-
Sara Pelucchi,
Raffaella Mariani,
Stefano Calza,
Anna Ludovica Fracanzani,
Giulia Litta Modignani,
Francesca Bertola,
Fabiana Busti,
Paola Trombini,
Mirella Fraquelli,
Gian Luca Forni,
Domenico Girelli,
Silvia Fargion,
Claudia Specchia, Alberto Piperno
[show abstract]
[hide abstract]
ABSTRACT: Background. Most patients with Hereditary Hemochromatosis are homozygous for the p.C282Y mutation in the HFE gene in Caucasian population. Penetrance and expression of Hemochromatosis largely differ in p.C282Y homozygous cases. Besides environmental factors, genetic factors might be implicated. Design and Methods. In the present study, we analysed 50 candidate genes involved in iron metabolism and evaluated the association between 214 single nucleotide polymorphisms in these genes and three phenotypic outcomes of iron overload (serum ferritin, iron removed and transferrin saturation) in a large group of 296 Italian p.C282Y homozygous cases. Polymorphisms were tested for genetic association with each single outcome using linear regression models adjusted for age, sex and alcohol consumption. Results. We found a series of 17 genetic variants located in different genes with possible additive effect on the studied outcomes. In order to evaluate if the selected polymorphisms could provide a predictive signature for adverse phenotype, we re-evaluated data by dividing patients in two extreme phenotype classes based on the three phenotypic outcomes. We found that only a small improvement in prediction can be achieved adding genetic information to clinical data. Among the selected polymorphisms, a significant association between rs3806562, located in the 5'UTR of CYBRD1, and transferrin saturation was observed. This variant belongs to the same haplotype block which contains the CYBRD1 polymorphism rs884409, found to be associated with serum ferritin in another population of p.C282Y homozygotes, and able to modulate promoter activity. Luciferase assay indicates that rs3806562 has not a significant functional role, suggesting that it is a genetic marker linked to the putative genetic modifier rs884409. Conclusions. While our results support the hypothesis that polymorphisms in genes regulating iron metabolism may modulate penetrance of HFE-HH, with emphasis on CYBRD1, they strengthen the notion that none of these polymorphisms alone is a major modifier of HH phenotype.
Haematologica 07/2012; · 6.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate whether the patatin-like phospholipase domain containing-3 gene (PNPLA3) I148M polymorphism is associated with steatosis, fibrosis stage, and cirrhosis in hereditary hemochromatosis (HH).
We studied 174 consecutive unrelated homozygous for the C282Y HFE mutation of HH (C282Y+/+ HH) patients from Northern Italy, for whom the presence of cirrhosis could be determined based on histological or clinical criteria, without excessive alcohol intake (< 30/20 g/d in males or females) or hepatitis B virus and hepatitis C virus viral hepatitis. Steatosis was evaluated in 123 patients by histology (n = 100) or ultrasound (n = 23). The PNPLA3 rs738409 single nucleotide polymorphism, encoding for the p.148M protein variant, was genotyped by a Taqman assay (assay on demand, Applied Biosystems). The association of the PNPLA3 I148M protein variant (p.I148M) with steatosis, fibrosis stage, and cirrhosis was evaluated by logistic regression analysis.
PNPLA3 genotype was not associated with metabolic parameters, including body mass index (BMI), the presence of diabetes, and lipid levels, but the presence of the p.148M variant at risk was independently associated with steatosis [odds ratio (OR) 1.84 per p.148M allele, 95% confidence interval (CI): 1.05-3.31; P = 0.037], independently of BMI and alanine aminotransaminase (ALT) levels. The p.148M variant was also associated with higher aspartate aminotransferase (P = 0.0014) and ALT levels (P = 0.017) at diagnosis, independently of BMI and the severity of iron overload. In patients with liver biopsy, the 148M variant was independently associated with the severity (stage) of fibrosis (estimated coefficient 0.56 ± 0.27, P = 0.041). In the overall series of patients, the p.148M variant was associated with cirrhosis in lean (P = 0.049), but not in overweight patients (P = not significant). At logistic regression analysis, cirrhosis was associated with BMI ≥ 25 (OR 1.82, 95% CI: 1.02-3.55), ferritin > 1000 ng/mL at diagnosis (OR 19.3, 95% CI: 5.3-125), and with the G allele in patients with BMI < 25 (OR 3.26, 95% CI: 1.3-10.3).
The PNPLA3 I148M polymorphism may represent a permissive factor for fibrosis progression in patients with C282Y+/+ HH.
World Journal of Gastroenterology 06/2012; 18(22):2813-20. · 2.47 Impact Factor
-
Giulia Ravasi,
Sara Pelucchi,
Paola Trombini,
Raffaella Mariani,
Naohisa Tomosugi,
Giulia Litta Modignani,
Matteo Pozzi,
Elizabeth Nemeth,
Tomas Ganz,
Hisao Hayashi,
Donatella Barisani, Alberto Piperno
[show abstract]
[hide abstract]
ABSTRACT: Hepcidin is a regulatory hormone that plays a major role in controlling body iron homeostasis. Circulating factors (holotransferrin, cytokines, erythroid regulators) might variably contribute to hepcidin modulation in different pathological conditions. There are few studies analysing the relationship between hepcidin transcript and related protein expression profiles in humans. Our aims were: a. to measure hepcidin expression at either hepatic, serum and urinary level in three paradigmatic iron overload conditions (hemochromatosis, thalassemia and dysmetabolic iron overload syndrome) and in controls; b. to measure mRNA hepcidin expression in two different hepatic cell lines (HepG2 and Huh-7) exposed to patients and controls sera to assess whether circulating factors could influence hepcidin transcription in different pathological conditions. Our findings suggest that hepcidin assays reflect hepatic hepcidin production, but also indicate that correlation is not ideal, likely due to methodological limits and to several post-trascriptional events. In vitro study showed that THAL sera down-regulated, HFE-HH and C-NAFLD sera up-regulated hepcidin synthesis. HAMP mRNA expression in Huh-7 cells exposed to sera form C-Donors, HFE-HH and THAL reproduced, at lower level, the results observed in HepG2, suggesting the important but not critical role of HFE in hepcidin regulation.
PLoS ONE 01/2012; 7(5):e36425. · 4.09 Impact Factor
-
Veronica Mainini,
Erica Gianazza,
Clizia Chinello,
Grzegorz Bilo,
Miriam Revera,
Andrea Giuliano,
Gianluca Caldara,
Carolina Lombardi, Alberto Piperno,
Fulvio Magni,
Gianfranco Parati
[show abstract]
[hide abstract]
ABSTRACT: The exposure of healthy subjects to high altitude represents a model to explore the pathophysiology of diseases related to tissue hypoxia and to evaluate pharmacological approaches potentially useful as a therapy for chronic diseases related to hypoxia. We explored the urinary peptidome to detect alterations induced by the exposure of subjects to different altitudes (sea level, high altitude = 3500 m, very high altitude = 5400 m) and to pharmacological treatment. Urine samples were collected from 47 subjects, randomly and blindly assigned to placebo (n = 24) or Telmisartan (n = 23). Samples were purified by the use of magnetic beads, then analysed by MALDI-TOF MS. Results showed that the urinary peptidome is not affected by the administration of Telmisartan, neither at the sea level nor at high and very high altitudes. In contrast, the urinary protein profiles are modified when subjects are exposed to high and very high altitudes, and we detected six peptides differentially expressed in hypobaric hypoxia at high or very high altitude compared to the sea level. Two of them were identified as fragments of the glycoprotein uromodulin and of the α1-antitrypsin. This is the first proteomic study showing that hypobaric hypoxia conditions affect the urinary peptidome.
Molecular BioSystems 12/2011; 8(4):959-66. · 3.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The pathogenesis of dysmetabolic iron overload syndrome (DIOS) is still unclear. Hepcidin is the key regulator of iron homeostasis controlling iron absorption and macrophage release.
To investigate hepcidin regulation by iron in DIOS.
We analysed urinary hepcidin at baseline and 24 h after a 65 mg oral iron dose in 24 patients at diagnosis and after iron depletion (n = 13) and compared data with those previously observed in 23 healthy controls. Serum iron indices, liver histology and metabolic data were available for all patients.
At diagnosis, hepcidin values were significantly higher than in controls (P < 0.001). After iron depletion, hepcidin levels decreased to normal values in all patients. At baseline, a significant response of hepcidin to iron challenge was observed only in the subgroup with lower basal hepcidin concentration (P = 0.007). In iron-depleted patients, urinary hepcidin significantly increased after oral iron test (P = 0 .006).
Ours findings suggest that in DIOS, the progression of iron accumulation is counteracted by the increase in hepcidin production and progressive reduction of iron absorption, explaining why these patients develop a mild-moderate iron overload that tends to a plateau.
Liver international: official journal of the International Association for the Study of the Liver 08/2011; 31(7):994-1000. · 3.82 Impact Factor
-
Movement Disorders 05/2011; 26(10):1964-6. · 4.51 Impact Factor
-
Pietro Amedeo Modesti,
Stefano Rapi,
Rita Paniccia,
Gregorz Bilo,
Miriam Revera,
Piergiuseppe Agostoni, Alberto Piperno,
Giulia Elisa Cambi,
Angela Rogolino,
Annibale Biggeri,
Giuseppe Mancia,
Gian Franco Gensini,
Rosanna Abbate,
Gianfranco Parati
[show abstract]
[hide abstract]
ABSTRACT: Acute mountain sickness (AMS) is a neurological disorder that may be unpredictably experienced by subjects ascending at a high altitude. The aim of the present study was to develop a predictive index, measured at an intermediate altitude, to predict the onset of AMS at a higher altitude.
In the first part, 47 subjects were investigated and blood withdrawals were performed before ascent, at an intermediate altitude (3440 m), and after acute and chronic exposition to high altitude (Mount Everest Base Camp, 5400 m (MEBC1 and MEBC2)). Parameters independently associated to the Lake Louise scoring (LLS) system, including the self-reported and the clinical sections, and coefficients estimated from the model obtained through stepwise regression analysis were used to create a predictive index. The possibility of the index, measured after an overnight stay at intermediate altitude (Gnifetti hut, 3647 m), to predict AMS (defined as headache and LLS ≥ 4) at final altitude (Capanna Margherita, 4559 m), was then investigated in a prospective study performed on 44 subjects in the Italian Alps.
During the expedition to MEBC, oxygen saturation, hematocrit, day of expedition, and maximum velocity of clot formation were selected as independently associated with LLS and were included in the predictive index. In the Italian Alps, subjects with a predictive index value ≥ 5.92 at an intermediate altitude had an odds ratio of 8.1 (95% confidence limits = 1.7-38.6, sensitivity = 85%, specificity = 59%) for developing AMS within 48 h of reaching high altitude.
In conclusion, a predictive index combining clinical and hematological parameters measured at an intermediate step on the way to the top may provide information on impending AMS.
Medicine and science in sports and exercise 03/2011; 43(10):1811-8. · 3.71 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Endocrine complications in Β-thalassemia represent a prominent cause of morbidity. Above all, dysfunction of GH-IGF-1 axis is of a major concern because of its pathogenic role on cardiac and bone disease, frequently described in this clinical setting. The aim of this paper is to analyze GH-IGF-1 axis in a cohort of 25 adult patients affected by Β-thalassemia. We found that GH deficiency was present in only 8% of our patients if diagnosis was based on GH peak below 9μg/L to two GH provocative tests instead of only one, and was mainly related to iron overload. On the contrary, IGF-1 production was impaired in a higher percentage of patients (72%), without significant correlation with iron burden. Of note, patients with hepatitis C virus infection showed lower IGF-1 concentrations than uninfected subjects despite a normal GH reserve, suggesting that partial GH insensitivity at the post-receptor level may play a key role in IGF-1 deficiency described in thalassemic patients.
Pediatric endocrinology reviews: PER 03/2011; 8 Suppl 2:284-9.
-
Domenico Girelli,
Paola Trombini,
Fabiana Busti,
Natascia Campostrini,
Marco Sandri,
Sara Pelucchi,
Mark Westerman,
Tomas Ganz,
Elizabeta Nemeth, Alberto Piperno,
Clara Camaschella
[show abstract]
[hide abstract]
ABSTRACT: Inadequate hepcidin production leads to iron overload in nearly all types of hemochromatosis. We explored the acute response of hepcidin to iron challenge in 25 patients with HFE-hemochromatosis, in two with TFR2-hemochromatosis and in 13 controls. Sixteen patients (10 C282Y/C282Y homozygotes, 6 C282Y/H63D compound heterozygotes) had increased iron stores, while nine (6 C282Y/C282Y homozygotes, 3 C282Y/H63D compound heterozygotes) were studied after phlebotomy-induced normalization of iron stores.
We analyzed serum iron, transferrin saturation, and serum hepcidin by both enzyme-linked immunosorbent assay and mass-spectrometry at baseline, and 4, 8, 12 and 24 hours after a single 65-mg dose of oral iron.
Serum iron and transferrin saturation significantly increased at 4 hours and returned to baseline values at 8-12 hours in all groups, except in the iron-normalized patients who showed the highest and longest increase of both parameters. The level of hepcidin increased significantly at 4 hours and returned to baseline at 24 hours in controls and in the C282Y/H63D compound heterozygotes at diagnosis. The hepcidin response was smaller in C282Y-homozygotes than in controls, barely detectable in the patients with iron-depleted HFE-hemochromatosis and absent in those with TFR2-hemochromatosis. Conclusions Our results are consistent with a scenario in which TFR2 plays a prominent and HFE a contributory role in the hepcidin response to a dose of oral iron. In iron-normalized patients with HFE hemochromatosis, both the low baseline hepcidin level and the weak response to iron contribute to hyperabsorption of iron.
Haematologica 12/2010; 96(4):500-6. · 6.42 Impact Factor
-
Alberto Piperno,
Stefania Galimberti,
Raffaella Mariani,
Sara Pelucchi,
Giulia Ravasi,
Carolina Lombardi,
Grzegorz Bilo,
Miriam Revera,
Andrea Giuliano,
Andrea Faini,
Veronica Mainini,
Mark Westerman,
Tomas Ganz,
Maria Grazia Valsecchi,
Giuseppe Mancia,
Gianfranco Parati
[show abstract]
[hide abstract]
ABSTRACT: Iron is tightly connected to oxygen homeostasis and erythropoiesis. Our aim was to better understand how hypoxia regulates iron acquisition for erythropoiesis in humans, a topic relevant to common hypoxia-related disorders. Forty-seven healthy volunteers participated in the HIGHCARE project. Blood samples were collected at sea level and after acute and chronic exposure to high altitude (3400-5400 m above sea level). We investigated the modifications in hematocrit, serum iron indices, erythropoietin, markers of erythropoietic activity, interleukin-6, and serum hepcidin. Hepcidin decreased within 40 hours after acute hypoxia exposure (P < .05) at 3400 m, reaching the lowest level at 5400 m (80% reduction). Erythropoietin significantly increased (P < .001) within 16 hours after hypoxia exposure followed by a marked erythropoietic response supported by the increased iron supply. Growth differentiation factor-15 progressively increased during the study period. Serum ferritin showed a very rapid decrease, suggesting the existence of hypoxia-dependent mechanism(s) regulating storage iron mobilization. The strong correlation between serum ferritin and hepcidin at each point during the study indicates that iron itself or the kinetics of iron use in response to hypoxia may signal hepcidin down-regulation. The combined and significant changes in other variables probably contribute to the suppression of hepcidin in this setting.
Blood 12/2010; 117(10):2953-9. · 9.90 Impact Factor
-
Yoshibumi Kaneko,
Hiroaki Miyajima, Alberto Piperno,
Naohisa Tomosugi,
Hisao Hayashi,
Natsuko Morotomi,
Ken-ichi Tsuchida,
Takaaki Ikeda,
Akihisa Ishikawa,
Yusuke Ota,
Shinya Wakusawa,
Kentaro Yoshioka,
Satoshi Kono,
Sara Pelucchi,
Ai Hattori,
Yasuaki Tatsumi,
Toshihide Okada,
Masakazu Yamagishi
[show abstract]
[hide abstract]
ABSTRACT: Iron overload syndromes include a wide spectrum of genetic and acquired conditions. Recent studies suggest suppressed hepcidin synthesis in the liver to be the molecular basis of hemochromatosis. However, a liver with acquired iron overload synthesizes an adequate amount of hepcidin. Thus, hepcidin could function as a biochemical marker for differential diagnosis of iron overload syndromes.
We measured serum iron parameters and hepcidin-25 levels followed by sequencing HFE, HJV, HAMP, TFR2, and SLC40A1 genes in 13 Japanese patients with iron overload syndromes. In addition, we performed direct measurement of serum hepcidin-25 levels using liquid chromatography-tandem mass spectrometry in 3 Japanese patients with aceruloplasminemia and 4 Italians with HFE hemochromatosis.
One patient with HJV hemochromatosis, 2 with TFR2 hemochromatosis, and 3 with ferroportin disease were found among the 13 Japanese patients. The remaining 7 Japanese patients showed no evidence for genetic basis of iron overload syndrome. As far as the serum hepcidin-25 was concerned, seven patients with hemochromatosis and 3 with aceruloplasminemia showed markedly decreased serum hepcidin-25 levels. In contrast, 3 patients with ferroportin disease and 7 with secondary iron overload syndromes showed serum hepcidin levels parallel to their hyperferritinemia. Patients with iron overload syndromes were divided into 2 phenotypes presenting as low and high hepcidinemia. These were then associated with their genotypes.
Determining serum hepcidin-25 levels may aid differential diagnosis of iron overload syndromes prior to genetic analysis.
Journal of Gastroenterology 11/2010; 45(11):1163-71. · 4.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The clinical presentation of hereditary hemochromatosis has changed markedly in recent years. The aim of this study was to analyze a large series of consecutive Italian patients with hemochromatosis diagnosed between 1976 and 2007 to determine whether the genetic background and the presence of acquired risk factors influenced the severity of iron overload and the natural history of the disease. A cohort of 452 Italian patients with iron overload-338 HFE-related (C282Y homozygotes or compound C82Y/H63D heterozygotes) and 114 non-HFE-related-were followed prospectively for a median of 112 months. Alcohol intake, smoking habits, and iron removed to depletion were similar in patients with and without HFE-related iron overload. Hepatitis B virus (4% and 9%; P = 0.04) and hepatitis C virus (6% and 19%; P = 0.002) infections were more frequent in patients with non-HFE-related iron overload. Seventy-three percent of patients with HFE and 61% of patients with non-HFE-related disease had no acquired risk factor. Cirrhosis was significantly more frequent in non-HFE patients independent of the presence of acquired risk factors (P = 0.02). Sex, alcohol intake, prevalence of smoking, hepatitis C virus infection, glucose, lipids, iron-related parameters, and prevalence of C282Y/H63D differed significantly over the years. At enrollment, cirrhosis was present in 145 cases and was significantly more frequent in the first decade (80%, 47%, and 13%; P = 0.001). Survival did not differ across the decades in cirrhotic patients; hepatocellular carcinoma occurred similarly in HFE and non-HFE patients. CONCLUSION: Patients with HFE and non-HFE-related iron overload have comparable iron overload and similar clinical history. Patients who were diagnosed during the last 10 years and were not identified as cirrhotic at enrollment have less severe disease and lower prevalence of acquired risk factors, independent of genetic background.
Hepatology 02/2010; 51(2):501-10. · 11.66 Impact Factor
-
Hisao Hayashi, Alberto Piperno,
Naohisa Tomosugi,
Kazuhiko Hayashi,
Fumiaki Kimura,
Shinya Wakusawa,
Motoyoshi Yano,
Yasuaki Tatsumi,
Ai Hattori,
Sara Pelucchi,
Yoshiaki Katano,
Hidemi Goto
[show abstract]
[hide abstract]
ABSTRACT: In chronic hepatitis C, iron might play an important role as a hepatotoxic co-factor. Therefore, venesection, a standard treatment for hemochromatosis, has been proposed as an alternative for patients who respond poorly to anti-viral therapy. To improve our understanding of iron-induced hepatotoxicity, we compared the responses to venesection between patients with chronic hepatitis C and those with HFE-hemochromatosis.
Fourteen Japanese patients with chronic hepatitis C and eight Italian patients with HFE-hemochromatosis underwent repeated venesection with a serum ferritin endpoint of 20 and 50 ng/mL, respectively. Serum iron indices and liver function tests were measured in pre- and post treatment blood samples from each patient. Body iron stores were calculated using the removed blood volume.
In both patients with hepatitis and hemochromatosis, serum ferritin, aminotransferase and hepcidin 25 were reduced after venesection. The serum aminotransferase activity, but not the serum ferritin level, was predictive of effective iron removal treatment. Hepcidin regulation was set at an inappropriately low level in hemochromatosis patients (11.1 ± 9.2 ng/mL), but not so in hepatitis patients (30.7 ± 14.5 ng/mL). Inversely, the estimated body iron stores of hemochromatosis patients were 5,960 ± 2,750 mg, while those of hepatitis patients were 730 ± 560 mg. Judging from the liver enzyme reduction ratio, patients with hepatitis seemed to be more sensitive to iron hepatotoxicity than hemochromatosis patients.
Even though the threshold of iron hepatotoxicity and benefit of its removal differ between patients with chronic hepatitis C and those with HFE-hemochromatosis, venesection is a valid choice of treatment to reduce liver disease activity in both diseases.
Internal Medicine 01/2010; 49(22):2371-7. · 0.94 Impact Factor
-
Blood 05/2009; 113(16):3886. · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: By modulating hepcidin production, an organism controls intestinal iron absorption, iron uptake and mobilization from stores to meet body iron need. In recent years there has been important advancement in our knowledge of hepcidin regulation that also has implications for understanding the physiopathology of some human disorders. Since the discovery of hepcidin and the demonstration of its pivotal role in iron homeostasis, there has been a substantial interest in developing a reliable assay of the hormone in biological fluids. Measurement of hepcidin in biological fluids can improve our understanding of iron diseases and be a useful tool for diagnosis and clinical management of these disorders. We reviewed the literature and our own research on hepcidin to give an updated status of the situation in this rapidly evolving field.
World Journal of Gastroenterology 03/2009; 15(5):538-51. · 2.47 Impact Factor
-
British Journal of Haematology 01/2009; 143(5):746-7. · 4.94 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Transferrin receptor-2 (TFR2) regulates hepatic hepcidin secretion and when mutated causes type-3 hemochromatosis. No functional study is available in humans. We studied a 47 year-old woman with hemochromatosis. TFR2 DNA and its hepatic transcript were directly sequenced. Hepatic expression of hepcidin and other iron-related genes were measured by qRT-PCR. Urinary hepcidin was measured at baseline and after an oral iron challenge (ferrous sulfate, 65 mg) by SELDI-TOF-MS. A novel homozygous TFR2 mutation was identified in the splicing donor site of intron 4 (c.614+4 A>G) causing exon 4 skipping. Hepcidin and hemojuvelin expression were markedly reduced. Urinary hepcidin was lower than normal and further decreased after iron challenge. This is the first description of iron-related gene expression profiles in a TFR2 mutated patient. The decreased hepatic and urinary expression of hepcidin and lack of acute response to iron challenge confirms the primary role of TFR2 in iron homeostasis.
Haematologica 01/2009; 94(2):276-9. · 6.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: THERE ARE TWO MAIN MECHANISMS BY WHICH IRON OVERLOAD DEVELOPS IN THALASSEMIAS: increased iron absorption due to ineffective erythropoiesis and blood transfusions. In nontransfused patients with severe thalassemia, abnormal dietary iron absorption increases body iron burden between 2 and 5 g per year. If regular transfusions are required, this doubles the rate of iron accumulation leading to earlier massive iron overload and iron-related damage. Iron metabolism largely differs between thalassemias and sickle cell disease, but chronic transfusion therapy partially normalize many of the disparities between the diseases, making iron overload an important issue to be considered in the management of patients with sickle cell disease too. The present review summarizes the actual knowledge on the regulatory pathways of iron homeostasis. In particular, the data presented indicate the inextricably link between erythropoiesis and iron metabolism and the key role of hepcidin in coordinating iron procurement according to erythropoietic requirement. The role of erythropoietin, hypoxia, erythroid-dependent soluble factors and iron in regulating hepcidin transcription are discussed as well as differences and similarities in iron homeostasis between thalassemia syndromes and sickle cell disease.
Mediterranean Journal of Hematology and Infectious Diseases 01/2009; 1(1):e2009006.
-
Alessia Riva,
Paola Trombini,
Raffaella Mariani,
Alessandra Salvioni,
Sabina Coletti,
Silvia Bonfadini,
Valentina Paolini,
Matteo Pozzi,
Rita Facchetti,
Giorgio Bovo, Alberto Piperno
[show abstract]
[hide abstract]
ABSTRACT: To re-evaluate the diagnostic criteria of insulin resistance hepatic iron overload based on clinical, biochemical and histopathological findings.
We studied 81 patients with hepatic iron overload not explained by known genetic and acquired causes. The metabolic syndrome (MS) was defined according to ATPIII criteria. Iron overload was assessed by liver biopsy. Liver histology was evaluated by Ishak's score and iron accumulation by Deugnier's score; steatosis was diagnosed when present in >or=5% of hepatocytes.
According to transferrin saturation levels, we observed significant differences in the amount of hepatic iron overload and iron distribution, as well as the number of metabolic abnormalities. Using Receiving Operating Curve analysis, we found that the presence of two components of the MS differentiated two groups with a statistically significant different hepatic iron overload (P<0.0001). Patients with >or=2 metabolic alterations and steatosis had lower amount of hepatic iron, lower transferrin saturation and higher sinusoidal iron than patients with <2 MS components and absence of steatosis.
In our patients, the presence of >or2 alterations of the MS and hepatic steatosis was associated with a moderate form of iron overload with a prevalent sinusoidal distribution and a normal transferrin saturation, suggesting the existence of a peculiar pathogenetic mechanism of iron accumulation. These patients may have the typical dysmetabolic iron overload syndrome. By contrast, patients with transferrin saturation>or=60% had more severe iron overload, few or no metabolic abnormalities and a hemochromatosis-like pattern of iron overload.
World Journal of Gastroenterology 09/2008; 14(30):4745-52. · 2.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Many patients with hepatic iron overload do not have identifiable mutations and often present with metabolic disorders and hepatic steatosis. Since the pathophysiology of Dysmetabolic Hepatic Iron Overload (DHIO) is still obscure, the aim of this study was to evaluate, in these patients, possible alterations in iron-related molecule expression.
Iron-related gene mRNA levels were determined by quantitative-PCR in liver biopsies of subjects with NAFLD without iron overload and patients with HFE-hemochromatosis, beta-thalassemia major and DHIO. Urinary hepcidin was measured by immunoblotting.
No alterations in mRNA expression of either iron transporters or exporters were found in DHIO. mRNA and urinary hepcidin levels normalized for the amount of iron overload showed a significantly lower ratio than in controls, although not as low as in hemochromatosis or beta-thalassemia. Differently from what observed in hemochromatosis, hepcidin mRNA did not correlate with urinary hepcidin.
Patients with DHIO show appropriate regulation of mRNAs encoding proteins involved in iron uptake and efflux but dysregulation of hepcidin production. The relatively elevated urinary hepcidin can explain the iron phenotype in DHIO (more macrophage iron retention and low/normal transferrin saturation).
Journal of Hepatology 08/2008; 49(1):123-33. · 9.26 Impact Factor
