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PubMed2002

Role of HFE in iron metabolism, hereditary haemochromatosis, anaemia of chronic disease, and secondary iron overload.

Hereditary haemochromatosis is an iron overloading disorder caused by common mutations in the HFE gene. However, information with respect to the function of HFE protein does not explain how mutations in HFE lead to hereditary haemochromatosis. We propose a molecular model in which HFE has two mutually exclusive activities in cells: inhibition of uptake or inhibition of release of iron. The balance between serum transferrin saturation and serum transferrin-receptor concentrations determines which of these functions predominates. With this input, HFE enables the intestinal crypt cells and reticuloendothelial system to interpret the body's iron requirements and regulate iron absorption and distribution. In our model, mutations in HFE result in over absorption of dietary iron, and patterns of tissue iron deposition in agreement with clinical observations of hereditary haemochromatosis.

Anemia↗

PubMed1994

Liver iron quantification: studies in aqueous iron solutions, iron overloaded rats, and patients with hereditary hemochromatosis.

For the noninvasive liver iron quantification by MRI in human iron overload diseases, fundamental proton relaxation mechanisms were studied in aqueous solutions with ferritin and other iron compounds, in experimentally iron overloaded rats, and in patients with iron overload diseases. MR-relaxation rates as a function of iron concentrations in the range of 0-7.5 mg Fe/g aqueous iron solutions, 0-5.4 mg Fe/g rat liver in vivo, and 0.16-4.9 mg Fe/g human liver in vivo were determined from multi- and sets of single-spin echo sequences (1.5 T imager). As predicted by theory, transverse relaxation rates (1/T2) in aqueous iron solutions, in liver tissue of rats, and in human liver tissue increased linearly with the iron concentration. A preliminary calibration for the liver iron quantification by MRI was performed from in vivo measurements of liver 1/T2-relaxation rates and liver iron quantification by atomic absorption spectroscopy in biopsies from 13 patients. With the single spin-echo method, precise in vivo liver iron quantification in humans also above 2.0 mg Fe/g liver tissue (T2 < 15 ms) should be accomplished on any imager with shortest spin-echo time available, at least TE < 20 ms.

Adult↗

PubMed2006

Iron overload manifesting as apparent exacerbation of hepatic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Iron overload presenting as exacerbation of hepatic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation has not been previously described. We report 6 patients with established hepatic GVHD in whom iron overload (median serum ferritin, 7231 mug/dL; median transferrin saturation, 77%) resulting from a lifetime median of 20 units of packed red blood cell transfusions was manifested by worsening of liver function. Liver biopsies performed in 4 patients confirmed severe iron overload and also hepatic GVHD. Analysis for the C282Y and H63D hemochromatosis gene mutation was negative for the homozygous state in all 6 patients. Erythropoietin-assisted phlebotomy resulted in normalization of liver function at a median of 7 months and of serum ferritin at a median of 11 months. Immunosuppressive therapy was successfully tapered in all 4 patients who completed the phlebotomy program, and this supported the impression that iron overload, rather than GVHD, was the principal cause of liver dysfunction. At a median follow-up of 50 months (range, 18-76 months) from the transplantation and 25 months (range, 5-36 months) from ferritin normalization, all 4 patients require maintenance phlebotomy. We conclude that iron overload can mimic GVHD exacerbation, thus resulting in unnecessary continuation or intensification of immunosuppressive therapy for GVHD, and that maintenance phlebotomy is necessary after successful iron-reduction therapy.

Adult↗

PubMed2001

Nitric oxide and iron overload. Limitations of ESR detection by DETC.

The ability of the ESR technique based on diethyldithiocarbamate (DETC) administration was studied as a suitable method to assess NO generation in vivo. The technique was successfully employed to measure NO generation after LPS treatment. DETC2-Fe-NO adducts were detected in liver homogenates of iron overloaded animals. When iron was administered to the animals simultaneously with LPS, NO-dependent signal increased 122%, but the content of NO2- and NO3- in sera was significantly lower (44%) as compared to LPS-treated rats. Iron dextran administration was responsible for a three-fold increase in the DETC2-Fe-NO content in non-LPS treated rats, while NOS activity and sera NO2- and NO3- levels remained unaffected. The adduct generation rate by a chemical NO-source was recorded in the presence of either control or iron overloaded homogenates supplemented with DETC in vivo. The exposure of liver homogenates to NO was performed either by the addition of 1 mM SNAP as NO donor or infusing an aqueous NO solution. In the presence of iron overloaded samples the adduct generation rate was 3.8-4.4-fold higher than in the presence of control samples. This effect restricts the applicability of the method to experimental conditions where iron levels remain constant, therefore it is not suitable for NO generation studies in experimental models where animals were subjected to iron overload.

Animals↗

PubMed1995

Changes in transferrin saturation after treatment with the oral iron chelator deferiprone in patients with iron overload.

AIMS: To evaluate the changes in transferrin saturation in patients with iron overload following the oral administration of the iron chelator deferiprone; to assess the correlation between the degree of transferrin desaturation, the deferiprone dose, and urinary iron excretion. METHODS: Serum samples were obtained from 16 patients with iron overload at different time intervals following the oral administration of deferiprone (50 mg/kg). These samples were analysed using 6M urea/polyacrylamide gel electrophoresis (UPAGE). This method is able to resolve serum transferrin into four different forms (free iron, two forms of monoferric, and diferric). The deferiprone concentration in these samples was estimated using high pressure liquid chromatography (HPLC). Zero time samples (t0) from 10 patients were incubated with 150 microM deferiprone or normal saline either at room temperature or at 37 degrees C for 30 minutes and 24 hours, and also at -20 degrees C for six weeks. Samples were then analysed using UPAGE. RESULTS: A maximum decrease in transferrin saturation from (mean (SD)) 93.0 (10.6)% to 54.5 (17.2)% was observed 72.5 (50.0) minutes after deferiprone administration and in most of the patients coincided with peak deferiprone concentration. This was associated with a maximum rise in the percentage of iron free transferrin (apotransferrin) from 2.9 (7.0)% to 27.3 (17.8)%. The total amount of iron estimated to be removed from transferrin constituted 21.3 (20.2)% of the 24 hour urinary iron excretion measured during the study. When deferiprone (150 mumol/l) was incubated in vitro with t0 samples from 10 patients for 30 minutes and 24 hours at room temperature, 37 degrees C, and at -20 degrees C for six weeks, deferiprone was more efficient at removing iron from transferrin at 37 degrees C, with maximum transferrin desaturation accomplished within 30 minutes compared with 24 hours at room temperature. CONCLUSIONS: The results confirm that deferiprone can remove iron from transferrin when administered orally to patients with iron overload and that transferrin bound iron may, therefore, be a significant source of the iron chelated by deferiprone in vivo.

Administration, Oral↗

PubMed2004

Unexpectedly high but still asymptomatic iron overload in a patient with pyruvate kinase deficiency.

Iron overload is a serious condition, which may lead to irreversible organ damage. The risk of iron accumulation in pyruvate kinase deficiency (PKD) has traditionally been regarded as low, but recent evidence has questioned this notion. We here present a case of a young PKD patient showing evidence of asymptomatic iron accumulation measured as liver iron concentration (LIC) obtained noninvasively by magnetic resonance imaging. The iron overload was not related to blood transfusions, but rather secondary to concomitant risk factors leading to increased intestinal iron absorption, such as chronic hemolysis and splenectomy. The iron status of PKD patients, preferably assessed by LIC measurements, should therefore be evaluated regularly also in asymptomatic patients. This evaluation should start already at a young age, in order to initiate iron chelation before the development of iron-induced organ damage.

Adult↗

PubMed1983

Iron overload disorders: natural history, pathogenesis, diagnosis, and therapy.

Hemochromatosis is a syndrome which, when fully expressed, is manifested by melanoderma , diabetes mellitus, and liver cirrhosis, with iron overload involving parenchymal and reticuloendothelial cells in many organ systems. This clinical presentation may arise as a consequence of either hereditary or acquired abnormalities of iron overload, although the mechanisms are quite different. In hereditary hemochromatosis (also known as primary, or idiopathic, hemochromatosis), increased intestinal iron absorption leads to excessive accumulations of iron, throughout the body, particularly in parenchymal cells. In secondary forms of iron overload including transfusional hemosiderosis, alcoholic cirrhosis, thalassemia, sideroblastic anemia, and porphyria cutanea tarda, iron accumulates in the reticuloendothelial system initially, but with increasing amounts of total body iron, excessive iron deposits eventually accumulate in parenchymal cells throughout the body producing a picture indistinguishable from hereditary hemochromatosis. In this article, the course, prognosis, and therapy of iron overload will be reviewed in detail. Clinical and experimental data concerning the pathogenesis of the different forms of iron overload will be examined critically. In particular, information relating to possible abnormalities of reticuloendothelial function, intestinal mucosal iron transport, and alterations in serum and tissue isoferritin patterns in hereditary hemochromatosis will be analyzed, and possible directions for future research will be suggested. The mode of inheritance and linkage with the major histocompatibility (HLA) complex will be discussed. Theories on the pathogenesis of tissue damage by excess iron will be evaluated. Methods for measuring the extent of iron overload in clinical practice will be described, including measurements of serum iron, serum ferritin, iron absorption, cobalt excretion, desferrioxamine excretion, liver biopsy and tissue iron determinations, and HLA typing. Finally, unresolved problems in the understanding of the disease process, diagnosis, and therapy will be delineated.

Anemia, Hypochromic↗

PubMed2002

The labile iron pool of hepatocytes in chronic and acute iron overload and chelator-induced iron deprivation.

BACKGROUND: The cytosolic labile iron pool (LIP) is a transitory, catalytically active compartment that has been implicated in cell iron homeostasis and in metal-induced cytotoxicity. AIMS: We attempted to define LIP levels in living hepatocytes derived from chronic overloaded rats and from normal hepatocytes either acutely loaded with iron or depleted by chelation. METHODS: LIP levels were measured in living rat hepatocytes derived from normal and iron-fed rats. RESULTS: Steady-state LIP levels in untreated hepatocytes ( approximately 0.2 microM) were raised by 1.8-fold following iron loading and were reduced by 0.66-fold by short-term chelation treatment. Changes in LIP were accompanied by the corresponding changes in iron-responsive protein (IRP) activity and ferritin levels, that, in rat hepatocytes isolated from chronically loaded animals, raised by approximately 19-fold. CONCLUSIONS: Whereas ferritin levels provide an index of long-term or cumulative iron loading, LIP measurements provide an "instantaneous" parameter of iron availability within hepatocytes. The latter was associated with the cell chelatable pool in cells derived from normal and iron-loaded animals, both of which showed similar accessibility to iron chelators.

Acute Disease↗

PubMed2003

[Case finding of iron overload in a university hospital].

BACKGROUND: The epidemiologic importance of iron overload disorders and the clinical lack of its diagnosis led us to an active search of cases among the hospitalized patients in a general university hospital. This situation will make it possible to have a larger and earlier number of diagnosis together with a preventive intervention and an effective treatment. PATIENTS AND METHODS: A transverse study was performed on patients admitted to a fifteen beds ward in the internal medicine department. They have all been applied, without exclusion criteria, the iron metabolism parameters survey. The transferrin saturation (TS), due to its sensitivity, specificity and positive predictive value, has been considered appropriate for the phenotypic screening of the iron overload disorders. Subjects with fasting TS of 45% or more were considered as risk population. RESULTS: The study comprised 117 patients with an average age of 69.9 +/- 15.04. The high-risk population rate was 13.8% with an average age of 60.8 +/- 20.17, as compared to the low-risk population with an average age of 71.3 +/- 13.7 (p < 0.05). The most outstanding illnesses associated to the high-risk population are chronic hepatitis and diabetes mellitus (31.25%). An 18.7% of the cases show undernourishment. CONCLUSIONS: The iron overload is a prevalent illness whose early diagnosis requires a high clinical suspicion. The active search among the hospitalized patients, who have been made a TS, benefits the new cases detection. The TS is a screening technique with a high diagnostic profitability if you evaluate correctly the false positives. For that reason, we think the TS has to be included within the analytic requests which patients are made when admitted to hospital.

Adult↗

PubMed1992

Iron-induced ascorbate oxidation in plasma as monitored by ascorbate free radical formation. No spin-trapping evidence for the hydroxyl radical in iron-overloaded plasma.

A study was made of the interaction of plasma ascorbate and ascorbate free radical (AFR) with exogenously added iron. The quantitative determination of AFR has the advantage that transient increases in ascorbate oxidation can be directly monitored by e.p.r. spectroscopy. An AFR signal was found in the plasma of all donors and was unaffected by superoxide dismutase, catalase and the strong iron chelator deferoxamine. These findings and the rapid decrease in AFR under a nitrogen atmosphere suggest that plasma AFR is probably a result of air auto-oxidation. Iron loading of plasma did not affect the intensity of the AFR signal until the iron concentration approached or exceeded the plasma latent iron-binding capacity. In iron-overloaded plasma, the intensity of the AFR signal increased to about 10 times the normal level before decreasing rapidly to undetectable levels after 15-20 min. Determination of plasma ascorbate showed that the disappearance of AFR was due to a complete loss of the vitamin. When 50 microM-ascorbate was loaded with iron in iso-osmotic phosphate buffer there was an increase in the AFR signal, independent of the iron concentration, which was stable at least for 15 min. Thus the rate of ascorbate loss in the iso-osmotic phosphate buffer was considerably lower than in iron-overloaded plasma. The addition of different iron chelators produced comparable effects on the intensity of the AFR signal in both iron-overloaded plasma and ascorbate solution. These results suggest that the characteristic behaviour of plasma AFR after iron loading is due to its specific iron-binding capacity and to plasma ferroxidase activity. The ferroxidase activity of plasma is important to promote the transfer of Fe2+ into transferrin without a transient ascorbate oxidation. Spin-trapping studies with 5,5-dimethyl-1-pyrroline N-oxide and N-t-butyl-alpha-phenylnitrone revealed that iron-overloaded plasma was unable to produce spin-trap adducts even in the presence of 50-300 microM-hydrogen peroxide or 100 microM-azide. Evidence of OH. radical formation was obtained only after the addition of EDTA. Therefore, iron-overloaded plasma itself does not produce a Fenton reaction and, if ascorbate does indeed have a free-radical-mediated pro-oxidant role, it is not detectable in plasma by spin-trapping experiments.

Ascorbic Acid↗

PubMed2002

[Should the insulin resistance associated with hepatic iron overload be researched during diabetes mellitus type II?].

The insulin resistance-associated hepatic iron overload is the first aetiology of iron overload disorders in France. If we do not know its mechanism, the prevalence among type II diabetic patients is around 40%. Hyperferritinaemia is present in all cases, but is not specific of the diagnosis. This pathology features liver fibrosis among 10% of the patients and some cases of primary liver cancer have been described. Moreover, a large body of evidence favors the direct involvement of iron in the development of extra hepatic neoplasia, while therapeutic phlebotomy to maintain low to normal body iron stores can prevent all known complications of insulin resistance-associated hepatic iron overload. In addition, treatment of type II diabetes mellitus and other features of insulin resistance syndrome is essential. In conclusion, it is important to detect this syndrome during type II diabetes mellitus.

Diabetes Mellitus, Type 2↗

PubMedDate not supplied

Toxicity associated with iron overload found in hemochromatosis: possible mechanism in a rat model.

Hemochromatosis is characterized by pathologic iron overload which often leads to various pathological conditions. The mechanism by which excess iron induces these conditions is not clearly understood. Using rats as the model, this investigation was conducted to explore the mechanism of toxicity associated with iron overload. Sprague-Dawley male rats were fed a 3% carbonyl iron-supplemented diet for eight weeks to achieve iron accumulation. Liver iron reached approximately 2 mg/g which is more than 16 times the control values (mean +/- SD, 0.12 +/- 0.02 mg/g, p < 0.001). Serum iron was consistently higher in the experimental rats (mg/L): 3.41 +/- 0.58 versus 1.89 +/- 0.18, p < 0.001. The high levels of iron accompanied enhanced oxidative damage in the hepatic nuclear DNA when 8-hydroxy-2'-deoxyguanosine (8-OHdG) was measured as a product of DNA oxidation. The levels of 8-OHdG in the experimental samples were significantly higher than the controls (8-OHdG X 10(-5)/dG): 4.22 +/- 1.82 versus 1.84 +/- 0.33, p < 0.05. The results of serum enzyme assays suggest that iron overload caused mild hepatocellular damage: alanine transaminase significantly increased; lactate dehydrogenase did not change; alkaline phosphatase decreased. Since the accumulation of 8-OHdG in the nuclear DNA is highly deleterious to cells, these data suggest oxidative damage in the nuclear DNA may be a critical factor in inducing diseases associated with iron overload.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2001

Histologic features of the liver in insulin resistance-associated iron overload. A study of 139 patients.

The aim of the present study was to describe histologic features of the liver in insulin resistance-associated hepatic iron overload (IR-HIO), defined as the association of metabolic disorders and hepatic iron overload. We included 139 patients in the study on the basis of one or more metabolic disorders and liver iron overload unrelated to usual causes. Liver biopsy specimens were reviewed, and histologic data were compared with those of a previously published, well-defined population with genetic hemochromatosis. Iron overload was characterized by a mixed pattern with iron deposits in hepatocytes and sinusoidal cells. Steatosis was present in 59.7% of patients with inflammation in 32.4% of cases. Periportal fibrosis was found in 67.4% of patients. These patients were older, had higher sinusoidal iron scores, and had a higher prevalence of steatosis and inflammation than patients without fibrosis. Iron overload in IR-HIO was histologically different from that in genetic hemochromatosis.

Adult↗

PubMed2000

Hepatic iron concentration combined with long-term monitoring of serum ferritin to predict complications of iron overload in thalassaemia major.

Clinical complications of transfusional iron overload are still common in patients with thalassaemia major (TM) and it is not clear how best to monitor body iron stores during long-term follow-up to anticipate tissue damage. In this study, we have reviewed a group of 32 patients who underwent liver biopsy between 1984 and 1986. We developed a method of assessing the trend in serum ferritin (TSF) during long-term monitoring and compared this with mean serum ferritin (MSF) and initial liver iron (LI) concentration to determine whether, individually or in combination, they were accurate in predicting clinical outcome. LI levels were low (< 7 mg/g), medium (7-15 mg/g) and high (> 15 mg/g dry weight) in 15, 7 and 10 patients respectively. MSF was low (< 1500 microg/l), medium (1500-2500 microg/l) and high (> 2500 microg/l) in 10, 14 and 8 patients. TSF was low, medium and high risk in 9, 9 and 11 out of 29 evaluable patients. During a median follow-up of 13.6 years (range 2.3-14.8 years) after biopsy, nine patients died and an additional three patients developed heart failure. Hypothyroidism developed in five, hypoparathyroidism in four, and diabetes mellitus in seven patients. Cirrhosis developed in four of 10 evaluable patients. The clinical end-point of death or cardiac failure was significantly associated with increasing iron load using all three means of assessment. Although numbers were insufficient for statistical analysis, MSF or TSF were more closely associated with complications of iron overload than LI. There was no clear additional value in combining LI with MSF or TSF. The data show that quantitation of liver iron from a single liver biopsy has little value in long-term monitoring of iron stores. Most complications can be avoided if ferritin levels can be brought down to <1500 microg/l.

Adolescent↗

PubMed2006

Neuroprotective effects of iron chelator Desferal on dopaminergic neurons in the substantia nigra of rats with iron-overload.

The aim of the present study was to investigate whether the iron chelator Desferal prevents the degeneration of dopaminergic neurons in the substantia nigra (SN) induced by iron-overload in rats. Using fast cyclic voltammetry, tyrosine hydroxylase (TH) immunohistochemistry, Perls' iron staining, and high-performance liquid chromatography-electrochemical detection, we measured the degeneration of dopaminergic neurons and increased iron content in the SN of rats overloaded with iron dextran and assessed the effects of treatment with Desferal. The results showed that iron dextran overload increased the iron content in the SN, decreased dopamine release and content, and reduced the numbers of TH-immunoreactive neurons. Treatment with Desferal prevented the increased iron content in the SN. As a result, dopamine release and content remained at almost normal levels, while the numbers of TH-immunoreactive neurons remained at control values. This study suggests that the iron chelator Desferal is neuroprotective against iron-overload, so iron chelators that can cross the blood-brain barrier may have the potential to treat cases where abnormal iron accumulation in the brain is associated with the degenerative processes, as in Parkinson's disease.

Animals↗

PubMed1999

Iron overload in porphyria cutanea tarda.

BACKGROUND AND OBJECTIVE: Porphyria cutanea tarda (PCT) is a disorder of porphyrin metabolism associated with decreased activity of uroporphyrinogen decarboxylase (URO-D) in the liver. The relevance of iron in the pathogenesis of PCT is well established: iron overload is one of the factors that trigger the clinical manifestations of the disease and iron depletion remains the cornerstone of therapy for PCT. A role for genetic hemochromatosis in the pathogenesis of iron overload in PCT has been hypothesized in the past but only after the recent identification of the genetic defect causing hemochromatosis has the nature of this association been partially elucidated. This review will outline current concepts of the pathophysiology of iron overload in PCT as well as recent contributions to the molecular epidemiology of hemochromatosis defects in PCT. EVIDENCE AND INFORMATION SOURCES: The authors of the present review have a long-standing interest in the pathogenesis, etiology and epidemiology of iron overload syndromes. Evidence from journal articles covered by the Science Citation Index(R) and Medline(R) has been reviewed and collated with personal data and experience. STATE OF THE ART AND PERPECTIVES: Mild to moderate iron overload plays a key role in the pathogenesis of PCT. The recent identification of genetic mutations of the hemochromatosis gene (HFE) in the majority of patients with PCT confirms previous hypotheses on the association between PCT and hemochromatosis, allows a step forward in the understanding of the pathophysiology of the disturbance of iron metabolism in the liver of PCT patients, and provides an easily detectable genetic marker which could have a useful clinical application. Besides the epidemiological relevance of the association between PCT and hemochromatosis, however, it remains to be fully understood how iron overload, and in particular the cellular modifications of the iron status secondary to hemochromatosis mutations, affect the activity of URO-D, and how the altered iron metabolism interacts with the other two common triggers for PCT and etiological agents for the associated liver disease: alcohol and hepatitis viruses. The availability of a genetic marker for hemochromatosis will allow some of these issues to be addressed by studying aspects of porphyrins and iron metabolism in liver samples obtained from patients with PCT, liver disease of different etiology and different HFE genotypes, and by in vitro studies on genotyped cells and tissues.

DNA Mutational Analysis↗

PubMed2005

[Study of deferoxamine in subcutaneous profusion treatment of iron overload in myelodysplastic syndromes].

BACKGROUND AND OBJECTIVE: The progressive accumulation of iron in the organism contribute to one of the most important problems of morbidity and mortality in patients with myelodysplastic syndrome (MDS). We present an observational protocol, multicentre, open and non-aleatheorised, in patients diagnosed with MDS on transfusional regime with iron overload. The study was meant to prove the effectiveness of the parenteral treatment with desferrioxamine using continuous devices of subcutaneous profusion and evaluate the evolution of iron overload as well as transfusional requirements. PATIENTS AND METHOD: There were 28 patients (12 men and 16 women), 12 AR, 15 AS and 1 unknown. Average monitoring lasted 13.5 months and there was a gradual loss of patients. 11 of them had gone during the first year. RESULTS: After 12 months the average of ferritin decreased by 258.51 ng/dl (DE 1208.04; p = 9.4) and after 24 months, it decreased by 979.6 ng/dl (DE 810.31; p = 0.1). After 12 months the average of requirements increased by 60.57 gHb/month (DE 183.7; p = 0.029) and after 24 months, it increased by 167.3 g/Hb/month (DE 406.5; p = 0.36). CONCLUSIONS: Desferroxiamine treatment is effective at least to prevent an iron overload in these patients, and therefore should be incorporated in the clinical practice.

Aged↗

PubMed1997

A new syndrome of liver iron overload with normal transferrin saturation.

BACKGROUND: We investigated patients who had unexplained hepatic iron overload and normal transferrin saturation. METHODS: 65 patients with a median liver iron concentration of 65 mumol/g dry weight of liver (normal < 36 mumol/g), hyperferritinaemia (566 micrograms/L; normal < 400 micrograms/L), and normal transferrin saturations (32%) were compared with genetic haemochromatosis (GH) controls including homozygous (matched for sex and serum ferritin concentration) and heterozygous individuals. Relatives of patients who had ratios of liver iron concentration to age greater than 1.9 were also studied. FINDINGS: The 65 patients were significantly older and had significantly less hepatic iron overload than individuals with genetic haemochromatosis. The frequency of HLA-A3 antigen was significantly lower in these patients than in individuals with homozygous (p < 0.0001) or heterozygous (p < 0.0002) GH. Five HLA-identical siblings of the patients had normal serum ferritin concentrations. Most of the patients (95%) had one or more of the following conditions; obesity, hyperlipidaemia, abnormal glucose metabolism, or hypertension. INTERPRETATION: We have found a new non-HLA-linked iron-overload syndrome which suggests a link between iron excess and metabolic disorders. The current diagnostic criteria for genetic haemochromatosis should be reviewed.

Adolescent↗