. Only three of the 12 feeds met this requirement. In all feeds the iron content was minimally three times higher than the recently suggested iron requirement of 25 mg/kg. In general, the total iron intake is not reduced sufficiently by providing cooked rice or fruit together with commercial feeds.

Should we genetically test everyone for haemochromatosis?

The increasing availability of DNA-based diagnostic tests has raised issues about whether these should be applied to the population at large in order to identify, treat or prevent a range of diseases. DNA tests raise concerns in the community for several reasons. There is the possibility of stigmatisation and discrimination between those who test positive and those who don't. High-risk individuals may be identified for whom no proven effective intervention is possible, or conversely may test "positive" for a disease that does not eventuate. Controversy concerning prenatal diagnosis and termination of affected pregnancies may arise. Haemochromatosis, however, is a disease that is not only treatable but also preventable if those at high risk are identified presymptomatically. This paper will identify and discuss key issues regarding DNA-based population screening for haemochromatosis, and argue that population-based genetic screening for haemochromatosis should be supported when a number of contentious issues are addressed. In the context of a health system with limited resources haemochromatosis is the paradigm of a disorder where there is an ethical and clinical imperative to encourage presymptomatic DNA testing for all in ethnically relevant communities.

The significance of haemochromatosis gene mutations in the general population: implications for screening

BACKGROUND

Haemochromatosis is associated with mutations in the HFE gene but the significance of these mutations in the general population is unknown.

AIMS

To determine the frequency of HFE gene mutations in the general population, their effect on serum iron indexes, and their role in screening for haemochromatosis.

METHODS

Deoxyribonucleic acid (DNA) from 1064 randomly selected subjects was analysed for the C282Y and H63D mutations in the HFE gene. Serum iron, transferrin saturation, and ferritin were measured and individuals with increased iron indexes were investigated to confirm or exclude a clinical diagnosis of haemochromatosis.

RESULTS

Mutations were identified in 409 individuals (38.4%) with heterozygote (carrier) frequencies of 13.2% and 24.3% for the C282Y and H63D mutations respectively. Heterozygosity for either mutation significantly increased serum iron and transferrin saturation but despite a similar trend for ferritin, this was only significant for C282Y homozygotes. Five individuals (0.47%) were homozygous for the C282Y mutation, three of whom had haemochromatosis confirmed by liver biopsy (0.28%). The other two C282Y homozygotes would not have been detected by phenotypic screening alone.

CONCLUSIONS

HFE mutations are present in 38.4% of the population, affect serum iron indexes, and are important determinants of iron status. The population frequency of genetically defined haemochromatosis (C282Y homozygosity) is approximately one in 200 and is higher than the prevalence of clinically apparent haemochromatosis.

Public health surveillance for hereditary hemochromatosis

The recent realization that hemochromatosis is a common condition has created opportunities to develop unified public health surveillance for this disorder and its complications and to design programs to prevent unnecessary illness and death resulting from this disorder. Public health surveillance for hemochromatosis can be used to measure the magnitude of the problem (for example, to establish the number of persons with evidence of early iron overload); identify research needs; reveal the natural history of the disease; detect changes in health care practices, such as use of screening tests; and evaluate interventions, such as phlebotomy. Existing surveillance has been limited to periodic measurement of morbidity and mortality done by using hospital discharge records, health examination surveys, vital statistics, and data from small research registries. The improvement of surveillance will entail the ongoing collection of information from population-based surveys, such as the Behavioral Risk Factor Surveillance System; the collection of data on provider practices (for example, through the National Ambulatory Medical Care Survey); and the establishment of population-based registries. Creating population-based registries requires consensus on case definitions; strategies to encourage case ascertainment and reporting; policies and procedures for protecting privacy and ensuring confidentiality; and partnerships among providers, researchers, and public health officials. Longitudinal data from population-based registries will provide insight into determinants of disease expression, such as pattern or degree of iron overload. This information is critical for developing evidence-based recommendations for population screening, monitoring changes in medical practices, and assessing the effect of preventive measures.

Haemochromatosis

Genetic haemochromatosis (GH) is the most common, autosomal recessive disorder in Northern Europe. The studies which led to the identification of the HFE gene are described. In the UK over 90% of patients with GH are homozygous for the C282Y mutation of this gene. This mutation is confined to populations of European origin. The significance of another mutation, H63D, in causing iron overload is less certain. Preliminary studies on the localization of the protein and the effects of the mutations are described. Genetic testing and the measurement of iron status now provide the means to allow for widespread testing for the prevention of iron overload and its consequences. However, questions remain about the clinical penetrance of GH.

Screening for hemochromatosis: phenotype versus genotype

Hereditary hemochromatosis is one of the most common inherited disorders among Caucasians of European ancestry. Malregulation of iron absorption from the duodenum eventually leads to iron overload. Although the time required to become iron loaded is variable, it is clear that most homozygotes will eventually become symptomatic. The clinical manifestations can be prevented by prophylactic phlebotomy therapy. Screening young populations is therefore a key to the prevention of disease-related morbidity. Protocols based on the phenotype of high transferrin saturation already exist. The recent identification of a candidate gene for hemochromatosis now allows for a potential genetic screen. Both the phenotypic and the genotypic methods of screening have inherent advantages and disadvantages. Iron-depletion therapy of homozygotes before the development of disease-related morbidity results in normal longevity. National initiatives for hemochromatosis screening will prevent morbidity by identifying and treating young, healthy homozygotes. Healthy, iron-depleted homozygotes should be eligible for health and life insurance at standard rates. Furthermore, healthy homozygotes would make ideal blood donors.

[Should we screen for hemochromatosis? Critical analysis of the literature]

This paper focus on the main issues to evaluate before planning public health interventions which may optimise the prevention of hemochromatosis. The main indicators are considered: prevalence, morbidity and mortality of the disease, efficacy of the available treatment, sensitivity, specificity and predictive values of the screening tests; potential benefit of a national screening program in a public health perspective. These are evaluated through a critical appraisal of the clinical, epidemiologic and economic literature on hemochromatosis. The paper emphasizes how individual behavior and preferences become crucial to take into account when well-being subjects will face a population-based screening program. We conclude that further arguments are required before the implementation of a national screening program for hemochromatosis.

Review article: the screening, diagnosis and optimal management of haemochromatosis

Haemochromatosis was first recognized as a disease entity over a century ago and its hereditary nature recognized over 60 years ago. However it was only in late 1996 that the haemochromatosis gene was cloned and a single C282Y mutation confirmed as being the cause of all HLA-linked iron overload in Caucasian populations. Haemochromatosis is common, occurring in approximately 1 in 300 people in Caucasian populations, and untreated can cause serious morbidity and early death. However, the disease remains much underdiagnosed for reasons such as lack of awareness of the disease, the presence of normal liver function tests and the lack or non-specific nature of symptoms. A commercially available DNA-based test for the haemochromatosis gene is likely to be available in the near future but its place in the diagnosis and management of the disorder is not yet clear. Assessment of body iron stores by measurement of serum ferritin and transferrin saturation, hepatic iron stores and hepatic architecture by liver biopsy will remain important in the future. The haemochromatosis mutation itself has as yet no known influence on morbidity other than via iron loading and organ failure, in particular, hepatic cirrhosis. Thus, diagnosing patients before the development of hepatic cirrhosis is crucial because iron depletion by venesection treatment before the development of cirrhosis results in a normal life expectancy.

The prevalence of hereditary haemochromatosis in a diabetic population

Hereditary haemochromatosis is an under-diagnosed and treatable cause of chronic liver disease. Its prevalence indicates that selective population screening may be worthwhile, but opinion differs as to whether diabetic patients constitute such a group. We studied 727 patients attending a teaching hospital diabetic clinic. On first testing, 7.4% had abnormally high iron indices, but only 3% remained abnormal on retesting. Of these patients, those at high risk were offered liver biopsy for histological assessment and iron assay. Only one had hereditary haemochromatosis, but all had abnormal liver histology--largely steatosis but some with fibrosis. These findings raise questions regarding the true prevalence of this disorder in North-East England, do not indicate that targeted screening of diabetic patients is worthwhile, and incidentally highlight the potential importance of diabetes as a cause of liver disease.

A reader's guide to economic analysis in the GI literature

To evaluate economic analyses and determine their value for clinical practice, the reader must have a clear understanding of how these analyses are performed and how the results can be applied to clinical practice. This second article in the "Primer on Economic Analysis for the Gastroenterologist" focuses on the critical assessment of economic evaluations in the gastrointestinal literature.

OBJECTIVES

The purpose of this article is (1) to review the criteria for the critical appraisal of an economic analysis, and (2) to apply these criteria to two recent articles that examine the cost-effectiveness of screening for hemochromatosis.

METHODS

The criteria for the critical appraisal of an economic analysis are outlined. To demonstrate the application of these criteria to the gastroenterology literature, they are used to evaluate two recent articles that examine the cost-effectiveness of screening for hemochromatosis.

SUMMARY/CONCLUSIONS

The reader of economic analyses in the gastroenterology literature is provided with a framework for the evaluation of such analyses and how they apply to gastroenterology. A systematic method for examining economic analyses and determining their value for the reader is illustrated.

[Genetic hemochromatosis: importance of population screening?]

Genetic hemochromatosis is a metabolic autosomal-recessive disease characterized by an iron excessive absorption; its subsequent accumulation in the liver, hearth, pancreas and endocrine glands, gives rise to organ damage and dysfunction. Recent studies of both screening tests and natural history have shown that the illness, once thought to be rare and fatal, is quite frequent (up to 2-5 homozygotes for 1000 inhabitants) and when recognized and treated before onset of cirrhosis, subjects affected have a normal life expectancy. Consequently, in order to reduce mortality from genetic hemochromatosis, mainly due to liver cirrhosis, frequently complicated with hepatocellular carcinoma, or congestive hearth failure, early diagnosis and therapeutic phlebotomy are essential. In order to achieve these aims, besides high clinical suspicion and familiar study, is fundamental to conduct systematic screening since, at present, little use is being made of this, even though numerous studies have recently shown its low cost and efficacy. The Authors, after an extensive review of the literature, underline the feasibility of screening on the general population and its extremely advantageous cost/benefit ratio.

Population screening for haemochromatosis: a unifying analysis of published intervention trials

OBJECTIVES

To examine the efficacy of population screening for haemochromatosis by analysing the screening performance of seven intervention trials, and to compare this with the expected performance derived from family studies.

SETTING

Seven population intervention trials carried out between 1983 and 1995 in Australia, Scandinavia, Iceland, and the United State.

METHODS

Seven of 23 English language trials identified were suitable for the meta-analysis. Transferrin saturation and serum ferritin measurements derived from family studies were used to predict detection and false positive rates for each trial.

RESULTS

The seven trials used various screening and diagnostic criteria. A total of 18,396 men and 12,254 women were screened. Because some cases were not detected by screening, and some screen positive individuals did not complete diagnostic testing, the prevalence of homozygous individuals was underestimated in all the trials. The reported and predicted percentages of screen positive individuals nearly always agreed. The homozygote prevalence was estimated to be 34 men and 40 women per 10,000 (prevalence predicted from family studies is 53 per 10,000). Clinical manifestations were present in 50% of male and 44% of female homozygotes.

CONCLUSIONS

False positive rates, homozygote prevalences, and frequency of clinical manifestations were in general agreement with predictions from family studies. However, incomplete understanding about a number of issues requires that further pilot trials be carried out before screening can be considered part of routine medical practice.

Screening for hemochromatosis in children of homozygotes: prevalence and cost-effectiveness

Although hereditary hemochromatosis is an autosomal recessive disease, most homozygotes are concerned with the genetic implications for their children. The optimal age for testing children and the cost implications of screening their children have not been clearly established. A clinical database consisting of 255 children from families with at least one homozygote is used to assess the prevalence of homozygotes among children of homozygous parents and to review the biochemical abnormalities and life-threatening symptoms in these young adults. Decision analysis is used to estimate the cost and utility of screening children of a homozygous parent. Eleven homozygotes were discovered among children of homozygotes. Only one male had a life-threatening event, cirrhosis. Decision analysis estimated cost saving of $12 per child screened ($ net present value) and a saving of 10 quality-adjusted days per child screened at age 10 years compared with not screening. If screening began at age 20 years, there is a cost saving of $65 per child screened. Sensitivity analysis showed that the major factors influencing cost savings were the cost of venesections, sensitivity and specificity of the screening tests, and prevalence of disease. Because the prevalence of hemochromatosis is higher in children of homozygotes than in the general population, screening with transferrin saturation and ferritin as early as age 10 years is recommended. Savings are augmented if the cost per venesection is eliminated by allowing hemochromatosis patients to become voluntary blood donors.

[Preclinical hereditary hemochromatosis--is there an indication for preventive screening?]

A 54 year-old previously healthy woman was admitted with staphylococcus aureus septicaemia. The patient had been treated with oral iron supplementation for two years due to fatigue. In the evaluation of postinfectious anaemia, serum transferrin saturation and serum ferritin were found persistently elevated with values of 74% and 950 micrograms/1, respectively. Hereditary haemochromatosis was suspected even though there was no history of liver disease or diabetes mellitus in the family. A bone marrow biopsy showed a normal content of haemosiderin iron. The liver biopsy revealed haemosiderosis, mainly located to the periportal hepatocytes, and fibrosis in the portal tracts. The HLA-type was A3, B7, B37. Over a period of ten months, a total of 3.9 g of iron was removed by venesection while S-ferritin declined to 31 micrograms/l. A sister to the proband had an identical HLA type, but normal iron status markers, either indicating heterozygosity or homozygosity with lack of penetrance. In preclinical hereditary haemochromatosis, early diagnosis and treatment is essential in order to prevent organ damage and to improve prognosis. Prophylactic screening is recommended. The identification of one homozygous subject in a Danish year-cohort of 60.000 persons costs approximately 40.000 Danish kroner (7.000 US+).